Maternal obesity is a global public health concern that affects every aspect of maternity care. It affects the short-term and long-term health of the mother and her offspring. Obese pregnant mothers are at an increased risk of developing complications during antenatal, intrapartum, and postnatal periods. Maternal complications include gestational diabetes mellitus, hypertensive disorder in pregnancy, pre-eclampsia and eclampsia, increased rate of cesarean delivery, pulmonary embolism, and maternal mortality; fetal complications include congenital malformation, stillbirth, and macrosomia. Moreover, both mother and infant are at an increased risk of developing subsequent non-communicable diseases and cardiovascular problems later in life. Several factors are associated with the likelihood of maternal obesity, including sociodemographic characteristics, obstetric characteristics, knowledge, and perception of health-promoting behavior. Gaining a sound understanding of these factors is vital to reaching the targets of Sustainable Developmental Goal 3—to reduce global maternal mortality and end preventable deaths of children under 5 years of age—by 2030. It is essential to identify pregnant women who are at risk of maternal obesity in order to plan and implement effective and timely interventions for optimal pregnancy outcomes. Importantly, maternal obesity as a significant pregnancy risk factor is largely modifiable.

Introduction: Maternal obesity presents significant health risks to mothers and their fetuses. This study aimed to determine the proportion, associated factors and outcomes of maternal obesity among pregnant women in Klang Valley, Malaysia. Methods: A retrospective cross-sectional study was conducted between January 2018 and March 2018 using secondary data from the Malaysian National Obstetric Registry (NOR) for the year 2015. All pregnant women with first-trimester booking at 12 weeks and below that were registered with the NOR and met the inclusion and exclusion criteria were included in the study. Descriptive statistics and multiple logistic regression analysis were used. Data were analysed using SPSS version 22.0. A total of 2113 respondents were included in this study to determine the proportion, associated factors and outcomes of maternal obesity. Regarding the univariate and multivariate analyses, respondents were classified into two groups: normal and obese. The obese group comprised overweight and obese mothers. The underweight group was excluded in the subsequent analysis. Results: Out of the 2113 respondents, 7.1% were underweight, 41.7% were of normal weight, 28.6% were overweight, 15.9% were in obese class I, 4.6% were in obese class II, and 2.1% were in obese class III according to the WHO (1995) reference. However, when the MOH (2003) cutoff point was used, there was a marked increase in the proportion of respondents in the overweight categories by 2.7% and obesity class I by 12.8%. The Indian (AdjOR 2.06, 95% CI: 1.11, 3.83, p=0.021) and Malay (AdjOR 1.75, 95% CI: 1.02, 3.00, p=0.040) ethnicities, as well as both multiparity (AdjOR 1.46, 95% CI: 1.23, 1.73, p <0.001) and grand multiparity (AdjOR 2.41, 95% CI: 1.78, 3.26, p <0.001), were significantly associated with maternal obesity. There were significant association between maternal obesity with hypertensive disorder in pregnancy (p=0.025), caesarean section delivery (p=0.002) and macrosomic infant (p <0.001). Conclusion: The identification of risk factors for maternal obesity is important to facilitate intervention programmes focused on improving the pregnancy outcomes for a high-risk group of women.