Effectiveness of Vaginal versus Intramuscular Progesterone for the Prevention of Preterm Delivery

Abstract

Objective:  The objective was to compare the effectiveness of vaginal versus intramuscular progesterone to prevent preterm delivery in patients with history of preterm labor in previous pregnancy.

Patients and Methods:  It was a Randomized Control Trial carried out in the Gynecology Unit in a Public sector Hospital, Lahore from March to December 2015. A total of 800 patients were enrolled through Antenatal OPD and were randomly divided into two groups by draw method. In Group-A, patients were administered 200mg of vaginal progesterone pessary once daily and in Group-B 250 mg of intramuscular progesterone was injected weekly. Treatment was continued until 37 completed weeks of gestation. The patients were followed up through their contact numbers and on routine follow up. This practice was abandoned if premature rupture of membranes occurred and the fetus was delivered before 37 weeks. All the parameters were recorded by the researcher on proforma. The data was analyzed using Statistical Package for the Social Sciences (SPSS) version 16.0. Chi Square test was applied to draw the comparison.

Results:  The mean age of patients was 26.16 ± 5.36 years (18 – 35 years). The 296 patients were Para 1, 290 were Para 2, 142 were Para 3, 51 were Para 4 and 21 females were Para 5. In all females, the mean gestational age at time of presentation was 22.00 ± 1.47 weeks, whereas, at time of delivery, mean gestational age was 36.05 ± 2.38 weeks. In vaginal progesterone group, the mean gestational age at time of delivery was 36.67 ± 1.92 weeks while in IM group, mean gestational age at time of delivery was 35.43 ± 2.62 weeks. The difference between both groups was statistically significant (P < 0.05). Effectiveness (delivery ≥ 37 weeks) was achieved in 379 (47%) cases, out of which 228 (57%) cases belonged to vaginal progesterone group and 151 (37.8%) cases belonged to IM progesterone group (P < 0.05). Post stratification with age and parity also showed that vaginal progesterone is more efficacious than IM progesterone (P < 0.05).

Conclusion:  We concluded that vaginal progesterone is more effective than intramuscular progesterone for the prevention of preterm labor in patients with history of preterm labor in previous pregnancy.