Three separate studies are outlined with the common objective of examining potential risk factors for breast cancer that may operate during very early life (in utero and perinatal).
Study A: In a population based case-control study, using birth records f rom two large birthing clinics (Trondheim and Bergen) and information from the Norwegian Cancer Registry, the project proposes to study: if there is a positive association between breast cancer risk and birth weight, birth length and placenta weight; if t here is any association between breast cancer risk and placenta weight, and to study associations between placenta characteristics and indicators of fetal body size (birth weight and length).
Study B: In a retrospective cohort study of 4,400 young women (13-19 years), the project wants to study their reproductive and somatic development at adolescence in relation to perinatal characteristics that were collected at birth and registered at the Medical Birth Registry. The primary goal will be to study peri natal factors that exhibit their hypothesized carcinogenic action during early life and established breast cancer risk factors that operate during the perimenarcheal years.
Study C: In a study of Norwegian women who were followed closely during pregnancy (1986-1988), the project proposes to examine associations between maternal influences (circulating estrogen and IGF-1 levels, and pre-eclampsia) that were registered during pregnancy, and perinatal factors (birth weight, placental weight, infant jaundice , and factors measured in umbilical cord blood) that were registered in their female offspring at birth. In a prospective follow-up at adolescence of these girls, one now proposes to collect information on physical growth, pubertal development, nutrition, and to measure estrogen and IGF levels.
