What's with the boys? Lower birth weight in boys from HPA-1a alloimmunized pregnancies - New insights from a large prospective screening study in Poland.

Abstract

Fetomaternal incompatibility in human platelet antigens (HPAs) can cause maternal alloimmunization, which in turn may lead to thrombocytopenia with or without intracranial hemorrhage (ICH) in the fetus or newborn. Retrospective studies suggest that boys from alloimmunized mothers may have higher risk of ICH and lower birth weight than girls. The objective of this study was to assess how maternal HPA-1a alloimmunization, sex of the neonate and birth weight relates in a large prospective cohort. Through a national screening study in Poland (PREVFNAIT) involving HPA-1 typing of 24,259 pregnant women during 2013-2017, 606 HPA-1a negative pregnant women and their offspring were identified and included. Various multivariate models were used to assess if and how maternal HPA-1a alloimmunization status was associated with birth weight and risk of having a small for gestational age (SGA) neonate, and if and how sex of the neonate mattered. Most immunized pregnancies had male fetuses (69 %). Women carrying a male fetus had increased likelihood of having an SGA newborn if they were HPA-1a alloimmunized compared to non-immunized mothers. Increasing maternal anti-HPA-1a antibody levels were significantly associated with reduced birth weight and SGA risk among male-fetus pregnancies, but not if the fetus was female. In conclusion, anti-HPA-1a antibodies in a male fetus pregnancy is associated with increased risk of SGA and lower birth weight, especially if the antibody level is high. Sex of the fetus may therefore be considered as a new clinical predictor of more severe FNAIT neonatal outcome.

• Authors: Tina Coucheron, Malgorzata Uhrynowska, Katarzyna Guz, Agnieszka Orzińska, Marzena Debska, Agnieszka Gierszon, Maria Therese Ahlen, Eirin Listau Bertelsen, Gerd Berge, Anne Husebekk, Ewa Brojer, Heidi Tiller
• Journal: Journal of reproductive immunology (J Reprod Immunol) Vol. 160 Pg. 104168 (Dec 2023) ISSN: 1872-7603 [Electronic] Ireland
• PMID: 37992463 (Publication Type: Journal Article)
• Copyright: Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.