957: Congenital malformation risk according to hemoglobin A1c values in a contemporary cohort with pregestational diabetes

Abstract

To evaluate the association between hemoglobin (hgb) A1c values and likelihood of fetal abnormalities in women with pregestational diabetes. All women with pregestational diabetes who delivered at our institution from May 1, 2009 through December 31, 2018 were ascertained. Hemoglobin A1c values were obtained at the first prenatal visit. Women who delivered a singleton live- or stillborn infant with a major malformation as defined by EUROCAT criteria were identified, excluding infants with confirmed chromosomal abnormalities. In infants with multiple system anomalies, each malformation was considered separately. Hgb A1c values were analyzed categorically using Mantel-Haenszel and continuously with linear regression for trend. A total of 1676 pregnancies in 1403 women with pregestational diabetes delivered at our institution, and in 1574 an hgb A1c was obtained at time of presentation. There were 129 pregnancies in 128 women who delivered an infant with at least one major malformation, an overall anomaly rate of approximately 8%. Twenty-four infants had multiple organ system anomalies. Mean hgb A1c was significantly higher in pregnancies with anomalous infants, 9.3 ± 2.1% versus 8.0 ± 2.1%, p< .001. There was no difference in gestational age at the time hgb A1c was obtained, 13 ± 8.3 versus 14 ± 8.7 weeks. Table 1 presents rates of fetal organ system anomalies according to maternal hgb A1c values. All organ system anomalies were significantly associated with hgb A1c Hemoglobin A1c (p< .05) with the exception of fetal gastrointestinal and pulmonary anomalies, which were also the least prevalent. Figure 1 shows probability of an anomaly with increasing hemoglobin A1c values. In women with pregestational diabetes, hgb A1c is strongly associated with fetal anomaly risk. Data from a contemporary cohort may facilitate counseling.View Large Image Figure ViewerDownload Hi-res image Download (PPT)