Influence of gestational weight gain on baby's birth weight in Addis Ababa, Central Ethiopia: a follow-up study

Background: Gestational weight gain (GWG) is an important indicator of fetal well-being during pregnancy. Inadequate or excessive GWG could have undesirable effects on birth weight. However, information regarding the influence of GWG on birth weight is lacking from the Ethiopian setting. Objective: This study aimed to determine the influence of GWG and other maternal-related factors on birth weight in Addis Ababa, Ethiopia. Design and methods: A cohort of pregnant women who received the first antenatal care before or at 16 weeks of gestation in health centres in Addis Ababa were followed from 10 January 2019 to 25 September 2019. Data were collected using a structured questionnaire and medical record reviews. We conducted a multivariable linear regression analysis to determine the independent effect of gestational weight on birth weight. Results: Of the 395 women enrolled in the study, the participants’ pregnancy outcome was available for 329 (83.3%). The mean birth weight was 3130 (SD, 509) g. The proportion of low birth weight (<2500 g) was 7.5% (95% CI 4.8% to 11.0%). Babies born to underweight women were 150.9 g (95% CI 5.8 to 308.6 g, p=0.049) lighter than babies born to normal-weight women. Similarly, babies whose mothers gained inadequate weight were 248 g (95% CI 112.8 to 383.6 g, p<0.001) lighter than those who gained adequate weight. Moreover, babies whose mothers had a previous history of abortion or miscarriages or developed gestational hypertension in the current pregnancy were 147.2 g (95% CI 3.2 to 291.3 g, p=0.045) and 310.7 g (95% CI 62.7 to 552.8 g, p=0.012) lighter, respectively, compared with those whose mothers had not. Conclusions: Prepregnancy weight, GWG, having had a previous history of abortion or miscarriages, and developing gestational hypertension during a current pregnancy were independently associated with birth weight. Pregnancy-related weight management should be actively promoted through intensive counseling during routine antenatal care contacts.