PurposeLow birth weight (LBW) is one of the major public health problems in India. Hence, there is a need to identify risk factors that, when modified, will reduce the burden of unhealthy children on the healthcare system. The objective of this study was to determine whether periodontitis among mothers in the rural population of India is a risk factor for LBW babies.MethodsA hospital-based case control study was conducted among 340 postpartum mothers. The cases consisted of 170 women who had given birth to babies weighing <2,500 g, while the control group consisted of 170 women who had given birth to babies weighing ≥2,500 g. Details of the mothers were taken from the hospital records and through a personal interview, and a full-mouth periodontal examination was performed postpartum, which included probing depth, clinical attachment level, and bleeding on probing on six sites per tooth.ResultsLBW cases had a significantly worse periodontal status than the controls, having an odds ratio (OR) of 2.94 (P=0.01). The multivariate logistic regression model demonstrated that periodontal disease is a significant independent risk factor with an adjusted odds ratio (aOR) of 2.85 for the LBW group (95% confidence interval [CI], 1.62-5.5). Other factors showing significant associations with LBW were pre-eclampsia (aOR, 4.49; 95% CI, 1.4-14.7), preterm labor (aOR, 5.5; 95% CI, 3.2-9.9), and vaginal type of delivery (aOR, 2.74; 95% CI, 1.4-5.2).ConclusionsPeriodontitis represents a strong, independent, and clinically significant risk factor for LBW. Periodontal therapy should form a part of the antenatal preventive care among rural women in India.Graphical Abstract