Prediction of Gestational Diabetes Mellitus and Hypertensive Disorders in Pregnancy Using Insulin Resistance at 11-14 Weeks Period of Gestation

Abstract

Background: Hypertensive disorders of pregnancy and gestational diabetes (GDM) are all associated with increased risks of poor maternal and perinatal outcomes. It has been hypothesized that the association could be due to at least in part, to insulin resistance. Although insulin resistance is a physiologic phenomenon in normal pregnancy, in predisposed individuals it could lead to hyper-insulinemia with development of GDM, hypertensive disorders of pregnancy (gestational hypertension, pre-eclampsia and eclampsia) or both. In the present study the role of insulin resistance in early prediction of gestational diabetes mellitus and hypertensive disorders in pregnancy. Researchers attempted to study the correlation of insulin resistance at 11 to 14 weeks period of gestation and outcome in terms of GDM and hypertensive disorders in pregnancy and explore the possible use of insulin resistance in their early prediction. Objectives: Prediction of gestational diabetes mellitus and hypertensive disorders in pregnancy using insulin resistance at 11-14 weeks of gestation. To evaluate if combined maternal markers (insulin resistance, mean arterial pressure and uterine artery Doppler pulsatility index) in first trimester of pregnancy (11-14 weeks) is more effective in predicting the same. Methodology: The study is a prospective observational study carried out from December 2015 to November 2016, in the Department of Obstetrics and Gynaecology at Dr. T.M.A. Pai Hospital, Udupi. The study population consists of pregnant women booked between 11-14 weeks of gestation with viable pregnancy, who are willing for blood investigation to determine insulin resistance and also those women who gave consent to do uterine artery Doppler. Total 165 patients are included in the study. Out of them 118 patients gave consent to do uterine artery Doppler during NT scan. All patients are followed up for presence of development of gestational diabetes mellitus and hypertensive disorders of pregnancy with mode of delivery, intrapartum and postpartum complications. Results: Likelihood ratio by taking HOMA-IR cut off as 1.87 at 11-14 weeks of gestation was 2.5 stating that with HOMA-IR value as 1.87, pregnant women were 2.5 times more likely to develop gestational diabetes mellitus or hypertensive disorders of pregnancy with advancing gestation. It was observed that HOMA-IR values increased with increase in BMI in present study with p value-0.013, thus was found statistically significant. Out of 72 patients having HOMA-IR ≥ 1.87, 32 patients developed either GDM/HTN which accounted for 45% of women who developed gestational diabetes mellitus or hypertensive disorders in pregnancy. There was an increasing trend in HOMA-IR at 11-14 weeks period of gestation in women who later developed gestational diabetes mellitus or hypertensive disorders in pregnancy. Out of 9 patients having gestational hypertension, 7 patients were having HOMA-IR ≥ 1.87, which accounted for 78% of patients developing gestational hypertension (HTN) in pregnancy. HOMA-IR was a useful marker in predictive gestational hypertension (p value <0.01). Out of 32 patients having gestational diabetes mellitus, 26 patients were having HOMA-IR ≥ 1.87, which accounted for 81% of patients developing gestational diabetes mellitus (GDM) in pregnancy. HOMA-IR was a useful marker in predicting gestational diabetes mellitus (P value <0.01). The combined parameters of study showed 100% sensitivity and 100% negative predictive value for predictability of GDM/HTN in pregnancy. Conclusion: HOMA-IR can be used to predict GDM/Hypertensive disorders of pregnancy at 11-14 weeks gestation with reasonable accuracy. Combined screening algorithm with HOMA-IR, MAP and uterine artery Doppler has limited role and may help only in select high risk population. The prospect of screen positive women being given low dose aspirin (75mg) and advice regarding appropriate dietary management to help prevent the development of hypertensive disorders/GDM in later gestation needs to be explored by larger trials.