Transplacental Transport Rates of Anti-Pertussis Toxin–IgG and Anti-Filamentous Hemagglutinin–IgG Antibodies in Newborns by Week of Birth

The aim of this study is to investigate the lack of knowledge about the transplacental transport of antibodies in unvaccinated term and preterm infants and possible differences in antibody-mediated immunity in the fetus depending on maternal vaccination in their own infancy.The study was conducted as a prospective cross-sectional study between 2017 and 2018 and included a total of 334 participants. The study included 194 pregnant women with a preterm birth (before 37 weeks) and 140 pregnant women with a term birth. Both umbilical cord blood and maternal blood were used to measure serum levels of anti-pertussis toxin (PT) immunoglobulin (Ig) G and anti-filamentous hemagglutinin (FHA) IgG.The results showed that anti-FHA IgG antibody levels in the cord blood of women who had delivered at term were significantly higher than those of preterm infants (<i>p</i> = 0.002). The placental transfer rate of anti-PT IgG was higher in women who delivered prematurely, but this difference was not statistically significant (<i>p</i> = 0.128). However, transfer rates for anti-FHA were significantly higher in women who had delivered prematurely (<i>p</i> = 0.001). In addition, transmission rates for both antibodies were found to be significantly lower in women who delivered before 32 weeks gestation than in women who delivered at term (<i>p</i> = 0.006, <i>p</i> < 0.001). Antibody transfer rates were found to be positively correlated with both gestational age and birth weight.In summary, although placental antibody transfer rates increased with gestational age, transfer rates and antibody levels were low in pregnant women, particularly in women who had given birth before 32 weeks gestation. · Transport. · Anti-PT IgG. · Anti-FHA IgG antibodies.