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179: Women with chronic hypertension treated during pregnancy - perinatal outcomes related to graduated 24-hour urinary protein excretion levels measured prior to 20 weeks

      Objective

      To analyze the relationship between perinatal outcomes and stratified 24-hour urine protein excretion determined prior to 20 weeks in women with chronic hypertension (CHTN) treated during pregnancy.

      Study Design

      This retrospective cohort study included pregnant women with CHTN for whom therapy was initiated and who completed urine protein quantification prior to 20 weeks. Management of these women is coordinated within a dedicated high-risk prenatal clinic. 24-hour urine protein excretion levels determined prior to 20 weeks were stratified as follows: <50 mg, 50-100 mg, 101-200 mg, 201-300 mg, 301-500 mg, 501-1000 mg, and >1000 mg. The frequencies of superimposed preeclampsia (SPE), preterm birth (PTB) and small-for-gestational age (SGA) infants <10th percentile were compared for each group according to these graded proteinuria levels.

      Results

      Between January 2002 and December 2014, a total of 514 women met inclusion criteria and selected outcomes are shown in the Figure. The rates of SPE, PTB <34 weeks, PTB <37 weeks, and SGA were all significantly increased as 24-hour protein excretion levels increased (p-value for trend <0.001). The frequency of SGA infants was unrelated to co-existent rates of SPE when compared across strata of proteinuria levels (p=0.30). When outcomes of women with protein excretion levels <300mg/day were analyzed separately, there remained a significant association between increasing proteinuria strata and rates of SPE and PTB (Figure).

      Conclusion

      As the quantity of baseline proteinuria increased in pregnant women with treated CHTN, the frequencies of SPE, PTB, and SGA all significantly increased. This relationship remained significant for SPE and PTB at proteinuria levels heretofore considered to be within normal range (<300 mg/24 hours).
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