Frequency of Microbial Colonization of the Maternal Vagina in Preterm Premature rupture of Membranes

Abstract

Objective: To determine the frequency of microbial colonization of the maternal vagina in preterm premature rupture of membranes (PPROM).

Methodology: This cross-sectional study commenced at the Department of Obstetrics and Gynecology, Nishtar Hospital, Multan, Pakistan, from March 2025 to August 2025. A total of 111 pregnant women between 20 to 45 years, who presented with PPROM within 12 hours and had a live fetus with a gestational age between 28-36 weeks were studied. The frequency of commonly isolated pathogens were documented. Culture confirmed vaginal microbial colonization was defined as growth of any predefined organism on high vaginal swab culture. Participants were not selected on the basis of positive culture or suspected vaginal infection. Data  analysis was performed using IBM-SPSS 26.0, taking p<0.05 as signficiant for inferential statistics.

Results: In a total of 111 women, the median age, and gestational age were 29.0 (27.0-32.0) years, and 33.0 (30.0-35.0) weeks, respectively. There were 23 (20.7%) women who were primparous, while 88 (79.3%) were multiparous. Evaluation of socio-economic status revealed that 45 (30.5%) women belonged to low socio-economic status. Residential affiliation was rural among 69 (62.8%) women. Vaginal swab cultures yielded identifiable microorganisms in all 111 (100%) women. Escherichia coli (E. coli) was isolated in 32 (28.8%) women, Enterococcus faecalis in 22 (19.8%), Group B streptococcus in 18 (16.2%), Staphylococcus aureus in 19 (17.1%), and Staphylococcus haemolyticus in 20 (8.0%) women. Gestational age was observed to have significant association with microbial distribution (p=0.011).

Conclusion: The frequency of culture confirmed microbial colonization of the maternal vagina was universal among women with PPROM. The culture profile in PPROM in this study supports a mixed aerobic colonisation pattern with substantial contributions from E. coli, enterococci, GBS, and staphylococci, and demonstrates gestational age-related differences in organism distribution.