RAPIDIRON Trial Follow-up Study: RAPIDIRON-KIDS Study

The RAPIDIRON-KIDS Study has two primary hypotheses: 1. Infants born to RAPIDIRON Trial maternal participants from the intravenous (IV) iron arms will have higher hemoglobin and ferritin levels at birth (determined by cord blood) and at 4 months of age compared to infants born to mothers in the oral arm; and 2. Offspring born to RAPIDIRON Trial participants who received IV iron treatment will have higher developmental quotients (DQs) on the cognitive domain of the Bayley Scales of Infant Development (BSID) at 2 years of age compared to offspring born to RAPIDIRON Trial participants given oral iron treatment. The specific aims of this study are as follows: * To provide evidence that a single-dose of IV iron (either ferric carboxymaltose or iron isomaltoside, also known as ferric derisomaltose) given to pregnant women in the second trimester during the RAPIDIRON Trial will prove more effective for prevention of neonatal and postnatal iron deficiency in the offspring than the oral iron given to pregnant women per the parent trial protocol * To assess if the offspring of women in the parent trial IV iron arms have better neurodevelopmental outcomes compared to the offspring of women treated with oral iron; and * To determine longer-term hematologic effects in previously randomized mothers by obtaining ongoing hematologic indices, documented history of transfusion and hospitalization, and quality of life based on the use of a validated instrument. This study will recruit pregnant mothers currently participating in the RAPIDIRON Trial, who will be approached to give consent for themselves and their offspring for participation in the RAPIDIRON-KIDS Study. Participation in RAPIDIRON-KIDS will involve assessments at birth, 6 weeks, 4 months, 12 months, 24 months, and 36 months of age. In addition to iron status, anthropometry, and questionnaires relating to child feeding and maternal quality of life, the following neurobehavioral tests will be utilized to assess the offspring at various timepoints: Preferential Looking Test, Ages \& Stages Questionnaire 3, Bayley Scales of Infant Development, Behavioral Rating Scale, India Scale for Assessment of Autism, and the Child Behavior Checklist for Ages 1.5-5. Please see the protocol for additional details.