Physical activity for pregnant women

This is an English summary of the Danish report: Fysisk aktivitet for gravide 

Physical activity for pregnant women – knowledge about prevention and health benefits' presents the evidence on the association between physical activity, sedentary behaviour and health among pregnant and postpartum women. The report includes scientific literature from the Danish Health Authority (Sundhedsstyrelsen) and international systematic reviews conducted by research institutions and authorities from various countries: World Health Organization, USA, Canada, and Australia.

In the report the level of the evidence is described as strong, moderate, low, very low or insufficient. The indicated levels of evidence are based on the assessment made in the literature reviews that form the basis of the report. In these literature reviews, the level of evidence is based on an evaluation of the amount and quality of research in the area and whether there is consistency in the results of the studies. Strong evidence indicates great confidence in the observed relationship between physical activity and a given health outcome. In order to obtain strong evidence for an association, much research and several high-quality studies that point in the same direction is required. In the case of insufficient evidence, there is insufficient research to determine whether there is an association. Amongst other things, this may be because it has not yet been sufficiently investigated, which often characterizes new areas of research.

Physical activity during pregnancy and in postpartum period benefits both the health of the pregnant woman and the child. Furthermore, the pregnant woman has the same benefits of physical activity as other non-pregnant women, including a lower mortality risk and a lower risk of developing cardiometabolic diseases, cancer, and improved mental health and cognitive functioning. The main conclusions on the evidence of the effect of physical activity and sedentary behaviour on maternal and fetal health are summarized below.

Physical activity and maternal and fetal health

• There is strong certainty evidence that physical activity reduces risk of unhealthy weight gain during pregnancy and gestational diabetes.
• There is moderate to strong certainty evidence that physical activity during pregnancy is not associated with increased risk of gestational hypertension, preeclampsia, miscarriage, or stillbirth. Also, there is moderate certainty evidence that physical activity during pregnancy does not increase the risk of preterm birth.
• There is moderate certainty evidence that physical activity after childbirth reduces symptoms of postpartum depression, while there is insufficient to low certainty evidence on the effect of physical activity during pregnancy and depressive symptoms both during pregnancy and in the postpartum period.
• There is low to moderate certainty evidence that physical activity is not associated with increased risk of low or high birth weight.
• There is insufficient evidence to determine if there is an association between physical activity during pregnancy and pregnancy related lower back pain and pelvic pain, caesarean section or instrumental delivery. Some meta-analysis indicate that physical activity may help to reduce the severity of low back pain and pelvic pain during pregnancy as well as reduce the risk of unplanned caesarean section and instrumental delivery.

Dose-response relationship in relation to amount and intensity of physical activity

• There is insufficient evidence to determine if there is a dose-response relationship between physical activity (duration, frequency, and intensity) and maternal and fetal health outcomes such as gestational diabetes, gestational hypertension, preeclampsia, unhealthy weight gain during pregnancy, postpartum depression, preterm birth, low or high birthweight, miscarriage or still birth.

Types of physical activity

• There is moderate certainty evidence that pregnant women should incorporate a variety of aerobic and muscle-strengthening activities (e.g., swimming, water exercises, stretching, and yoga).

Sedentary behaviour and health

• There is insufficient evidence for an association between sedentary behaviour and pregnancy-related health outcomes and birth outcomes. However, findings indicate that sedentary behaviour during pregnancy increases the risk of gestational diabetes and high birthweight in new-borns (e.g., macrosomia).

Knowledge gaps and future perspectives

Many women reduce their level of physical activity during pregnancy due to pain and discomfort. However, physical activity during pregnancy has significant health effects for the pregnant woman as well as for the unborn child. For this reason, it is important to strengthen knowledge on how to motivate pregnant women to be and maintain a physically active lifestyle during and after pregnancy.

Previous research has pointed to possible health risks of physical activity during pregnancy, but recent research shows no evidence for an association between physical activity and an increased risk to the fetus – neither in relation to premature birth, miscarriage, or stillbirth. However, there is insufficient evidence for an association between sedentary behavior and the maternal and fetal health. Future research is needed to gain further knowledge about how physical activity contributes to health of the pregnant women and her unborn/newborn child.