OBJECTIVE: To determine the optimal timing of elective repair, the primary objective of this study was to assess if parity at the time of repair and subsequent pregnancy were associated with reoperation for recurrence. The secondary objective was to examine if parity was associated with hernia formation requiring surgical repair.

SUMMARY BACKGROUND DATA: Women of childbearing age constitute 18% of patients operated on for a primary ventral hernia, but consensus is lacking on the management in women who might subsequently become pregnant.

METHODS: In this nationwide retrospective cohort-study, all women born in Denmark from 1962 to 1971 were eligible for inclusion and followed from age 15 to 45 years. The follow-up rate was 100%. Data on pregnancies and surgical procedures were obtained from the Danish Medical Birth Registry and National Patient Registry. Extended Cox regression and Poisson regression were used for statistical analysis.

RESULTS: In total, 470,646 women were included, of whom 2113 underwent repair of a primary ventral hernia. The 10-year cumulative incidence of reoperation for recurrence was 14.1% (95% CI 12.3%-16.0%). Parity at the time of repair was not associated with reoperation for recurrence, while a subsequent pregnancy was associated with a 1.6-fold increased risk (hazard ratio 1.58, 95% CI 1.08-2.31). Parous women had a 7-fold increased risk of undergoing hernia repair compared with nulliparous, in an age-adjusted model (incidence rate ratio 7.04, 95% CI 5.87-8.43).

CONCLUSION: To reduce the risk of hernia recurrence, the optimal timing of elective repair is after the last pregnancy.