Abstract:〔Abstract〕 Objective To analyze the influence factors of pre pregnancy environmental on the incidence of fetal congenital heart defect. Methods From January 2020 to August 2022, 73 fetuses with congenital heart defect diagnosed by ultrasound in Xinxiang Maternal and Child Health Hospital were selected as the observation group, and 73 healthy fetuses with ultrasound in the same period were selected as the control group.Compare the general information and pre pregnancy environmental exposure of two groups of pregnant women and fetuses, and screen for independent influencing factors using binary logistic regression. Results There was a statistically significant difference between the two groups of pregnant women in their exposure to heavy metals, exposure to toxic chemicals, working in high radiation environments, noisy work environments, and passive smoking before pregnancy (P < 0.05); There was no statistically significant difference (P > 0.05) between the two groups of pregnant women in terms of age, education level, gestational age, and parity. The results of multivariate logistic regression showed that heavy metal exposure, exposure to toxic chemicals, and working in high radiation environments were independent risk factors for fetal congenital heart disease (OR > 1, P < 0.05). Conclusion Pre pregnancy exposure to heavy metals, toxic chemicals, strong radiation environment and other environmental factors are closely related to the occurrence of fetal congenital heart defect. Clinical guidance should be given to pregnant women to avoid exposure in the above environment to reduce the risk of fetal congenital heart defect.