High maternal BMI and low maternal blood BDNF may determine the limit of detection of amniotic fluid BDNF throughout gestation: Analysis of mother-fetus trios and literature review

Abstract

Objective An increasing number of studies show the importance of brain-derived neurotrophic factor (BDNF) acting at the feto-placental interface, however, only a few studies describe BDNF levels in amniotic fluid (AF). Methods In this cross-sectional, prospective study, 109 maternal blood-amniotic fluid pairs (including 66 maternal blood-fetal-blood-amniotic fluid trios) were analyzed. BDNF concentrations were measured with a commercially available immunoassay. Results In 71 AF from 109 samples, AF-BDNF concentrations were below the lowest limit of Quantitation (LLoQ) of 1.19 pg/ml (group A), leaving 38 samples with measurable BDNF concentrations (group B). Patients in group A showed significantly higher maternal BMI before pregnancy (mean±SD 26.3± 6.7 (kg/m2) vs. 23.8 ±4.5 (kg/m2) p = 0.04) and lower maternal blood BDNF concentrations than the other group (mean±SD 510.6 ± 554.7 pg/ml vs. mean±SD 910.1± 690.1 pg/ml; p<0.0001). Spearman correlation showed a negative correlation between maternal BMI before pregnancy and maternal BDNF concentrations (r = -0.25, p = 0.01). Conclusion Our study is the first to correlate AF-BDNF samples with the corresponding maternal and fetal blood-BDNF samples. The significant negative correlation between maternal BMI before pregnancy and maternal BDNF and AF-BDNF concentrations below the limit of detection has to be evaluated in further studies.

Correlating maternal and cord-blood inflammatory markers and BDNF with human fetal brain activity recorded by magnetoencephalography: An exploratory study

“…Furthermore, all three band ratios involving the delta band have moderate positive correlations with maternal BDNF. Our findings also point to the fact that the fetal development may be assisted by the maternal BDNF that reaches the fetal brain through the utero-placental barrier ( Antonakopoulos et al, 2018 ; Flöck et al, 2016 , 2022 ; Kodomari et al, 2009 ), since cord-blood BDNF levels have mainly negligible correlations with RP in the four bands. BDNF plays a crucial role in the modulation of neurogenesis and maturation of neural pathways during neurodevelopment ( Su et al, 2021 ).…”

“…This could be because neurotrophins are transported from the mother into various compartments of the fetal environment such as the amniotic fluid and the placenta ( Cai et al, 2017 ; Flöck et al, 2016 ; Mayeur et al, 2011 ). In a recent study, Flöck et al, (2022) reported that amniotic-fluid BDNF levels have a maternal or placental source ( Flöck et al, 2022 ). Furthermore, they reported that cord-blood BDNF reflects mainly its synthesis by the fetus ( Flöck et al, 2022 ).…”

“…In a recent study, Flöck et al, (2022) reported that amniotic-fluid BDNF levels have a maternal or placental source ( Flöck et al, 2022 ). Furthermore, they reported that cord-blood BDNF reflects mainly its synthesis by the fetus ( Flöck et al, 2022 ). Cord-blood BDNF has been reported to increase with gestational age ( Cai et al, 2017 ; Chouthai et al, 2003 ; Flöck et al, 2016 ; Mayeur et al, 2011 ; Spulber et al, 2010 ).…”

Association of amniotic fluid Neurotrophins levels with intrauterine growth restriction

“…16 Even the evaluation of amniotic fluid levels of neurotrophins is not, however, entirely free of bias as Flock et al reported that high maternal BMI and low maternal blood BDNF may differentiate the limit of detection of amniotic fluid BDNF throughout gestation. 17 Possibly the best way to observe potential differences among growth restricted and AGA fetuses is to review cord blood levels of neurotrophins. To date, this has been investigated only in term pregnancies by Briana et al in pregnancies complicated by gestational diabetes mellitus with the authors mentioning the absence of a specific correlation with fetal growth percentiles.…”