Maternal morbidity after caesarean section in developing countries: long term follow-up of a large factorial trial

Caesarean section is one of the commonest operations undertaken worldwide and yet despite the number of caesarean sections being performed and the impact of this operation on the short and long term health of women, we know very little about which approaches to doing the caesarean section are associated with the lowest risk of complications. The CORONIS trial will compare five aspects of the surgical procedures used at the time of caesarean section in 15,000 women to see which of these aspects is associated with the lowest risk of complications. The five pairs of procedures to be compared are: (a) two different approaches to opening the abdominal wall (?blunt? versus ?sharp?); (b) whether the cut on the womb is repaired while the womb is kept inside the womans pelvis or whether it is repaired outside (extra-abdominal versus intra-abdominal repair of the uterine incision); (c) whether the cut on the womb is closed in one layer of stitches or two (single versus double layer closure of the uterus); (d) whether the peritoneum, which is a thin membrane which covers all the organs inside the abdomen, letting them slide over each other easily, (closure versus non-closure of the pelvic and parietal peritoneum); (e) which of two different types of stitch material should be used for closing the womb (Vicryl versus catgut sutures for closure of the uterus and rectus sheath). This follow-up study will allow us to assess the consequences of the different techniques used at 3 years after the original operation.

Caesarean section is one of the most common operations in the world, yet the techniques used to perform it have not been adequately evaluated in randomised controlled trials. Operative techniques vary between surgeons, and the frequency of the operation means than even small improvements in outcome may allow substantial improvements in the health of mothers, particularly in developing countries, where post-operative morbidity is high. The CORONIS trial will evaluate alternative techniques for the five most important aspects of the operation in a fractional factorial randomised controlled trial of 15,000 women: ?blunt? v. ?sharp? abdominal entry; extra-abdominal v. pelvic repair of the uterine incision; single v. double layer closure of the uterus; closure v. non-closure of the pelvic and parietal peritoneum; chromic catgut v. Vicryl for closure of the uterus. The short-term primary outcome of the study is serious maternal morbidity. This follow-up study will allow us to assess long-term outcomes at 3 years after the original caesarean section to determine the impact of the different techniques on outcomes including: involuntary infertility and outcomes of subsequent pregnancies including uterine rupture.