When a woman becomes pregnant past the age of 35, she is considered to be of advanced maternal age. As a woman ages, her egg stores are lower and the remaining eggs may not be as healthy and viable as they were when she was in her 20s.
Obstetricians use the age of 35 as the key point in determining whether or not a woman needs advanced medical care during pregnancy due to a potential increase in pregnancy risk. Not all women over the age of 35 have complicated pregnancies, but obstetricians remain on high alert throughout the pregnancy, just in case.
Risk of Down Syndrome
One of the most notable pregnancy risks for women of advanced maternal age is Down Syndrome. By the age of 40, about one in 400 women are at risk of having an infant with Down Syndrome. Past the age of 40, the risk of Down Syndrome increases exponentially. By the advanced maternal age of 49, about one in 12 women are at risk. Down Syndrome is a chromosomal defect thought to be associated with aging eggs. Obstetricians will often request amniocentesis or chorionic villus sampling (CVS) to determine the risk of Down Syndrome in the fetus.
Risk of Having Fraternal Twins
With advanced maternal age comes an increased chance of fraternal twin pregnancy. In addition to age, number of pregnancies also comes into play. If a woman aged 35 becomes pregnant and she has four pregnancies prior to the current pregnancy, she is three times more likely to conceive fraternal twins.
Other Health Risks Facing Women of Advanced Maternal Age
As women age, they are more likely to suffer from diseases and conditions associated with aging, such as diabetes, hypertension and arthritis. Some of these conditions and the age of the body in general, may increase risk of gestational diabetes, pregnancy-induced hypertension and premature labor.
Testing Associated with Advanced Maternal age and Risk of Miscarriage
The two most common tests suggested in women of advanced maternal age are CVS and amniocentesis. Both tests increase the risk of miscarriage; in both women of advanced maternal age and women of normal maternal age, but the risk is less than one percent. The tests are completely optional and are not required for obstetric care, so the pregnant woman must weigh the risks of CVS and amniocentesis with the benefits of early detection of potential fetal health conditions.