The studies supporting this did not control for factors not related to abortion or miscarriage, and hence the causes of this correlation have not been determined, although multiple possibilities have been suggested.Some purported risks of abortion are promoted primarily by anti-abortion groups,
but lack scientific support. For example, the question of a link between induced abortion and breast cancer has been investigated extensively. Major medical and scientific bodies (including the WHO, National Cancer Institute, American Cancer Society, Royal College of OBGYN and American Congress of OBGYN) have concluded that abortion does not cause breast cancer.In the past even illegality has not automatically meant that the abortions were unsafe. Referring to the U.S., historian Linda Gordon states: "In fact, illegal abortions in this country have an impressive safety record. ": 25  According to Rickie Solinger,

A related myth, promulgated by a broad spectrum of people concerned about abortion and public policy, is that before legalization abortionists were dirty and dangerous back-alley butchers.... [T]he historical evidence does not support such claims. : 4 

Authors Jerome Bates and Edward Zawadzki describe the case of an illegal abortionist in the eastern U.S. in the early 20th century who was proud of having successfully completed 13,844 abortions without any fatality. : 59 
In 1870s New York City the famous abortionist/midwife Madame Restell (Anna Trow Lohman) appears to have lost very few women among her more than 100,000 patients—a lower mortality rate than the childbirth mortality rate at the time.
Adults
GH treatment can confer a number of measurable benefits to severely GH-deficient adults, such as enhanced energy and strength, and improved bone density. Muscle mass may increase at the expense of adipose tissue. Although adults with hypopituitarism have been shown to have a reduced life expectancy, and a cardiovascular mortality rate of more than double controls, treatment has not been shown to improve mortality, although blood lipid levels do improve. Similarly, although measurements of bone density improve with treatment, rates of fractures have not been shown to improve.Effects on quality of life are unproven, with a number of studies finding that adults with GHD had near-normal indicators of QoL at baseline (giving little scope for improvement), and many using outdated dosing strategies. However, it may be that those adults with poor QoL at the start of treatment do benefit. Epidemiology
The incidence of idiopathic GHD in infants is about 1 in every 3800 live births, and rates in older children are rising as more children survive childhood cancers which are treated with radiotherapy, although exact rates are hard to obtain. The incidence of genuine adult-onset GHD, normally due to pituitary tumours, is estimated at 10 per million.