Have you noticed a few extra pounds padding your waistline? You may be in the throes of midlife expansion — a familiar complaint among women in their 40s and 50s. During this time either you gain weight or you find that maintaining your usual weight has somehow become more difficult. You also discover that the weight you gain tends to accumulate around your abdomen, rather than your hips and thighs.
But you don't have to accept weight gain as inevitable. Take steps to prevent weight gain before it starts. And if you've already begun adding to your waistline, it's never too late to reverse course through proper diet and exercise.
Causes of middle age weight gain
For most women, increases and shifts in weight begin during perimenopause — the years leading up to menopause. On average, women gain about a pound a year during this time.
But changing hormone levels associated with menopause aren't necessarily the cause of weight gain. Aging and lifestyle factors play a big role in your changing body composition, including:
Exercising less. Menopausal women tend to exercise less than other women, which can lead to weight gain.
Eating more. Eating more means you'll take in more calories, which are converted to fat if you don't burn them for energy.
Burning fewer calories. The number of calories you need for energy decreases as you age because aging promotes the replacement of muscle with fat. Muscle burns more calories than fat does. When your body composition shifts to more fat and less muscle, your metabolism slows down.
Genetic factors may play a role in weight gain as well. If your parents and other close relatives carry extra weight around the abdomen, you may be predisposed to do so, too.
Weight gain can also have serious implications for your health. Excess weight increases your risk of high cholesterol, high blood pressure and insulin resistance, which can lead to type 2 diabetes. These factors also put you at increased risk of heart disease and stroke.
There's also evidence that weight gain during the menopausal years increases breast cancer risk. Women who gain in excess of 20 pounds after menopause increase their breast cancer risk by nearly 20 percent. But women who lose weight after menopause can reduce their risk of breast cancer by that much and more — women who lose 20 pounds after menopause reduce their breast cancer risk by as much as 23 percent. Even smaller amounts of weight loss after menopause lead to a modest risk reduction.
What you can do to prevent or reverse weight gain
There's no magic formula for avoiding weight gain as you get older. The strategies for maintaining a healthy weight at any age remain the same: Watch what you eat and get moving.
The most effective approach to reversing weight gain after menopause includes a combination of the following:
Increase your physical activity. Aerobic exercise boosts your metabolism and helps you burn fat. Strength training exercises increase muscle mass, boost your metabolism and strengthen your bones.
You can become more physically active even without starting a formal exercise program. Just spend more time doing the things you love that also get you moving. Do more gardening and dancing. Take longer walks or try out a bike. Make it your goal to be active for a total of 30 minutes or more a day on most days.
Increased physical activity, including strength training, may be the single most important factor for maintaining a healthy body composition — more lean muscle mass and less body fat — as you get older.
Reduce calories. Pay attention to the foods you're eating and slightly reduce the amount of calories you consume each day. By choosing a varied diet composed mainly of fruits and vegetables, you can safely cut back on calories and lose weight. Be careful not to cut back too drastically on calorie intake, or your body will respond by conserving energy, making extra pounds harder to shed.
Because your metabolism slows as you get older, you need about 200 fewer calories a day to maintain your weight as you get into your mid- to late 40s. This shouldn't be a problem if you eat only when hungry and only enough to satisfy your hunger.
Decrease dietary fat. Eating large amounts of high-fat foods adds excess calories, which can lead to weight gain and obesity. Limit fat to 20 percent to 35 percent of your daily calories. Emphasize fats from healthier sources, such as nuts and olive, canola and peanut oils.
Dealing with life's changes
Inevitably, your body shape changes as you get older, shrinking here, sagging there and expanding in the places where you want it least. So what if you can't fit into your old jeans? Eat a little less and exercise a little more, and you'll be doing a lot to maintain your health and vitality.
From MayoClinic.com
Monday, December 10, 2007
Hormone replacement therapy: Benefits and alternatives
Until July 2002, hormone replacement therapy had been the standard therapy in the United States for treating menopausal symptoms. Not only did hormone replacement therapy relieve such discomforts as hot flashes and vaginal dryness, it also seemed to protect against several postmenopausal conditions, such as osteoporosis and heart disease.
But in July 2002, the Women's Health Initiative — a large, multitiered clinical trial sponsored by the National Institutes of Health — reported that hormone replacement therapy actually posed more health risks than benefits for women in the clinical trial. And as the number of health hazards attributed to hormone replacement therapy grew, doctors discontinued routine prescriptions for this popular treatment.
You might be wondering how this shift in opinion over hormone replacement therapy, also known as hormone therapy for menopause, affects you personally. In some cases, hormone replacement therapy is still your best option for treating menopausal symptoms. In other cases, it's wise to consider alternatives.
A turning point for hormone replacement therapy
Concerns about hormone replacement therapy stem from the results of both the combined estrogen-progestin and the estrogen-alone arms of the Women's Health Initiative (WHI) clinical trial.
Combination estrogen-progestin therapy (Prempro)
For women taking the combination estrogen-progestin used in the study (Prempro), researchers found an increased risk of:
Heart disease
Breast cancer
Stroke
Blood clots
Dementia
In addition, researchers found that women taking combination estrogen-progestin experienced an increase in mammography abnormalities. The increased number of false-positives — signs of possible breast cancer that ultimately prove inaccurate — was attributed to the increased breast tissue density that estrogen induces. Women on combination therapy should be aware that they may require more frequent mammograms and additional testing as a result of this therapy.
As for quality-of-life measures, such as sleep, emotional health, general health, physical functioning and sexual satisfaction, the WHI found that for women taking combination hormone replacement therapy — most of whom didn't have troublesome menopausal symptoms — combination HRT didn't provide meaningful improvement in symptoms.
Estrogen-alone therapy (Premarin)
For women taking estrogen alone (Premarin), the WHI found no increased risk of breast cancer or heart disease, as was found with women on combination therapy, but researchers did find a slightly increased risk of stroke.
In addition, researchers found that, as with women on combination therapy, women taking estrogen alone were more likely to have abnormal mammograms than were women not on HRT. The increased number of false-positives — signs of possible breast cancer that ultimately prove inaccurate — was attributed to the increased breast tissue density that estrogen induces. Women on estrogen-alone therapy should be aware that they may require more frequent mammograms and additional testing as a result of this therapy.
Some HRT benefits still valid
Researchers did note important benefits of hormone replacement therapy in the WHI study — including a decreased risk of osteoporosis-related hip fractures and colorectal cancer. These benefits were valid for women whether they were taking combination therapy or estrogen alone.
It's all in the timing: Age is an important factor
The WHI's study population consisted of older postmenopausal women. Participants were an average age of 63 at the start of the trial. What's less certain is whether the study findings can be applied to younger women, such as women who typically start estrogen early in menopause.
A more complete analysis of data from the estrogen-alone arm of the WHI suggests there's less of a risk of heart disease if you take estrogen early in your postmenopausal years. The data analysis revealed participants age 50 to 59 who took estrogen experienced fewer heart attacks and deaths from coronary artery disease than study participants who took a placebo.
Many questions regarding younger postmenopausal women and hormone replacement therapy exist. To address some of these issues, a randomized, controlled clinical trial — the Kronos Early Estrogen Prevention Study (KEEPS) — exploring estrogen use and heart disease in younger postmenopausal women is under way, but it won't be completed for several years.
Who can benefit from hormone replacement therapy?
Despite the inherent health risks, hormone replacement therapy still has a role in treating menopausal symptoms. For some women — such as those who experience moderate to severe hot flashes or other menopausal symptoms — the benefits of short-term therapy outweigh the potential risks.
"The absolute risk to an individual woman taking hormone therapy is quite low and may be acceptable to you depending on your symptoms," says Sharonne Hayes, M.D., cardiologist and director of the Women's Heart Clinic at Mayo Clinic, Rochester, Minn. "Talk with your doctor about your personal risks."
Hormone replacement therapy might still be your treatment of choice if you have:
Hot flashes. Hormone replacement therapy is still the most effective treatment for troublesome menopausal hot flashes and night sweats.
Vaginal discomfort. Hormone replacement therapy can ease vaginal symptoms of menopause, such as dryness, itching, burning and discomfort with intercourse.
Osteoporosis. Hormone replacement therapy continues to be an option for osteoporosis prevention, but it's recommended only when other medications for osteoporosis prevention have been considered and determined not to be best for you.
If you're already taking hormone replacement therapy, should you keep taking it?
If you're already taking hormone replacement therapy to relieve menopausal symptoms, review its benefits and risks with your doctor.
"Consider the reason you started hormone replacement therapy and whether the reason remains relevant," Dr. Hayes advises. "If you started hormone therapy for hot flashes several years ago, you may no longer have hot flashes and could stop taking the drug."
Your doctor may periodically advise modifications to your regimen. For example, if you're taking a particular dose of estrogen, you may be able to lower the dose. Switching from an estrogen pill to a patch may offer certain benefits. In treating isolated vaginal symptoms, estrogen in a vaginal cream, tablet or ring is usually a better choice than a pill or a skin patch. That's because estrogen applied directly to your vagina remains localized to that area to treat your symptoms and doesn't circulate throughout your body as does estrogen ingested through a pill or absorbed through a patch.
Women on hormone replacement therapy should take the lowest effective dose for the shortest amount of time needed to treat symptoms.
Who should avoid hormone replacement therapy?
Women with breast cancer or a history of blood clots should not take hormone replacement therapy. Also avoid hormone replacement therapy for preventing memory loss, heart disease, heart attacks or strokes.
Instead, talk to your doctor about other medications you can take or lifestyle changes you can make for long-term protection from these conditions.
Alternatives to hormone replacement therapy
You may be able to manage your menopausal symptoms by making healthy lifestyle choices. In fact, your doctor may recommend that you try making changes to your exercise or eating habits before you try medication. After adjustments to your lifestyle, if you're still dealing with bothersome symptoms, you have several options besides hormone replacement therapy to help relieve discomfort.
Protect your long-term health
One of the previously believed benefits of hormone replacement therapy was that it promoted long-term health of postmenopausal women, from reducing risk of heart disease to making bones stronger. But since that's no longer the case, here are some alternatives.
A healthy heart
Good-for-your-heart health tips include:
Don't smoke.
Be physically active.
Eat a low-fat, high-fiber diet, with a variety of fruits and vegetables.
Maintain a healthy weight.
Manage high blood pressure.
Keep cholesterol and triglyceride levels in check.
Control diabetes.
Avoid excess alcohol.
Healthy bones
Keep your bones healthy and strong with:
Calcium and vitamin D. Make sure you're getting enough of these nutrients in your diet to keep your bones strong.
Exercise. Regular physical activity — especially weight-bearing exercises such as walking or dancing — can help keep your bones strong and healthy.
Medication. Certain medicines, when taken on a regular basis, can also protect your bone health. These include medicines from a class of drugs known as bisphosphonates, such as alendronate (Fosamax) and risedronate (Actonel), as well as raloxifene (Evista), teriparatide (Forteo) and calcitonin.
Every situation is different
When it comes to hormone replacement therapy, no one-size-fits-all solution exists. Each woman's experience with menopause is unique.
As researchers learn more about hormone replacement therapy and other menopausal treatments, recommendations may change. Review your current treatments with your doctor on a regular basis to make sure they're still your best option.
But in July 2002, the Women's Health Initiative — a large, multitiered clinical trial sponsored by the National Institutes of Health — reported that hormone replacement therapy actually posed more health risks than benefits for women in the clinical trial. And as the number of health hazards attributed to hormone replacement therapy grew, doctors discontinued routine prescriptions for this popular treatment.
You might be wondering how this shift in opinion over hormone replacement therapy, also known as hormone therapy for menopause, affects you personally. In some cases, hormone replacement therapy is still your best option for treating menopausal symptoms. In other cases, it's wise to consider alternatives.
A turning point for hormone replacement therapy
Concerns about hormone replacement therapy stem from the results of both the combined estrogen-progestin and the estrogen-alone arms of the Women's Health Initiative (WHI) clinical trial.
Combination estrogen-progestin therapy (Prempro)
For women taking the combination estrogen-progestin used in the study (Prempro), researchers found an increased risk of:
Heart disease
Breast cancer
Stroke
Blood clots
Dementia
In addition, researchers found that women taking combination estrogen-progestin experienced an increase in mammography abnormalities. The increased number of false-positives — signs of possible breast cancer that ultimately prove inaccurate — was attributed to the increased breast tissue density that estrogen induces. Women on combination therapy should be aware that they may require more frequent mammograms and additional testing as a result of this therapy.
As for quality-of-life measures, such as sleep, emotional health, general health, physical functioning and sexual satisfaction, the WHI found that for women taking combination hormone replacement therapy — most of whom didn't have troublesome menopausal symptoms — combination HRT didn't provide meaningful improvement in symptoms.
Estrogen-alone therapy (Premarin)
For women taking estrogen alone (Premarin), the WHI found no increased risk of breast cancer or heart disease, as was found with women on combination therapy, but researchers did find a slightly increased risk of stroke.
In addition, researchers found that, as with women on combination therapy, women taking estrogen alone were more likely to have abnormal mammograms than were women not on HRT. The increased number of false-positives — signs of possible breast cancer that ultimately prove inaccurate — was attributed to the increased breast tissue density that estrogen induces. Women on estrogen-alone therapy should be aware that they may require more frequent mammograms and additional testing as a result of this therapy.
Some HRT benefits still valid
Researchers did note important benefits of hormone replacement therapy in the WHI study — including a decreased risk of osteoporosis-related hip fractures and colorectal cancer. These benefits were valid for women whether they were taking combination therapy or estrogen alone.
It's all in the timing: Age is an important factor
The WHI's study population consisted of older postmenopausal women. Participants were an average age of 63 at the start of the trial. What's less certain is whether the study findings can be applied to younger women, such as women who typically start estrogen early in menopause.
A more complete analysis of data from the estrogen-alone arm of the WHI suggests there's less of a risk of heart disease if you take estrogen early in your postmenopausal years. The data analysis revealed participants age 50 to 59 who took estrogen experienced fewer heart attacks and deaths from coronary artery disease than study participants who took a placebo.
Many questions regarding younger postmenopausal women and hormone replacement therapy exist. To address some of these issues, a randomized, controlled clinical trial — the Kronos Early Estrogen Prevention Study (KEEPS) — exploring estrogen use and heart disease in younger postmenopausal women is under way, but it won't be completed for several years.
Who can benefit from hormone replacement therapy?
Despite the inherent health risks, hormone replacement therapy still has a role in treating menopausal symptoms. For some women — such as those who experience moderate to severe hot flashes or other menopausal symptoms — the benefits of short-term therapy outweigh the potential risks.
"The absolute risk to an individual woman taking hormone therapy is quite low and may be acceptable to you depending on your symptoms," says Sharonne Hayes, M.D., cardiologist and director of the Women's Heart Clinic at Mayo Clinic, Rochester, Minn. "Talk with your doctor about your personal risks."
Hormone replacement therapy might still be your treatment of choice if you have:
Hot flashes. Hormone replacement therapy is still the most effective treatment for troublesome menopausal hot flashes and night sweats.
Vaginal discomfort. Hormone replacement therapy can ease vaginal symptoms of menopause, such as dryness, itching, burning and discomfort with intercourse.
Osteoporosis. Hormone replacement therapy continues to be an option for osteoporosis prevention, but it's recommended only when other medications for osteoporosis prevention have been considered and determined not to be best for you.
If you're already taking hormone replacement therapy, should you keep taking it?
If you're already taking hormone replacement therapy to relieve menopausal symptoms, review its benefits and risks with your doctor.
"Consider the reason you started hormone replacement therapy and whether the reason remains relevant," Dr. Hayes advises. "If you started hormone therapy for hot flashes several years ago, you may no longer have hot flashes and could stop taking the drug."
Your doctor may periodically advise modifications to your regimen. For example, if you're taking a particular dose of estrogen, you may be able to lower the dose. Switching from an estrogen pill to a patch may offer certain benefits. In treating isolated vaginal symptoms, estrogen in a vaginal cream, tablet or ring is usually a better choice than a pill or a skin patch. That's because estrogen applied directly to your vagina remains localized to that area to treat your symptoms and doesn't circulate throughout your body as does estrogen ingested through a pill or absorbed through a patch.
Women on hormone replacement therapy should take the lowest effective dose for the shortest amount of time needed to treat symptoms.
Who should avoid hormone replacement therapy?
Women with breast cancer or a history of blood clots should not take hormone replacement therapy. Also avoid hormone replacement therapy for preventing memory loss, heart disease, heart attacks or strokes.
Instead, talk to your doctor about other medications you can take or lifestyle changes you can make for long-term protection from these conditions.
Alternatives to hormone replacement therapy
You may be able to manage your menopausal symptoms by making healthy lifestyle choices. In fact, your doctor may recommend that you try making changes to your exercise or eating habits before you try medication. After adjustments to your lifestyle, if you're still dealing with bothersome symptoms, you have several options besides hormone replacement therapy to help relieve discomfort.
Protect your long-term health
One of the previously believed benefits of hormone replacement therapy was that it promoted long-term health of postmenopausal women, from reducing risk of heart disease to making bones stronger. But since that's no longer the case, here are some alternatives.
A healthy heart
Good-for-your-heart health tips include:
Don't smoke.
Be physically active.
Eat a low-fat, high-fiber diet, with a variety of fruits and vegetables.
Maintain a healthy weight.
Manage high blood pressure.
Keep cholesterol and triglyceride levels in check.
Control diabetes.
Avoid excess alcohol.
Healthy bones
Keep your bones healthy and strong with:
Calcium and vitamin D. Make sure you're getting enough of these nutrients in your diet to keep your bones strong.
Exercise. Regular physical activity — especially weight-bearing exercises such as walking or dancing — can help keep your bones strong and healthy.
Medication. Certain medicines, when taken on a regular basis, can also protect your bone health. These include medicines from a class of drugs known as bisphosphonates, such as alendronate (Fosamax) and risedronate (Actonel), as well as raloxifene (Evista), teriparatide (Forteo) and calcitonin.
Every situation is different
When it comes to hormone replacement therapy, no one-size-fits-all solution exists. Each woman's experience with menopause is unique.
As researchers learn more about hormone replacement therapy and other menopausal treatments, recommendations may change. Review your current treatments with your doctor on a regular basis to make sure they're still your best option.
Saturday, November 10, 2007
Fetal development: What happens during the first trimester?
You're pregnant. Congratulations! You'll undoubtedly spend the months ahead wondering how your baby is growing and developing. What does your baby look like? How big is he or she? When will you hear the heartbeat?
To help answer some of these questions, check out this weekly calendar of events for your baby's first three months in the womb.
Week 1: Getting ready
It may seem strange, but you're not actually pregnant the first week or two of the time allotted to your pregnancy. Yes, you read that correctly!
Conception typically occurs about two weeks after your period begins. To calculate your due date, your health care provider will count ahead 40 weeks from the start of your last period. This means your period is counted as part of your pregnancy — even though you weren't pregnant at the time.
Week 2: Fertilization
The sperm and egg unite in the fallopian tube to form a one-celled entity called a zygote. If more than one egg is released and fertilized, you may have multiple zygotes.
The zygote has 46 chromosomes — 23 from you and 23 from your partner. These chromosomes contain genetic material that will determine your baby's sex and traits such as eye color, hair color, height, facial features and — at least to some extent — intelligence and personality.
Soon after fertilization, the zygote will travel down one of your fallopian tubes toward the uterus. At the same time, it will begin dividing rapidly to form a cluster of cells resembling a tiny raspberry. The inner group of cells will become the embryo. The outer group of cells will become the membranes that nourish and protect it.
Week 3: Implantation
The zygote — by this time made up of about 500 cells — is now known as a blastocyst. When it reaches your uterus, the blastocyst will burrow into the uterine wall for nourishment. The placenta, which will nourish your baby throughout the pregnancy, also begins to form.
By the end of this week, you may be celebrating a positive pregnancy test.
Week 4: The embryonic period begins
The fourth week marks the beginning of the embryonic period, when the baby's brain, spinal cord, heart and other organs begin to form. Your baby is now 1/25 of an inch long.
The embryo is now made of three layers. The top layer — the ectoderm — will give rise to a groove along the midline of your baby's body. This will become the neural tube, where your baby's brain, spinal cord, spinal nerves and backbone will develop.
Your baby's heart and a primitive circulatory system will form in the middle layer of cells — the mesoderm. This layer of cells will also serve as the foundation for your baby's bones, muscles, kidneys and much of the reproductive system.
The inner layer of cells — the endoderm — will become a simple tube lined with mucous membranes. Your baby's lungs, intestines and bladder will develop here.
Week 5: Baby's heart begins to beat
Your baby at week 5 (three weeks from conception)
At week five, your baby is 1/17 of an inch long — about the size of the tip of a pen.
This week, your baby's heart and circulatory system are taking shape. Your baby's blood vessels will complete a circuit, and his or her heart will begin to beat. Although you won't be able to hear it yet, the motion of your baby's beating heart may be detected with an ultrasound exam.
With these changes, circulation begins — making the circulatory system the first functioning organ system.
Week 6: The neural tube closes
Your baby at week 6 (four weeks from conception)
Growth is rapid this week. Just four weeks after conception, your baby is about 1/8 of an inch long. The neural tube along your baby's back is now closed, and your baby's heart is beating with a regular rhythm.
Basic facial features will begin to appear, including an opening for the mouth and passageways that will make up the inner ear. The digestive and respiratory systems begin to form as well.
Small blocks of tissue that will form your baby's connective tissue, ribs and muscles are developing along your baby's midline. Small buds will soon grow into arms and legs.
Week 7: The umbilical cord appears
Your baby at week 7 (five weeks from conception)
Seven weeks into your pregnancy, your baby is 1/3 of an inch long — a little bigger than the top of a pencil eraser. He or she weighs less than an aspirin tablet.
The umbilical cord — the link between your baby and the placenta — is now clearly visible. The cavities and passages needed to circulate spinal fluid in your baby's brain have formed, but your baby's skull is still transparent.
The arm bud that sprouted last week now resembles a tiny paddle. Your baby's face takes on more definition this week, as a mouth perforation, tiny nostrils and ear indentations become visible.
Week 8: Baby's fingers and toes form
Eight weeks into your pregnancy, your baby is just over 1/2 of an inch long.
Your baby will develop webbed fingers and toes this week. Wrists, elbows and ankles are clearly visible, and your baby's eyelids are beginning to form. The ears, upper lip and tip of the nose also become recognizable.
As your baby's heart becomes more fully developed, it will pump at 150 beats a minute — about twice the usual adult rate.
Week 9: Movement begins
Your baby at week 9 (seven weeks from conception)
Your baby is now nearly 1 inch long and weighs a bit less than 1/8 of an ounce. The embryonic tail at the bottom of your baby's spinal cord is shrinking, helping him or her look less like a tadpole and more like a developing person.
Your baby's head — which is nearly half the size of his or her entire body — is now tucked down onto the chest. Nipples and hair follicles begin to form. Your baby's pancreas, bile ducts, gallbladder and anus are in place. The internal reproductive organs, such as testes or ovaries, start to develop.
Your baby may begin moving this week, but you won't be able to feel for it quite a while yet.
Week 10: Neurons multiply
Your baby at week 10 (eight weeks from conception)
By now, your baby's vital organs have a solid foundation. The embryonic tail has disappeared completely, and your baby has fully separated fingers and toes. The bones of your baby's skeleton begin to form.
This week, your baby's brain will produce almost 250,000 new neurons every minute.
Your baby's eyelids are no longer transparent. The outer ears are starting to assume their final form, and tooth buds are forming as well. If your baby is a boy, his testes will start producing the male hormone testosterone.
Week 11: Baby's sex may be apparent
Your baby at week 11 (nine weeks from conception)
From now until your 20th week of pregnancy — the halfway mark — your baby will increase his or her weight 30 times and will about triple in length. To make sure your baby gets enough nutrients, the blood vessels in your placenta are growing larger and multiplying.
Your baby is now officially described as a fetus. Your baby's ears are moving up and to the side of the head this week. By the end of the week, your baby's external genitalia will develop into a recognizable penis or clitoris and labia majora.
Week 12: Baby's fingernails and toenails appear
Twelve weeks into your pregnancy, your baby is nearly 3 inches long and weighs about 4/5 of an ounce.
This week marks the arrival of fingernails and toenails. Your baby's chin and nose will become more refined as well.
Taking care of your baby
Healthy lifestyle choices — beginning even before conception — can support your baby's development. Consider these simple do's and don'ts:
Do:
Take a prenatal vitamin or folic acid supplement.
Maintain a healthy weight.
Exercise regularly, with your health care provider's OK.
Eat healthfully.
Manage stress and any chronic health conditions.
See your health care provider for regular prenatal checkups.
Talk to your health care provider about any medications you're taking.
Don't:
Smoke.
Drink alcohol.
Use recreational drugs.
Your baby is growing and changing every day. To give your baby the best start, take good care of yourself.
To help answer some of these questions, check out this weekly calendar of events for your baby's first three months in the womb.
Week 1: Getting ready
It may seem strange, but you're not actually pregnant the first week or two of the time allotted to your pregnancy. Yes, you read that correctly!
Conception typically occurs about two weeks after your period begins. To calculate your due date, your health care provider will count ahead 40 weeks from the start of your last period. This means your period is counted as part of your pregnancy — even though you weren't pregnant at the time.
Week 2: Fertilization
The sperm and egg unite in the fallopian tube to form a one-celled entity called a zygote. If more than one egg is released and fertilized, you may have multiple zygotes.
The zygote has 46 chromosomes — 23 from you and 23 from your partner. These chromosomes contain genetic material that will determine your baby's sex and traits such as eye color, hair color, height, facial features and — at least to some extent — intelligence and personality.
Soon after fertilization, the zygote will travel down one of your fallopian tubes toward the uterus. At the same time, it will begin dividing rapidly to form a cluster of cells resembling a tiny raspberry. The inner group of cells will become the embryo. The outer group of cells will become the membranes that nourish and protect it.
Week 3: Implantation
The zygote — by this time made up of about 500 cells — is now known as a blastocyst. When it reaches your uterus, the blastocyst will burrow into the uterine wall for nourishment. The placenta, which will nourish your baby throughout the pregnancy, also begins to form.
By the end of this week, you may be celebrating a positive pregnancy test.
Week 4: The embryonic period begins
The fourth week marks the beginning of the embryonic period, when the baby's brain, spinal cord, heart and other organs begin to form. Your baby is now 1/25 of an inch long.
The embryo is now made of three layers. The top layer — the ectoderm — will give rise to a groove along the midline of your baby's body. This will become the neural tube, where your baby's brain, spinal cord, spinal nerves and backbone will develop.
Your baby's heart and a primitive circulatory system will form in the middle layer of cells — the mesoderm. This layer of cells will also serve as the foundation for your baby's bones, muscles, kidneys and much of the reproductive system.
The inner layer of cells — the endoderm — will become a simple tube lined with mucous membranes. Your baby's lungs, intestines and bladder will develop here.
Week 5: Baby's heart begins to beat
Your baby at week 5 (three weeks from conception)
At week five, your baby is 1/17 of an inch long — about the size of the tip of a pen.
This week, your baby's heart and circulatory system are taking shape. Your baby's blood vessels will complete a circuit, and his or her heart will begin to beat. Although you won't be able to hear it yet, the motion of your baby's beating heart may be detected with an ultrasound exam.
With these changes, circulation begins — making the circulatory system the first functioning organ system.
Week 6: The neural tube closes
Your baby at week 6 (four weeks from conception)
Growth is rapid this week. Just four weeks after conception, your baby is about 1/8 of an inch long. The neural tube along your baby's back is now closed, and your baby's heart is beating with a regular rhythm.
Basic facial features will begin to appear, including an opening for the mouth and passageways that will make up the inner ear. The digestive and respiratory systems begin to form as well.
Small blocks of tissue that will form your baby's connective tissue, ribs and muscles are developing along your baby's midline. Small buds will soon grow into arms and legs.
Week 7: The umbilical cord appears
Your baby at week 7 (five weeks from conception)
Seven weeks into your pregnancy, your baby is 1/3 of an inch long — a little bigger than the top of a pencil eraser. He or she weighs less than an aspirin tablet.
The umbilical cord — the link between your baby and the placenta — is now clearly visible. The cavities and passages needed to circulate spinal fluid in your baby's brain have formed, but your baby's skull is still transparent.
The arm bud that sprouted last week now resembles a tiny paddle. Your baby's face takes on more definition this week, as a mouth perforation, tiny nostrils and ear indentations become visible.
Week 8: Baby's fingers and toes form
Eight weeks into your pregnancy, your baby is just over 1/2 of an inch long.
Your baby will develop webbed fingers and toes this week. Wrists, elbows and ankles are clearly visible, and your baby's eyelids are beginning to form. The ears, upper lip and tip of the nose also become recognizable.
As your baby's heart becomes more fully developed, it will pump at 150 beats a minute — about twice the usual adult rate.
Week 9: Movement begins
Your baby at week 9 (seven weeks from conception)
Your baby is now nearly 1 inch long and weighs a bit less than 1/8 of an ounce. The embryonic tail at the bottom of your baby's spinal cord is shrinking, helping him or her look less like a tadpole and more like a developing person.
Your baby's head — which is nearly half the size of his or her entire body — is now tucked down onto the chest. Nipples and hair follicles begin to form. Your baby's pancreas, bile ducts, gallbladder and anus are in place. The internal reproductive organs, such as testes or ovaries, start to develop.
Your baby may begin moving this week, but you won't be able to feel for it quite a while yet.
Week 10: Neurons multiply
Your baby at week 10 (eight weeks from conception)
By now, your baby's vital organs have a solid foundation. The embryonic tail has disappeared completely, and your baby has fully separated fingers and toes. The bones of your baby's skeleton begin to form.
This week, your baby's brain will produce almost 250,000 new neurons every minute.
Your baby's eyelids are no longer transparent. The outer ears are starting to assume their final form, and tooth buds are forming as well. If your baby is a boy, his testes will start producing the male hormone testosterone.
Week 11: Baby's sex may be apparent
Your baby at week 11 (nine weeks from conception)
From now until your 20th week of pregnancy — the halfway mark — your baby will increase his or her weight 30 times and will about triple in length. To make sure your baby gets enough nutrients, the blood vessels in your placenta are growing larger and multiplying.
Your baby is now officially described as a fetus. Your baby's ears are moving up and to the side of the head this week. By the end of the week, your baby's external genitalia will develop into a recognizable penis or clitoris and labia majora.
Week 12: Baby's fingernails and toenails appear
Twelve weeks into your pregnancy, your baby is nearly 3 inches long and weighs about 4/5 of an ounce.
This week marks the arrival of fingernails and toenails. Your baby's chin and nose will become more refined as well.
Taking care of your baby
Healthy lifestyle choices — beginning even before conception — can support your baby's development. Consider these simple do's and don'ts:
Do:
Take a prenatal vitamin or folic acid supplement.
Maintain a healthy weight.
Exercise regularly, with your health care provider's OK.
Eat healthfully.
Manage stress and any chronic health conditions.
See your health care provider for regular prenatal checkups.
Talk to your health care provider about any medications you're taking.
Don't:
Smoke.
Drink alcohol.
Use recreational drugs.
Your baby is growing and changing every day. To give your baby the best start, take good care of yourself.
Wednesday, November 7, 2007
Fetal development: What happens during the second trimester?
As your pregnancy progresses, your baby will begin to seem more real. You may hear the heartbeat at your prenatal appointments, and your growing abdomen may force your favorite jeans to the back of the closet.
While you're adjusting to the changes in your body, your baby is quickly maturing. Two months ago, your baby was simply a cluster of cells. Now, he or she has functioning organs, nerves and muscles. You may be amazed by how much your baby changes from week to week.
Week 13: Baby flexes and kicks
You can't feel it yet, but your baby can move in a jerky fashion — flexing the arms and kicking the legs. This week, your baby might even be able to put a thumb in his or her mouth.
Your baby's eyelids are fused together to protect his or her developing eyes. Tissue that will become bone is developing around your baby's head and within the arms and legs. Tiny ribs may soon appear.
Week 14: Hormones gear up
The effect of hormones becomes apparent this week. For boys, the prostate gland is developing. For girls, the ovaries move from the abdomen into the pelvis.
Meconium — which will become your baby's first bowel movement after birth — is made in your baby's intestinal tract. By the end of the week, the roof of your baby's mouth will be completely formed.
Week 15: Skin begins to form
Your baby at week 15 (13 weeks from conception)
Your baby's skin starts out nearly transparent. Eyebrows and scalp hair may make an appearance. For babies destined to have dark hair, the hair follicles will begin producing pigment.
The bone and marrow that make up your baby's skeletal system are continuing to develop this week. Your baby's eyes and ears now have a baby-like appearance, and the ears have almost reached their final position.
Week 16: Facial expressions are possible
Your baby at week 16 (14 weeks from conception)
Sixteen weeks into your pregnancy, your baby is between 4 and 5 inches long and weighs a bit less than 3 ounces. He or she can now make a fist.
Your baby's eyes are becoming sensitive to light. More developed facial muscles may lead to various expressions, such as squinting and frowning. Your baby may have frequent bouts of hiccups as well. For girls, millions of eggs are forming in the ovaries.
Week 17: Fat accumulates
Fat stores begin to develop under your baby's skin this week. The fat will provide energy and help keep your baby warm after birth.
Week 18: Baby begins to hear
As the nerve endings from your baby's brain "hook up" to the ears, your baby may hear your heart beating, your stomach rumbling or blood moving through the umbilical cord. He or she may even be startled by loud noises. Your baby can swallow this week, too.
Week 19: Lanugo covers baby's skin
Your baby's delicate skin is now protected with a pasty white coating called vernix. Under the vernix, a fine, down-like hair called lanugo covers your baby's body.
Your baby's kidneys are already producing urine. The urine is excreted into the amniotic sac, which surrounds and protects your baby.
As your baby's hearing continues to improve, he or she may pick up your voice in conversations — although it's probably hard to hear clearly through the amniotic fluid and protective paste covering your baby's ears.
Thanks to the millions of motor neurons developing in the brain, your baby can make reflexive muscle movements. If you haven't felt movement yet, you will soon.
Week 20: The halfway point
Halfway into your pregnancy, your baby is about 6 inches long and weighs about 9 ounces — a little over half a pound. You've probably begun to feel your baby's movements.
Under the protection of the vernix, your baby's skin is thickening and developing layers. Your baby now has thin eyebrows, hair on the scalp and well-developed limbs.
Week 21: Nourishment evolves
Although the placenta provides nearly all of your baby's nourishment, your baby will begin to absorb small amounts of sugar from swallowed amniotic fluid. This week, your baby's bone marrow starts making blood cells — a job done by the liver and spleen until this point.
Week 22: Taste buds develop
This week, your baby weighs in at about 1 pound.
Taste buds are starting to form on your baby's tongue, and your baby's brain and nerve endings can process the sensation of touch. Your baby may experiment by feeling his or her face or anything else within reach.
For boys, the testes begin to descend from the abdomen this week. For girls, the uterus and ovaries are in place — complete with a lifetime supply of eggs.
Week 23: Lungs prepare for life outside the womb
Your baby at week 23 (21 weeks from conception)
Your baby's lungs are beginning to produce surfactant, the substance that allows the air sacs in the lungs to inflate — and keeps them from collapsing and sticking together when they deflate. "Practice" breathing moves amniotic fluid in and out of your baby's lungs.
Your baby will begin to look more like a newborn as the skin becomes less transparent and fat production kicks into high gear.
With intensive medical care, some babies born at 23 weeks can survive. There are serious risks, however, such as bleeding in the brain and impaired vision. Advances in fetal medicine are steadily improving the odds for the tiniest preemies.
Week 24: Sense of balance develops
By now, your baby weighs about 1 1/2 pounds. Footprints and fingerprints are forming.
Thanks to a fully developed inner ear, which controls balance, your baby may have a sense of whether he or she is upside-down or right side up in the womb. You may notice a regular sleeping and waking cycle.
Babies born at 24 weeks have more than a 50 percent chance of survival. The odds get better with every passing week. Still, complications are frequent and serious.
Week 25: Exploration continues
Your baby's hands are now fully developed, although the nerve connections to the hands have a long way to go. Exploring the structures inside your uterus may become baby's prime entertainment.
Week 26: Eyes remain closed
Your baby weighs between 1 1/2 and 2 pounds. The eyebrows and eyelashes are well formed, and the hair on your baby's head is longer and more plentiful. Although your baby's eyes are fully developed, they may not open for another two weeks.
Week 27: Second trimester ends
This week marks the end of the second trimester. Your baby's lungs, liver and immune system are continuing to mature — and he or she has been growing like a weed. At 27 weeks, your baby's length will have tripled or even quadrupled from the 12-week mark.
If your baby is born this week, the chance of survival is at least 85 percent. However, serious complications are still possible.
Taking care of your baby
Healthy lifestyle choices throughout pregnancy will support your baby's development. Consider these simple do's and don'ts:
Do:
Take a prenatal vitamin.
Maintain a healthy weight.
Exercise regularly, with your health care provider's OK.
Eat healthfully.
Manage stress and any chronic health conditions.
See your health care provider for regular prenatal checkups.
Don't:
Smoke.
Drink alcohol.
Take medication without your health care provider's OK.
Your baby is growing and changing every day — and so are you. Marvel at the changes as you anticipate what's to come.
While you're adjusting to the changes in your body, your baby is quickly maturing. Two months ago, your baby was simply a cluster of cells. Now, he or she has functioning organs, nerves and muscles. You may be amazed by how much your baby changes from week to week.
Week 13: Baby flexes and kicks
You can't feel it yet, but your baby can move in a jerky fashion — flexing the arms and kicking the legs. This week, your baby might even be able to put a thumb in his or her mouth.
Your baby's eyelids are fused together to protect his or her developing eyes. Tissue that will become bone is developing around your baby's head and within the arms and legs. Tiny ribs may soon appear.
Week 14: Hormones gear up
The effect of hormones becomes apparent this week. For boys, the prostate gland is developing. For girls, the ovaries move from the abdomen into the pelvis.
Meconium — which will become your baby's first bowel movement after birth — is made in your baby's intestinal tract. By the end of the week, the roof of your baby's mouth will be completely formed.
Week 15: Skin begins to form
Your baby at week 15 (13 weeks from conception)
Your baby's skin starts out nearly transparent. Eyebrows and scalp hair may make an appearance. For babies destined to have dark hair, the hair follicles will begin producing pigment.
The bone and marrow that make up your baby's skeletal system are continuing to develop this week. Your baby's eyes and ears now have a baby-like appearance, and the ears have almost reached their final position.
Week 16: Facial expressions are possible
Your baby at week 16 (14 weeks from conception)
Sixteen weeks into your pregnancy, your baby is between 4 and 5 inches long and weighs a bit less than 3 ounces. He or she can now make a fist.
Your baby's eyes are becoming sensitive to light. More developed facial muscles may lead to various expressions, such as squinting and frowning. Your baby may have frequent bouts of hiccups as well. For girls, millions of eggs are forming in the ovaries.
Week 17: Fat accumulates
Fat stores begin to develop under your baby's skin this week. The fat will provide energy and help keep your baby warm after birth.
Week 18: Baby begins to hear
As the nerve endings from your baby's brain "hook up" to the ears, your baby may hear your heart beating, your stomach rumbling or blood moving through the umbilical cord. He or she may even be startled by loud noises. Your baby can swallow this week, too.
Week 19: Lanugo covers baby's skin
Your baby's delicate skin is now protected with a pasty white coating called vernix. Under the vernix, a fine, down-like hair called lanugo covers your baby's body.
Your baby's kidneys are already producing urine. The urine is excreted into the amniotic sac, which surrounds and protects your baby.
As your baby's hearing continues to improve, he or she may pick up your voice in conversations — although it's probably hard to hear clearly through the amniotic fluid and protective paste covering your baby's ears.
Thanks to the millions of motor neurons developing in the brain, your baby can make reflexive muscle movements. If you haven't felt movement yet, you will soon.
Week 20: The halfway point
Halfway into your pregnancy, your baby is about 6 inches long and weighs about 9 ounces — a little over half a pound. You've probably begun to feel your baby's movements.
Under the protection of the vernix, your baby's skin is thickening and developing layers. Your baby now has thin eyebrows, hair on the scalp and well-developed limbs.
Week 21: Nourishment evolves
Although the placenta provides nearly all of your baby's nourishment, your baby will begin to absorb small amounts of sugar from swallowed amniotic fluid. This week, your baby's bone marrow starts making blood cells — a job done by the liver and spleen until this point.
Week 22: Taste buds develop
This week, your baby weighs in at about 1 pound.
Taste buds are starting to form on your baby's tongue, and your baby's brain and nerve endings can process the sensation of touch. Your baby may experiment by feeling his or her face or anything else within reach.
For boys, the testes begin to descend from the abdomen this week. For girls, the uterus and ovaries are in place — complete with a lifetime supply of eggs.
Week 23: Lungs prepare for life outside the womb
Your baby at week 23 (21 weeks from conception)
Your baby's lungs are beginning to produce surfactant, the substance that allows the air sacs in the lungs to inflate — and keeps them from collapsing and sticking together when they deflate. "Practice" breathing moves amniotic fluid in and out of your baby's lungs.
Your baby will begin to look more like a newborn as the skin becomes less transparent and fat production kicks into high gear.
With intensive medical care, some babies born at 23 weeks can survive. There are serious risks, however, such as bleeding in the brain and impaired vision. Advances in fetal medicine are steadily improving the odds for the tiniest preemies.
Week 24: Sense of balance develops
By now, your baby weighs about 1 1/2 pounds. Footprints and fingerprints are forming.
Thanks to a fully developed inner ear, which controls balance, your baby may have a sense of whether he or she is upside-down or right side up in the womb. You may notice a regular sleeping and waking cycle.
Babies born at 24 weeks have more than a 50 percent chance of survival. The odds get better with every passing week. Still, complications are frequent and serious.
Week 25: Exploration continues
Your baby's hands are now fully developed, although the nerve connections to the hands have a long way to go. Exploring the structures inside your uterus may become baby's prime entertainment.
Week 26: Eyes remain closed
Your baby weighs between 1 1/2 and 2 pounds. The eyebrows and eyelashes are well formed, and the hair on your baby's head is longer and more plentiful. Although your baby's eyes are fully developed, they may not open for another two weeks.
Week 27: Second trimester ends
This week marks the end of the second trimester. Your baby's lungs, liver and immune system are continuing to mature — and he or she has been growing like a weed. At 27 weeks, your baby's length will have tripled or even quadrupled from the 12-week mark.
If your baby is born this week, the chance of survival is at least 85 percent. However, serious complications are still possible.
Taking care of your baby
Healthy lifestyle choices throughout pregnancy will support your baby's development. Consider these simple do's and don'ts:
Do:
Take a prenatal vitamin.
Maintain a healthy weight.
Exercise regularly, with your health care provider's OK.
Eat healthfully.
Manage stress and any chronic health conditions.
See your health care provider for regular prenatal checkups.
Don't:
Smoke.
Drink alcohol.
Take medication without your health care provider's OK.
Your baby is growing and changing every day — and so are you. Marvel at the changes as you anticipate what's to come.
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