Purpose: We recently demonstrated the efficacy of tadalafil treatment for fetal growth restriction (FGR). This study aimed to evaluate the utility of serum placental growth factor (PlGF) level for predicting the efficacy of tadalafil for the treatment of FGR. Materials and methods: The correlations between serum level of PlGF and fetal growth velocity were retrospectively assessed in nine pregnant women receiving tadalafil for FGR before 30 weeks' gestation. Results: Median gestational age was 26 weeks (range 26-28 weeks), and median deviation of estimated fetal weight from standard weight was -2.1 standard deviations (SD) (-2.2 to -1.9 SD) at the beginning of tadalafil treatment. The median serum PlGF level was 227 pg/ml (40.2-427.0 pg/ml) before tadalafil treatment and 278 pg/ml (66.2-729.5 pg/ml) more than 2 weeks after initiation of tadalafil treatment (median gestational week at measurement of PlGF after treatment, 33 weeks [28-33 weeks]). The median fetal growth velocity from enrollment to birth was 17.5 g/day (12.1-20.3 g/day). Maternal serum PlGF levels were increased after tadalafil treatment in all nine cases (median increase in PlGF, 73.1 pg/ml [26.0-281.5 pg/ml]). Notably, maternal serum PlGF level before tadalafil treatment significantly correlated with fetal growth velocity (R2 = 0.63, p < .01). Conclusions: Tadalafil treatment may increase maternal serum PlGF levels. Our results suggest that maternal serum PlGF levels can be used as a predictor of the efficacy of tadalafil treatment for FGR.
Keywords: Fetal growth restriction; fetal therapy; phosphodiesterase five inhibitor; placental growth factor; tadalafil.