Prepregnancy Glucose Levels Within Normal Range and Its Impact on Obstetric Complications in Subsequent Pregnancy: A Population Cohort Study

BACKGROUND: We sought to identify the influence of prepregnancy glucose levels on obstetric complications in subsequent pregnancy. METHODS: Women in Republic of Korea who had given birth between January 1st, 2007 and December 31st, 2010 were enrolled. The database of the Health Insurance Review and Assessment Service and data from a national health screening program for infants and children were used. Subjects were divided into seven groups according to their fasting glucose levels. RESULTS: 59,619 women were included for analysis, and 10.4%, 13.7%, 19.1%, 21.5%, 16.0%, 11.6%, and 7.5% women had glucose levels of < 75, 75–79, 80–84, 85–89, 90–94, 95–100 and > 100 mg/dL. Each 5 mg/dL increase in prepregnancy fasting glucose levels was associated with increased risk of gestational diabetes and macrosomia in subsequent pregnancy. Adjusted risk ratio for gestational diabetes per standard deviation prepregnancy glucose > 100 mg/dL was 2.015 (95% confidence interval, 1.649–2.462) and for macrosomia an adjusted risk ratio 1.389 (95% confidence interval, 1.147–1.682). CONCLUSION: Higher prepregnancy glucose level within normal range was related to gestational diabetes and macrosomia in following pregnancy. Our results may aid in the identification of women at future risk of obstetric complications and may guide to stratify women into normal and intensified care. TWEETABLE ABSTRACT: Higher prepregnancy glucose in normal range is associated with gestational diabetes and macrosomia.