Incidence of groin hernia repairs in women and parity: a population-based cohort study among women born in Sweden between 1956 and 1983

The aim of this study was to evaluate the association between parity and the incidence rate of groin hernia repair in women.

This study was based on two Swedish national registers, the Medical Birth Register (MBR), and the Swedish Hernia Register (SHR). The cohort constituted of women born between 1956 and 1983. Data on vaginal and cesarean deliveries were retrieved from the MBR. The birth and hernia registers were cross matched to identify hernia repairs carried out after deliveries.

A total of 1,535,379 women were born between 1956 and 1983. Among these, 1,417,237 (92.3%) were registered for at least one birth. The incidence rate for Inguinal Hernia Repair (IHR) and Femoral Hernia Repair (FHR) was 10.7 per 100,000 person-year and 2.6 per 100,000 person-year, respectively. Compared with women registered for one delivery, the incidence rate ratio for IHR was 1.31 (95% Confidence Interval: 1.23–1.40) among women registered for two deliveries, 1.70 (1.58–1.82) among women registered for ≥ 3 deliveries. Additionally, the incidence rate ratios were higher 1.30 (1.14–1.49) and 1.70 (1.49–1.95) for FHR among women with two and  ≥ 3 registered deliveries, respectively.

In the present cohort, higher parity was associated with a higher incidence of inguinal as well as FHRs.