Association between hypoproteinaemia with massive proteinuria and small for gestational age in pre-eclampsia: a single-centre, retrospective cohort study using propensity score matching

OBJECTIVE: To investigate the association between hypoproteinaemia with massive proteinuria and the incidence of small for gestational age in pre-eclampsia. DESIGN: Retrospective cohort study using propensity score matching. SETTING: Northwest Women’s and Children’s Hospital in Shaanxi Province, China, using data from January 2016 to December 2021. PARTICIPANTS: Patients diagnosed with pre-eclampsia were grouped into the massive proteinuria group if the maximum proteinuria was >3.5 g/day and the minimum serum albumin was <30 g/L; otherwise, they were placed in the control group. OUTCOME MEASURES: The primary outcome was the incidence of small for gestational age infants. Secondary outcomes included fetal death, admission to the neonatal intensive care unit, a 5 min APGAR score <7, severe small for gestational age, fetal growth restriction, birth weight, premature birth, and maternal outcomes such as eclampsia, encephalopathy, placental abruption, haemolysis, elevated liver enzymes and low platelet syndrome, heart failure and retinal detachment. RESULTS: In total, 468 patients (234 from each group) were included, and the groups were well matched. The incidences of small for gestational age (33.76% vs 20.51%, OR 1.646, 95% CI 1.208 to 2.243, p=0.001), severe small for gestational age (14.70% vs 7.69%, OR 1.833, 95% CI 1.063 to 3.162, p=0.026), fetal growth restriction (23.93% vs 16.24%, OR 1.474, 95% CI 1.018 to 2.133, p=0.038), and the numbers of infants admitted to the neonatal intensive care unit (67.52% vs 58.55%, OR 1.153, 95% CI 1.003 to 1.326, p=0.044) were significantly higher in patients with hypoproteinaemia and massive proteinuria than in the control group. In addition, the median birth weight was significantly lower in the massive proteinuria group. There were no significant differences in maternal outcomes except for renal parameters, which were worse in the massive proteinuria group. CONCLUSION: Hypoproteinaemia with massive proteinuria was associated with fetal growth and a higher incidence of small for gestational age infants in pre-eclampsia.