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

Abstract

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 weight, waist and hip circumference, conicity index, gestational weight gain, and maternal weight retention 2, 4 and 6 months post-partum. However, this relationship was not significant when it came to the weight of the baby at birth, and 2, 4 and 6 months post-partum (P < .05). According to the results of this study, the greatest amount of weight loss was observed in mothers with normal BMI, the greatest decrease in hip circumference was in obese mothers, and the greatest values of waist circumference and conicity index belonged to underweight mothers. Also, the highest frequency of mothers with excessive weight gain was in the obese mothers, while the highest values of post-partum weight retention (> 6 kg) were observed inunderweight mothers. The results of this study also showed that the highest frequency of low birth weight (LBW) was found in babies born to underweight mothers and the lowest frequency of breastfeeding until 6 months was observed in obese mothers. Conclusion: In this study, the greatest decrease in anthropometric indices such as weight, waist circumference, hip circumference, and conicity index was observed in obese mothers while the lowest decrease was experienced by overweight women. Also, the results of the present study 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.