P15.09: Association of abnormal vaginal colonisation and preterm delivery: effect of cervical length

Abstract

The exact relationship between abnormal vaginal colonisation and adverse pregnancy outcome in preterm labour remains unclear. Therefore, we hypothesised that women with shorter cervical length (CL) are predisposed to ascending infection in women with preterm labour (PTL) or short CL. We aimed to examine abnormal vaginal colonisation rate according to cervical shortening and to compare the association between abnormal vaginal colonisation and spontaneous preterm delivery (SPTD) before 34 weeks according to CL in women with PTL or short CL. This study included 580 patients who admitted to our high-risk unit due to PTL or short CL and underwent vaginal culture and measurement of CL at admission between 2005 and 2015. Maternal age, parity, parity, body mass index and CL at admission, vaginal culture result, birth weight of neonates, and SPTD before 34 weeks were retrospectively reviewed. The study population was divided three groups according to the degree of cervical shortening; CL < 0.5cm (n=113), 0.5cm to 1.5cm (n=145), ≥ 1.5cm (n=322). There was no difference in abnormal vaginal colonisation rate according to the CL shortening (17.7%, 17.9%, 13.7% in group with CL < 0.5cm, 0.5cm to 1.5cm, ≥ 1.5cm, respectively, p=0.22). Overall, the rate of SPTD was not different according to the presence or absence of abnormal vaginal colonisation in three groups (93.3% vs 68.3%, p=0.06 in group with CL < 0.5cm; 40.9% vs 55.7% p=0.21 in group with 0.5cm to 1.5cm, 42.4% vs 33.2% p=0.30 in group with CL ≥ 1.5cm). However, in group with CL < 0.5cm, the presence of gram negative bacteria (but not gram positive) was significantly associated with higher SPTD (100% vs 68.6%, p=0.03). In other two groups, there was no difference in the rate of SPTD according to either the presence of gram positive or negative bacteria. Our data showed that maternal vaginal colonisation by gram-negative bacteria in advanced cervical shortening in PTL or short CL is associated with SPTD before 34 weeks. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.