African ancestry and the threshold for preterm birth in French Guiana: Impact of prematurity irrespective of ethnicity

Abstract

Introduction: in French Guiana, preterm birth has remained at 13% despite efforts to improve antenatal care. It has been hypothesized that this high preterm birth rate is partly explained by the fact that women of African descent naturally tend to deliver earlier than Caucasian women. Our aim was to test this hypothesis using birth registry data.

Methods: one data set was used: the 2013- 2014 registry data for 12,983 live births, which included place of birth and adjustment variables such as social factors and comorbidities. Birth length by ethnicity/place of birth was analyzed. The proportion of neonatal intensive care unit transfer for births at 36 weeks was examined by ethnicity/place of birth and adjusted for potential
confounders using logistic regression.

Results: the median length of gestation was one week lower among Surinamese mothers (38 weeks) compared to other birthplaces. The birth was 0.5-0.8 weeks earlier in mothers born in countries with a predominant African ancestry compared to metropolitan France. After adjustment for social variables, preterm birth was still more common in populations of predominantly African ancestry: French Guiana, Suriname, and Haiti. However, at 36 weeks, there were no statistical differences between ethnic origins regarding complications requiring intensive care.

Conclusion: although we found that women of African descent generally delivered earlier than Caucasian women or women born in mainland France, we found no argument to suggest that this was "physiological". In fact, looking only at 36 weeks, there were no differences in terms of complications requiring neonatal intensive care. This suggests that, irrespective of ethnicity, being born before 37 weeks is associated with neonatal complications and that the assumption that the high rates of preterm birth are partly artefactual cannot be supported by the available data.