Women who have induced abortions have an increased risk of HIV infection of 172%, and researchers are at least 99% confident of this result.
"Significantly higher prevalences of infection [HIV-1] were associated with induced abortion (0.49%) than with delivery (0.18%) (OR: 2.72; 95% CI: 2.29-3.22)" [European Journal of Epidemiology, Deliveries, abortion and HIV-1 infection in Rome, 1989-1994, 1997, 13:373-378.]
A typical 15 year old American girl has a 10% lifetime risk of breast cancer.
If she gets pregnant in her teens and has the baby she reduces her risk to 7.5%. However, if she has an abortion, her risk of breast cancer rises to 15% (assuming she has at least one child in her 20's).
If the abortion causes permanent infertility and/or for other reasons, she never has another pregnancy, her risk rises to 30%.
[Brinton LA, Hoover R, Fraumeni IF, Ir. (1983) Brit. J. Cancer. 47:757-62]