Is there a difference in placental pathology in pregnancies complicated with gestational diabetes A2 versus gestational diabetes A1, versus one abnormal value, on 100 gr glucose tolerance test?

Abstract

Introduction: The objective of the study was to investigate pregnancy outcome and placental pathology lesions among patients with gestational diabetes mellitus (GDM) versus patients with one abnormal value (OAV), in the oral glucose tolerance test (OGTT).

Methods: A prospective study was performed from 2016 to 2019. All participants performed an OGTT between 24 and 28 weeks. Included patients who delivered at term (>37 weeks) with the diagnosis of GDMA2 (treated with insulin), GDMA1 (controlled with diet) and those with OAV. Maternal characteristics, pregnancy outcomes, and placental histopathology reports were compared between the GDMA2, GDMA1, and OAV groups. Placental lesions were classified according to "Amsterdam" criteria to maternal and fetal vascular malperfusion (MVM, FVM) lesions, and inflammatory lesions.

Results: The GDMA2 group (n = 59) was characterized by higher maternal BMI (p < 0.001), increased rate of chronic hypertension (p < 0.01), cesarean delivery (CD) (p < 0.001), adverse neonatal outcomes (p < 0.001) and prolonged hospitalization (p < 0.001) as compared to the GDMA1 (n = 73) and the OAV group (n = 124). Average placental weight in the GDMA2 group were higher (p = 0.004). There were no between groups differences in the rate of placental MVM or inflammatory lesions. The OAV and GDMA1 groups were characterized by an increased rate of FVM lesions, as compared to the GDMA2 group (p = 0.02).

Discussion: GDMA2 is associated with increased rate of CD and adverse neonatal outcome. The similar rate of placental MVM lesions among the study groups, and the increased rate of FVM lesions observed among the OAV group, implies of impaired placental function among the OAV group as in GDM pregnancies.

Keywords: Gestational diabetes; One abnormal value; Placental pathology; Vascular malperfsion lesions.