EARLY VS ROUTINE GDM SCREENING IN OBESE PREGNANT WOMEN

A prospective observational study was designed to assess the high risk of obesity in antenatal patients. The study took place over a period of 6 months (July 2019- Dec 2019) in a tertiary care hospital , GMC Jammu. Patients were subjected to early (before 14 weeks) and later (24-28 weeks) screening of GDM randomly according to the first antenatal visit done at the hospital. Multivariable logistic regression was used to examine the correlations of GDM and its outcomes. All data were analyzed and t score and p value were calculated. P<0.05 was considered statistically significant.As per the results obtained the adverse effects of macrosomia, primary caesarean section, shoulder dystocia, polyhydramnios and neonatal hypoglycemia were higher in routine group although the difference were not statistically significant.

Gestational diabetes when treated leads to improved pregnancy outcomes but obese women with gestational diabetes continue to have worse outcomes. (6) NICE guidelines recommends that we assess the risk of gestational diabetes using risk factors in a healthy population.
At South Asian population being a high risk population especially the Indian females with a 11 fold higher risk of developing glucose intolerance during pregnancy, compounded with the delayed starting of antenatal check-ups in the rural and semi urban population which in turn leads to late GDM screening, we planned a study in a tertiary care hospital catering to patients of all socio-economic strata to study if there was any significance difference in the materno-fetal outcomes if GDM was diagnosed and treated early on rather than at 24-28 weeks in obese patients.

Material And Methods:-
A prospective observational study was designed to assess the high risk of obesity in antenatal patients. The study took place over a period of 6 months (July 2019-Dec 2019) in a tertiary care hospital , GMC Jammu. Patients were subjected to early (before 14 weeks) and later (24-28 weeks) screening of GDM randomly according to the first antenatal visit done at the hospital. Patients with BMI>= 30 were eligible for the study. An OGTT was done on all patients and diagnosis of GDM was made according to the NICE guidelines as below: If the woman has either: a fasting plasma glucose level of 5.6 mmol/litre (100.8 mg/dl) or above or a 2-hour plasma glucose level of 7.8 mmol/litre (140.4 mg/dl) or above.
Upon diagnosis the GDM was managed according to the institute guidelines, followed up with regular ANC and institutional deliveries.
Primary outcome was defined by the presence of adverse outcomes in terms of macrosomia(birth weight > 4 kg), primary caesarean delivery, shoulder dystocia, neonatal hypoglycemia(<35 mg/dl) , stillbirth, hypertensive disorders of pregnancy(bp> 140/90), need for diabetic medication and polyhydramnios.

Statistical Analysis
Multivariable logistic regression was used to examine the correlations of GDM and its outcomes. All data were analyzedand t score and p value were calculated. P<0.05 was considered statistically significant.

Results:-
In our study out of the total patients who came for antenatal visits over a span of 6 months in the hospital1072 patients were obese and out of these 278 were diagnosed with gestational diabetes.
They were randomised into early and routine screening according to the gestational age at first visit. After excluding the patientswho lost to follow up and non-compliance 254 patients were followed upto term and analysed for primary outcomes. The patients were divided into early group who were tested before 14 weeks of pregnancy and routine group who were screened at 28 weeks, the latter also included the patient who were initially screened negative in early group.
As per the results obtained the adverse effects of macrosomia, primary caesarean section, shoulder dystocia, polyhydramnios and neonatal hypoglycemia were higher in routine group although the difference were not statistically significant.
The number of stillbirths in both groups were the same.
The need for medication was observed to be higher in the early group17.4 % as compared to the routine group 13.9%, although it was not statistically significant.

Discussion:-
Pregnancy is accompanied by insulin resistance, caused mainly by the diabetogenic hormones secreted by the placenta. GDM is unmasked in patients whose pancreatic function in unable to overcome the same. The main adverse effects of GDM are increased risks of HDP, LGA newborns and caesarean births. These short term effects can be reduced by treatment of GDM so it is all the more important to timely screen, diagnose and intervene especially in a high risk population with obesity.
According to the study by sudhasinghe in 2018 hyperglycaemia in Pregnancy diagnosed and followed up in a suburban community setting in South Asia, had significantly worse pregnancy outcomes with a high risk of maternal pre-diabetes/diabetes in first post-partum year. (12)In amultivariate analysis by Filardi, Asian ethnicity, age ≥ 35 years and pre-pregnancy BMI ≥ 25 kg/m 2 were independent predictors of use of insulin therapy. Prevalence of prior gestational diabetes was seen to be higher in overweight/obese women (p = 0.002)(13)The Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study also showed a positive correlation between rising maternal glycemic concentrations and macrosomia which was defined by a birth weight above the 90 th percentile. In the study by Ijas et al, the babies of GDM mothers had twice the risk of hypoglycemia compared to the babies in the reference group. The rate of preterm delivery was also higher in overweight and obese women with GDM and the rate of low 5min Apgar score was increased in obese women with GDM, both of which may lead to increased need for treatment at neonatal ward. (9) It was also found that while overweight/obesity alone are associated with macrosomia, caesarean delivery, treatment at neonatal ward (obesity only), delivery induction and low Apgar score, GDM amplifies these risks. (9) Keeping in mind the benefits of awell timed intervention we designed a prospective study to further probe the notion if early diagnosis of GDM could significantly lower the aforementioned maternal and fetal risks. No significant results were found after analysis of the primary outcomes in our study.
In a randomized controlled trial as well, it was found that screening obese women for gestational diabetes between 14 and 20 weeks' gestation was not associated with a decrease in a composite adverse perinatal outcome of macrosomia,primary caesarean delivery,HDP, shoulder dystocia, hyperbilirubinemia, or neonatal hypoglycemia.
In yet another study Hong et al stated that pregnant women who were screened early required oral antidiabetic agents or insulin more frequently than those without an early screen, but had similar rates of cesarean delivery, preeclampsia, and macrosomia. (15) Similarly, Roeder et al randomized women with a hemoglobin A1c in the pre-diabetes range (5.76.4%) or fasting plasma glucose 92 mg/dL prior to 15 weeks. Women were randomly assigned to early pregnancy treatment compared to third-trimester treatment. No difference was seen in the primary and secondary outcomes of cord blood C-peptide >90th percentile, fat mass, weight for length percentile at birth, macrosomia, or maternal gestational weight gain.
Similarly in a study by Shub et al it was found that the early diagnosis of GDM does not substantially increase rates of adverse outcomes compared to GDM diagnosed in later pregnancy or no GDM in women with risk factors for GDM.However infants of women with early GDM, but not late GDM, were more likely to have the neonatal composite outcome than infants of women without GDM, mainly due to an increase in neonatal hypoglycaemia. (10) In the article published by bashir et al more patients in the routine-GDM group were managed on diet alone compared with Early-GDM (53.6% vs 27.5%, p<0.001) . Our study also had similar clinical results although not statistically significant. Maternal outcomes observed were also similar between the two groups apart from a higher incidence of preterm labour (11) Further studies are required in the population as GDM is a important and increasing problem in the pregnant demographic.Alsoamong pregnant women, the prevalence of obesity was over 40% in 31 districts in the country, with the highest prevalence of 72% in Shupiyan district of our state(Jammu and Kashmir) (16). Hence screening and targeting GDM is the need of the hour.