Alcantara Melia, Harper Sam B, Shapiro Gabriel D, Bushnik Tracey, Kaufman Jay S, Vang Zoua, Mashford-Pringle Angela, Yang Seungmi
McGill University Department of Epidemiology Biostatistics and Occupational Health, Montreal, Québec, Canada.
Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada.
BMJ Public Health. 2025 Jul 31;3(2):e001231. doi: 10.1136/bmjph-2024-001231. eCollection 2025.
Foreign-born mothers are generally believed to experience better perinatal outcomes than Canadian-born mothers, despite relatively lower socioeconomic status. However, the magnitude and direction of inequalities by nativity status vary across outcomes. Little is known about factors contributing to the health inequalities by nativity status across different perinatal outcomes. Thus, we aim to examine the direction and magnitude of inequalities by nativity status across perinatal outcomes and estimate the contributions of select individual-level characteristics to the inequalities in Canada.
Using 132 639 singleton births from the 2016 Canadian Birth-Census Cohort, we estimated the risk of preterm birth (PTB), small-for-gestational-age (SGA) and large-for-gestational-age (LGA) birth, stillbirth, and infant and neonatal death by maternal nativity status. We estimated the contribution of maternal race, maternal and paternal education, paternal nativity status and employment, family income and homeownership, as well as maternal age, marital status, activity limitations and parity to inequalities specific to each outcome, using Kitagawa's decomposition method.
Compared with Canadian-born mothers, foreign-born mothers experienced higher rates of all outcomes examined (eg, 627 (95% CI 608, 646) PTBs per 10 000 live births among foreign-born mothers vs 580 (568, 592) among Canadian-born mothers), except for LGA births (677 (648, 706) per 10 000 for foreign-born vs 1006 (959, 1054) for Canadian-born mothers). Non-White maternal race explained the largest proportion of the observed differences for non-fatal outcomes, while the highest income quartile explained the most for the differences in fatal outcomes.
Foreign-born women fared worse than Canadian-born women for all adverse perinatal outcomes examined apart from LGA births. Our results highlight differential contributions of determinants to perinatal health inequalities by maternal nativity status across outcomes.
尽管外国出生的母亲社会经济地位相对较低，但人们普遍认为她们的围产期结局比加拿大出生的母亲更好。然而，出生地状态导致的不平等程度和方向因结局而异。对于不同围产期结局中出生地状态导致的健康不平等的影响因素，人们知之甚少。因此，我们旨在研究出生地状态在围产期结局方面的不平等方向和程度，并估计加拿大特定个体层面特征对不平等的影响。
利用2016年加拿大出生人口普查队列中的132639例单胎出生数据，我们按母亲出生地状态估计了早产（PTB）、小于胎龄（SGA）和大于胎龄（LGA）出生、死产以及婴儿和新生儿死亡的风险。我们使用北川分解方法，估计了母亲种族、母亲和父亲的教育程度、父亲的出生地状态和就业情况、家庭收入和住房所有权，以及母亲年龄、婚姻状况、活动受限情况和产次对每种结局特定不平等的影响。
与加拿大出生的母亲相比，外国出生的母亲在所研究的所有结局中的发生率更高（例如，外国出生的母亲每10000例活产中有627例（95%CI 608, 646）早产，而加拿大出生的母亲为580例（568, 592）），LGA出生除外（外国出生的母亲每10000例中有677例（648, 706），加拿大出生的母亲为每10000例中有1006例（959, 1054））。非白人母亲种族对非致命结局中观察到的差异解释比例最大，而最高收入四分位数对致命结局差异的解释最多。
除LGA出生外，外国出生的女性在所有不良围产期结局方面比加拿大出生的女性情况更差。我们的结果突出了决定因素对不同围产期结局中母亲出生地状态导致的围产期健康不平等的不同影响。
