Nifedipine for the treatment of preterm labor in twin and singleton pregnancies.

Purpose: To investigate the outcomes of singleton and twin pregnancies that were complicated by spontaneous preterm labor and received nifedipine tocolysis.

Methods: We identified the following subjects from a computerized, hospital database: 58 singleton and 32 twin pregnancies that were between 24 and 34 weeks of gestation, admitted for spontaneous preterm labor without rupture of the membranes, and receiving tocolysis with nifedipine. Data were analyzed using the Chi-square test, the Mann-Whitney test, and the Kaplan-Meier survival analysis.

Results: Spontaneous, preterm delivery occurred in 31.1% cases of singleton and 81.3% of twin pregnancies. Although the 22% of the mothers of twins did not have cervical changes upon admission, 37% of twins were delivered within 48 h. Mean for delivery weeks from admission to 36 weeks was significantly less for twin than it was for singleton gestations (32.3 ± 1.0 vs. 35.0 ± 0.5 weeks, respectively; Mantel-Cox X (2) = 41.118; p < 0.001). The maternal side effects were not significantly different between the groups. No serious cardiovascular complication had been found in either group.

Conclusions: Tocolysis with nifedipine is effective and safe for use in both singleton and twin gestations.