caa a22 4500 386397120 CHVBK 20180307112142.0 cr unu---uuuuu 161130e198901 xx s 000 0 eng 10.1017/S0021932000017752 doi S0021932000017752 pii (NATIONALLICENCE)cambridge-10.1017/S0021932000017752 Demographic components of seasonality of pregnancy [Elektronische Daten] Previous studies of the seasonality of pregnancy and birth have typically been based on monthly numbers or proportions of pregnancies or births (i.e. their distribution throughout the year) without any explicit accounting of the size of the population actually at risk of pregnancy by month. From data on monthly populations at risk and monthly probabilities of pregnancy this paper determines the relative contribution of each component to the monthly distribution of pregnancies. The data come from the National Survey of Family Growth, Cycle III. While there is some seasonality in the size of the at-risk population, it contributes little to the overall monthly variation of pregnancy, which is determined mainly by seasonality of pregnancy probability (fecundability). Copyright © Cambridge University Press 1989 Kallan Jeffrey E. Center for Demography and Ecology, University of Wisconsin, Madison Udry J. Richard Carolina Population Center, University of North Carolina, Chapel Hill, USA Journal of Biosocial Science Cambridge University Press 21/1(1989-01), 101-108 0021-9320 21:1<101 1989 21 JBS https://doi.org/10.1017/S0021932000017752 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0021932000017752 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kallan Jeffrey E. Center for Demography and Ecology, University of Wisconsin, Madison NATIONALLICENCE 700 1- Udry J. Richard Carolina Population Center, University of North Carolina, Chapel Hill, USA NATIONALLICENCE 773 0- Journal of Biosocial Science Cambridge University Press 21/1(1989-01), 101-108 0021-9320 21:1<101 1989 21 JBS CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge