It might seem very simple, but the key to having normal birth weight infants is exercise. You’re shocked, I know, but exercising during your second and third trimester can reduce the likelihood of having overweight babies by 50%. There are many benefits of having normal birth weight infants, but one important benefit is that you won’t have to have a cesarean delivery, which is common for high birth weight infants.

Research presented by Rubén Barakat of the Polytechnic University of Madrid, Alejandro Lucía of the European University of Madrid, and Jonatan Ruiz of the University of Granada, show that “Taking moderate-intensity exercise three times a week during the second and third trimester of pregnancy halves the risk of having a high birth weight newborn.”

The study involved 510 Spanish women who were pregnant and admitted to living a sedentary life, which is defined by the study as exercising less than 20 minutes for fewer than three days a week. Part of the women were used as a control group, which the rest participated in 55 minutes of aerobic and flexibility exercise three times a week. The results showed that the women who exercised three time a week were just as likely to develop pregnancy complications like gestational diabetes, but they the risk of having a child with macrosomia, or being at least 4 kilos over weight, was reduced by 58% and the risk of cesarean birth was reduced by 34%.

Jonatan Ruiz, researcher in the University of Granada Department of Physical and Sports Education and corresponding author of the study, says that the results "reinforce the need to encourage more supervised exercise interventions during pregnancy to combat the negative effects of gestational diabetes mellitus."

According to the National Diabetes Information Clearinghouse (NDIC), the best way to prevent gestational diabetes is through diet and exercise, though generally it’s best to lose the weight before becoming pregnant.

Having infants with high birth weight doesn’t necessarily mean that your child will continue to be overweight into adolescence, but if you don’t want to have a cesarean birth, it’s probably best to keep your weight down before and during pregnancy. That doesn’t mean that you won’t gain weight, that’s expected of any women expecting a child. However, retaining a healthy lifestyle during pregnancy is probably the best thing you can do for you and your child besides taking your supplements and vitamins.

Source: University of Granada (2013, July 16). Exercising during pregnancy reduces the risk of high birth weight newborns and of Caesarean delivery, study suggests. ScienceDaily.