Association of Pre-Pregnancy Body Mass Index and Gestational Weight Gain with Preterm Delivery in Pregnant Women

Abstract

The perinatal mortality rate, which is one of the important adverse pregnancy outcome and includes stillbirths and infant death within first week of life is estimated to be nearly 40 deaths per 1,000 pregnancies in Gujarat. Also the infant mortality rates have been estimated to be 50 deaths before age of one year per 1,000 pregnancies. It is stated that children whose mothers are illiterate or belong to low socio-economic class have two and half times more chances to die within 1 year of their birth compared to those whose mothers have completed atleast 10 years of education or belong to high socio-economic class. There are nearly 13% of women who does not receive proper antenatal care and facility during pregnancy. In India, there are nearly half of the women (52%) who possess normal BMI range: rest are either underweight or overweight. Approximately 55% of the women of total population in India are anaemic. These maternal parameters directly affect the children causing 48% of the children to be malnourished and 43% to be underweight. Therefore, it is imperative to examine the association of pre-pregnancy Body Mass Index (BMI) as well as Gestational Weight Gain (GWG) with diverse pregnancy outcomes such as gestational diabetes, gestational hypertension and also with preterm delivery, caesarean delivery, etc. The present study was designed to investigate the prevalence, GWG, various pregnancy outcomes of underweight, overweight or obese pregnant women, and to explore the relationship between pre-pregnancy BMI as well as gestational weight gain during pregnancy and adverse pregnancy outcomes. This is a prospective, multi-centric study involving pregnant women with gestation week ≤20 weeks in Ahmedabad in Gujarat region. Our study observed that out of 226 women enrolled, 44 women (19.47%) were underweight, 137 women (60.62%) were normal, 30 women (13.27%) were overweight and 15 women (6.64%) were obese. The incidence of caesarean delivery (56.92%) was found more in nuclear family as compared to joint family (46.92%). It was found that in women taking no junk food at all, the chances of LBW were 16.39%, which was less as compared to mothers who had junk food. It was also observed that amongst women taking 1 glass milk daily (42.92%), about 55.67% of had normal type of delivery. Amongst women taking 1 fruit daily (57.52%), 53% women had normal delivery. Present study spotted decrease in risk of caesarean delivery with increase in maternal haemoglobin level from 9.0 gm/dl till 12.0 gm/dl. Average weight gain observed in underweight was 12.93 ± 1.90, in normal 12.32 ± 1.71, in overweight 10.23 ± 1.28 and in obese 9.6 ± 1.50. A negative correlation was found between GWG and pre-pregnancy BMI, i.e. as pre-pregnancy BMI increase, the GWG decrease. The incidence of pre-term delivery (9.49%) was much less in normal BMI range. The average infant birth weight observed in underweight women was 2.63 ± 0.47, in normal was 2.9 ± 0.49, in overweight was 2.92 ± 0.56 and in obese was 2.95 ± 0.86. It is observed that highest birth weight is obtained in obese women, which decreases as the maternal BMI range decreases. The incidence of LBW in normal and overweight women was 15.33 and 16.67%, which was low as compared to obese and underweight women. Our study reveals that parameters such as GWG, type of family, intake of milk, fruits and junk food, haemoglobin concentration directly affects the pregnancy outcomes such as term of delivery, type of delivery and infant birth weight.