OBJECTIVE: To determine the risk of postpartum hemorrhage among patients who were treated with nifedipine for tocolysis of preterm labor.

METHODS: A prospective cohort study was conducted with 66 pregnant women admitted for preterm labor. One group of women was given nifedipine to give time for the administration of corticosteroids for fetal lung maturity and/or control of preterm labor and another group was not given nifedipine as they were admitted in advanced stage of labor (ie, more than or equal to 4 cm cervical dilatation). Independent/paired sample t-test, Mann-Whitney U/Wilcoxon signed rank test, and Fisher's exact test were used to determine the difference of mean, median, and frequency between and within groups, respectively. STATA 12.0 was used for data analysis.

RESULTS: There was more blood loss during delivery, which was statistically significant, among those who received nifedipine compared to those who have not taken the medicine (350 mL versus 250 mL, p = 0.021). Furthermore, the decreases in hemoglobin and hematocrit were also lower among those who did not receive nifedipine compared to those who received nifedipine for tocolysis (8.5 mg/dL versus 16.0 mg/dL, p = 0.014 and 0.03 versus 0.05, p = 0.010), again, statistically significant.

CONCLUSION: Nifedipine used as tocolytic appear to increase blood loss during delivery, which was statistically significant. Greater amount of blood loss may be anticipated among those with nifedipine intake thus helping the obstetrician in preparing for active management of postpartum hemorrhage and preventing maternal morbidity and mortality.