Interethnic mating and risk for preterm birth among Arab-American mothers: Evidence from the Arab-American Birth Outcomes Study

Arab ethnicity (AE) mothers have lower preterm birth (PTB) risk than white mothers. Little is known about the determinants
of PTB among AE women or the role of interethnic mating in shaping PTB risk among this group. We assessed the relationship
between interethnic mating and risk for PTB, very PTB, and late PTB among AE mothers. Data was collected for all births (N = 21,621) to AE women in Michigan between 2000 and 2005. Self-reported ancestry was used to determine paternal AE as well
as to identify AE mothers. We used bivariate chi-square tests and multivariable logistic regression to assess the relationship
between paternal non-AE and risk for PTB, very PTB, and late PTB among AE mothers. All analyses were also conducted among
non-Arab white mothers as a control. Among AE mothers, paternal non-Arab ethnicity was associated with higher risk of PTB
(OR = 1.18, 95% CI = 1.06, 1.30) and late PTB (OR = 1.24, 95% CI = 1.20, 1.38) compared to paternal Arab ethnicity. Paternal
non-Arab ethnicity was not associated with risk for any outcome among non-Arab white mothers. Future studies could assess
the causal mechanisms underlying the association between interethnic mating and risk for PTB.