As many women are pursuing careers and other adventures in life before starting a family, many expectant mothers will find themselves labeled “Advanced Maternal Age” or AMA. This means the mother will be 35 or older at the time of the due date. There are risks in all pregnancies, and some of the risks are increased in AMA women. Prenatal care for the AMA patient includes extra counseling, monitoring, and testing to ensure healthy outcomes for the mother and infant.
When counseling an AMA patient, I typically review the following risks and management:
1. Risk of miscarriage: Unfortunately there is not a specific treatment or prevention for miscarriage. Testing and evaluation for a miscarriage would not be done unless there is a history of recurrent pregnancy loss (three or more miscarriages in the first trimester in a row).
2. Aneuploidy: The rate of miscarriage is increased partly due to an increased rate of genetic abnormalities, or aneuploidy. As women age, the risk of aneuploidy increases. For example, the age related risk of Down Syndrome at 30 is 1/940. At age 40 the risk is 1/85. AMA women are counseled about the risks of genetic abnormalities and are offered genetic screening or diagnostic testing. Genetic screening testing will provide a risk assessment, but is not 100% accurate. Diagnostic testing will provide a definite result but requires a more invasive procedure such as amniocentesis (a thin needle is used to collect fluid from inside the uterus to send to the lab). An anatomy ultrasound is performed for all pregnancies around 18 to 20 weeks to screen for abnormalities. In AMA women, the ultrasound is very detailed due to the increased risk of aneuploidy. An ultrasound can identify markers of genetic problems, but can also miss up to ⅔ of abnormalities.
3. The risk of medical complications is increased in the AMA population: These include gestational diabetes, hypertension, and pre-eclampsia. A test for gestational diabetes is performed between 24 and 28 weeks in all pregnancies. Routine prenatal visits with blood pressure and urine checks help to identify hypertension and pre-eclampsia.
4. Risk of growth restriction: Routine visits will monitor weight gain and fundal height which correlate with fetal growth. A third trimester growth ultrasound can be done to ensure adequate growth.
5. Risk of stillbirth: Within the age group of women 35-39, there is a slightly increased risk of stillbirth above the baseline risk. We are unable to extrapolate whether the association is driven by the 38- and 39- year old patients being grouped with the 35-year-old patients. I recommend that patients do fetal kick counts at least once daily, and a non-stress test once per week after 36 weeks. A non-stress test monitors the baby’s heart rate for 20 minutes and helps determine fetal well-being. AMA women can be counseled on delivery planning with discussion of induction of labor between 39-40 weeks, or later.
Although this may seem like a lot of risks and complications, with the appropriate care and monitoring during pregnancy, AMA women can have safe pregnancies and healthy babies! Though the risks cannot be prevented, monitoring and surveillance for complications and treatment if necessary, will help ensure the best outcome possible for the infant and mother. The majority of women in this age range will have routine, uncomplicated pregnancies. If you are concerned about the risks or specific medical conditions that you have prior to pregnancy, you should make an appointment for a preconception visit with your OB/gyn.
American College of Obstetricians and Gynecologists. Screening for Fetal Aneuploidy. Practice Bulletin 163. May, 2016.
By Loriana Soma, M.D. - Expert Obstetrician/Gynecologist