Non-Proteinuric Preeclampsia: Prevalence, Factors Associated and End-Organ Dysfunction at Mbarara Regional Referral Hospital in Southwestern Uganda

Abstract

Background: Formerly, preeclampsia was only diagnosed if high blood pressure and proteinuria were present in a gravid woman at or past 20 gestation weeks. Although it is possible to have preeclampsia yet never have proteinuria, the literature on how common and factors associated with non-proteinuric preeclampsia as well as whether the frequency of end-organ dysfunction among women with nonproteinuric differs from those with proteinuric pre-eclampsia is scant. Objectives: To determine the prevalence of, factors associated with non-proteinuric preeclampsia, and compare the frequency of end-organ dysfunction between women with non-proteinuric and proteinuric preeclampsia. Methods: Between November 2019 and May 2020, women with pre-eclampsia were consecutively enrolled in a cross-sectional study at Mbarara Regional Referral Hospital. We interviewed all pregnant women ≥20 gestation weeks presenting with hypertension ≥140/90mmHg and recorded their sociodemographic, medical, and obstetric characteristics. We excluded women with chronic hypertension and pregnancy hypertension. We measured bedside proteinuria on clean-catch urine, complete blood count, and renal function and liver enzyme tests. Pre-eclampsia was defined as hypertension plus any feature of severity including <100,000 platelets/ul, creatinine >1.1g/dl, and liver transaminases ≥ twice upper normal limit with or without proteinuria. We computed the proportion of total participants with nonproteinuric pre-eclampsia at ≤+2 urine dipstick cut-off, determined the factors associated with nonproteinuric preeclampsia using logistic regression; and used Chi-square test to compare the frequency of end-organ dysfunction between non-proteinuric preeclampsia and proteinuric groups. Results: We enrolled 134 of the screened 136 participants. Their mean age was 26.9 (SD±7.1) years and 51.5% were primigravid. The prevalence of non-proteinuric preeclampsia was 24.6% (95% CI: 17.9-32.7). Primigravidity (aOR 2.70 95%CI:1.09-6.72, p=0.032) was the factor independently associated with nonproteinuric pre-eclampsia. There was a non-significant difference in the frequency of end-organ dysfunction in women with non-proteinuric and proteinuric pre-eclampsia, p=0.309. Conclusion: Non-proteinuric preeclampsia is common, especially among primigravidae. End-organ dysfunction occurs similarly in women with non-proteinuric and proteinuric preeclampsia. Obstetrics care providers should emphasize laboratory testing, beyond proteinuria, among all women with hypertensive disorders of pregnancy to optimally diagnose and manage non-proteinuric preeclampsia.

Synopsis Non-proteinuric preeclampsia is common and associated with primigravidity. Since women suffer similar end-organ dysfunction, proteinuria testing alone is insufficient to diagnose their pre-eclampsia syndrome.