Who develops carpal tunnel syndrome during pregnancy: An analysis of obesity, gestational weight gain, and parity.

PURPOSE: To examine the prevalence, onset, and risk factors of carpal tunnel syndrome during pregnancy.

METHODS: Maternal electronic medical records were linked to birth certificate records using social security number. The outcome of carpal tunnel syndrome during pregnancy was defined as ICD9 code 354.0 given at a prenatal visit. Chi-square, t-test, and adjusted logistic regression were performed.

RESULTS: We analyzed 17,623 prenatal visits from the Hospital of the University of Pennsylvania from 1/2003-12/2007. Mean maternal age was 26.4 (6.5) years, with 21% white, 69% black, and 46% overweight or obese. Ninety-one (2.8%) mothers participated in 765 prenatal visits given a carpal tunnel syndrome diagnosis code. Compared to mothers without carpal tunnel syndrome, mothers with carpal tunnel syndrome were older (29.72 (5.42) versus 26.04 (6.37) years, p = 0.005), gained more weight during pregnancy (40.65 (10.13) pounds versus 34.2 (9.41) pounds, p = 0.04), and more likely to have college education (69.9% versus 44.5%, p = 0.03). Average onset (SD) of carpal tunnel syndrome was 18.1 (8.4) weeks' gestation.

CONCLUSION: Mothers with carpal tunnel syndrome had high rates of overweight, obesity, and excessive gestational weight gain. Diagnosis of carpal tunnel syndrome was rare but often occurred in the first and second trimesters, earlier than the frequently reported third trimester onset seen in literature. When looking at predictors of carpal tunnel syndrome, obese prepregnancy body mass index (BMI ≥ 30 kg/m(2)) and excessive gestational weight gain, greater than two previous live births, higher level of maternal education and more prenatal care (>10 visits) were associated with increased risk of carpal tunnel syndrome. Higher maternal age was not associated with carpal tunnel syndrome diagnosis after adjusting for weight and parity, suggesting mediation by these covariates.