This prospective cohort study focuses on the relationship between maternal environmental enteric dysfunction (EED) and maternal aflatoxin B1 exposure and birth outcomes, particularly infant anthropometry and gestational age, in Mukono, Uganda.

The problem of stunting, which has long-term health and economic consequences both at the individual and population level, persists in low and middle income countries (LMICs). It has been recognized that an estimated 20% of stunting begins in-utero. Although poor maternal nutrition during pregnancy is often blamed, it has been hypothesized that maternal EED status and maternal aflatoxin exposure during pregnancy may also play a role. However, to date, there have been no studies which have attempted to show the association between EED in pregnant women and negative birth outcomes. Furthermore, few studies have examined the association between maternal aflatoxin exposure during pregnancy and negative birth outcomes.

In this prospective cohort study, pregnant women were enrolled at their first prenatal visit and birth outcome data was assessed within 48 hours of delivery. EED was measured via lactulose: mannitol (L:M) ratios and serum concentrations of antibodies to the bacterial components flagellin and lipopolysaccharide (LPS). Aflatoxin exposure was assessed by measuring the serum concentration of AFB1-lysine adduct from a blood sample taken at enrollment. Data on covariates were obtained from two surveys, one at enrollment and one three weeks prior to participant's estimated date of delivery.

The specific aims of this study were as follows:

1. To evaluate the relationship between markers of EED in pregnancy and negative birth outcomes, including low birth weight, stunting at birth, small head circumference, and premature delivery.
2. To evaluate the relationship aflatoxin B1 exposure in pregnancy and negative birth outcomes, including low birth weight, stunting at birth, small head circumference, and premature delivery.

Inclusion Criteria:

• Carrying a singleton pregnancy
• 18-45 years old
• Residing within 10 kilometers of Mukono Town

Exclusion Criteria:

• Younger than 18 years old or older than 45 years old
• HIV-positive (verified via routine rapid HIV test conducted at first prenatal visit)
• Severely malnourished (defined as BMI <16.0 kg/m^2)
• Severely anemic (defined as Hb <7 g/dl)
• Planning to move away from Mukono District prior to delivery

All pregnant women aged 18-45 years who visited Mukono Health Center IV in Mukono, Uganda for their first prenatal visit and who qualified for the study based on inclusion/exclusion criteria were invited to join the study until enrollment target was met.