The serum brain-derived neurotrophic factor concentration prior to initiation of an in vitro fertilization cycle predicts outcome

•Sera obtained before cycle initiation from IVF patients who did not become pregnant, had a transient implantation, an ectopic pregnancy or a term delivery were evaluated.•Brain-derived neurotrophic factor (BDNF) concentrations were highest in women with a subsequent ectopic pregnancy, intermediate in women who did not become pregnant and lowest in women with at least a transient intrauterine implantation.•An elevated BDNF level predicted ectopic pregnancy with high sensitivity and specificity.

Our objective was to determine if the concentration of circulating brain-derived neurotrophic factor (BDNF) prior to cycle initiation predicts outcome in women undergoing in vitro fertilization (IVF). Stored serum samples from 226 women − 54 with a live birth, 45 with a spontaneous abortion, 38 with a biochemical pregnancy, 54 who did not become pregnant and 35 with an ectopic pregnancy- were retrospectively blindly tested for BDNF by ELISA. The median serum concentration of BDNF was highest in women with an extrauterine ectopic pregnancy (7.3 ng/ml), intermediate in women whose embryos did not implant (5.5 ng/ml) and lowest in women with a spontaneous abortion (4.2 ng/ml), biochemical pregnancy (3.8 ng/ml) or a live birth (3.6 ng/ml) (P < 0.0001). Among women with a positive pregnancy test an elevated BDNF level predicted an ectopic pregnancy with a sensitivity of 0.853 (0.689, 0.950) and a specificity of 0.949 (0.897, 0.979). We conclude that elevated BDNF in serum obtained before IVF cycle initiation is predictive of an extrauterine pregnancy.