392: Postpartum cervical length and the risk for preterm birth in the following pregnancy

Abstract

We previously demonstrated that cervical length (CL) following preterm birth (PTB) during the first 2 postpartum days is significantly shorter compared with CL measured following term deliveries. In this study, we aim to examine the correlation between postpartum CL following PTB and the risk for recurrent PTB. In a prospective study conducted between 2016-2019, CL was measured transvaginally following PTB and term pregnancies at 8, 24, 48hrs & 6wks. Measurements were performed by a single operator (R.L) blinded to gestational age. Gestational age at delivery was presented as mean and range. Normal postpartum CL was determined following spontaneous term deliveries, presented as mean±SD. Abnormal CL was defined as 2SD below the mean. Of the 1348 patients that participated in the study, 247 delivered before 34wks. (e-PTB) and 141 women delivered between 34-37wks. (l-PTB). Women with PTB history were treated with progesterone. 77 women with e-PTB and 63 women with l-PTB delivered again during the study period. e-PTB: 54 women had abnormal CL at 8hrs. (0.86±0.13cm) and 48hrs. (1.78±0.19cm) postpartum. All delivered significantly earlier in the next pregnancy (30.3wks. (24-32.4)). All 23 women who had normal postpartum CL delivered at term (38.2wks (37.1-40.5)). l-PTB: 5 patients had abnormal CL at 8hrs. and 48hrs. postpartum [0.94±0.21cm and 1.95±0.11cm, respectively]. All, had e-PTB in the next pregnancy (31.6wks (30.3-33.5)). All 58 patients had normal postpartum CL delivered at term (38.6wks (37.6-40.2)). Sensitivity, specificity, NPV and PPV for prediction of future PTB were 83%, 85%, 94% and 62%, respectively, 8hrs postpartum, and 100% in all 4 parameters 48hrs postpartum. Postpartum CL measurement should be considered following PTB. Normal postpartum CL following PTB might call for preventive treatment with progesterone, while short postpartum CL may represent an extremely high-risk group that could benefit from close surveillance in the late 2nd trimester when intervention such as cerclage or pessary could be offered for shortening despite progesterone therapy.View Large Image Figure ViewerDownload Hi-res image Download (PPT)