Brain-derived neurotrophic factor (BDNF) plays crucial roles in brain function. Numerous studies report alterations in BDNF levels in human serum in various neurological conditions, including mood disorders such as depression. However, little is known about BDNF levels in the blood during pregnancy. We asked whether maternal depression and/or anxiety during pregnancy were associated with altered serum BDNF levels in mothers (n = 251) and their new-born infants (n = 212). As prenatal exposure to maternal mood disorders significantly increases the risk of neurological conditions in later life, we also examined the possibility of placental BDNF transfer by developing a new mouse model. We found no association between maternal symptoms of depression and either maternal or infant cord blood serum BDNF. However, maternal symptoms of anxiety correlated with significantly raised maternal serum BDNF exclusively in mothers of boys (r = 0.281; P = 0.005; n = 99). Serum BDNF was significantly lower in male infants than female infants but neither correlated with maternal anxiety symptoms. Consistent with this observation, we found no evidence for BDNF transfer across the placenta. We conclude that the placenta protects the developing fetus from maternal changes in serum BDNF that could otherwise have adverse consequences for fetal development.

脑源性神经营养因子 (BDNF) 在大脑功能中起着至关重要的作用。许多研究报告了各种神经系统疾病（包括抑郁症等情绪障碍）中人血清中 BDNF 水平的变化。然而，人们对怀孕期间血液中的 BDNF 水平知之甚少。我们询问母亲怀孕期间的抑郁和/或焦虑是否与母亲 ( n  = 251) 及其新生儿 ( n = 212）。由于产前暴露于母体情绪障碍会显着增加晚年出现神经系统疾病的风险，我们还通过开发一种新的小鼠模型检查了胎盘 BDNF 转移的可能性。我们发现抑郁症的母亲症状与母亲或婴儿脐带血 BDNF 之间没有关联。然而，母亲的焦虑症状与显着升高的母体血清 BDNF 仅在男孩的母亲中相关（r  = 0.281；P  = 0.005；n = 99). 男婴的血清 BDNF 显着低于女婴，但两者均与母亲的焦虑症状无关。与这一观察结果一致，我们没有发现 BDNF 跨胎盘转移的证据。我们得出结论，胎盘保护发育中的胎儿免受母体血清 BDNF 变化的影响，否则可能对胎儿发育产生不利影响。