The sFlt-1/PlGF ratio as a predictor for poor pregnancy and neonatal outcomes.

Background: Soluble fms-like tyrosine kinase receptor-1 (sFlt-1)/placental growth factor (PlGF) ratio has been studied extensively as a predictive marker for pre-eclampsia. However, its usefulness for predicting neonatal outcomes remains unknown. This study aimed to evaluate the association of sFlt-1/PlGF ratio with pregnancy outcomes, neonatal morbidities and short-term postnatal growth patterns in pregnant women and their babies.

Methods: sFlt-1 and PlGF were measured in women with fetal intrauterine growth retardation (IUGR) or pre-eclampsia during gestational age (GA) of 16-36 weeks. These women were classified into high- and low-ratio groups with a sFlt-1/PlGF cut-off ratio of 85. The maternal and neonatal outcomes were retrospectively reviewed and compared between the two groups.

Results: A total of 25 pregnant women were recruited. Thirteen of them had a sFlt-1/PlGF ratio over 85 and twelve had a ratio of less than 85. The median duration from elevation of sFlt-1/PlGF to delivery was 4.5 weeks. Women in the high SFlt-1/PlGF ratio group had higher rates of intrauterine fetal demise (2/13 vs. 0/12) and early termination (1/13 vs. 0/12). The surviving offspring in this group had a higher incidence of preterm birth (GA: 31.4 ± 2.9 weeks vs. 37.3 ± 1.3 weeks, p < 0.001), lower birth weight (1142 ± 472 g vs. 2311 ± 236 g, p < 0.001), higher incidence of respiratory distress syndrome (6/10 vs. 0/12, p = 0.002) and bronchopulmonary dysplasia (4/10 vs. 0/12, p = 0.01). However, the percentile of body weight, height and head circumference at 28 days of age, 56 days of age and the corrected age of 6 months were comparable between groups.

Conclusions: High sFlt-1/PlGF ratio in pregnant women is associated with poor pregnancy and neonatal outcomes. Therefore, the monitoring of sFlt-1/PlGF ratio in pregnant women with fetal IUGR and timely management for placenta-associated diseases are recommended.