While most pregnancies proceed without complications, in a small percentage of cases, difficulties arise. Complications are more common in women of advanced maternal age, and just as conceiving can be more challenging at age 40, maintaining a healthy pregnancy is a bit more difficult as well. Good pre-conception health, appropriate body weight and an eye toward nutrition help ensure that a pregnancy proceeds in as trouble-free a manner as possible, but it's important to know that there are a few complications to watch for.
Miscarriage
One of the most dramatic and serious of the complications associated with advanced-age pregnancy is miscarriage, or spontaneous abortion of the developing embryo or fetus. In his book "What You Didn't Think to Ask Your Obstetrician," Dr. Raymond Poliakin explains that miscarriage is defined as the spontaneous termination of a pregnancy at or before 20 weeks of gestation. The major reason for miscarriage is a genetic abnormality in the fetus, which explains why these events are more common in older moms. Because a woman is born with all of the eggs she'll ever ovulate, her eggs--unlike a man's sperm, which are produced throughout life--are just as old as she is. Older eggs have been exposed to environmental radiation, toxins and other potentially damaging factors for more years than younger eggs have, making them more likely to be genetically aberrant.
Pre-eclampsia
Also called pregnancy-induced hypertension, pre-eclampsia is high blood pressure during pregnancy. According to Heidi Murkoff and Sharon Mazel in their book, "What to Expect When You're Expecting," pre-eclampsia generally develops after the 20th week of gestation and is more common in women over 40 years of age. It's a serious complication--if untreated, it can lead to seizures in the mother and premature delivery of the infant. Women over 40 are carefully monitored during their prenatal checkups to ensure that blood pressure is normal, and signs of developing pre-eclampsia are treated with bed rest and fetal monitoring.
Placenta Previa
Poliakin points out that placenta previa is also more common in 40-year-old mothers than in their younger counterparts. This condition occurs when the placenta attaches to the lower portion of the uterus, blocking the cervix. Early pregnancy placenta previa can correct itself--the placenta migrates to a higher position in the uterus much of the time--but third trimester previas can result in severe vaginal bleeding as the uterus thins near the cervix and tears the placenta away from the uterine lining. Babies older than 35 weeks gestational age are generally delivered soon after placenta previa is discovered, but younger fetuses benefit from additional time in the uterus, and most practitioners will try to manage the condition with bed rest for as long as possible.
References
- "What You Didn't Think to Ask Your Obstetrician"; Raymond Poliakin, M.D.; 2007
- "What to Expect When You're Expecting"; Heidi Murkoff and Sharon Mazel; 2008
