RAPIDIRON Trial Follow-up Study: RAPIDIRON-KIDS Study

As a follow-up to the RAPIDIRON Trial (NCT05358509), this study will follow the previously randomized mothers as well as their offspring after birth to assess neurodevelopmental, hematologic, and health outcomes. The study's overarching goal is to determine if the offspring born to RAPIDIRON Trial mothers in the intravenous iron groups, compared to the oral iron group, will achieve superior neurodevelopment, iron stores, and growth at specific time points during the first three years of life. Differences will be assessed between offspring based on the iron deficiency anemia (IDA) treatment of the mother.

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.

Eligibility Criteria:
Inclusion Criteria:

* Informed consent of the RAPIDIRON Trial participant for their study inclusion and that of their offspring for the RAPIDIRON-KIDS Study
* Expressed intent of the RAPIDIRON Trial participant to remain in the designated Karnataka research are for delivery and during the follow-up period for the RAPIDIRON-KIDS Study to enable participation in study visits
* For the offspring - live-born singleton infants of Karnataka maternal participants randomized and treated in the RAPIDIRON Trial, if consent is provided by the mother

Exclusion Criteria:

* Unwillingness of maternal participant to provide RAPIDIRON-KIDS Study consent for herself and her offspring