Discussion
various chronic disorders, glucose intolerance, LBW, macrosomia, hyperglycemia, weight gain, GDM, birth trauma
PRETERM BIRTH, GLUCOSE INTOLERANCE, NEONATAL HYPOCALCEMIA, NEONATAL HYPOGLYCEMIA, EARLY PREGNANCY, GDM, HYPERGLYCEMIA, SECONDARY, CHRONIC DISORDERS, HYPERBILIRUBINEMIA, PREECLAMPSIA
In this secondary analysis of a randomized community non-inferiority trial involving pregnant women with FPG level between 5.1-5.6 mmol/l in the first trimester of pregnancy, we found that GDM treatment at the first trimester of pregnancy was not associated with a reduced risk of adverse maternal and neonatal outcomes, including macrosomia, LBW, primary C-S, preterm birth, neonatal hypoglycemia, neonatal hypocalcemia, hyperbilirubinemia, preeclampsia, NICU admission, and birth trauma. Moreover, the adjusted risks of adverse pregnancy outcomes in pregnant women with FPG between 5.1-5.6 mmol/l who did not receive GDM care but developed GDM in the second trimester were not significantly different from those with FPG between 5.1-5.6 mmol/l at first trimester who received GDM cares.There is ongoing debate regarding the benefits and risks of screening for and treating hyperglycemia in the first trimester of pregnancy (Our community randomized trial results showed that early diagnosis and treatment of GDM did not improve pregnancy outcomes. However, there are few randomized trial to compare early versus routine screening for GDM. In agreement with our findings, Osmundson et al. (2016), conducted an RCT, to assess the effect of early GDM treatment prior to 14 weeks gestation in women with a hemoglobin A1c (Hb A1c) levels between 5.7–6.4%. The study randomly assigned 42 pregnant women to receive GDM treatment and 41 to receive usual prenatal care. The results showed that early treatment for women with prediabetes-range A1C levels in the first-trimester did not significantly reduce the risk of GDM diagnosis by the second trimester (In another RCT, Roeder et al. (2019) assessed whether treating women with mild glucose intolerance earlier in pregnancy would be beneficial in the reduction of adverse perinatal outcomes. Pregnant women with hyperglycemia, including Hb A1c ≥5.7% and/or FPG ≥5.1 mmol/l in early pregnancy were randomized to early pregnancy or third-trimester treatment of GDM. Results of the study showed that treatment in early pregnancy did not significantly improve maternal or neonatal outcomes, including macrosomia, weight for length percentile at birth, maternal gestational weight gain, fat mass, and cord blood C-peptide > 90th percentile (Our study revealed that an FPG of 5.1 mmol/l may not be considered an optimal glycemic target early in pregnancy; it was not associated with an improvement in pregnancy outcomes, and 82% (1725/2099) those pregnant women who had FPG values 5.1-5.6 mmol/l and did not receive treatment for GDM in the first trimester, did not meet the GDM criteria at second trimester. These results are consistent with those of a study conducted among Chinese subjects, which reported a 37% incidence of GDM for women with FPG values between 5.1 and 5.6 mmol/l at the first prenatal visit (Our study has several strengths, including community-based trial design of study, large sample size, geographic distribution of the regions involved, broad inclusion criteria and using similar laboratory protocols. Unlike many previous studies, which focused on high-risk populations, our study evaluated a general population of pregnant women. We also adjusted for potential risk factors, which adds to the strength of our findings. Additionally, the early enrollment of participants, on average at eight weeks of gestation, is a further strength of our study. However, there are some limitations to our trial that should be acknowledged. According to the Iranian national guidelines for prenatal care, pregnant women with known chronic disorders should be directly referred to the second level of the healthcare system and receive their prenatal care there, rather than in a primary healthcare setting, which was the platform of our study. Evaluating the adverse feto-maternal and neonatal outcomes in these high-risk groups was beyond our research aim of study. As a result, our findings are not generalizable to those with various chronic disorders. Moreover, we did not measure HbA1c in our study. Additionally, we did not used a central reference laboratory for measurements. However, all of procedures, equipment, and supplies were homogeneous in all laboratory sites, and monthly external quality-controls were done for each laboratory. Our study was conducted among Iranian women; the results may not be applicable to other populations.In conclusion, our study suggests that using the first-trimester FPG values of 5.1-5.6 mmol/l as the criteria to diagnose GDM is not recommended. Treatment of these women did not lead to improved adverse pregnancy outcomes, and they may not require the special prenatal care recommended for those with a GDM diagnosis. Therefore, we recommend that this group of pregnant women be re-screened for GDM at 24-28 weeks of gestation.