When a woman is trying to get pregnant and she becomes pregnant past the age of 35, she is considered to be of advanced maternal age. There are several reasons why a pregnancy beyond that age could be an issue. It's more difficult to get pregnant as a woman gets older, it may take longer to get pregnant, and if a woman becomes pregnant at 35 years of age and beyond there are more pregnancy complications such as more miscarriages and medical issues such as diabetes and hypertension.
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 a woman's age of 35 and older as one of the key points in determining whether or not a woman needs advanced medical care during pregnancy due to a potential increase in pregnancy risk. Most women over the age of 35 do not have complicated pregnancies, but obstetricians remain on high alert throughout the pregnancy, just in case.
Difficulties Getting Pregnant
At 35 years of age and beyond, it's more difficult to get pregnant as a woman gets older, and it may take longer to get pregnant. This is mostly related to a woman's eggs getting older, the quality of her eggs diminish, and she is less likelky to ovulate, and her eggs are less likely to get fertilized and implant.
Increased Risk of Down Syndrome
One of the most notable pregnancy risks for women of advanced maternal age is Down Syndrome. Down Syndrome is a chromosomal defect thought to be associated with aging eggs. By the age of 40, about one in 100 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. Obstetricians will often request amniocentesis or chorionic villus sampling (CVS) to determine the risk of Down Syndrome in the fetus.
Increased Risk of Preterm Birth
Several studies have shown a relationship between preterm birth (PTB) and advanced maternal age. In a large retrospective Canadian study women >= 40 years of age had increased risk factors for PTB such as chronic hypertension, use of assisted reproductive technology (ART), pre-gestational and gestational diabetes, invasive procedures during pregnancy, and placenta previa. Their risk of PTB was 20% higher when compared to those age 30-34 years.
Increased 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 invasive 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.
Fortunately, there are noninvasive tests available that can provide information on risks of the fetus having certain chromosomal conditions. These test are cell-free DNA, a blood test done as early as 10 weeks, and nuchal translucency screening.