Background: Guidelines identified maternal and infant relationships with gestational weight gain but were based on lower general population BMI with limited ethnic diversity.
Aim: was to evaluate the effects of gestational weight gain on pregnancy outcomes in pregnant women with different pre-pregnancy body mass index (BMI) to establish optimal GWG for each BMI category.
Subjects and methods: This is a prospective study carried out by follow up 550 cases of pre-pregnant women who attended antenatal care unit at the department of obstetrics and gynecology from the first of April 2021 to tle last of December 2022. The patients were cateogarized according to pre pregnancy BMI according to WHO classification into three groups: Group I: 18.5- 24 kg/m², Group II: 25- 29.9 kg/m² and Group III:  >30 kg/m². Group III was classified to: Class 1: 30- 34 kg/m² Moderate, Class 2:35- 39.9 kg/m² severe and Class 3: >40 kg/m² very severe according to body mass index (BMI).
Results: Obese females have statistically significant higher weight gain and BMI increase during pregnancy than non-obese females. Weight gain >13kg was statistically significant higher in obsess than non-obsess females. Among our included females 32.36% develop complications; the commonest complications were medical complications 25.09% followed by infant complications in 23.37%. The commonest infant complication was LGA in 16.7%.
Conclusions: obese females have statistically significant higher age, higher fetal birth weight, higher weight gain and BMI increase than non-obese females. Medical, obstetric, fetal complications and LGA were statistically significant higher in obese than non-obese females.