In Your 20s

When Siobhan Bennett was pregnant with her two daughters during her mid 20s, she had an easy time of it, and she figured things would be the same when she was expecting her son at age 45. "No one sat me down to say, 'Look, your body's twenty years older now,'" says Bennett of Allentown, Pennsylvania. "I was far more fatigued this last time around -- the difference was night and day."

When you decide to have a baby is largely a function of where you are in life. Did you find a partner early or late? Are you planning a big family or a small one? Each age makes for a different experience. Although every woman is unique, the physical and emotional aspects of pregnancy are at least partly influenced by how old you are. Here's what you can expect.

In Your 20s: Primed for Pregnancy

From a purely physical standpoint, this is the prime time for getting pregnant -- and the earlier you are in your 20s, the faster you may conceive. The irregular cycles common in your teenage years have evened out, so ovulation is more predictable. Plus, your eggs (you're born with all you'll have) are fresh and healthy, making them good candidates for fertilization, says Geeta K. Swamy, MD, an ob-gyn at Duke University Medical Center.

Not only is it easiest to get pregnant in your 20s, it's also easier to be pregnant. "Usually, a younger body can best handle the additional load on the bones, back, and muscles during pregnancy," says Cosmas J.M. van de Ven, MD, who specializes in high-risk obstetrics at the University of Michigan Medical School in Ann Arbor. Your joints have been subjected to minimal wear and tear, and you're likely in the peak condition of your adult life, possibly years away from medical problems that may arise with increasing age.

And if you're young, chances are your own parents are, too -- meaning more hands-on help for you and more fun times for your children. "Not only can younger grandparents help with childcare, but it's wonderful when, in years ahead, they're still able to attend school functions or even go along on field trips," says Diane G. Sanford, PhD, coauthor of the Postpartum Survival Guide (New Harbinger).

The risk of pregnancy-related complications is generally low in your 20s, with a notable exception: preeclampsia, or pregnancy-induced hypertension. Preeclampsia is less related to age, however, than the fact that this condition usually occurs with a first pregnancy -- and most expectant women in their 20s are first-time moms, says Robert H. Berry, MD, an ob-gyn at UMass Memorial Medical Center in Worcester. You may also run a greater risk of a low birth weight baby if you've continued bad health habits from your teen years, such as smoking, poor nutrition, and risky sex that leads to sexually transmitted diseases.

While the physical factors of pregnancy generally favor a 20-something, that doesn't necessarily mean this is the decade to have a baby -- particularly if you're feeling your way into a career or a marriage. "You may not have had enough time to fulfill your own needs, such as professional success or spending time alone with your partner," says Paula Ford-Martin, author of The Everything Pregnancy Book (Adams Media).

What you lack in life experience, however, you may make up for in enthusiasm about impending motherhood. "A woman in her 20s may not spend so much time overthinking the pregnancy," says Sanford. "She may be more upbeat and less anxious about having a baby, taking the classes, and becoming a mom." And just a few years may make a big difference in your emotional preparedness. "There was no way I felt mature enough to have a baby at 21, even though I knew I wanted a family," says Heather Toto, who recently became a first-time mom at 28. "But by this time, I've been working for a few years -- I'm a middle-school teacher -- and my husband and I are more financially secure. Now the time is right."

Image zoom Peter LaMastro

In Your 30s: Gaining Maturity vs. Waning Fertility

Many women who've rounded the bend of 30 may feel they've made great strides professionally and personally, making them more emotionally prepared for pregnancy. "For me, being in my 30s became all about having a family," says Mary Lindewirth of Gillette, New Jersey. "I had a great job, my husband and I were fixing up a house that we had bought, and we took wonderful vacations -- but I knew that if we didn't have kids we'd look back someday and wonder what we had really achieved."

The catch: While you were gaining life experience, your eggs continued to mature as well -- and now they're showing their age. The average woman is born with half a million available eggs, but those most sensitive to ripening are released first, leaving you with the slower specimens as you get older. So even if you conceived at the get-go last decade, don't expect the same speedy results now. You'll probably be trying for another three to six months, says Dr. Berry, even if you're in great shape and have no medical issues that affect fertility (such as endometriosis or uterine fibroids).

Waning fertility is most noticeable after the mid 30s, as Lindewirth can attest. "I was 35 when I conceived my first son, and it didn't take that long -- just four months," she says. "I wanted to have another baby as soon as possible afterward, but it didn't happen. I gave myself until 40 to conceive, and I just made it at age 39."

Once you get pregnant, however, you'll likely find that if you're fit and healthy, you may enjoy the energy usually associated with a younger woman. "Your physical well-being during pregnancy depends more on who you are than how old you are," says Dr. Berry. Be aware, though, that this is the decade when chronic conditions such as diabetes or high blood pressure, which complicate pregnancy, first become evident, says Dr. Swamy. This is especially true if you've packed on pounds with the passing years, since obesity increases the risk of many medical problems.

Also, even if you're in decent shape, starting at age 35, you have an increasing risk for pregnancy-specific conditions including gestational diabetes. In fact, age 35 marks the official start for "high risk" pregnancy. Why the scary-sounding cutoff? Because at 35, the odds of your having a baby with a chromosomal problem such as Down syndrome (in which a baby is born with an extra chromosome) are about equal to the risk of miscarriage from amniocentesis, a diagnostic test for chromosomal defects that examines amniotic fluid. (The fluid is removed through a needle inserted in the mother's abdomen.) "However, that risk [about 1 in 295] is actually still quite small -- it's just that it's higher compared with the risk of a 25-year-old," says Dr. van de Ven.

In addition, the risk of certain conditions, such as placenta previa, in which the placenta grows near the cervix and causes bleeding, increases with the number of previous pregnancies or cesarean sections, which is why it's most common among older women, notes Dr. Berry.

Kathleen Van Gorden Morse of Little Compton, Rhode Island, mulled over all her options when she became pregnant at 35. "Although I had friends my age who went straight to amnio, I wanted to start with a safer option, so I chose a type of ultrasound that looks at the baby's neck," says Van Gorden Morse. Known as nuchal translucency, this high-resolution ultrasound measures the skin fold at the back of the fetus' neck. "If it's larger than normal, it indicates a potential chromosomal defect," says Michelle Sang, MD, an ob-gyn in Portland, Oregon.

Image zoom Peter LaMastro

In Your 40s: Older, Yes, but Also Much Wiser

There's no getting around it: From a medical standpoint, this is the toughest decade for pregnancy. By now, you've run through your highest-quality eggs, making conception slower than ever. "You're left with those eggs that have not only taken the longest to respond to the body's cues for release, but they also don't function well during fertilization," says Dr. Berry. This further raises the risk of chromosomal abnormalities and miscarriage. Meanwhile, your menstrual cycle may grow increasingly irregular well before menopause, which also compromises fertility. (And otherwise health-conscious women in this age group may be slow to seek out prenatal care -- they often assume the skipped period that signals pregnancy is the first sign of menopause. "When my doctor gave me the news, he said, 'You're going through a change, but not the change you think,'" recalls Bennett.)

Interestingly, while it's now hardest to get pregnant, this is also when you're most likely to carry multiples -- itself a high-risk pregnancy -- even without medical intervention. "It may be that shifting hormone levels during menopause stimulate the release of more than one egg at ovulation -- like a natural fertility drug," says Dr. Berry.

Standard blood work (the alpha-fetoprotein or AFP, also known as triple or quad screening) that estimates the risk of chromosomal defects such as Down syndrome is usually considered a waste of time and money, says Dr. Swamy. Screening will invariably reveal risk, which now accelerates more rapidly, from about 1 in 86 at age 40 to 1 in 21 at age 45. Women at 40-plus who opt for testing usually go straight to the definitive tests -- amnio or chorionic villus sampling (CVS), which involves removing a bit of tissue from the placenta and carries about a 1 percent risk of miscarriage. (CVS is also available for younger women, but many decide against it because, for them, the procedure's miscarriage risk still outweighs the Down's risk.)

Pregnancy may exacerbate chronic conditions as well as early signs of aging, such as stiff, sore joints; varicose veins may also get worse. "It's all magnified with pregnancy," says Dr. Sang. A slower metabolism may have profound effects, too: "I ate the same but gained twice as much weight with my son as I had with my earlier pregnancies, and the greater load sapped a lot more of my energy," says Bennett. Despite this, she headed up a major arts festival until the day she went into labor.

Doctors may be quick to tick off the physical downsides of later pregnancy, but a list of other pluses balances the scales. You have greater financial stability, for starters, which may enable you to focus more on motherhood. Life experience may have made you more patient and flexible. "First-time motherhood can seriously rattle long-established routines, but a woman in her 40s knows more about life's ups and downs and can better take shake-ups in stride," says Sanford.

And you've likely proved yourself professionally -- you may now be more content to stay home, or more confident about melding motherhood and a career. "You're more savvy, and not as afraid to step up to the plate and negotiate your terms for employment," says Ford-Martin. "Older mothers will ask for family-friendly workplace arrangements like telecommuting, flextime, and job sharing."

That self-confidence may also carry itself into the doctor's office, where you're more inclined to speak up about your preferences regarding labor and delivery. "Women who are a bit older tend to be more active in their pregnancy and overall healthcare," says Dr. Swamy. "They may ask their ob-gyn more questions about things we consider to be standard practice, such as prenatal labs, diabetes testing, and ultrasounds."

Finally, says Bennett, she's learned coping strategies over the years that have served her well in her second round as a mom of a newborn -- including an afternoon teatime and taking one day a week when she leaves the baby with other family members. "One day I saw three movies in a row," she says. "Now I know that it's important to indulge myself, and I think it makes me a better mother."

Rachelle Vander Schaaf is a writer in Macungie, Pennsylvania, and a mother of two.

Originally published in American Baby magazine, February 2004.