Breast cancer risk in mothers of twins.

The risk of breast cancer associated with delivering a twin birth was examined in a population-based nested case-control study of nearly 4800 Swedish women with breast cancer and 47000 age-matched control subjects. All were aged less than 50 years and parous. After adjustment for age at first birth and parity, a 29% reduction in breast cancer risk was observed in mothers of twins relative to those who were not (odds ratio = 0.

Preterm birth and low birthweight among children of Swedish and immigrant women between 1978 and 1990.

The aim of the study was to estimate the occurrence of low birthweight (LBW) and preterm birth among immigrant and Swedish women in Sweden. Eligible for analysis were all 1,270,407 singleton births in Sweden between 1978 and 1990 to mothers aged between 15 and 44 years, whose own country of birth was known. The mothers of the children were born in Sweden (88.

Prenatal and neonatal risk factors for childhood myeloid leukemia.

Information about the etiology of childhood myeloid leukemia is limited. A population-based nested case-control study of prenatal and neonatal risk factors for childhood myeloid leukemia was performed with the use of the Swedish National Cancer Register and the Swedish Birth Register. A total of 98 cases of myeloid leukemia were identified in successive birth cohorts from 1973 through 1989.

Breast cancer in Swedish women before age 50: evidence of a dual effect of completed pregnancy.

We set out to detect a transient increase in risk of breast cancer following childbirth, the existence of which has been postulated, but for which empirical evidence is contradictory. Breast cancers and births occurring among the cohort of Swedish women born after 1939 were linked, yielding 3,439 cases and 25,140 age-matched controls with at least two children. Within three years of their last childbirth, women had an estimated rate of breast cancer of 1.

Prenatal and neonatal risk factors for childhood lymphatic leukemia.

Background: Because the incidence of childhood acute lymphatic leukemia peaks between 2 and 4 years of age, the risk factors may exert their influence during the prenatal and/or the neonatal periods. Results of previous studies of perinatal risk factors have been contradictory, perhaps because most studies either have been hospital based or have been restricted to limited geographical areas.

Purpose: A nationwide case-control study was carried out to identify maternal and perinatal risk factors for this disease.