The goal of this trial is to learn if replacing household soil floors with concrete floors can prevent deaths of infants around the time of birth, including stillbirths and deaths in the first month of life in rural Bangladesh. The primary question the study aims to answer is: Does residing in a home with a concrete vs. soil floor reduce the perinatal and neonatal morality in index children and their younger siblings up to 6 years post-installation of concrete floors?

Researchers will compare participants in households with concrete floors (intervention) vs. soil floors (comparison group) to see if concrete floors reduce the rate of perinatal death and child death up the 6 years post-intervention.

This study will extend an ongoing NIH-funded randomized trial in which households with soil floors where a pregnant woman resided were randomly chosen to receive a concrete floor intervention or to retain their existing soil floor. This study will track pregnancies, births, and deaths among infants born to pregnant mothers in the original study to measure effects of household concrete flooring up to 6 years after the concrete floors were installed.

This study extends follow-up of an interventional, randomized controlled trial that enrolled 800 households in rural Bangladesh with soil floors where a pregnant woman resided and randomized them 1:1 to receive a concrete floor or keep their existing soil floor (Cement flooRs AnD chiLd hEalth (CRADLE), NCT05372068). The original trial installed concrete floors in the intervention arm during their pregnancy and will measure the primary endpoint when children born to enrolled pregnant women (i.e., index children) reach age 2 years. This study extends follow-up to up to 6 years after concrete floors were installed to measure perinatal and child mortality among all children born to CRADLE-enrolled mothers during the study period, including index children and children born in subsequent pregnancies. For subsequent pregnancies occurring during the study period, research staff will visit study homes in the perinatal period to ascertain birth outcomes and child deaths. For index children previously enrolled in the CRADLE trial, research staff will ascertain child deaths by phone once per year. For each death identified during the study period, research staff will perform verbal and social autopsy, and cause of death will be classified using the International Classification of Diseases, 11th Revision (ICD-11).

Inclusion Criteria:

• Prior enrollment in the CRADLE trial (NCT05372068), in either arm, and currently residing in the original CRADLE-enrolled household
• Residence in Sirajganj or Tangail districts in Bangladesh
• No major non-compliance (e.g., no removal of concrete floor in intervention arm or installation of concrete floor in control arm)
• No plan to relocate within the study follow-up period
• Incident pregnancy occurring after CRADLE trial enrollment, confirmed after 26 weeks gestation

All human subjects data will be de-identified and published. Identifiers that will be removed include participant names, address, date of birth, and geocoordinates. All data will be made available at the individual level (outcomes, covariates) or household level (in the case of the household survey variables, i.e. wealth).

De-identified data will be made publicly available within 2 years of the end of the study or at the time of publication, whichever is sooner.

To be determined