Background
Birthweight and gestational age are important factors of not only newborn health by also child development and can contribute to delayed cognitive abilities. However, no study has analyzed the association of birthweight and gestational age with school trajectory measured simultaneously by school entry, grade repetition, and school dropout. This study aims, first, to analyze the association of birthweight or gestational age with school entry, and second, to explore the relationship between birthweight or gestational age and grade repetition and school dropout among children in Ouagadougou, Burkina Faso.

Methods
This study used longitudinal data from the Ouagadougou Health and Demographic Surveillance System. Our samples consisted of children born between 2008 and 2014 who were at least three years old at the beginning of the 2017–18 school year. Samples included 13,676, 3152, and 3498 children for the analysis of the school entry, grade repetition, and dropout, respectively. A discrete-time survival model was used to examine the relationship between birthweight or gestational age and school entry, grade repetition, and dropout. The association between birthweight or gestational age and age at school entry were assessed using a Poisson regression.

Results
The incidence rate of school entry was 18.1 per 100 people-years. The incidence of first repetition and dropout were 12.6 and 5.9, respectively. The probability of school entry decreased by 31% (HR:0.69, 95%CI: 0.56–0.85) and 8% (HR:0.92, 95%CI: 0.85–0.99) for children weighing less than 2000 g and those weighing between 2000 and 2499 g, respectively, compared to those born with a normal weight (weight ≥ 2500 g). The age at school entry of children with a birthweight less than 2000 g and between 2000 and 2499 g was 7% (IRR: 1.07, 95%CI: 1.06–1.08) and 3% (IRR: 1.03, 95%CI: 1.00-1.06) higher than children born at a normal birthweight, respectively. Gestational age was not associated with school entry or age at school entry. Similarly, birthweight and gestational age were not associated with grade repetition or dropout.

Conclusion
This study shows that low birthweight is negatively associated with school entry and age at school entry in Ouagadougou. Efforts to avoid low birthweights should be part of maternal and prenatal health care because the associated difficulties may be difficult to overcome later in the child’s life. Further longitudinal studies are needed to better understand the relationship between development at birth and school trajectory.

Birthweight, Gestational age, School entry, Age at school entry, Grade repetition, Dropout