Maternal and perinatal placental dysfunction severity in extremely high values of sFlt1/PlGF ratio: A retrospective observational study.

OBJECTIVE

The soluble fms-like tyrosine kinase-1 (sFlt1)/placental growth factor (PlGF) ratio can rule out pre-eclampsia (PE) when negative, but the precise significance of extremely high values is not well known. This study sought to determine the median interval between obtaining an sFlt1/PlGF ratio ≥ 500 and delivery in order to clarify its prognostic contribution.

METHODS

Between 2014 and 2021, data were collected from singleton ongoing pregnancies with an sFlt1/PlGF ratio ≥ 500 at Nantes University Hospital. Features able to influence the interval between obtaining an sFlt1/PlGF ratio ≥ 500 and delivery were identified, and maternal and perinatal morbidity and mortality were studied.

RESULTS

Among 54 pregnancies, the median interval between obtaining an sFlt1/PlGF ratio ≥ 500 and delivery was 3 days. On multivariate analysis, factors influencing the length of this interval were a diagnosis of PE at the time of ratio collection, and an sFlt1/PlGF ratio ≥ 1000. These rare situations were associated with severe fetal and maternal conditions, delivery at around 28 weeks of gestation, and a perinatal mortality rate of 30 %.

CONCLUSION

An sFlt1/PlGF ratio ≥ 500 reflects an extreme perinatal situation with high risk of imminent delivery, often occurring at a very premature gestation. If these findings are confirmed on a broader scale, this situation could result in fast referral to a level 3 maternity unit to manage those patients at imminent risk of delivery.