title: Maternal bereavement during pregnancy and the risk of stillbirth: a nationwide cohort study in Sweden.
abstract: Increasing evidence suggests that maternal stress during pregnancy may influence pregnancy outcomes. In a nationwide Swedish study including almost 3 million births taking place during 1973-2006, we investigated whether maternal bereavement during pregnancy is associated with stillbirth risk. Through individual record linkage between several population-based registers, we obtained information on demographic, health-related, and pregnancy-related factors and deaths of mothers' first-degree relatives. There were 11,071 stillbirths (3.8 per 1,000 births) in the cohort. After adjustment for potential confounders, infants of mothers who had lost any first-degree relative the year before or during pregnancy had an 18% higher risk of stillbirth than unexposed offspring (95% confidence interval (CI): 1.06, 1.31). Corresponding hazard ratios were 1.67 (95% CI: 1.18, 2.36) for maternal loss of an older child, 2.06 (95% CI: 1.44, 2.94) for loss of a sibling, and 1.07 (95% CI: 0.95, 1.21) for loss of a parent. The relationship between maternal bereavement and stillbirth did not vary by time of death or by whether the relative's death was expected or unexpected. Death of a close relative is one of the most severe sources of stress, and future studies need to investigate whether less severe but more common stressors also increase stillbirth risk.
authors.affiliation: Department of Medicine, Clinical Epidemiology Unit, Karolinska University Hospital and Karolinska Institute, Stockholm, Sweden. krisztina.laszlo@ki.se
authors.forename: Krisztina D
authors.initials: KD
authors.lastname: László
authors.forename: Tobias
authors.initials: T
authors.lastname: Svensson
authors.forename: Jiong
authors.initials: J
authors.lastname: Li
authors.forename: Carsten
authors.initials: C
authors.lastname: Obel
authors.forename: Mogens
authors.initials: M
authors.lastname: Vestergaard
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
authors.forename: Sven
authors.initials: S
authors.lastname: Cnattingius
mesh_terms: D000328:Adult; D001601:Bereavement; D015331:Cohort Studies; D005190:Family / Q000523:psychology*; D005260:Female; D006304:Health Status; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology* / Q000523:psychology; D011256:Pregnancy Outcome; D012959:Socioeconomic Factors; D050497:Stillbirth / Q000453:epidemiology*; D013315:Stress, Psychological / Q000453:epidemiology* / Q000523:psychology; D013548:Sweden / Q000453:epidemiology