MATERNAL BODY MASS INDEX AND BIRTH OUTCOME

Emmanuel Christian Ako Besseri
Obstetrics and Gynaecology, University of Yaounde 1
June, 2013
 

Abstract

INTRODUCTION:
The increase in the prevalence of maternal obesity is of great concern as it has been found to be associated with adverse health outcomes affecting the mother, her foetus, neonate and child. Unfortunately, the association between obesity and adverse pregnancy outcomes is not universally acknowledged, which only serves to perpetuate the problem.

OBJECTIVES:
Our main objective was to assess the effect of maternal obesity on birth outcome. Specifically, we sought to: 1) Describe the socio-demographic/anthropometric characteristics of obese and non-obese pregnant women. 2) Determine the antepartum and intrapartum outcomes amongst obese and non-obese pregnant women.3) Compare the immediate postpartum period amongst obese and non-obese pregnant women.

METHODOLOGY:
To attain our objectives, we carried out a cross-sectional analytic hospital-based study involving pregnant women admitted into the maternity of the Yaounde Central Hospital and Biyem-Assi District Hospital from August 2012 to March 2013. Pregnant women in labour with gestational age more than 28 weeks, who consented to participate in the study and had a documented follow-up during pregnancy, were recruited. Pregnant women with multifoetal gestation, scarred uterus and those with medical conditions such as diabetes mellitus, hypertension, asthma, sickle cell anaemia and heart disease were excluded from our study. Selected participants were then divided into two groups, the obese group (BMI ≥ 30) and the non-obese group (BMI < 30). Routine data such as personal, obstetric, medical and surgical history were collected and labour was monitored until delivery. The birth outcome was studied for each group and comparison of parameters such as antepartum complications, induction of labour, augmentation of labour, duration of labour, mode of delivery, postpartum haemorrhage, birth weight of newborn, and APGAR score was made. Analysis of the data collected was done using Epi Info software version 7.1.1.14. The study was approved by the Ethical Committee of The Faculty of Medicine and Biomedical Sciences; University of Yaounde I.

RESULTS:
A total of 200 pregnant women were recruited into our study; 100 each in the obese and non-obese categories. The mean age was 29.21 ± 6.40 years in the obese group which is significantly higher than the mean age of 25.76 ± 5.46 years in the non-obese group (p = 0.0001). There were 19 grand multipara women in the obese group and 7 in the non-obese group; giving a significant statistical difference (p = 0.019 and odds ratio = 3.12). Marital and economic status did not have any link with obesity. There existed an association between the highest level of education and obesity, with a fewer number of obese pregnant women (25) than non-obese pregnant women (40) who had gone beyond high school (p = 0.034 and odds ratio = 0.50). In the obese group, 11 women had gestational diabetes mellitus (GDM) while only 2 women in the non-obese group had GDM (p = 0.018 and odds ratio = 6.06). In the obese group, 39 women were induced as against 23 in the non-obese group (p = 0.021 and odds ratio = 2.14). The mean duration of the active phase of labour was 10.3±5.7 hrs in the obese group and 7.5±3.2 hrs in the non-obese group (p = 0.000). In the obese group, 30 women suffered from severe pre-eclampsia while in the non-obese group only 13 women suffered from severe pre-eclampsia (p = 0.006 and odds ratio = 2.87). In the obese group, there was 1 post-term deliveries as against 5 post-term deliveries in the non-obese group (p = 0.212 and odds ratio = 0.19). There was a significant statistical difference in the number of obese and non-obese pregnant women who had a caesarean section (CS); with 41 of them in the obese group and 23 in the non-obese group (p = 0.010 and odds ratio = 2.33). Assessing postpartum complications in the obese group of pregnant women, 27 had placenta retention, 5 had postpartum haemorrhage, and 9 had cervical/vaginal tear. In the non-obese group, 18 pregnant women had placenta retention, 2 had postpartum haemorrhage, and 4 had cervical/vaginal tear. There was a statistical significant difference in the number of women in the obese and non-obese group who gave birth to macrosomic babies (babies weighing more than 4000g); with 21 of them in the obese group and 8 in the non-obese group (p = 0.015 and odds = 3.06). Finally, the difference in the number of women in the obese and non-obese group whose babies had a poor 1st minute APGAR score of less than 7 was significant; with 27 in the obese group and 14 in the non-obese group (p = 0.035 and odds ratio = 2.27).

CONCLUSIONS:
At the end of our study, we made the following conclusions: Most older, less educated women who have given birth more than five times are usually obese. Gestational diabetes mellitus (GDM) is directly linked to maternal obesity; with six times more likelihood for obese pregnant women to develop GDM. There is an association between obesity and induction of labour as well as prolong labour. The likelihood for an obese pregnant woman developing severe pre-eclampsia is three times higher than in a non-obese pregnant woman. There exist an association between obesity and the mode of delivery; with obese pregnant women having two times more odds of giving birth through caesarean delivery. The likelihood for an obese pregnant woman to have an early postpartum complication (placenta retention, postpartum haemorrhage, cervical/vaginal tear) is two times greater than in a non-obese pregnant woman. Obese pregnant women have three times more risks of given birth to macrosomic babies. Maternal obesity is associated with increased morbidity in newborns.

RECOMMENDATIONS:
We do recommend to Obstetricians and Gynaecologists that, obese pregnant women should be closely monitored because they are most likely to have adverse pregnancy outcome. Also, the delivery of obese pregnant women should be conducted by the most experience in the team to avoid intrapartum and postpartum adverse complications for the mother – neonate couple. We also recommend to antenatal clinic attendants to intensify health education on obesity to avoid excessive weight gain during pregnancy. Finally, we recommend to the Faculty of Medicine and Biomedical Sciences to encourage studies that will include other regions of the country to be able to analyse the effects of obesity on maternal and foetal outcomes.


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