Pregnancy of women with type 1 diabetes mellitus - the effect of preconception care on perinatal results. Ten years of experience

Introduction: Despite the ever-improving medical care, pregnancies of women with type 1 diabetes mellitus (T1DM) are at increased risk of complications for both mother and child. Optimal compensation of diabetes before and during pregnancy is an essential protective factor reducing the risk of congenital malformations, pregnancy loss, and other complications.The pregnancy of women with T1DM should be planned, ideally at a time of optimal diabetes compensation. Target glycated hemoglobin (HbA1c) values until the range of 42-48 mmol/mol should be achieved at least three months before pregnancy. Our work aimed to evaluate the perinatal results of pregnancies in women with T1DM and the effect of preconception counseling and adequate T1DM compensation before pregnancy on perinatal outcomes. Methods and results: Retrospective analysis of pregnancy and perinatal outcomes of women with T1DM were followed up at the Department of Gynecology and Obstetrics, General University Hospital in Prague and First Faculty of Medicine, Charles University between 2008 to 2018. A total of 221 women with T1DM were included in the analysis. Adequate (HbA1c) <= 48 mmol/mol at least 3 months before conception) and inadequate diabetes compensation at the beginning of the pregnancy had 59 (26.7%) and 162 (72.3%) women, respectively. Pregnancies of women with adequate diabetes compensation were more often planned (55.9 vs. 24.7%; P < 0.0001), had a lower incidence of any form of diabetic microangiopathy (13.6 vs. 37.7%; P = 0.001), pre-eclampsia (0 vs. 6.8%; P = 0.036), better compensation of diabetes during pregnancy (mean HbA1c during pregnancy 39.9 +/- 6.7 vs. 49.9 +/- 12.2; P < 0.0001), and their pregnancy was less often terminated from medical indication (congenital malformation of the fetus or decompensation of T1DM) (0 vs. 7.4%; P = 0.032). Pregnancies of women with adequate diabetes compensation before conception were less often complicated by fetal macrosomia (birth weight > 95th percentile; 22.0 vs. 35.8%; P = 0.027). Conclusion: The pregnancy of women with T1DM is burdened by a number of perinatal and neonatal complications. In the study group, most women with T1DM became pregnant unintentionally at a time of inadequate diabetes compensation. Women who achieved adequate diabetes compensation before pregnancy had a lower incidence of perinatal complications. Therefore, it is advised that women with T1DM should plan their pregnancy, attend preconception and antenatal care, and give birth in perinatal centers, which provide coordinated care from diabetologists, gynecologists, obstetricians, and neonatologists.