A Guide to Pregnancy After 35

While the overall birthrate in the United States is dropping, especially among people in their 20s, there has been a dramatic increase over recent decades in the number of people giving birth at age 35 and older.

“There are many reasons for the trend in delayed childbearing,” says Dr. Robin Kalish, a maternal-fetal medicine specialist at the NewYork-Presbyterian Alexandra Cohen Hospital for Women and Newborns. These include career aspirations, financial security, availability of a wide range of birth control methods, and access to enhanced fertility treatments such as in vitro fertilization (IVF) and egg freezing, she says.

But as people get older, they face an increased risk of medical issues that can potentially complicate their pregnancy. While delivering at age 35 and older is officially considered “advanced maternal age,” Dr. Kalish notes that in reality, there’s no “magic number” for being at-risk for complications.

“A healthy 38-year-old could have an easier pregnancy than a 20-year-old who has multiple medical issues,” Dr. Kalish says. “It’s really a gradual increased risk little by little over age 35, and it’s incredibly individualized.”

Dr. Kalish adds that her over-40 patients usually ask her, “‘Am I too old?’ My answer is almost always, ‘No, you are not too old.’ And then their next question is, ‘Am I high-risk?’ Unfortunately, my answer is usually, ‘Yes.’ But with proper care and monitoring, the majority of women in that age range go on to have a healthy pregnancy.”

Health Matters spoke with Dr. Kalish, who is also a professor of Obstetrics and Gynecology at Weill Cornell Medicine, to understand what to expect during a pregnancy after age 35 and to learn tips to help have a healthy pregnancy for you and your baby.

Fertility gradually decreases beginning at age 32 and even more rapidly after age 37. “You are born with all the eggs you are ever going to have—which is millions,” explains Dr. Kalish. “As you get older, that number decreases. But it’s more than just the quantity of eggs. As you get older, the quality of eggs decreases as well.”

Both affect fertility. While it is hard to pinpoint the exact numbers, by age 40, the chance of conceiving each month is under 10%. By the time you’re 45, it’s about 1%. “In comparison, someone in their mid-20s has a roughly 25% chance each month of getting pregnant,” says Dr. Kalish.

If you’re thinking of getting pregnant, Dr. Kalish encourages everyone—especially those over 35—to schedule a pre-pregnancy visit with their OB-GYN. “A lot depends on a person’s age, their medical history, and their future goals,” she says. “At a pre-pregnancy visit, you and your doctor can come up with an individualized plan and put in place healthy lifestyle habits—like good nutrition and exercise—to help optimize your health for when the time is right to conceive.”

A pre-pregnancy visit can also be a good time to talk with your doctor about fertility options. “While the biology hasn’t changed over the decades, the technology has changed,” says Dr. Kalish. “There are more options than ever before when it comes to fertility treatments and therapies.”

A variety of increased complications can occur over age 35, any time from the beginning of a pregnancy to childbirth. “That’s not to say that most people over age 35 will experience these complications, but it’s worth noting that these risks are increased,” Dr. Kalish says.

Pregnant people over 35 are at an increased risk of:

• Gestational diabetes — This type of diabetes only occurs during pregnancy; your chance of developing it increases after age 25.
•  Preeclampsia — Characterized by high blood pressure during pregnancy or after childbirth, preeclampsia is more common among pregnant people who are very young or over age 40.
• Cesarean delivery (C-section) — Older women are at a higher risk for having pregnancy complications that require getting the baby out sooner.
•  Pre-term labor and/or low birth weight — This can be due to many medical reasons that require an early delivery, including the placenta not functioning well and not delivering adequate nutrients and blood supply to the fetus.
•  Stillbirth — This risk is relatively low; however, it becomes more common as a per-son ages.
•  Fetal chromosomal abnormalities — The risk of a chromosomal abnormality that can cause conditions like Down syndrome increases with age.

Many of these complications can be detected with routine prenatal checkups and tests. For example, a blood test can help diagnose gestational diabetes, and your doctor may suggest you monitor your blood pressure at home for preeclampsia. In addition, genetic screening tests (which tell you if you are high-risk or low-risk for a condition) can be used to screen for genetic conditions like Down syndrome, while diagnostic tests like amniocentesis can confirm or rule out a condition.

“It’s important for all mothers to have a robust conversation with their OB-GYN about screening and diagnostic tests, especially when it comes to chromosomal abnormalities,” says Dr. Kalish.

The fourth trimester —the 12 weeks after giving birth—is just as important for a mother’s health as the first three trimesters. Maternal mortality is on the rise in the U.S., especially for women 40 and older, whose death rate is seven times higher than those under age 25, according to the Centers for Disease Control and Prevention. “It’s still rare, but it is a huge focus for academic institutions like ours to understand how to reduce maternal complications and mortality,” says Dr. Kalish.

This is why it’s important to prioritize your postpartum follow-up visit with your doctor. According to the American College of Obstetricians and Gynecologists (ACOG), women should follow up with their obstetric healthcare team within the first three weeks of giving birth for a post-birth assessment and also have a more comprehensive postpartum evaluation by 12 weeks. These visits are to make sure mom is recovering well and baby is healthy. For those who are considered high-risk, check in with your doctor within the first week or two.

If you are experiencing symptoms — such as fever and chills, shortness of breath, dizziness, or brisk, bright bleeding — seek medical attention immediately.

Robin B. Kalish, M.D., FACOG, is a maternal-fetal medicine specialist at NewYork-Presbyterian/Weill Cornell Medical Center and NewYork-Presbyterian Alexandra Cohen Hospital for Women and Newborns. She is also vice chair of obstetrics and a professor of Obstetrics and Gynecology at Weill Cornell Medicine. Her expertise includes caring for women with medical conditions such as diabetes, hypertension, and lupus as well as women who conceived through in vitro fertilization (IVF) or are pregnant with multiples. In addition, she specializes in obstetric ultrasound and prenatal diagnosis including amniocentesis and chorionic villus sampling (CVS). While not all of Dr. Kalish’s patients are high-risk, she considers every pregnancy unique.