Presented at the Neonatal Society Spring Meeting 2019.

Authors: A Glazewska-Hallin, M Hickland, J Carter, H Watson, L Story, A Shennan

Institution(s)
Department of Women and Children’s Health, King’s College London

Introduction
Preterm deliveries have multiple aetiologies and management is dependent on cause. A recent under-recognised association, likely to be causative, has been made to full dilatation Caesarean sections (FDCS). These carry a 6-fold increased risk of early premature birth and late miscarriage(1). 14% of women with this history are in the risk group (2), approximately 8000 women annually in the UK. Data is limited regarding efficacy of transvaginal cerclage (TVC) in this cohort and the risk following emergency Caesarean sections.

Methods
A retrospective data analysis of women attending preterm surveillance clinic at St Thomas’ Hospital. Women who had a preterm birth or late miscarriage following a full dilatation Caesarean section and emergency Caesarean sections were identified. The control group comprised of women with a previous spontaneous preterm birth or late miscarriage with any mode of delivery. The primary outcome was delivery prior to 30 weeks gestation. A fisher’s exact test was used to compare groups.

Results
189 women experienced a subsequent spontaneous preterm birth or late miscarriage following an emergency Caesarean of which 64 received a TVC. There were 942 controls, of which 154 received TVS and 5/154 delivered <30 weeks (3%). 19/54 women in the FDCS group received a vaginal cerclage in their third pregnancy (including both history and ultrasound indicated) and significantly more of these women delivered before 30 weeks compared to controls (53% vs 3%, p<0.0001). In the emergency Caesarean group, 31/64 with a TVC delivered prior to 30 weeks, significantly less than controls (48% vs 3%, p<0.0001).

Conclusions
Both first stage emergency Caesareans and FDCS increase the risk of subsequent preterm birth, with a high incidence of delivery prior to 30 weeks. There is a higher TVC failure rate in these women. Further research is necessary to elucidate if ultrasound or MRI can predict outcome. Both preventative and therapeutic measures need to be investigated in this cohort of women who are at risk of recurrent, early preterm birth in spite of management.

References

1. Levine LD, Sammel MD, Hirshberg A, Elovitz MA, Srinivas SK. Does stage of labor at time of cesarean delivery affect risk of subsequent preterm birth? Am J Obstet Gynecol [Internet]. 2015;212(3):360.e1-360.e7. Available from: http://dx.doi.org/10.1016/j.ajog.2014.09.035
2. Watson HA, Carter J, David AL, Seed PT, Shennan AH. Full dilation cesarean section: a risk factor for recurrent second-trimester loss and preterm birth. Acta Obstet Gynecol Scand. 2017;96(9):1100–5.

Senior author supporting presentation on day of meeting: Dr Karen Luyt

Corresponding author e-mail address: agnieszka.glazewska-hallin@kcl.ac.uk