Objectives Crude oil is a common environmental contaminant that impacts the reproductive functions of women. Understanding the contractile mechanism of the gravid uterus and how it impacts fetal outcomes during crude oil-contaminated water (CCW) exposure is still evolving. This study investigates the effect of vitamin C supplementation during the ingestion of CCW from Bayelsa, Nigeria, on the contractile mechanism of the gravid uterus and fetal outcomes. Methods Fifteen nulliparous pregnant rats were randomly divided into 3 groups of 5 rats each and treated with normal saline (control), CCW (2.5 mL), and CCW + vitamin C (10 mg/kg bwt), respectively. Treatments were via oral gavage from gestation days 1–19. Gas chromatography-mass spectrometry of CCW, uterine oxidative biomarkers, and in vitro contractile activity of excised uterine tissue to acetylcholine, oxytocin, magnesium, and potassium were determined. Furthermore, uterine responses to acetylcholine after incubation with nifedipine, indomethacin, and N-nitro-L-arginine methyl ester were also recorded using the Ugo Basile data capsule acquisition system. Fetal weights, morphometric indices, and anogenital distance were also determined. Results Acetylcholine, oxytocin, magnesium, diclofenac, and indomethacin-mediated contractile mechanisms were significantly impaired with CCW exposure; however, vitamin C supplementation significantly attenuated the impaired uterine contractile activity. Maternal serum estrogen, weight, uterine superoxide dismutase, fetal weight, and anogenital distance were significantly reduced in the CCW group compared to the vitamin C supplemented group. Conclusions Ingestion of CCW impaired the uterine contractile mechanism, fetal developmental indices, oxidative biomarkers, and estrogen. Vitamin C supplementation modulated these by elevating uterine antioxidant enzymes and reducing free radicals.