Contraception and fertility in 2,000 women
Pearl, R.
Human Biology 4(3): 363-407
1932
ISSN/ISBN: 0018-7143 DOI: 10.2307/41447124Document Number: 476196
A prelimi nary report on the first 2,000 cases in an investigation of the prevalence and effectiveness of the use of contra ceptives in a sample of the American population living in large eastern cities. The purpose of the investigation was to get direct, observed evidence of a critical char acter on a disputed phase of the population problem-namely, the actual as distinguished from either the theo retical or the potential effect of contraceptive practices upon natural fertility in a defined sample of the popula tion. The study is to be extended. Definitive conclusions now would be premature. The methodology of the study has combined the case system and certain features of questionnaire method. Data were collected from women confined in obstetric clinics of hospitals, and were recorded by physicians trained in obstetrics. The 2,000 cases here discussed come almost entirely from lower economic and social levels; they represent deliveries in 38 different hospitals in 5 cities, Baltimore, Washington, Philadelphia, New York and Chicago; 69.5% are whites and 30.5% are negroes; 32.4% of white women and 26.9% of negro women had attended high school Or some higher institution of learning; 97% of white women and 78.1% of negro women were living in wedlock. The 2,000 women had experienced during their lives 5,496 pregnancies, or an average of 2.75 per woman. For whites the cor responding figures are 3,731, or 2.68 per woman; for negroes 1,765, or 2.89 per woman. Some attempt to prevent conception had been made by 35.8% of white women, and by 15.4% of negro women. Corresponding figure for white married women living in wedlock was 366%. The different methods of contraception used were such and were so distributed that, in this sample, white men alone bore 48.7% of the total burden of family limitation; white couples conjointly 2%. of the burden; and white women alone 49.3%. Among negroes the males assumed only 33.1% of the total responsibility; the couples conjointly 2.9% and women alone 64%. A new and more precise method for calculating person-years of exposure to risk of pregnancy is described. The mean number of years of exposure to risk of pregnancy for each married woman exposed was, in this experience, ap proximately one year greater for the C+ (contraception practised) white women than for the C-(contraception not practised) white women, and 0.84 year greater for the C+ negro women than for the C-negro women. The mean number of pregnancies per married woman as-experienced throughout the entire reproductive life to time of record was higher for the C + women than for the C-women in this sample, by an insignificant amount in white group and by a considerable amount among negroes. The pregnancy rate per 100 person-years exposure to risk of pregnancy is 14.57 points lower in the C+ group of white women than in the C-group. In other words the methods of contraception actually practised by this group of married white women were accompanied by a reduction in pregnancy rate per person per unit of time of only about 20% below that which obtained in a comparable group of C-women during approximately the same time. In case of negro married women in sample the pregnancy rate per 100 person years exposure to risk of pregnancy is considerably higher among the C+ women than among the C-women. There is some reason to think, though it is not yet demonstrated, that women who practise contraception are innately more fertile than women who do not, or than a random sample of women in general.