Evaluation of Basal Metabolic Index and Waist to Height Ratio as Anthropometric Indicators of Obesity Among Pregnant Women in Port Harcourt, Nigeria

Abstract

Excess body fat deposition is known to be unhealthy. There have been several discourses on defined anthropometric indices for the assessment and a better prediction of obesity in pregnant women. This is because certain cut-off values relating to obesity in pregnant subjects are highly influenced by age, sex, ethnicity and trimesters of pregnancy. This study is aimed at investigating the use of two basic anthropometric indices to measure obesity and evaluate its prevalence in the different trimesters of pregnancy. The research is a prospective study involving 460 pregnant women in the sample proportion of 110, 110, 240 in the 1 st , 2 nd , 3rd trimesters respectively chosen randomly from antenatal clinic of the Rivers State Primary Health care centre, Rumukuta, Port Harcourt, Nigeria. Measurements of height, weight, hip circumference (HP) were obtained. Body mass index (BMI) was calculated from values of height and weight. Waist to height ratio (WHtR) was also calculated from waist and hip values. The result showed a BMI prevalence of 3.6%, 7.3% and 0.8%; WHtR prevalence of 56.4%, 51.8% and 40% all in the 1 st , 2 nd and 3 rd trimesters respectively. A negative linear correlation was shown between the other indices and BMI as an independent variable in first trimester with value (r= -0.015) against a (r= 0.165) in WHtR. There was an association of WHtR against BMI with no statistically significant difference at level of 95% (p<0.05). Generally, the study provides a low prevalence of BMI and a high prevalence of WHtR in relation to WHO values as well as establishing 1 st trimester as a good indicator of obesity in pregnant women and WHtR as a better predictor of obesity in pregnant women in the population studied. The results of this study are therefore recommended as a guide for clinical judgement in preventive comprehensive health care services on obesity management.