According to the Centers for Disease Control and Prevention, the average age for women having their first child has slowly been increasing since the 1970s. As of 2013, the average age for having a first child was 26 years old; this average age is expected to increase since more women are having their first child in their 30s and 40s.
Being an “older” expecting mother has both benefits and potential risks. The benefits are that women in their 30s and 40s (and beyond) are more mature, perhaps more financially stable, and more experienced at life. The risks are that certain conditions in both the mother and fetus are more common in pregnancies of women aged 35 and older.
Now, nothing magically happens at the age of 35 that makes pregnancy suddenly riskier. It’s all a matter of statistics and probabilities – statistically speaking, women aged 35 and over are more likely to develop high blood pressure and diabetes during their pregnancies. These conditions can cause problems including premature delivery, miscarriage, developmental problems with the fetus, or birth complications.
Older women are also more likely to have a baby that has a chromosomal disorder. The American College of Obstetrics and Gynecology states that “A 35-year-old woman has a 1-in-92 chance of having a baby with any chromosomal disorder compared with a 1-in-476 chance for a 25-year-old woman. The risk of having a baby with Down syndrome is 1-in-378 for a 35-year-old woman and 1-in-1,250 for a 25-year-old.”
▪ Ultrasound – This procedure uses high-frequency sound waves to create a picture of the baby and placenta. Ultrasound is used for a variety of reasons, including the determination of gestational age and for examining certain physical structures (and potential deformities) in the fetus.
▪ Blood tests – Using a blood sample from the mother, these tests screen for conditions in the fetus that are more common in older mothers. These tests include the quad marker screen, which helps show your baby’s risk of Down syndrome or other chromosome abnormalities, and neural tube defects, such as spina bifida (incomplete closure of the backbone) and anencephaly (parts of brain and skull missing).
▪ Non-invasive prenatal test (NIPT) – This is a newer test, which is of particular importance to women aged 35 and older. For this test, a sample of the mother’s blood is collected, since the mother’s blood contains fragments of DNA from the fetus. Using this sample, the DNA of the fetus is analyzed to look for the presence of chromosomal disorders, such as trisomy 21 (Down syndrome) and trisomy 18 (Edwards syndrome). The gender of the baby can also be determined by the DNA analysis. These newer tests have proven to be highly accurate, with over 99% sensitivity (the ability to find “true positive” results). The MaterniT21® PLUS test is a commercially available NIPT, and can determine if trisomy 21, as well as other trisomies, is present. This type of non-invasive test is a technological advancement in prenatal care, as it provides important information about the pregnancy, without introducing the risk of miscarriage.
▪ Diagnostic Tests – Both chorionic villus sampling (CVS) and amniocentesis are diagnostic tests, meaning, they have the ability to diagnose the presence of disorders in the baby, but these tests carry higher risks and can initiate miscarriage in a small number of cases. Both of these diagnostic tests involve placing a needle into the uterus to gather a sample of cells. The decision to have a diagnostic test can be difficult to make, and the pros and cons must be weighed. Women aged 35 and over tend to have more of these tests than younger women, since the risk of chromosomal disorders in the fetus is higher in older mothers.
Although there are some increased risks for pregnant women aged 35 and over, obtaining good prenatal care and testing can provide expecting mothers with important information about their health and the health of the developing fetus. Working closely with your healthcare provider and using the predictive capabilities of prenatal testing can help ensure a successful and healthy pregnancy.