It is safe to do most forms of exercise during pregnancy, but expectant mothers should be aware that physical activity alone will not prevent them from putting on excessive weight, Brazilian researchers revealed in BJOG – An International Journal of Obstetrics & Gynaecology. Gaining too much weight during pregnancy, or being overweight during pregnancy raises certain risks for the mother and child – there is a greater chance the baby might have a birth defect, while the mother may suffer from high blood pressure and other health problems.

Simony Nascimento, from the Department of Obstetrics and Gynecology, UNICAMP Medical School, Campinas, Brazil, and team set out to determine how effective and safe physical exercise might be regarding maternal and perinatal outcomes and the perception of QoL (quality of life) in overweight/obese pregnant mothers.

They carried out a randomized, controlled clinical trial on 82 pregnant women aged at least 18 years. Their BMI (body mass index) before they were pregnant was at least 26. All the women were from 14 to 24 weeks pregnant.

BMI is a rough measurement of a person’s weight in relation to their height. An individual of normal weight has a BMI of between 18 and 25, overweight is between 25 and 30, and obese is 30+.

They were randomly selected into two groups:

  • The study group – they did exercise with supervision and were given counseling on home exercise or daily walking, nutrition and weight gain.
  • The control group – they were monitored through a standard prenatal care program. There was no extra information or supervision on exercise, etc.

The researchers’ focus (primary outcomes) was how much weight the mothers’ gained during the program, as well as how much excessive weight they gained during their pregnancy. They also gathered data on the participants’ blood pressure, perinatal outcomes and quality of life.

The researchers found that:

  • 47% of those in the study group gained more weight than they should have done, compared to 57% of those in the control group.
  • Gestational weight gain was the same in both groups.
  • Blood pressure was similar in the two groups
  • There was no statistical difference in the weight gain experienced by obese women in both groups – from 23 to 24 pounds
  • Overweight women gained 22 pounds (average) in the study group and 36 pounds in the control group
  • Most of the mothers in both groups had C-section deliveries
  • Babies’ health at birth were similar in both groups

The authors caution that this was a small study.

In an Abstract in the journal, the authors concluded:

“The exercise program was not associated with control of gestational weight gain in our sample as a whole, but was beneficial for lower gestational weight gain in overweight women. Exercise was not associated with adverse perinatal outcomes and did not affect variation in arterial blood pressure or the perception of QoL.”

Written by Christian Nordqvist