During pregnancy, a woman is responsible for both her own health and the health of her unborn child. Multiple studies have demonstrated the health of your growing baby is dependent not only on genetics, but also on the environment in which it’s developing. Sometimes small changes during pregnancy may have a profound effect on life after birth.

For instance, in one study tracing genes in over 21,500 people, researchers found those genes not transmitted to the children also had a major effect on education and health.^1,2 Another study evaluated how a mother’s psychological state affected the developing baby and found babies who developed best experienced a consistent environment before and after birth.³

In other words, if moms were healthy before and after birth, or depressed before and after birth, those children did better than those born of mothers who were healthy before birth and depressed afterward. Maternal obesity has been linked to an increased chance a child may experience asthma. Second-hand smoke has also been tied to asthma and breathing problems, even when experienced before birth.⁴

Low levels of vitamin D may increase the risk of gestational diabetes, preeclampsia,^5,6 and low birth weight. Outdoor air pollution may increase the risk of low birth weight and impaired lung development and function during childhood. A recent animal study has now found offspring born to mice made to exercise during pregnancy had a lower risk of weight gain after birth.⁷

Exercise During Pregnancy May Reduce Your Child’s Risk of Obesity

The current research builds on past studies evaluating the effects of exercise during pregnancy to prevent gestational diabetes and improve outcomes in women who are overweight and obese during pregnancy.⁸ The featured study was presented at the American Physiological Society’s annual meeting.

The scientists recommend women, whether or not they are currently obese or have diabetes, should exercise regularly during pregnancy as it appears to benefit the future metabolic health of their children.⁹ Although previous studies have shown exercise by obese [pregnant women] benefits their offspring, this is the first research to demonstrate that the same is true when nonobese females exercise,” a press release from the American Physiological Society said.¹⁰

In this animal study, the researchers encouraged pregnant mice to perform 60 minutes of moderate exercise every morning. Offspring born to mice that did not exercise were used as a control group. After weaning, the mice born to the group who exercised had increased levels of protein associated with greater brown adipose tissue.¹¹

The researchers also found the offspring in the exercise group had higher body temperatures, indicating the brown fat was more efficient than in those who were born to mice who did not exercise. This higher thermogenic function has been shown to prevent metabolic dysfunction.

The mice then followed a high-fat diet for eight weeks after weaning. Those in the exercise group gained less weight and demonstrated fewer symptoms of metabolic disease. Based on these findings, the researchers plan additional studies, hoping to gain a better understanding of the protective biological mechanisms involved.¹²

Exercise During Pregnancy Is Important and Safe

Although there are considerable physiological and psychological changes occurring during pregnancy that tend to promote sedentary behaviors, lack of activity is associated with an elevated risk of high blood pressure, greater weight gain, gestational diabetes and a long-term risk for obesity and cardiovascular disease.

One reason women may experience difficulty getting adequate amounts of exercise is the increased amount of fatigue, nausea and complications they may experience during pregnancy. Some of the first studies on the relationship between physical activity and improved birth outcomes were published in the early 20th century.¹³

Prenatal exercise programs were introduced in the 1920s and 1930s with the goal of easing labor and delivery. In 1949, the U.S. Children’s Bureau published a standard recommendation for physical activity in the absence of maternal complications. Those recommendations included housework, gardening, daily walks and swimming, with a recommendation to avoid participation in sports.

In the 1970s and 1980s recommendations were highly specific and focused on improving fitness while easing labor and delivery. By 2002, the American College of Obstetrics and Gynecology updated their guidelines and recommended 30 minutes of moderate-intensity physical activity during most days of the week.¹⁴

For the first time guidelines also included vigorous-intensity physical activity for women who habitually engaged in this type of activity before pregnancy. Researchers continue to find physical activity recommendations during pregnancy resulted in clear advantages for both mother and child.¹⁵

Exercise tends to reduce excessive weight gain, the risk of cesarean section, reduces lower back pain and urinary incontinence, while increasing the incidence of vaginal deliveries.¹⁶ Unfortunately, Maria Perales, lead author of a study from the Department of Physical Activity and Sports Science at Camilo José Cela University found:¹⁷

“The percentage of women who meet the recommendations for exercise during pregnancy is very low. This is due in part to uncertainty about what type of exercise should be recommended and which should be avoided.”