Objective: To determine whether a group of normal weight women with a low-risk pregnancy who increased their prepregnant weight by more than 25% experienced a longer second stage of labor or a higher proportion of operative deliveries than a group of normal weight women who increased their prepregnant weight by 25% or less.
Design: Comparative, descriptive, retrospective chart review.
Setting: A 480-bed tertiary care medical center.
Participants: One hundred four primigravidas who had normal weight for height at conception and who experienced low-risk pregnancy.
Main outcome measures: Length of second stage labor and mode of delivery.
Results: A statistically significant difference was found in the mean length of second stage labor between the two groups, t(94) = -2.05, p = 0.02. A higher proportion of operative deliveries (vacuum, forceps, or cesarean section) occurred in the group that increased their prepregnant weight by more than 25%, chi 2(3, N = 104) = 15.87, p = 0.001.
Conclusions: The amount of weight gained during pregnancy influences progress and intervention during the second stage of labor.