Race and genetics in understanding the complexities of preterm birth

Preterm birth (PTB; <37 completed weeks of gestation), is one of the major clinical dilemmas of pregnancy. Understanding PTB has been difficult, as the risk factors and pathophysiological factors associated with PTB are poorly understood. Our current knowledge of risk factors and biomarkers in predicting the ‘high-risk’ status during pregnancy has not been successful in reducing the PTB rate, and it has continued to rise in the past few decades. Disparities in the PTB rates observed among different racial groups further complicate the understanding of PTB, suggesting that the risk factors and biomarkers are not universal, and that risk assessment should be made based on a multitude of factors associated with a given individual (personalized risk assessment). Genetic variations and their interactions with the environment can produce distinct risk profiles during pregnancy. In this review, complexities associated with spontaneous PTB are discussed and, to unravel these complexities, using race as a surrogate, current findings on genetic and biomarker differences and their interaction with the environment in determining pregnancy outcomes are discussed.