The relationship of pre-pregnancy body mass index with maternal anthropometric indices, weight retention and the baby’s weight and nutrition in the first 6 months post-partum

PURPOSE: Pre-pregnancy body fat mass is one of the important indicators of the mother's and the infant's health. Therefore, the purpose of this study was to investigate relationship of pre-pregnancy body mass index (PPBMI) with maternal anthropometric indices and weight retention as well as the baby's weight and nutrition in the first 6 months post-partum. MATERIALS AND METHODS: This is a prospective cohort study including 397 mothers giving birth to healthy babies and referring to health centers in Ahvaz (southwest of Iran) in 2022. The following data were extracted from the participants' electronic record: body mass index (BMI) before or at the beginning of pregnancy, gestational weight gain, and weight at the time of delivery. In addition to demographic information, the following data were also evaluated: maternal anthropometric indices including weight, hip and waist circumference, and conicity index during the first 10 days post-partum, along with the weight and nutrition pattern of the baby 2, 4 and 6 months post-partum. RESULTS: The mean age of the mothers was 29.96±5.7 years. The frequency of mothers according to BMI classification (i.e., underweight, normal, overweight, and obese) was 4.3%, 38.5%, 37%, and 20.3%, respectively. In this study, PPBMI had a significant relationship with decreasive changes of weight, waist and hip circumferen and conicity index after child birth, 2, 4 and 6 months post-partum (P<0.05) but the mean reduction of these anthropoemetric indices at 6(th) month postpartum were not related to PPBMI (P>0.05). However, this relationship was not significant when it came to the weight of the baby (P > .05). The lowest reduction in weight, waist and hip circumference and conicity index belonged to overweight mothers but the highest frequency of mothers with excesive gestational weight gain, the lowest frequency of breastfeeding until 6 months and also the lowest values of postpartum weight retention were observed in obese mothers (P<0.05). CONCLUSION: According to the findings of this study, the decrease in anthropometric indices up to 6 months after delivery in overweight mothers is less than other BMI groups, but the consequences related to weight and nutrition in infants of obese mothers need special attention. Also, the results re-emphasize the importance of focusing on provision of educational and counseling services to mothers in order to improve their nutrition and weight, especially before pregnancy.