AEA RCT Registry

Trial Information

General Information

Title

The Cognitive Link between in Utero Nutrition and Schooling: Experimental Evidence from Tanzania

RCT ID

AEARCTR-0000145

First published

March 10, 2014, 2:46 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Last updated

March 10, 2014, 2:50 AM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Country

Tanzania, United Republic of

Region

Dar es Salaam

Primary Investigator

Name

Plamen Nikolov

Affiliation

State University of New York (Binghamton) & Harvard University

Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status

Completed

Start date

2002-11-15

End date

2013-09-01

Keywords

Education, Health, Welfare

Additional Keywords

tanzania, folic acid, cognition, education, non-cognitive skills, parental investment

JEL code(s)

J24, I25, D13

Secondary IDs

Abstract

Because of the high returns of schooling in developing countries, policy-makers have placed considerable attention to increasing school access. However, an important mechanism through which brain development in utero can affect demand for education exists. Cognitive development in utero, due to maternal deficiency in folic acid, can biologically constrain children’s demand for education. Using a more scientifically credible research designed to detect causal effects than has been used in previous research, we examine how reductions in micronutrient deficiency in utero impact subsequent child schooling attainment in Tanzania. We also examine to what extent parents allocate resources so as to compensate for or to reinforce inequalities across children in cognitive endowments. Capturing the behavioral response to the biological intervention allows us to disentangle the biological effect from the household response to the original randomized intervention. To execute this strategy, we follow up on a randomized control trial with micronutrient supplements offered to HIV-negative pregnant women in Dar es Salaam, Tanzania between 2001-2003. While data collection is still ongoing, very preliminary results show cognitive improvements among children born to mothers in the micronutrient supplementation group from the original RCT.

External Link(s)

Project Blurb

Registration Citation

Citation

Nikolov, Plamen. 2014. "The Cognitive Link between in Utero Nutrition and Schooling: Experimental Evidence from Tanzania." AEA RCT Registry. March 10. https://doi.org/10.1257/rct.145-3.0

Former Citation

Nikolov, Plamen. 2014. "The Cognitive Link between in Utero Nutrition and Schooling: Experimental Evidence from Tanzania." AEA RCT Registry. March 10. https://www.socialscienceregistry.org/trials/145/history/1280

Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)

The double-blind trial, assigning 8468 pregnant women to receive a daily oral dose of either a micronutrient supplement or placebo, examined the effect of nutrient supplementation on low birth weight (<2500g), prematurity, and fetal death. The randomized trial started between 2001-2004 with pregnant women in Dar es Salaam, Tanzania to account for differences in physical health outcomes at birth for children. Pregnant women who attended antenatal clinicsAccording to a DHS 1996 (Bureau of Statistics, 1996), 97% of pregnant women attend antenatal care (ANC), and 70% do so at least four times. in Dar es Salaam, Tanzania, between August 2001 and July 2004 were invited to participate in the trial. Simple random sampling was used. Requirements for eligibility included a negative test for HIV infection, a plan to stay in the city until delivery and for 1 year thereafter, and an estimated gestational age between 6 and 27 weeks according to the date of the last menstrual period. A list was prepared according to a randomization sequence in blocks of 20; at enrollment, each eligible woman was assigned to the next numbered bottle. The treatment tablet included 20 mg of micronutrient B2, 25 mg of micronutrient B6, 50 mg of micronutrient B12, and 0.8 mg of B9 (folic acid).The active tablets and placebo were similar in shape, size, and color and were packaged in identical coded bottles.Average take up rate of treatment in the original RCT was 0.88.

Intervention Start Date

2002-11-15

Intervention End Date

2013-09-01

Primary Outcomes

Primary Outcomes (end points)

health status at birth;
health status within first 6 months;
cognitive outcomes for children for children born to mothers who participated in the RCT between 2001-2004;
non-cognitive outcomes for children for children born to mothers who participated in the RCT between 2001-2004
parental investments after children's birth
educational status for for children born to mothers who participated in the RCT between 2001-2004;
labor market outcomes for families who had a member participating in the RCT between 2001-2004;

Primary Outcomes (explanation)

n/a

Secondary Outcomes

Secondary Outcomes (end points)

Secondary Outcomes (explanation)

Experimental Design

The double-blind trial, assigning 8468 pregnant women to receive a daily oral dose of either a micronutrient supplement or placebo, examined the effect of nutrient supplementation on low birth weight (<2500g), prematurity, and fetal death. The randomized trial started between 2001-2004 with pregnant women in Dar es Salaam, Tanzania to account for differences in physical health outcomes at birth for children. Pregnant women who attended antenatal clinicsAccording to a DHS 1996 (Bureau of Statistics, 1996), 97% of pregnant women attend antenatal care (ANC), and 70% do so at least four times. in Dar es Salaam, Tanzania, between August 2001 and July 2004 were invited to participate in the trial. Simple random sampling was used. Requirements for eligibility included a negative test for HIV infection, a plan to stay in the city until delivery and for 1 year thereafter, and an estimated gestational age between 6 and 27 weeks according to the date of the last menstrual period. A list was prepared according to a randomization sequence in blocks of 20; at enrollment, each eligible woman was assigned to the next numbered bottle. The treatment tablet included 20 mg of micronutrient B2, 25 mg of micronutrient B6, 50 mg of micronutrient B12, and 0.8 mg of B9 (folic acid).The active tablets and placebo were similar in shape, size, and color and were packaged in identical coded bottles.Average take up rate of treatment in the original RCT was 0.88.

Experimental Design Details

Randomization Method

block randomization

Randomization Unit

individual

Was the treatment clustered?

No

Experiment Characteristics

Sample size: planned number of clusters

8468 individuals

Sample size: planned number of observations

8468

Sample size (or number of clusters) by treatment arms

4234 in treatment group; 4234 in control group.

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name

Harvard University CUHS

IRB Approval Date

2011-11-01

IRB Approval Number

F19899-122

Analysis Plan

The Cognitive Link between in Utero Nutrition and Schooling: Experimental Evidence from Tanzania

Pre-Trial

General Information

Locations

Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Registration Citation

Interventions

Primary Outcomes

Secondary Outcomes

Experimental Design

Experiment Characteristics

Institutional Review Boards (IRBs)

Post-Trial

Study Withdrawal

Intervention

Data Publication

Program Files

Relevant Paper(s)

Reports & Other Materials