Multicenter, Open-Label, Randomized Study of Nipocalimab or IVIG in Pregnancies At Risk of Fetal and Neonatal Alloimmune Thrombocytopenia (FNAIT)

Inclusion Criteria: * Pregnant and an estimated gestational age (GA) from week 13\* to 18 at visit 1 \*Randomization for high-risk FNAIT participants to occur at GA Week 12 * Has a history of greater than or equal to (\>=) 1 prior pregnancy with FNAIT based on medical records including: a) neonatal platelet count less than (\<) 150\*10\^9/Liter with no fetal/neonatal intracranial hemorrhage (ICH) or severe fetal/neonatal hemorrhage (standard-risk) OR b) fetus/neonate with ICH or severe hemorrhage in a fetus/neonate (high-risk) * Current pregnancy with presence of maternal anti-HPA-1a and/o…