Background:
Gestational diabetes mellitus (GDM) is a major cause of adverse pregnancy and neonatal outcomes (1). Strict glycaemic control throughout pregnancy is an effective method to manage these adverse outcomes (2,3).
Objective:
To evaluate maternal characteristics and perinatal outcomes of pregnancies affected by GDM managed with diet alone versus requiring insulin.
Methods:
Retrospective analysis of women with GDM between January 2018 and December 2019 at Royal Women’s Hospital, Victoria using medical records.
Results:
Over two years, 1748 women were diagnosed with GDM of whom 721 (41.25%) were managed with dietary changes alone and 1027 (58.75%) required additional insulin.
Maternal age was higher in women managed with diet (35.40 years vs 32.85 years, p<0.001). Maternal BMI was higher in women requiring insulin (29.22 kg/m2 vs. 26.37 kg/m2, p<0.001).
The occurrence of pregnancy-induced hypertension, pre-eclampsia and eclampsia were similar.
Women requiring insulin had higher rates of labour induction (55.0% vs. 41.2%, p<0.001) and elective caesarean sections (26.5% vs. 20.5%, p=0.005). Furthermore, infants of those requiring insulin demonstrated higher rates of large for gestational age (LGA) (2.8% vs. 1.1%, p=0.022) and macrosomia (3.6% vs 1.5%, p=0.014). However, gestational age at the time of induction was similar (38 weeks).
There were no significant differences in neonatal complications (Apgar scores, birth trauma, hypoglycaemia, small for gestational age, fetal growth restriction, admission to special care nursery, mortality). However, the rate of premature births was higher in women managed by diet alone (4.0% vs 2.1%, p=0.031).
Conclusions:
This study demonstrated rates of LGA, macrosomia, induction of labour and elective caesarean sections remained higher in women with GDM managed with insulin compared to diet alone, although no significant differences in neonatal complications were observed.
Pregnancies affected by GDM remain high-risk and require prospective studies to explore further interventions to improve pregnancy and neonatal outcomes in the GDM population.
References:
1. HAPO Study Cooperative Research Group MB, Lowe LP, Dyer AR, Trimble ER, Chaovarindr U, Coustan DR, Hadden DR, McCance DR, Hod M, McIntyre HD, Oats JJ, Persson B, Rogers MS, Sacks DA. Hyperglycaemia and adverse outcomes. N Engl J Med. 2008;358(19):1991-2002
2. Crowther CA, Hiller JE, Moss JR, McPhee AJ, Jeffries WS, et al. Effect of treatment of gestational diabetes mellitus on pregnancy outcomes. N Engl J Med. 2005;352(24):2477-86
3. Landon MB, Spong CY, Thom E, Carpenter MW, Ramin SM, et al. A multicenter, randomized trial of treatment for gestational diabetes. N Engl J Med. 2009;361(14):1339-48