Tocolytic Effectiveness of Nifedipine in Management of Preterm Labor: A Tertiary Center Experience

Abstract

Objective: This study aimed to compare the efficacy of nifedipine use in our clinic for treatment of preterm labor with diferent effacement degrees, and to compare our results with the literature.

Methods: 440 singleton pregnant women with intact amnionic membrane pregnant women in their 23 and 36 weeks were retrospectively evaluated. Because of different criterias defining preterm labor in the literature, patients were divided into two groups as 4 or over contractions in 20 minutes and cervical opening at 2 cm and/or above and/or effachment at 80% or above (Group A, n=230) and 4 or over contractions in 20 minutes and cervical opening below 2 min and effechment below 80% (Group B, n=210). Descriptive statistics were conducted using chi-square and Mann Whitney U test, and statistically significance was p <0.05.

Results: Demographics, reproductive history and pregnancy weeks of the groups were similar. The average time between the start of tocolysis and the birth was 4 times higer in Group B (0.1-99.2, mean 28.4) than that of Group A (0.1-78.9, mean 7.4 days, p<0.001). Delay after tocoloysis at days 1 to 7 was statistically remarkable in Group B (p<0.001, for each). Preterm labor resulting in early birth was more remarkable in Group A in both before 34 weeks and 37 weeks (p<0.001, for each; n=88, 38.3% vs n=36, 17.1% and n=171, 74.3% vs n=98, 46.7%, respectively and n=269/124, 28.2 vs 61.1%). Delay with nifedipine at day 1 (87.5%), day 2 (79.1%), day 3 (74.8%) and day 7 (65.5%) was also compatable with the literature.

Conclusions: Nifedipine is an effective tocolytic agent in preterm labor regardless of the effachment degree.