Maternal and fetal responses to the stresses of lactation concurrent with pregnancy and of short recuperative intervals.

In many regions of the world, women breastfeed one child while pregnant with the next. Among rural Guatemalan women participating in a nutrition-supplementation trial, lactation overlapped with pregnancy in 253 of 504 (50.2%) of the pregnancies. For cases where overlap occurred, 41.4% continued to breast-feed into the second trimester and 3.2%, in the third trimester. The maternal and fetal responses to the energetic stresses of overlap and of the duration of the recuperative (nonpregnant, nonlactating) interval were assessed. Overlap resulted in increased supplement intake. Short recuperative periods (less than 6 mo) resulted in increased supplement intake and reduced maternal fat stores. The energetic stresses of overlap and short recuperative periods did not significantly affect fetal growth. The mother appears to buffer the energetic stress, protecting fetal growth. This research demonstrates that evidence of depletion of maternal nutrient stores caused by a demanding reproductive history is found when reproductive stress is characterized adequately.