Proteinuria and Hypertensive Disorders in Pregnancy

Hypertensive disorders in pregnancy encompass a spectrum of conditions characterised by elevated blood pressure arising after 20 weeks’ gestation. Among these, pre-eclampsia is distinguished by the new onset of hypertension accompanied by proteinuria or other organ dysfunction. Proteinuria reflects glomerular endothelial injury and increased permeability of the renal filtration barrier. Its severity correlates with maternal complications such as eclampsia, renal impairment and haemostatic disturbances, as well as with foetal risks including growth restriction, preterm birth and perinatal mortality. Beyond diagnostic criteria, quantification methods range from simple dipstick screening to 24-hour urine collection and spot urinary protein-creatinine ratio assays. Pathophysiological mechanisms involve placental hypoperfusion, oxidative stress and systemic endothelial activation. Globally, hypertensive disorders affect up to 10 per cent of pregnancies, posing a leading cause of maternal and neonatal morbidity, particularly in low-resource settings. Early recognition of proteinuria, coupled with blood pressure control and timely delivery, remains central to improving perinatal outcomes.

Research from Nature Portfolio

Recent work on the relationship between proteinuria and ocular changes in pre-eclampsia has revealed a significant association between the antepartum protein-creatinine ratio and alterations in choroidal thickness. Patients with higher proteinuria exhibited increased choroidal thickness before delivery and a more pronounced postpartum reduction, suggesting systemic microvascular effects extend to the retinal circulation. This finding underscores the utility of ophthalmic assessment as a non-invasive window into endothelial health.

Another study has identified the timing of proteinuria or hypertension onset as a predictor of progression from isolated gestational proteinuria or hypertension to full-blown pre-eclampsia. Earlier onset of either sign, particularly before 34 weeks’ gestation, conferred a markedly increased risk of developing additional pre-eclampsia features within days. These insights highlight the prognostic value of early surveillance and may inform individualised monitoring protocols.

Proteinuria and Hypertensive Disorders in Pregnancy publication trend

The graph below shows the total number of articles in proteinuria and hypertensive disorders in pregnancy across all publications each year (not limited to Nature Index journals).

Technical terms

Proteinuria: Excess protein in urine, indicating glomerular filtration barrier disruption.

Pre-eclampsia: Pregnancy-specific syndrome defined by hypertension after 20 weeks’ gestation plus proteinuria or organ dysfunction.

Spot protein-creatinine ratio: A single urine sample measurement comparing protein and creatinine concentrations to estimate daily protein excretion.

Dipstick test: Semi-quantitative screening method using reagent-impregnated strips to detect urinary protein.

Choroidal thickness: Measurement of the vascular layer beneath the retina, indicative of systemic microvascular changes.

References

1. Association Between Maternal Smoking, Isolated Proteinuria During Pregnancy and Preterm Birth: A Finnish Registry Analysis. Kidney International Reports (2024).
2. Relationship between proteinuria and changes in antepartum and postpartum choroidal thickness in patients with pre-eclampsia. Scientific Reports (2024).
3. Earlier onset of proteinuria or hypertension is a predictor of progression from gestational hypertension or gestational proteinuria to preeclampsia. Scientific Reports (2021).
4. Association of Proteinuria Threshold in Pre-Eclampsia with Maternal and Perinatal Outcomes: A Nested Case Control Cohort of High Risk Women. PLOS ONE (2013).
5. Protein-creatinine ratio and albumin-creatinine ratio for the diagnosis of significant proteinuria in pregnant women with hypertension: Systematic review and meta-analysis of diagnostic test accuracy. Pregnancy Hypertension (2021).