Abstract. Objective: Examine the relationship between maternal gestational hypertension (GH) and gastroschisis. Study design: This retrospective, observational study used a local dataset of 30 300 NICU patients and 3 429 498 U.S. birth certiﬁcate records to examine the prevalence of GH using univariate and logistic regression. Since body mass index (BMI) was not available in the data, we used Monte Carlo simulation of BMI followed by logistic regression to estimate the inﬂuence of this missing variable in the birth certiﬁcate data. Results: In the local dataset, maternal GH was lower in mothers of gastroschisis cases compared to the mothers of all other NICU admissions (0/188 vs. 4 351/30 112 [14.5%], p < 0.001). Adjusting for covariates, the odds ratio (OR) for GH among mothers of gastroschisis patients was 0.04 (95% conﬁdence interval [CI] = 0.01–0.28, p = 0.001). In birth certiﬁcate data, GH was lower in mothers of gastroschisis cases compared to all others (22/927 [2.4%] vs. 144 521/3 428 571 [4.2%], p = 0.005). Adjustment for covariates and simulated BMI also showed a lower prevalence of GH in mothers of gastroschisis cases (OR = 0.58, 95% CI = 0.35–0.94, p = 0.005). Conclusion: Women delivering a live-born infant with gastroschisis may have a decreased prevalence of GH. This unique observation warrants additional conﬁrmatory studies. Such studies might provide insight into both GH and gastroschisis.