Are the 2009 Institute of Medicine gestational weight gain recommendations applicable in a contemporary South-East Asian pregnancy cohort? Results of a prospective analysis

by Yong Ting Tai, Jun Kit Khoo, Quan Hziung Lim, Lee-Ling Lim, Sharmila Sunita Paramasivam, Jeyakantha Ratnasingam, Nicholas Ken Yoong Hee, Tharsini Sarvanandan, Ying Guat Ooi, Victoria Wei Fang Boey, Saravanaa Nalliah, Peng Chiong Tan, Mukhri Hamdan, Pavai Sthaneshwar, Nurshadia Samingan, Azanna Ahmad Kamar, Azriyanti Anuar Zaini, Syahrizan Samsuddin, Md Syazwan Md Amin, Nurbazlin Musa, Shubash Shander Ganapathy, Karuthan Chinna, Muhammad Yazid Jalaludin, Shireene Ratna Vethakkan

Gestational Weight Gain (GWG) modulates pregnancy outcomes and long-term offspring metabolic health. The 2009 Institute of Medicine (IOM) GWG recommendations have largely been validated in Caucasian and mono-ethnic East Asian cohorts. Asians are at higher metabolic risk at a lower body mass index (BMI), and this has prompted the World Health Organization (WHO) to identify lower BMI cut-offs for risk evaluation amongst Asians. This prospective observational cohort study aimed to determine if 2009 IOM GWG thresholds are applicable in a contemporary multi-ethnic South-East Asian cohort. We recruited 875 mothers from an urban Malaysian tertiary clinic during screening for gestational diabetes mellitus (GDM) from 2014–2021. Data collected included measures of insulin-sensitivity, total GWG (maternal weight at delivery–self-reported pre-gravid weight), and neonatal anthropometrics (birthweight and skinfold-thickness measured with Harpenden calipers). BMI was stratified by Caucasian (overweight ≥25kg/m², obese ≥30kg/m²) as well as Asian (overweight ≥23kg/m², obese ≥27.5kg/ m²) cut-offs, and patients categorized by 2009 IOM GWG reference ranges. The cohort comprised 67% Malay-, 23% Chinese- and 10% Indian-descent mothers with a high prevalence of overweight/obesity (Asian cut-offs 56.9% vs Caucasian 44%). When Asian BMI cut-offs were deployed, excessive GWG incidence increased (34.1% → 40.6%) whilst inadequate GWG declined (30% → 24.8%) (p<0.05). Upon multivariate-analysis (adjusting for age, parity, race, GDM, insulin-sensitivity, baby-gender) excessive GWG categorized with Caucasian BMI cut-offs was significantly associated with increased risk of macrosomia (adjusted odds ratio (aOR) 8.65, 95% confidence interval (CI) 1.07–70.01), Neonatal-Fat-Mass (NFM) >90th centile (aOR 2.14, 95% CI 1.02–4.45) and Sum-of-Skinfold Thickness (SSFT) >90th centile (aOR 3.88, 95% CI 1.77–8.51). Excessive GWG by Asian cut-offs was also associated with increased risk of SSFT >90th centile (aOR 5.75, 95% CI 2.35–14.10). Inadequate GWG by both Caucasian and Asian BMI cut-offs was associated with Small-for-Gestational-Age (SGA) status (aOR 4.30, 95% CI 2.48–7.45 and aOR 3.66, 95% CI 2.13–6.30 respectively). In conclusion, the 2009 IOM GWG recommendations, using either Caucasian or regional Asian BMI cut-offs, are applicable in a contemporary Malay majority South-East Asian cohort in terms of predicting abnormal neonatal adiposity. Importantly, the association with neonatal adiposity is independent of increased maternal insulin resistance characteristic of Asians.