Mild periconceptional hyperglycemia: predictor of adverse fetomaternal outcomes in gestational diabetes?

AIM

To clarify whether mild first trimester hyperglycaemia (characteristic of early-onset GDM) is associated with higher incidence of congenital malformations and other adverse fetomaternal outcomes compared to women with second trimester hyperglycaemia (later-onset GDM).

DESIGN AND METHODS

We analyzed the Portuguese National GDM database, containing data collected between 2011 and 2017. Two study groups were defined: Group 1-Women with GDM diagnosed during the first trimester (with fasting glycemia ≥ 92 and < 126 mg/dL); Group 2-Women with GDM diagnosed after the first 12 weeks of gestation, with either fasting glycemia or oral glucose tolerance test, according to the International Association of Pregnancy and Diabetes Study Group criteria. The fetomaternal characteristics of each group were compared.

RESULTS

A total of 18.518 pregnant women diagnosed with GDM were included which 34.4% of them belonged to Group 1. Pregnant women from this group were significantly younger and had a higher median BMI than the women from the other group. Overall, there was no significant differences in maternal morbidity parameters between groups. Non-evolutive pregnancies were significantly more frequent along the present gestation in the group 1 (1.1% vs. 0.1%, p < 0.001), as was fetal death (0.6% vs. 0.2%, p < 0.001). Congenital malformations did not differ significantly between groups (3.2% vs. 2.8%, p = 0.155).

CONCLUSIONS

The mild near conceptional hyperglycaemic state characteristic of an early-onset GDM seems to be associated with an increased prevalence of non-evolutive pregnancies and foetal deaths when compared to later-onset GDM.

Should the IADPSG criteria be applied when diagnosing early-onset gestational diabetes?

AIMS

To investigate whether the broad interpretation of the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria with application to the early pregnancy, which is adopted as the standard in Japan, is appropriate.

METHODS

We conducted this investigation by comparing diabetes-related adverse pregnancy outcomes among women treated for gestational diabetes mellitus (GDM) following an early-pregnancy diagnosis (early-onset GDM, n = 528) and those treated for GDM following a mid-pregnancy diagnosis, which is the international standard (Mid-term-onset GDM, n = 147).

RESULTS

Gestational weight gain was significantly lower in the early-onset GDM group (7.5 kg) than in the mid-term-onset GDM group (8.4 kg). The frequency of hypertensive disorders of pregnancy tended to be lower in the early-onset GDM group (5.6% vs. 8.8%, p = 0.085), but infant birth weight did not differ significantly between the groups. No between-group difference was observed in macrosomia, large-for-gestational-age (LGA), small-for-gestational age (SGA), low Apgar score, shoulder dystocia, cesarean delivery, NICU admission, hyperbilirubinemia, neonatal hypoglycemia, or respiratory distress syndrome. The frequency of LGA showed a significant association with pre-pregnancy body mass index, but did not differ according to the timing of therapy initiation.

CONCLUSIONS

We could not find the effectiveness of therapeutic interventions initiated after GDM diagnosis in the early pregnancy based on the IADPSG criteria, compared with therapeutic interventions after a mid-pregnancy GDM diagnosis. It was suggested that the IADPSG criteria for diagnosing GDM at 24-28 weeks' gestation should not be applied to Japanese women in the early pregnancy by a broader interpretation.

Screening and Treatment for Early-Onset Gestational Diabetes Mellitus: a Systematic Review and Meta-analysis

We conducted a systematic review to evaluate the current evidence for screening and treatment for early-onset gestational diabetes mellitus (GDM) RECENT FINDINGS: Many of the women with early GDM in the first trimester do not have evidence of hyperglycemia at 24-28 weeks' gestation. A high proportion (15-70%) of women with GDM can be detected early in pregnancy depending on the setting, criteria used and screening strategy. However, there remains no good evidence for any of the diagnostic criteria for early-onset GDM. In a meta-analysis of 13 cohort studies, perinatal mortality (relative risk (RR) 3.58 [1.91, 6.71]), neonatal hypoglycemia (RR 1.61 [1.02, 2.55]), and insulin use (RR 1.71 [1.45, 2.03]) were greater among early-onset GDM women compared to late-onset GDM women, despite treatment. Considering the high likelihood of benefit from treatment, there is an urgent need for randomized controlled trials that investigate any benefits and possible harms of treatment of early-onset GDM.