To investigate the relationship between maternal gingival bleeding during pregnancy and neurodevelopmental delay in their one-year-old children, and to provide scientific evidence for prenatal and early childhood health care.

Based on the Anhui-Wuhu Birth Cohort established by the Wuhu Maternal and Child Health Hospital in Anhui province, 528 mothers and their one-year-old children who had regular prenatal check-ups at the Wuhu Maternal and Child Health Hospital since early pregnancy (<13⁺⁶ weeks) and were followed up in December 2022 were included in this study. A self-designed questionnaire, "Maternal and Child Health Questionnaire during Pregnancy and Postpartum", was used to investigate maternal gingival bleeding symptoms during early and mid-pregnancy. The Chinese version of the "Ages and Stages Questionnaires, Third Edition (ASQ-3)" was used to assess the neurodevelopment of one-year-old children. Multivariable unconditional logistic regression models were used to analyze the relationship between maternal gingival bleeding symptoms during pregnancy and neurodevelopmental delay in their one-year-old children.

A total of 442 mother-child pairs with complete data from early and mid-pregnancy were included in the final analysis, including 229 boys and 213 girls. Among the mothers, 27 (6.10%), 16 (3.62%), and 84 (19.00%) experienced oral bleeding, bleeding when biting hard objects, and bleeding when brushing teeth during early pregnancy, respectively; 45 (10.18%), 26 (5.88%), and 102 (23.08%) experienced the same during mid-pregnancy, respectively. Among the one-year-old children, 201 (45.48%), 54 (12.22%), 85 (19.23%), 79 (17.87%), 66 (14.93%), and 88 (19.91%) experienced overall neurodevelopmental delay, communication delay, gross motor delay, fine motor delay, problem-solving delay, and personal-social delay, respectively. After adjusting for confounding factors, including maternal age, education level, annual household income, pre-pregnancy body mass index, primiparity status at the time of prenatal follow-up, history of cesarean section, passive smoking during pregnancy, depression during pregnancy, child's sex, season of birth, mode of delivery, preterm birth, low birth weight, and feeding mode, maternal bleeding when brushing teeth during mid-pregnancy was positively associated with communication delay (OR=2.06, 95%CI: 1.04–4.76) and gross motor delay (OR=2.00, 95%CI: 1.13–3.54) in their one-year-old children. After stratification by sex, maternal oral bleeding in early pregnancy was positively associated with delayed gross motor skill development (OR=4.22, 95%CI: 1.07–16.63), fine motor skill development (OR=5.99, 95%CI: 1.35–26.57) in boys, and delayed problem-solving skill development (OR=3.49, 95%CI: 1.35–14.93) in girls. Maternal bleeding when biting hard objects in early pregnancy (OR=8.27, 95%CI: 1.44–47.56) and bleeding when brushing teeth (OR=3.97, 95%CI: 1.55–10.17) were both positively associated with delayed gross motor skill development in boys. Maternal bleeding when biting hard objects in mid-pregnancy was positively associated with delayed gross motor skill development (OR=4.85, 95%CI: 1.05–22.49) in boys, and maternal bleeding when brushing teeth in mid-pregnancy was positively associated with delayed gross motor skill development (OR=3.42, 95%CI: 1.41–8.27) and communication skill development (OR=2.93, 95%CI: –1.08–7.98) in boys.

Maternal gingival bleeding during pregnancy is a risk factor for neurodevelopmental delay in their one-year-old children and is related to gender. Therefore, it is necessary to improve the level of oral health care services for pregnant women.