Mount Auburn Healthcare Connection

Learn More:

• Related Links
• Quiz

Pregnancy rates for women over 35 are increasing dramatically and pregnancies for women under 30 are decreasing. This trend is due to several factors. In particular, women are putting off childbearing so they can complete or continue their educations or pursue their career goals before they start raising children. Assisted reproductive techniques, such as IVF (in vitro fertilization) have also contributed to the increase in pregnancies over 35 or even 40 years of age.

Leslie MacDonald, M.D., an obstetrician at Mount Auburn Hospital in Cambridge, a teaching hospital of Harvard Medical School, says “While we may label pregnancies over the age of 35 as ‘high risk,’ the vast majority of women do very well and have completely normal pregnancies and healthy babies.” She indicates that many of her patients today are over 35 or 40 and that they do very well with their pregnancies, although they typically have some concerns about how the pregnancy will progress.

Women who become pregnant when they are 35 or older may be worried about chromosomal abnormalities, such as Down’s Syndrome. Although abnormalities are slightly more common in this age group, they are rare. At the age of 35, your risk of having a baby with a birth defect is about one-half of one percent. At the age of 40, the risk goes up to about 1.5 percent. These risk percentages, while still higher than they would be in a 25-year-old, need to be put into perspective because the reality is that more than 98 percent of babies are just fine.

Dr. MacDonald also emphasizes that we now have ever-increasing tools to help in identifying pregnancies that are at risk. During an early risk assessment, which is typically conducted at about 11-13 weeks into a pregnancy, blood tests are combined with an ultrasound that looks at the thickness at the back of a baby’s neck. These tests indicate an estimated risk for having a baby with a chromosomal abnormality. If this test suggests that possibility, there are additional highly advanced tests available to further pinpoint any possible problems. Most women over 35 are also offered an amniocentesis test and also a Level 2 ultrasound, which are more targeted tests that can reveal fetal abnormalities.

There is an increased risk of miscarriage in women over 35, but Dr. MacDonald says miscarriage usually means the baby was not developing correctly in the first place. She also emphasizes that a miscarriage does not have a negative impact on a woman’s ability to have a normal pregnancy in the future. Women over 35 also have a slightly increased risk of other complications, such as diabetes or high blood pressure, but Dr. MacDonald says, “We can usually effectively treat women with these complications and monitor their babies so that the result is a normal pregnancy with a healthy baby.

Women over 35 also have a slightly increased likelihood of needing a caesarean section, but Dr. MacDonald points out that the risk of a C-section is slight and if you do need one you should be reassured that this is a very safe operation for both mothers and babies.

Leading a healthy lifestyle during pregnancy is the most important step a woman can take for herself. Dr. MacDonald says, “You can’t change your age, but you can make good decisions about how you lead your life by eating a healthy diet, exercising, maintaining a healthy weight, and getting good prenatal care.” If you smoke, you should stop and you should also avoid alcohol and caffeine. It’s also a good idea for anyone planning to become pregnant to start taking a multivitamin with folic acid in it, which reduces risks of birth defects.

If possible, a pre-pregnancy consultation is always a good idea. At that time, any women with preexisting medical conditions should make sure they discuss these with their practitioner so these conditions can be monitored and controlled during the pregnancy. Also your doctor needs to know about any medications you regularly take to make sure they will be safe to take during pregnancy.

Dr. MacDonald offers encouragement to women over 35 or 40 who want to become pregnant. She says, “Women today who are over 35 or 40 tend to be medically younger than women used to be at that age. They are generally healthier, which improves their ability to have safe pregnancies. If you are an older mother, it’s very possible today to have a normal pregnancy and a healthy baby if you have good prenatal care and lead a healthy lifestyle. ”

To sign up for the Mount Auburn Hospital prepared childbirth series of classes, please call us at 617-499-5094.