Early pregnancy glycaemia predicts postpartum diabetes mellitus

Catherine E Callinan; Karilynn Rockhill; Brendan Boe; Kent D Heyborne

doi:10.1016/j.ejogrb.2022.09.022

Early pregnancy glycaemia predicts postpartum diabetes mellitus

Eur J Obstet Gynecol Reprod Biol. 2022 Nov:278:148-152. doi: 10.1016/j.ejogrb.2022.09.022. Epub 2022 Sep 26.

Authors

Catherine E Callinan¹, Karilynn Rockhill², Brendan Boe³, Kent D Heyborne⁴

Affiliations

¹ Denver Health and Hospital Authority, Denver, CO, USA; University of Colorado School of Medicine, Aurora, CO, USA. Electronic address: Catherine.Callinan@cuanschutz.edu.
² Denver Health and Hospital Authority, Denver, CO, USA.
³ Altru Health System, Grand Forks, ND, USA.
⁴ Denver Health and Hospital Authority, Denver, CO, USA; University of Colorado School of Medicine, Aurora, CO, USA.

PMID: 36181752
DOI: 10.1016/j.ejogrb.2022.09.022

Abstract

Objective: To determine the association between early pregnancy glycaemia, as measured by glycosylated haemoglobin A1c (HbA1c) at the first prenatal visit, and persistent postpartum diabetes mellitus (DM).

Study design: All women first diagnosed with DM during pregnancy who had both HbA1c prior to 24 weeks and postpartum DM testing were included. The proportions of women with normal (<5.7%), prediabetic (5.7-6.4%) and elevated (≥6.5%) early HbA1c who tested positive for postpartum DM were compared. Test characteristics of HbA1c to predict persistent postpartum DM were calculated.

Results: One hundred and twenty-one women met the study inclusion criteria. HbA1c was obtained at a median gestational age of 9 weeks. Twenty-two women (18.2%) had persistent postpartum DM, which was highly correlated with early HbA1c: 16 (73%) women had an elevated HbA1c, five (22.7%) women had a prediabetic HbA1c and only one (4.5%) woman had a normal HbA1c. Of 65 women with gestational DM and a normal early HbA1c, only one (1.5%) had persistent DM within the first year (negative predictive value 98.5%). Sixteen of 18 women with an elevated early HbA1c had persistent postpartum DM (positive predictive value 88.9%). These percentages were significant overall and between groups (p < 0.001). No clinical or demographic factors were highly predictive of postpartum DM.

Conclusions: Early pregnancy glycaemia, as measured by HbA1c at the first prenatal visit, is highly predictive of persistent postpartum DM, and may allow clinically important risk stratification to prioritize postpartum testing and care. Postpartum DM is rare amongst women with gestational DM who begin the pregnancy with a normal HbA1c, while postpartum DM is highly likely for those with an elevated HbA1c in early pregnancy. Nearly three-quarters of women who tested positive for DM post partum had an elevated HbA1c in early pregnancy, indicating that they had undiagnosed DM prior to conception.

Keywords: Diabetes mellitus; Gestational diabetes; Glycosylated haemoglobin A1c; HbA1c; Post partum; Pregnancy; Prenatal care.

MeSH terms

Blood Glucose
Diabetes, Gestational* / diagnosis
Female
Glycated Hemoglobin / analysis
Humans
Infant
Postpartum Period
Prediabetic State* / diagnosis
Pregnancy
Pregnancy in Diabetics*
Puerperal Disorders* / diagnosis

Substances

Blood Glucose
Glycated Hemoglobin A