Prenatal growth and risk of occlusive and haemorrhagic stroke in Swedish men and women born 1915-29: historical cohort study

Abstract

Evidence for an inverse association of impaired fetal growth with stroke is less securely established than that with coronary heart disease. Even less is known about the association of fetal growth with occlusive stroke and haemorrhagic stroke. Participants, methods, and resultsThe cohort comprises all 14 611 births in the Uppsala Academic Hospital between 1915 and 1929.1 Socioeconomic circumstances and neonatal characteristics, including gestational age (number of completed weeks since last menstrual period), were available for 96% of the subjects from hospital records and follow up is 98% complete. Analyses were restricted to singletons born at 30-45 weeks' gestation for whom information was available in the 1960 and 1970 censuses. Data on occurrence of first stroke were obtained from the Swedish national hospital discharge register 2 and from the national cause of death register. Two subtypes of stroke were defined-haemorrhagic (ICD-8 (international classification of diseases, 8th revision) 430-431; ICD-9 430-432) and occlusive (ICD-8 432-436; ICD-9 433-436). Each participant was considered at risk from the time of the 1970 census to date of first stroke, emigration, death, or end of follow up (31 December 1996).The 10 853 men and women had 991 first strokes-156 haemorrhagic, 775 occlusive, and 60 ill defined. Death certificates identified 41 (26%) first haemorrhagic strokes and 17 (2%) occlusive strokes. Of haemorrhagic strokes, 21 (13%) were subarachnoid and 135 (87%) intracerebral or unspecified intracranial haemorrhages.Cox proportional hazards model showed birth weight inversely associated with risk of haemorrhagic stroke and little evidence of association with occlusive stroke. Hazard ratio per 1 kg increase in birth weight (adjusted for sex and period of birth) was 0.61 (95% confidence interval 0.45 to 0.83) for haemorrhagic stroke and 0.89 (0.77 to 1.03) for occlusive stroke. Adjustment for socioeconomic factors at birth and at the time of the 1960 and 1970 censuses had little effect on estimates (table). When head circumference and birth length were adjusted for separately and in combination, the inverse association between birth weight and haemorrhagic stroke strengthened but there was little effect on the association of birth weight with occlusive stroke. Adjustment for gestational age had no substantive effect on the estimates.

Infant Growth and Stroke in Adult Life

“…16 We divided stroke into 3 categories, thrombotic, hemorrhagic, and other, based on groupings in the international classification of disease that have been used in previous analyses. [5][6][7] The number of cases in our study was insufficient for examination of smaller diagnostic groupings, such as subarachnoid hemorrhage.…”

“…[1][2][3][4][5][6] This association is independent of the length of gestation and therefore reflects slow fetal growth. Low body mass index at birth was also associated with later stroke.…”

“…tudies in the United States 1,2 and Europe [3][4][5][6] have shown that low birth weight is associated with an increased risk of stroke in adult life. The association with birth weight remains after adjustment for gestational age, which suggests that it results from slow fetal growth.…”

Prospective study of body size and risk for stroke amongst women below age 60

“…One study found that each additional kilogram of birth weight was associated with a 11% decreased risk of stroke, with the exception of macrosomic infants [20]. In another cohort of women and men from Sweden, each kilogram increase in birth weight was associated with a 41% decreased risk of haemorrhagic stroke [21]. In the study by Singhal and Lucas, stroke risk generally rose with adult BMI and dropped with high birth weight, implicating rapid weight gain as a risk factor for stroke, as suggested by the 'growth acceleration' hypothesis [22].…”

Birth characteristics and adult cancer incidence: Swedish cohort of over 11,000 men and women

“…This cohort has previously been used to investigate breast cancer incidence 11 as well as circulatory morbidity 12 and mortality 2 in relation to birth characteristics.…”