Double diabetes as an effect modifier for adverse perinatal outcome in pregnant women with type 1 diabetes mellitus - a retrospective multicenter cohort study

Abstract

Introduction: Double diabetes (DDiab) is defined as T1DM coexisting with insulin resistance (IR), metabolic syndrome (MetS), and/or obesity. Little evidence is available regarding how frequent DDiab is among T1DM pregnancies and whether it affects the perinatal outcome in this population.

Aims of the study: To explore the prevalence of DDiab in early pregnancy in the cohort of pregnant women with T1DM and to examine the association between an early-pregnancy DDiab status and fetomaternal complications characteristic for T1DM in pregnancy.

Material and methods: A retrospective data analysis of the multicenter cohort of N=495 pregnant women in singleton pregnancy complicated with T1DM followed from early pregnancy until delivery in three tertiary referral centers. DDiab status was defined as T1DM plus pre-pregnancy obesity defined as BMI≥30 kg/m² measured at the first antenatal visit (DDiabOb), or T1DM plus pre-pregnancy IR defined as eGDR (estimated Glucose Disposal Rate) below the 25^th centile for the cohort measured at the first antenatal visit (DDiabIR). Proportions of the adverse pregnancy outcomes were compared between DDiabOb and Non-DDiabOb and between DDiabIR and Non-DDiabIR patients.

Characteristics of the study group: (data presented as mean(SD) or percentage): age: 30.0(5.1) years; age when T1DM diagnosed: 17.5(8.5) years; T1DM duration: 12.0(7,9) years; microvascular complications (White classes R,F,RF): 11.9%, pre-pregnancy counselling: 26.6%, baseline gestational age: 10.5(4.3) weeks, pre-pregnancy BMI: 23.7(4.3) kg/m²; chronic hypertension: 9.1%, gestational hypertension (PIH) 10.7%, preeclampsia (PET): 3.2%; nulliparity 53.8%, smoking in pregnancy: 4.8%, eGWG: 22.4%, DDiabOB: 10.1%; DdiabIR: 25.2%; LGA: 44.0%, and NICU admission: 20.8%.

Results: (data from the univariate analysis given as OR(95%CI)): both DDiabOB and DDiabIR status increased the risk for eGWG [23.15 (10.82; 55.59); 3.03 (1.80; 5.08), respectively]. DDiabIR status increased the risk for PET [4.79 (1.68;14.6)], preterm delivery [1.84 (1.13; 3.21)], congenital malformation [2.15 (1.07;4.25)], and NICU hospitalization [2.2 (1.20;4.01)]. Both DDiabOB and DDiabIR accurately ruled out PET (NPV 97.3%/98.3%, accuracy: 88.3%/75.6%, respectively), congenital malformation (NPV 85.6%/88.4%, accuracy: 78.9/69.8, respectively), and perinatal mortality (NPV 98.7%/99.2%, accuracy: 88.8%/74.5%, respectively).

Conclusions: Double diabetes became a frequent complication in T1DM pregnant population. Double diabetes diagnosed in early pregnancy allows for further stratification of the T1DM pregnant population for additional maternal risk.

Keywords: maternal outcome; metabolic syndrome; neonatal outcome; obesity; pregnancy.