Comparison of Fetomaternal Outcomes in Nifedipine Combined with Sildenafil Citrate Versus Nifedipine Alone for the Management of Threatened Preterm Labour

Sildenafil, a smooth muscle relaxant, has been explored as an adjuvant to delay the onset of preterm labor. By inhibiting uterine contractions, it helps prolong pregnancy and improve fetal outcomes. Objectives: To evaluate the effects of Nifedipine on the mother and fetus during impending preterm labour, alone or with sildenafil citrate. Methods: The quasi-experimental trial was conducted at Sir Ganga Ram Hospital Lahore. Patients were randomly assigned to receive either 20 mg Nifedipine orally (stat dose) followed by 10 mg every 8 hours with 25 mg sildenafil citrate orally at 8-hour intervals or 20 mg without sildenafil citrate. The medication therapy lasted 72 hours. Chi-square and independent sample t-tests were used to compare groups in SPSS version 26.0. Results: Baseline age, gestational age and parity were similar in both groups (p>0.05). With mean gestational age at delivery 34.47 ± 2.18 weeks, the frequencies of term, preterm and very preterm were 15.0%, 77.5% and 7.5%, respectively. Nifedipine with Sildenafil citrate group had significantly higher term deliveries (30.0% vs. 0.0%; p-value=0.002) and normal weight births (35.0% vs. 5.0%; p=0.005) compared to Nifedipine alone group; however maternal readmission and neonatal intensive care unit admission rates were not statistically different between groups (p>0.05). There was no mortality feto-maternal observed. Conclusions: It was concluded that oral sildenafil citrate combined with Nifedipine is an effective option as tocolytic therapy for threatened preterm labour. The prolongation of pregnancy will improve fetal weight, and reduce neonatal intensive care unit admissions and preterm deliveries with minimum maternal and fetal side effects.