answers: 1971
context: radioimmunoassay in 1959. Radioimmunoassays require sophisticated apparatus and special radiation precautions and are expensive. Organon International obtained the first patent on a home pregnancy test in 1969, two years after product designer Margaret Crane noticed that the laboratory testing procedure was relatively simple and made a prototype. The product became available in Canada in 1971, and the United States in 1977, after delays caused by concerns over sexual morality and the ability of women to perform test and cope with the results without a doctor. Another home pregnancy testing kit was based on the work of Judith Vaitukaitis and Glenn </s> weeks' gestation. The embryo can be observed and measured by about five and a half weeks. The heartbeat may be seen as early as six weeks, and is usually visible by seven weeks' gestation. A systematic review published in 1998 showed that home pregnancy test kits, when used by experienced technicians, are almost as accurate as professional laboratory testing (97.4%). When used by consumers, however, the accuracy fell to 75%: the review authors noted that many users misunderstood or failed to follow the instructions included in the kits. Improper usage may cause both false negatives and false positives. False negative </s> Margaret Crane Margaret M. Crane (Meg Crane) is a United States inventor and graphic designer who lives in New York. Crane created the first at home pregnancy test in 1967 while working at Organon in West Orange, New Jersey. She is the listed inventor on US Patent 3,579,306 and 215,7774. There was resistance to marketing pregnancy tests for consumers rather than doctors, and the home pregnancy test did not become available until 1977, except for a market test in Canada in 1972. She was also a juror in the 2004 trial of Martha Stewart for lying to federal investigators during
question: when did the first home pregnancy test come out