Despite intensive research on the cytokine resistin only few studies investigated mother-newborn-pairs during healthy pregnancy and reported about interactions with clinical obstetric variables or other cytokines. Comparison of existing studies is difficult due to differences between assays, sample collection, gestational age, definition of healthy controls and patient characteristics. Furthermore, differences between rodent models and humans do not allow for a direct comparison. In this cross-sectional, prospective study 109 healthy mother-newborn pairs were analyzed. Maternal venous blood samples were taken on admission to the labor ward; newborn venous blood samples were drawn from the placental part of the umbilical cord (UC), immediately after clamping. Resistin, leptin, adiponectin, TNF-α, IL-6 and brain derived neurotrophic factor (BDNF) serum concentrations were measured with commercially available immunoassays. Determinants of maternal and newborn resistin levels were analyzed using simple and multiple linear regression. UC resistin levels were higher than maternal concentrations (median 17.69 ng/mL, IQR 7.36 vs. median 8.04 ng/mL, IQR 4.30). Correlation between UC and maternal resistin levels was moderate (R = 0.503, p < 0.01). In multiple regression analysis levels of maternal resistin and newborn TNF-α remained significant determining factors for UC resistin levels. Gestational age and maternal BDNF-levels remained significant factors for maternal resistin levels. In healthy, term newborns and their respective mothers a positive correlation between maternal and newborn levels and an association with gestational age around term can be found and point to a placental source of resistin. Further investigations are needed to clarify the possible contribution of transplacental transport of resistin into the fetal circulation. Except for gestational age most of the clinical obstetric variables tested do not seem to be determining factors for fetal or maternal resistin. Interactions of resistin with other cytokines like TNF-α and BDNF could be the missing link for the conflicting results in literature.

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). 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. 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). 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.

The Objective of our study was to investigate the influence of dietary (dGDM) and insulin-dependent (iGDM) gestational diabetes (GDM) on BDNF blood levels of corresponding maternal-neonatal pairs and compare them to pregnancies unaffected by GDM. Blood samples from 293 maternal-neonatal pairs were analyzed. Statistical analysis was performed using multiple regression analysis for association of log-transformed maternal and neonatal BDNF levels in relation to GDM, gestational age, neonatal sex, and mode of delivery. This was followed by a 2:1 matching of healthy and diabetic pairs. Maternal and neonatal BDNF levels were lowest in the iGDM group, followed by the dGDM group and healthy controls (maternal: healthy 665 ± 562 (26–2343) pg/mL vs. dGDM 593 ± 446 (25–1522) pg/mL vs. iGDM 541 ± 446 (68–2184) pg/mL; neonate: healthy 541 ± 464 (9.5–2802) pg/mL vs. dGDM 375 ± 342 (1–1491) pg/mL vs. iGDM 330 ± 326 (47–1384) pg/mL). After multiple regression analysis and additional 2:1 matching neonatal log-BDNF was significantly lower (−152.05 pg/mL, p = 0.027) in neonates of mothers with GDM compared to healthy pairs; maternal log-BDNF was also lower (−79.6 pg/mL), but did not reach significance. Our study is the first to analyze BDNF in matched maternal-neonatal pairs of GDM patients compared to a metabolically unaffected control group.

Cytokines are reported to be associated with various pregnancy complications and health outcomes of the offspring. However, reference values during pregnancy have not been established, effects of c...