Advanced Maternal Age in Pregnancy July 29, 2016

As a woman over 35 who might have another baby, I agree the terms “advanced maternal age” and “geriatric pregnancy” are not pleasant, especially when you find yourself in these categories. Pregnancy after 35 can result in a happy and healthy newborn, however these pregnancies are associated with some risk.

Fertility begins to decline in our early 30's and a more drastic decline is seen after age 37. This occurs because each of us is born with all the eggs we will ever have and with time, these eggs diminish in number and quality. Gynecologic conditions that can affect fertility, such as endometriosis, uterine polyps, or uterine fibroids, also increase as we age.

Once pregnant, there is an increased risk of miscarriage in older women. Whereas in general the risk of miscarriage is around 20%, in women who are 35-39 the risk is closer to 25%, and in women 40 or older the risk is 50%. This is due to a combination of factors but in part due to the higher risk for chromosomal problems such as Down Syndrome. As an example, the risk of having a baby affected with Down Syndrome is 1/1030 in a 25 year old woman, or much less than 1% risk. The risk increases to 1/240 in a 35 year old woman, and again to 1/52 in a 40 year old woman. A pregnant woman over 35 also has a 4-8 fold higher risk for ectopic pregnancy.

Pregnancy related complications such as high blood pressure, pre-eclampsia, gestational diabetes, placental abruption, and placenta previa occur at a higher rate in women 35 or older. Unexplained intrauterine fetal demise (when baby passes away inside the uterus without warning) also occurs at a higher rate in older pregnant patients, especially after the due date. This is a devastating result and without a doubt one of the most difficult outcomes for a patient and her obstetrician to encounter.

I would never tell a woman who is 35 or older to avoid pregnancy just because the risks are increased. However, because of these risks, I manage a pregnancy differently in women who are of advanced maternal age. I counsel my patients about additional testing that can be performed to screen for chromosomal problems. This testing is elective but is especially important for older pregnant patients to consider. We follow your pregnancy more closely to monitor for complications, especially in the last month by performing nonstress tests. Because of the increased risk for demise, the standard of care is to recommend labor induction between 39 and 40 weeks.

Although the risks are sobering to think about if you are planning a pregnancy, there are many advantages to being well informed and prepared. I have taken care of many older pregnant patients and most women have the perfect outcome – a healthy newborn baby.

Reference: Effect of advanced age on fertility and pregnancy in women.