Caesarean section and risk for endometriosis: a prospective cohort study of Swedish registries

Abstract

Objective To investigate the association between caesarean section and later endometriosis. Design A prospective cohort study. Setting The Swedish Patient Register (PAR) and the Swedish Medical Birth Registry (MBR). Sample Women who were delivered in Sweden between 1986 and 2004. Methods Women with the diagnosis of endometriosis, defined as codes 617 (International Classification of Diseases, ninth revision, ICD–9) or N80 (ICD–10), were retrieved from the PAR. Obstetric outcome was assessed through linkage with the MBR. Out of 709 090 women, 3110 were treated as inpatients with a first diagnosis of endometriosis after their first delivery. Women with a diagnosis of endometriosis before their first delivery were excluded. Cox analyses were performed to obtain hazard ratios for endometriosis and adjusted for maternal age at first delivery, body mass index, maternal smoking, and years of involuntary childlessness at study entry. Kaplan–Meier estimates were performed to calculate the risk according to time elapsed. Main outcome In‐hospital diagnosis of endometriosis. Results The Cox analyses yielded a hazard ratio of 1.8 (95% CI 1.7–1.9) for endometriosis in women who had had a previous caesarean section compared with women with vaginal deliveries only. The risk of endometriosis increased over time: one additional case of endometriosis was found for every 325 women undergoing caesarean section within 10 years. No increase in risk could be seen after two caesarean deliveries. The risk of caesarean scar endometrioma was 0.1%. Conclusion In addition to the recognised risk of scar endometrioma, we found an association between caesarean section and general pelvic endometriosis. Further studies are needed to confirm our findings.

Maternal Age and Risk of Labor and Delivery Complications

“…Finally, for the outcomes of endometritis and postpartum hemorrhage, type of delivery (cesarean or vaginal), retained placenta, and manual removal of placenta were also included as covariates, as these are known risk factors. 34,35 Assessment of potential multicollinearity among the independent variables showed no collinearity issues; all variance inflation factors (VIF) were < 2.6. Race was missing for nearly 15% of the discharges; thus, when adjusting for race, “missing” was included as one of the categories of race.…”

“…25–34 ICD-9-CM diagnosis codes used to identify these conditions are listed in Table 2. Patient and hospital characteristics were also accounted for including race, urban/rural patient location, median community household income for patient’s zip code of residence, expected payment source/insurance type, and hospital region of the country.…”

Interinstitutional variations in mode of birth after a previous caesarean section: a cross-sectional study in six German hospitals

“…This applies in different ways both to vaginal birth after caesarean section (VBAC) [16,17] and to elective repeat caesarean section (ERCS) [1,3,14,22]. VBAC is generally supported by the fact that the proportion of women with a low risk pregnancy who are able to have a successful vaginal birth after a previous caesarean section is around 74% [4,12,24,32,37].…”

Birth after caesarean section

“…Infection risk was increased for all CS vs. vaginal deliveries, and the risk for venous thromboembolism was increased at least three-fold (Silver, 2012). Andolf et al (2013) found an association between CS and a later in-hospital diagnosis of general pelvic endometriosis. Women with a pre-delivery diagnosis of endometriosis were excluded.…”