Abstract
To determine the effects of aerobic fitness on pregnancy and the newborn, 20 primigravid
subjects were studied throughout gestation and immediately postpartum. The subjects
were classified as trained (T=10) or untrained (UT=10) based on the heart rate response
to submaximal cycle ergometry testing done in each trimester. There was no difference
between groups in the length of gestational period (T=40.75; UT=40.75 weeks) nor weight
gained vs prepregnancy measures (T=13.92; UT=13.30 kg). The first stage of labor was
extended in the UT, 13 h 58.8 min vs 11 h 18.0 min. UT had a longer second stage,
90.57 vs 70.0 min for T. Stage 3 was also prolonged in UT, 15.17 vs 7.43 min. In both
groups medication was used equally. Two of the ten T females had Caesarean sections
vs three of the ten in the UT group. The mean Apgar scores at 1 and 5 min were: T=7.70,
9.20; UT=7.90, 9.33, respectively. The birth weights of the T babies were marginally
higher than the UT newborns (3733.00 vs 3679.97 g). All babies were healthy and without
apparent abnormalities. There appears to be no positive or negative effects of maternal
fitness on the newborn. The reduction in the active stage of labor in the T group
may reflect their improved fitness levels.
Key words
exercise and pregnancy - cardiorespiratory fitness - fitness - outcome of pregnancy
