Incidence of Peripheral Nerve Decompression Surgery During Pregnancy and the First Year After Delivery in Finland From 1999 to 2017: A Retrospective Register-Based Cohort Study.

PURPOSE

We aimed to report the incidence of peripheral nerve decompression surgery during pregnancy and 12 months after delivery in Finland from 1999 to 2017.

METHODS

Using nationwide data from the Finnish Care Register for Health Care and the Finnish Medical Birth Register, all women of potentially childbearing age (15-49 years) who underwent peripheral nerve decompression surgery or had a pregnancy ending in delivery from January 1, 1999, to December 31, 2017, were included. Incidence rates and incidence rate ratios for operations were calculated for both childbearing women and the age-adjusted general female population.

RESULTS

In total, 308 women underwent carpal tunnel release (CTR) during pregnancy, and an additional 675 women underwent CTR within 12 months after delivery. The incidence of CTR during pregnancy was 38 per 100,000 person-years, with an incidence rate ratio of 0.5 (95% CI, 0.4-0.6), when compared with that in the general population. Women who were active smokers before becoming pregnant were more likely to undergo CTR during pregnancy (odds ratio, 2.4; 95% CI, 1.8-3.0). The highest rates of CTR were observed during the first trimester. The incidence of CTR in the first postpartum year increased steadily during the first 4 months to 79 per 100,000 person-years. During the latter 8 months, incidences were similar to those in the general population (incidence rate ratio, 1.0; 95% CI, 0.9-1.2). Women who smoked were more likely to undergo CTR during the first postpartum year (odds ratio, 1.6; 95% CI, 1.3-1.9).

CONCLUSIONS

Carpal tunnel release is performed more rarely during pregnancy than in the age-matched general population. Postpartum incidences increased toward the end of the first year, reaching those observed in the general population after the first 4 months. Smoking before pregnancy is associated with increased incidences of CTR both during pregnancy and the first year after delivery.

TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.