The goal of this observational child follow-up study is to examine the effects of prenatal nutrition and infection management interventions on long-term child neurodevelopment.

Participants are the offspring of mothers in the main study entitled "Enhancing Nutrition and Antenatal Infection Treatment (ENAT)" that was conducted in the rural Amhara region of Ethiopia. In the ENAT pragmatic clinical effectiveness study, 2399 pregnant women were randomized to receive routine prenatal care, a package of enhanced nutrition interventions (balanced energy protein supplement, iodized salt, iron-folic acid and counseling), a package of enhanced infection management interventions (genitourinary tract infection screening-treatment, deworming), or a combination of both packages. The impact of these antenatal nutrition and infection interventions on birth outcomes (infant birth size and gestational length) was examined in the main study. In this longitudinal cohort study, we will follow the offspring from the ENAT pregnancy cohort up to 24 months postnatal age and assess their growth, health and neurodevelopment.

The main questions it aims to answer are:

1. What are the effects of pregnancy interventions from the parent study (ENAT) on offspring neurodevelopmental outcomes?
2. What are the associations between maternal-newborn iron status and inflammation on infant neurodevelopment?
3. What are the associations between maternal iodine status and thyroid function on infant neurodevelopment?

We will follow children of mothers from the parent ENAT study to monitor their growth, health, and neurodevelopment up to 24 months postnatal age.

In low-resource settings, undernutrition and infections during the first 1000 days of life are prevalent, modifiable risk factors that may have lifelong effects on a child's cognitive and psychological development, yet effective interventions addressing prevailing mechanisms are still to be validated. Iron, protein and energy are critical nutrients that support the rapidly developing fetal brain, however, among women of reproductive age in Sub-Saharan Africa, 10% are underweight and 20% have iron deficiency anemia. Pregnancy infections are also common in Africa, where one in three women have a geo-helminthic infection resulting in blood loss, iron deficiency and inflammation. The interaction between iron and inflammation in pregnancy is particularly complex. NICHD has identified the complex relationship between nutrition, inflammation, and neurodevelopment as a major research gap. A barrier to progress is that mechanistic understanding of prenatal brain development is based on animal or observational studies. We present a unique opportunity to leverage an ongoing randomized controlled trial (RCT) to examine the consequences of pregnancy nutrition and inflammation on child neurodevelopment.

The Enhancing Nutrition and Antenatal Infection Treatment (ENAT) RCT enrolled pregnant women in Amhara, Ethiopia to study independent and overlapping effects of prenatal nutrition and infection interventions on birth outcomes. Women were randomized to receive: 1) standard prenatal care, 2) enhanced nutrition package (ENP) (counseling, iron-folic acid [IFA], iodized salt, and balanced energy protein [BEP] supplementation), 3) enhanced infection management package (EIMP) (anti-helminthics, urinary tract infection treatment), or 4) ENP+EIMP. The current follow-up study (Longitudinal Infant Development and Growth; LIDG) will investigate biological pathways by which ENAT interventions, specifically iron, protein-energy, and inflammation, influence child neurodevelopment.

Our overarching hypotheses are that improving prenatal nutrition will improve brain structural and network development, reducing inflammation will improve white matter maturation, and the combination will have synergistic effects on child neuro-cognitive outcomes. This study will follow up to 500 ENAT children to assess neurodevelopment through 24 months of age, including neurobehavior and neural networks.

Inclusion criteria:

• Mothers who have participated in ENAT study who consent to participate in the infant follow up study
• Intention to stay in the study catchment area
• Healthy infants without severe clinical signs or symptoms including headache, vomiting, or dizziness

Exclusion criteria:

• Major congenital anomalies
• Infants with severe morbidity or developmental disorder
• Neonatal encephalopathy
• Plan to move out of study catchment area

The participants of this study will be recruited from 6 rural health centers (serving a ~25,000 population) involved in ENAT study in West Gojjam and South Gondar zones, Amhara, Ethiopia (Lee et al., 2022). In this infant follow-up study, up to 500 selected infants from the parent ENAT study will be followed for 24 months for general health, growth, and development. A subset of these infants (up to 480) whose mothers provided biospecimens or whose mothers had mid-upper arm circumference (MUAC) of <23 cm in the parent study will be recruited for an advanced neurodevelopmental assessment study.