What do all soon-to-be parents want?  A healthy baby.  Being physically active during and after pregnancy may significantly improve the health outcomes for both baby and mother according to two recent studies.

Excessive weight at birth is associated with higher rates of health problems – and even death – in newborns.  To test whether a mother’s physical activity level can impact birth weight, researchers in Norway tracked the exercise habits of nearly 37,000 pregnant women1.  The women completed physical activity questionnaires at week 17 and week 30 of their pregnancies.  The weights of their newborns were recorded in a national registry upon delivery. 

The analyses clearly showed a strong association between regular physical activity (at least 3 times per week) at both time points and birth weight.  Women who exercised at this level reduced their risk of having babies with unhealthy high birth weights by 23-28 percent. 
 
Interestingly, in this study regular exercise the three months before the start of the pregnancy was not associated with a lower risk of excess birth weight.  So physically active moms-to-be need to be sure to keep up their activity throughout their pregnancy.  And for inactive women who become pregnant, perhaps these research findings will provide the motivation they need to get moving. 

There is another reason to get and stay physically active before, during, and after pregnancy.  A new study showed that being physically active while breastfeeding helped nursing moms retain more of their bone mass2.  That’s important because:

  • Breast milk is rich in calcium to help support the rapid growth of an infant’s bones and other tissues.
  • The calcium comes from the mother’s own stores, i.e., her bones.
  • Reduced bone mineral density increases risk of osteoporosis - or weak bones - later in life. 

It has been well-established that weight-bearing (walking, jogging, dancing, etc.) and strength-training types of exercises can stimulate the retention of bone minerals.  Thus, researchers hypothesized that getting breast-feeding moms to exercise would impact bone health.  And it did.  The breastfeeding women who exercised lost only 4.8 percent of bone mass compared to a 7.0 percent bone mass loss in the lactating moms who did not exercise.

So if you are a new mom, know a mom-to-be, or will be a mom someday, make sure you build regular physical activity into your life -- and keep it up for a lifetime.  It will help not only you, but also your baby.  While exercise is safe for the vast majority, be sure to work with your obstetrician to identify what, if any, limitations you might have with you specific pregnancy.

 


1 Owe KM et al.  Association between regular exercise and excessive newborn birth weight.  Obstetrics and Gynecology.  2009;114(4):770-776.
2 Lovelady CA et al.  Effect of exercise training on loss of bone mineral density during lactation.  Medicine and Science in Sports and Exercise.  2009 Sept 2 (epub ahead of print).