Changes of dendritic cell and natural killer cell on the cord blood with idiopathic fetal growth restriction.

Objective: To investigate the characteristics of dendritic cells (DC) and natural killer cells (NK) in umbilical cord blood of pregnant patients diagnosed with idiopathic fetal growth restriction (IFGR).

Methods: A prospective study cohort of IFGR patients was established who were in the third trimester (28-36 weeks), with a healthy, pregnant woman cohort selected as controls. Umbilical cord blood was collected.

Results: The study included 50 pregnant women in the IFGR group and 50 pregnant women in the healthy, control group. The incidence of SGA in the IFGR group was 52.0%, and the incidence of preterm birth was 18.0%. The incidence of neonatal complications in neonates with live birth in the IFGR group was 12.0%. The birth weight, body length and placental weight of the newborns in the IFGR group were significantly lower than those in the control group (p < .05). Flow cytometry revealed no significant difference in the proportion or maturity of DC in umbilical cord blood between IFGR group and control group (p > .05). The proportion of NK cells in umbilical cord blood of IFGR group was significantly higher than that of normal control group. The proportion of CD56dimCD16+ NK cells was also significantly higher than that of the normal control group (p < .05), but the expression of NK cell surface killing activator receptor NKG2D and inhibitory receptor NKG2A was not statistically significant (p > .05).

Conclusion: The number and proportion of DC cells in cord blood may not be the key factors affecting the outcomes observed during FGR pregnancies. However, we found the proportion of NK cells in cord blood to be significantly increased, as well as the ratio of CD56dimCD16 + NK to CD56highCD16-NK to be imbalanced, which may be one of the pathogenesis of the pathological pregnancy leading to IFGR.