OBJECTIVE: To evaluate pregnancy and neonatal outcomes, disease severity, and mother-to-child transmission of pregnant women with Chikungunya infection (CHIKV). DESIGN: Retrospective observational study. SETTING: Grenada. POPULATION: Women who gave birth during a Chikungunya outbreak between January 2014 and September 2015 were eligible. METHODS: This descriptive study investigated 731 mother-infant pairs who gave birth during a CHIKV outbreak. Women and infants underwent serological testing for CHIKV by ELISA. MAIN OUTCOME MEASURES: Primary outcomes: composite pregnancy complication (abruption, vaginal bleeding, preterm labour/cervical incompetence, cesarean delivery for fetal distress/abruption/placental abnormality or delivery for fetal distress) and composite neonatal morbidity. RESULTS: Of 416 mother-infant pairs, 150 (36%) had CHIKV during pregnancy, 135 (33%) had never had CHIKV, and 131 (31%) had CHIKV outside of pregnancy. Mean duration of joint pain was shorter among women infected during pregnancy (μ = 898 days, σ = 277 days) compared with infections outside of pregnancy (μ = 1064 days, σ = 244 days) (P < 0.0001). Rates of pregnancy complications (RR = 0.76, P = 0.599), intrapartum complications (RR = 1.50, P = 0.633), and neonatal outcomes were otherwise similar. Possible mother-to-child transmission occurred in two (1.3%) mother-infant pairs and two of eight intrapartum infections (25%). CONCLUSION: CHIKV infection during pregnancy may be protective against long-term joint pain sequelae that are often associated with acute CHIKV infection. Infection during pregnancy did not appear to pose a risk for pregnancy complications or neonatal health, but maternal infection just prior to delivery might have increased risk of mother-to-child transmission of CHIKV.