TY - JOUR
T1 - Age at first sexual intercourse and teenage pregnancy in Australian female twins
AU - Waldron, Mary
AU - Heath, Andrew C.
AU - Turkheimer, Eric
AU - Emery, Robert
AU - Bucholz, Kathleen K.
AU - Madden, Pamela A.F.
AU - Martin, Nicholas G.
N1 - Funding Information:
This work was supported by T32AA0750 from NIAAA and by grants AA07535, AA07720, AA10242, and AA1998.
PY - 2007/6
Y1 - 2007/6
N2 - Girls who report first sexual intercourse during their early teen years have much higher rates of teenage pregnancy and childbearing than girls who delay sexual onset until older adolescence. In this study, we examine genetic and environmental influences on variation in teenage pregnancy and covariation with age at first sexual intercourse in two cohorts of Australian female twins. In the older twin cohort, born 1893-1964, we observe substantial heritable variation in teenage pregnancy that is largely shared with heritable variation in age at first sexual intercourse, with shared environment contributintablg little to variation in teenage pregnancy. Genetic influences on teenage pregnancy are smaller and nonsignificant in the younger twin cohort, born 1964-1971, where shared environment contributes much more and overlaps entirely with shared environmental variation in age at first intercourse.
AB - Girls who report first sexual intercourse during their early teen years have much higher rates of teenage pregnancy and childbearing than girls who delay sexual onset until older adolescence. In this study, we examine genetic and environmental influences on variation in teenage pregnancy and covariation with age at first sexual intercourse in two cohorts of Australian female twins. In the older twin cohort, born 1893-1964, we observe substantial heritable variation in teenage pregnancy that is largely shared with heritable variation in age at first sexual intercourse, with shared environment contributintablg little to variation in teenage pregnancy. Genetic influences on teenage pregnancy are smaller and nonsignificant in the younger twin cohort, born 1964-1971, where shared environment contributes much more and overlaps entirely with shared environmental variation in age at first intercourse.
UR - http://www.scopus.com/inward/record.url?scp=34250846554&partnerID=8YFLogxK
U2 - 10.1375/twin.10.3.440
DO - 10.1375/twin.10.3.440
M3 - Article
C2 - 17564502
AN - SCOPUS:34250846554
SN - 1832-4274
VL - 10
SP - 440
EP - 449
JO - Twin Research and Human Genetics
JF - Twin Research and Human Genetics
IS - 3
ER -