The association between imbalances in vaginal microflora and duration of pregnancy as well as selected maternal and neonatal parameters

Abstract

Objectives: Abnormal vaginal flora (AVF) is a result of excessive growth of some aerobic bacteria and fungi in relation to the scarce presence of Lactobacillus spp. It has been suggested that AVF is responsible for preterm birth and such neonatal conditions as infections or sepsis. The aim of the study was to assess the influence of excessive vaginal colonization with aerobic bacteria and fungi on the selected postnatal parameters of newborns, duration of pregnancy and length of hospitalisation of neonates.

Material and methods: Retrospective data of all 1057 patients who delivered between 01.2019 and 06.2019 in the Department of Perinatology of Medical University of Lodz was analyzed. Eight hundred nine patients were included in this retrospective study. The study group consisted of 396 patients with abundant growth of aerobic bacteria and fungi obtained between 26 and 42 weeks of gestation, while 413 patients with physiologic vaginal biocenosis constituted the control group. Two hundred forty-eight patients (23.46%) were excluded from the study due to incomplete data.

Results: Patients with abnormal vaginal flora (AVF) gave birth prematurely (9.09%) more often than patients with balanced microflora (5.31%), p = 0.038. Newborns of mothers with AVF obtained an Apgar score under four more frequently (1.21% vs 0%; p = 0.024). Eutrophic neonates were born less frequently in the study group (82.08% vs 88.65%; p = 0.025). Hospitalisation period was longer for children of mothers with AVF (mean of 6.30 ± 9.87 days) than those of mothers from the control group (mean of 5.06 ± 5.30), p = 0.025. Newborns of mothers with AVF developed perinatal infections more often (23.97% vs 15.94%; p = 0.004). Four infants died in the study group whereas no deaths were recorded in the control group (p = 0.045). The most prevalent pathogens were: Streptococcus agalactiae (GBS) 57.32%, Candida spp. 39.64%, Klebsiella spp. 9.85%, Staphylococcus aureus 7.32%. Signs of infection were more frequently recorded in newborns of mothers infected with Klebsiella spp. (35.90% vs 19.16%; p = 0.011). Premature birth was more prevalent in GBS carriers (11.81% vs 6.28%; p = 0.022).

Conclusions: Abundant growth of aerobic bacteria in the 3rd trimester of gestation contributes to preterm birth, causes the development of infection signs in newborns, increases their mortality rate and prolongs hospitalisation period.

Keywords: PROM; aerobic vaginitis; vaginal microflora.