Perinatal outcomes in patients with preeclampsia and elevated sFlt-1/PlGF before term. A retrospective cohort study.

Objective: To determine the usefulness of different thresholds of the sFlt-1/PlGF ratio in predicting maternal and perinatal complications in preterm pregnancies with suspected preeclampsia.

Material and methods: This was a retrospective cohort study that analyzed 188 preterm preeclampsia patients with a sFlt-1/PlGF ratio >110 based on last value before delivery: 110-205 (controls), ≥206, ≥655, ≥1000 (cases). Perinatal outcomes were compared between controls and cases.

Results: An sFlt-1/PlGF ratio ≥206 was associated with higher risk of intrauterine growth restriction (14.3 % vs 36.4 %, p = 0.003), severe preeclampsia (66.1 % vs 84.8 %, p = 0.003), thrombocytopenia (3.6 % vs 15.2 %, p = 0.03), 5-minute Apgar ≤6 (0 % vs 10.6 %, p = 0.01) and lower gestational age at birth (33.7 vs 30.9 weeks, p < 0.00001). An sFlt-1/PlGF ratio ≥655 was associated with all the above plus proteinuria (1.3 vs 4.5 g/24 h, p = 0.0001), HELLP (1.8 % vs 17.3 %, p = 0.005) and 1-minute Apgar ≤6 (10.7 % vs 26.9 %, p = 0.03). An sFlt-1/PlGF ratio ≥1000 was associated with all the above plus liver enzyme abnormalities (8.9 % vs 25.6 %, p = 0.03) and stillbirths (0 % vs 10.3 %, p = 0.02).

Conclusion: In cases of preterm preeclampsia, an elevated sFlt-1/PlGF ratio is linked to increased maternal and perinatal complications. Ratios of ≥206 signal this heightened risk, while those of ≥1000 are additionally associated with a greater risk of stillbirth. These ratios could help in making better clinical decisions, regarding timing of delivery, weighing the risks of gestational age against the potential adverse events suggested by their values.