699: The number and type of prior preterm deliveries are major effectors on the risk for reccurence in the third delivery

Abstract

During the study period, 55 women met inclusion criteria, and 17 had an early PTB (31%). Women with an early PTB despite vaginal progesterone therapy had similar demographic/obstetric history as those who delivered !34 weeks. Women with an early PTB had a lower mean CL at diagnosis (12.2AE4.0 vs 15.8AE4.4mm, p¼.006). ROCC demonstrated that CL was associated with early PTB (AUC 0.75 (0.61-0.88, p¼.004), and CL<15mm was best predictive of early PTB with a sensitivity of 77% and specificity of 76% (Figure A). CL<15mm was associated with an early PTB with an OR of 10.5 (2.7-40.3, p¼.001) and survival curve log rank p<.001 (Figure B). CL<15mm was associated with a lower mean GA of delivery (30.0AE6.9 vs 36.4AE4.5, p<.001), lower mean birth weight (1683AE1089 vs 2772AE906g, p<.001), increased incidence of NICU admission (50% vs 24%, p¼.04) and composite perinatal morbidity/ mortality (53% vs 12%, p¼.008). CONCLUSION: A CL<15mm is associated with an increased risk of early PTB in women with short cervix, despite vaginal progesterone therapy, and is associated with increased perinatal morbidity/mortality. Further studies should be done on whether additional measures such as cerclage would benefit this subgroup of women.