Materials and Methods
This retrospective case-control study was performed in a single academic medical centre from March 2014 to October 2020. Women with uterine rupture or dehiscence were included in the study group and compared to women who had a successful TOLAC (the control group). Demographic and obstetrical data, as well as any record of infection during or within a month after a prior CD were investigated.
Rupture of the uterus was defined as complete disruption of the previous Cesarean scar with communication between the uterine and abdominal cavities. Dehiscence of the scar was defined as incomplete disruption that included ruptured uterine muscle with intact serosa as the only layer keeping the foetus in the uterus. All cases of rupture and dehiscence were identified during CD.
The electronic medical records (EMR), were reviewed for demographic characteristics (age, BMI, gravity, and parity) and for medical information (regarding phase of delivery at first CD, surgical technique, and inter-delivery interval), and neonatal birth weight. Infection was defined as either intrapartum with maternal temperature above 38°C during or up to 24 hours after delivery. Postpartum fever was defined as maternal temperature above 38°C, 24-48 hours after delivery, and SSI was defined according to the 2018 ACOG criteria and included endometritis, infected hematoma or infection of surgical wound up to 30 days from the previous CD.14 The diagnosis of SSI was determined based on the ICD-9 codes, analysis of laboratory data of wound cultures, non-prophylactic antibiotic prescriptions, and the clinical impression written by the medical team in the EMR.
Based on a uniform protocol, all patients undergoing CD received standard infection-prevention measures, including preoperative intravenous (IV) antibiotic prophylaxis with one to two grams of cefamezine based on maternal weight, surgical length and blood loss. For patients allergic to penicillin, clindamycin and gentamicin were administered.15
Intrapartum fever was treated with a combination of ampicillin and gentamicin, while patients with intrapartum fever undergoing CD also received IV metronidazole. Postpartum fever and endometritis were treated with IV Augmentin up to 48 hours from the last fever, according to protocols suggested by ACOG.16 Patients with large infected abdominal hematomas or any other severe infection were treated with a triad of ampicillin, gentamicin and IV metronidazole until improvement was noted or positive cultures allowed more specific treatment, according to institutional guidelines.
We compared three groups and subgroups: 1) All patients with rupture or dehiscence compared to controls (no rupture or dehiscence), 2) Rupture versus dehiscence, and 3) Rupture versus controls. We evaluated each group in terms of the type of infection as a risk-factor for rupture or dehiscence: intrapartum chorioamnionitis, postpartum endometritis, or SSI.