While weight and obesity have always concerned women due to looks and lifestyle issues, it is becoming increasingly evident that obesity is a matter of health, especially in pregnancy. Approximately 20 percent of women of reproductive age are obese. Research has shown that obesity increases the risk of adverse outcomes, including birth defects, labor and delivery complications, fetal and neonatal death and maternal complications. Such research has prompted new guidelines issued jointly by the Institute of Medicine and the National Research Council regarding maternal weight gain and obesity. The latest recommendations limit weight gain to 11-20 pounds in obese pregnant women in an attempt to further reduce their risks.

The data suggests these guidelines are not enough. Women who are obese (BMI >30) during pregnancy have a higher risk than normal weight women of having babies with certain birth defects.

Though the overall risk of birth defects occur in two to four percent of pregnancies, there is clear evidence that women who are obese prior to pregnancy have a two-fold risk of neural tube defects, like spina bifida, and a 30 percent higher risk of cardiovascular defects. Obesity may also limit the ability to screen for these abnormalities on ultrasound.

It is not clear exactly how obesity increases the risk of birth defects, but researchers suggest there may be a coexistence of maternal diabetes and hypertension, both known to increase the risk of birth defects. Obese women have also been shown to have nutritional deficiencies, especially reduced levels of folate. Folate is important in the prevention of neural tube defects.

When morbidly obese (BMI >40) mothers were compared to normal-weight mothers, there was an increase in adverse pregnancy outcomes, including preeclampsia (nearly five-fold), stillbirths (nearly three-fold), early neonatal death (nearly 3.5-fold) and large for gestational age infants (nearly four-fold). In addition, a pregnant woman with a BMI of 30 or higher has a Cesarean section rate of 33.3 percent, as compared to 20.9 percent in normal weight mothers. The obese mother also is more likely to suffer from post-operative complications, like infection, wound separation and bleeding.

Researchers and the March of Dimes, an organization dedicated to improving the health of babies by preventing birth defects, premature birth and infant mortality, hope the new recommendations and data will help patients and physicians bring attention to this growing public health issue.

With the help of their healthcare provider, women of childbearing age should attempt to reach a normal BMI and assess their risks prior to conception. In addition, all women should be counseled on adequate pre-pregnancy nutrition and supplementation. Once a woman is pregnant, prenatal care should focus on keeping weight gain within the recommended guidelines.

To learn more, contact Dr. Holly Stevens at Carolina Women’s Health Associates. Dr. Stevens and her physician partners are accepting new patients. With locations in China Grove and Salisbury, they are close to where you live and work. To schedule an appointment or for more information, call 704-636-9270 or visit www.carolinawomenshealth.com.

To learn more about our Family Maternity Center, visit www.rowan.org/baby or call 704-210-5544.