Placental expression of angiogenic factors in Trisomy 13

Increased levels of soluble fms-like tyrosine kinase (sFlt-1) in Trisomy 13 pregnancies are thought to be mediated by the placenta. This study aimed to compare sFlt-1 expression in Trisomy 13 (n = 7) placentas with that in control placentas (Trisomy 21, n = 11, and euploid, n = 6).

This was a retrospective case-control study analyzing paraffin-embedded placental blocks that were stained with hematoxylin and eosin and antibodies to sFlt-1. Their staining intensity was compared using a semiquantitative technique. The Kruskal-Wallis test and Wilcox rank sum test were used for statistical analysis.

The median staining was significantly higher in Trisomy 13 compared with control specimens (P = .008) (for Trisomy 13 vs Trisomy 21, P = .003, and Trisomy 13 vs euploid, P = .004).

Our study demonstrates that Trisomy 13 placentas express more sFlt-1 than control placentas. These results strengthen the hypothesis that the increased incidence of preeclampsia in Trisomy 13 pregnancies is secondary to placental up-regulation of sFlt-1.