434: Impact of hypertension on white’s classification of pregestational diabetes mellitus in pregnancy


      White’s classification (WC) was developed in 1949 based on a cohort of type 1 diabetics (DM) to estimate the risk of perinatal wastage. Based largely on the age of or time since diagnosis, the 1980 update to WC used the presence of chronic hypertension (HTN) to reclassify women as D—a recommendation that has largely fallen out of practice. Our aims were to assess the impact of HTN within each WC on perinatal outcomes.

      Study Design

      Retrospective cohort of all singletons with preexisting DM 2008-2013. Subjects were excluded for late care, fetal anomalies, and major maternal comorbidities unrelated to DM. Subjects were classified by age at diagnosis and years of DM according to WC; subjects in classes B and C were then stratified by the presence or absence of HTN. Maternal outcomes examined were preeclampsia and cesarean delivery (CD). Neonatal outcomes were macrosomia (>4000g), large for gestational age (LGA, >90th percentile), small for gestational age (SGA, <10th percentile), shoulder dystocia (SD), preterm delivery <34 weeks (PTD), and a composite neonatal outcome (stillbirth, neonatal death, SD, birth injury, seizures, CPR at delivery, intubation, pressors). Groups were compared using analysis of variance or χ2 test, as appropriate.


      Of 475 subjects, 128 (27%) were B, 86 (18%) C, 208 (44%) D, and 53 (11%) >D (R/F/RF/H). WC based on age of or time since diagnosis alone is significantly associated with all outcomes examined except for CD and SD (Table). Within each WC, HTN was significantly associated with a higher incidence of preeclampsia, SGA, PTD, and the composite neonatal outcome (Figure). The prevalence of adverse outcomes in class B and C with HTN resembles the prevalence of adverse outcomes in those with DM one class higher based on age and duration alone.


      The presence of HTN has a significant impact on perinatal outcomes within each WC. If the WC is used to counsel patients regarding pregnancy risks in DM, women with HTN should be upstaged one class and counseled accordingly.
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      Figure 1. A Comparison of Select Adverse Outcomes across the White Class and Presence/Absence of Chronic Hypertension
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      Table 1 Baseline maternal & pregnancy characteristics by white’s classification (based on age & years since diagnosis and end-organ damage)
      *chi-squared test for trend
      Data presented as n (%)
      B: Age at diagnosis >20 years and time since diagnosis <10 years
      C: Age at diagnosis 10-19 years, time since diagnosis 10-19 years
      D: Age at diagnosis <10 years, time since diagnosis >20 years
      F, R, RF, H: Presence of nephropathy, proliferative retinopathy, or heart disease