Multimodality Screening for Lower Genital Tract Infections Between 18 and 24 Weeks of Pregnancy and its Efficacy in Predicting Spontaneous Preterm Delivery

BACKGROUND

Predicting spontaneous preterm birth (SPTB) during mid-trimester would be very useful. We used a multimodality screening approach mainly focusing on urogenital infections among unselected obstetric population between 18 and 24 weeks in a tertiary center.

METHOD

Diagnosis of lower genital tract infection (LGTI) was attempted among 228 pregnant women using several factors-symptom of vaginal discharge, characteristic appearance of discharge on speculum, point of care tests using Amsel's criteria and gram staining of vaginal swab. Nugent's scoring was taken as gold standard. Urine microscopy/culture was obtained. Serum inflammatory markers were done. Total leukocyte count, neutrophil/lymphocyte ratio and C-reactive protein were obtained. Data on cervical length were obtained from mid-trimester scan.

RESULTS

Thirty patients complained of vaginal discharge. Speculum examination revealed discharge in 221 (96.92%), appearing pathological in 192 (86.87%). Amsel's criteria showed poor sensitivity to detect full (57%) and partial (24%) bacterial vaginosis (BV). On gram staining, 104 (45.61%) showed evidence of LGTI; 14 full BV (6.1%); 45 partial BV (19.5%); 40 candidiasis (17.5%); and two each of trichomoniasis and aerobic vaginitis. Appearance of vaginal discharge and microscopic diagnosis of LGTI were poorly correlated. Forty women (17.5%) had SPTB, 24 following membrane rupture and 16 following spontaneous labor. The presence of BV (specifically partial) increased the likelihood of SPTB with OR of 3.347 (CI 1.642, 6.823). Three of seven women with short cervix delivered preterm. No other screening modality was associated with SPTB.

CONCLUSION

Active screening for LGTI between 18 and 24 weeks shows high prevalence of BV in Indian setting. There is a strong link between partial BV and SPTB.