Association of Foetal Outcome with Maternal Body Mass Index (BMI)

Background: The worldwide obesity epidemic continues to be a major public health challenge, particularly in women of childbearing age. There is a need to understand the associations between maternal BMI and perinatal outcome.

Objectives: To evaluate recent trends in maternal body mass index (BMI) and to quantify its association with foetal outcome.

Methodology: It is a cross sectional study including a total of 384 pregnant women who were primi gravida and carry singleton pregnancy admitted at term in the department of Obstetrics and Gynaecology of DMCH for the management of labour. All the mothers were chosen by purposive sampling. The study populations were classified into four groups according to BMI. Group-I stands for 44 mothers who are underweight, Group-II consists of 234 mothers who are normal weight, Group III represents to 81 mothers who are overweight and Group IV signifies for 25 mothers who are obese. The women with multiple pregnancies, preterm labour and hypertension or diabetes were excluded from the study. Data regarding socio demographic, clinical, obstetrical and foetal outcome were recorded, afterwards the data were edited, managed and analyzed. The observations were plotted into tabular and figure form. The categorical variable was analyzed by chi square test and the quantitative variables were analyzed by ANOVA test. At all level 95% confidence interval & level of significance was p <0.05. The statistical analysis was done by SPSS version 23.

Results: The mean BMI of mothers in different groups (Group I, Group II, Group III and Group IV) were 18.37±1.06 kg/m2, 23.77±2.03 kg/m2, 26.54±2.47 kg/m2 and 32.15±1.17 kg/m2 respectively. The average BMI of total 384 mothers was 22.75±4.56 kg/m2. The highest 84% newborn had birth weight >2.5 kg in Group IV whereas 72.7% had ≤2.5 kg birth weight in Group I. Maximum (57%) mothers underwent NVD in Group I as long as the paramount (71%) mothers endured LSCS in Group III. Out of 384, total 180(46.9%) mothers had NVD and 204(53.1%) mothers deferred LSCS. APGAR score ≤7 was found 31.8%, 12.8%, 38.3% and 20% in Group I, Group II, Group III and Group IV independently. The P-value showed statistically significant of the groups (P=0.00016). Among 204 LSCS, 167(81.9%) mother sustained emergency and 37(18.1%) undertook elective LSCS. 52.9% of mothers went through LSCS were due to meconium staining liquor in Group IV which was subsequently followed by 46.6% in Group-III. 25.0%, 9.8%, 32.1% and 16% neonates required NICU admission in Group I, Group II, Group III and Group IV severally. There was a moderately positive significant correlation between maternal BMI and neonatal birth weight (r=+.383, p<0.001). All the statistics of requirements of NICU between one another group showed statistically significant difference.

Conclusion: Our study shows that maternal BMI has an effect on foetal outcome. Low BMI is associated with adverse perinatal outcome in terms of low birth weight while high BMI is associated macrosomia, LSCS and neonatal NICU admission. Regarding NICU requirements overweight mothers had more association with foetal outcome rather than obese. Therefore, definitely there is a role of pre pregnancy counseling regarding maintenance of weight of women especially during reproductive age group to maintain normal BMI as to have better perinatal outcome.