Each approach comes with theoretical pros and cons: For women who have a large pannus, the incision site may lie in a moist environment with a low transverse incision, and oxygen tension may be low. However, a Pfannenstiel incision usually will have better cosmesis than will a vertical incision, and generally will result in less postoperative pain.
On the other hand, said Dr. Marrs, vertical incisions can provide improved exposure of the uterus during delivery, and the moist environment underlying the pannus is avoided. However, wound tension may be higher, and subcutaneous thickness is likely to be higher than at the Pfannenstiel incision site.
The study, conducted at two academic medical centers, enrolled women with a body mass index (BMI) of at least 40 kg/m2 at a gestational age of 24 weeks or greater who required cesarean delivery. Consenting women were then randomized to receive Pfannenstiel or vertical incisions.
Women who had clinical chorioamnionitis, whose amniotic membranes had been ruptured for 18 hours or more, or who had placenta accreta were excluded. Also excluded were women with a private physician and those desiring vaginal delivery, said Dr. Marrs, a maternal-fetal medicine fellow at the University of Texas Medical Branch, Galveston.