Journal of Obstetrics and Gynaecology Canada
Volume 38, Issue 10, 2016, Pages 919-925.e2

Sex Ratios Among Births in British Columbia, 2000-2013 (Article)

Joseph K.S. , Lee L. , Williams K.
  • a Department of Obstetrics and Gynaecology, University of British Columbia and the Children's and Women's Hospital and Health Centre of British Columbia, Vancouver, BC, Canada, School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada
  • b Perinatal Services BC, Provincial Health Services Authority, Vancouver, BC, Canada
  • c Perinatal Services BC, Provincial Health Services Authority, Vancouver, BC, Canada

Abstract

Objective Previous studies have reported distorted sex ratios among live births within specific immigrant groups in Canada. We carried out an investigation into sex ratios in British Columbia. Methods All stillbirths and live births to residents of British Columbia from April 2000 to March 2013 were included in the study, with data obtained from the British Columbia Perinatal Data Registry. We examined sex ratios among births and among pregnancy terminations that resulted in a stillbirth or live birth. Analyses were stratified by congenital anomaly status, maternal residence, and parity. Results The study population included 567 225 stillbirths and live births. In the Fraser Health Authority, the sex ratio among births without congenital anomalies was 51.3% males (95% CI 51.1 to 51.5); this was significantly higher than the sex ratio of 40.7% males (95% CI 33.2 to 48.6) among late pregnancy terminations without congenital anomalies (P = 0.008). However, in British Columbia, excluding the Fraser Health Authority, the same sex ratios were 51.1% (95% CI 50.9 to 51.3) and 51.1% (95% CI 45.5 to 56.7), respectively (P = 0.99). Sex ratios among births to multiparous women were also significantly different in the Fraser Health Authority. Only a negligible fraction of the shortfall in female births in the Fraser Health Authority could be explained by sex ratio distortions among late pregnancy terminations. Conclusion Sex ratios among stillbirths and live births to residents of the Fraser Health Authority are distorted relative to those observed elsewhere in British Columbia. This is likely due to sex differences in early pregnancy terminations. © 2016 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada

Author Keywords

immigrants Congenital anomalies births Sex ratios Canada

Index Keywords

birth demography sex ratio human epidemiology sex difference Fraser Health Authority controlled study Humans pregnancy termination male female congenital malformation newborn pregnancy Article health care major clinical study live birth multipara parity stillbirth British Columbia

Link
https://www.scopus.com/inward/record.uri?eid=2-s2.0-84979766858&doi=10.1016%2fj.jogc.2016.06.005&partnerID=40&md5=0c2fb63560d577c7beb9da4fef94bb09

DOI: 10.1016/j.jogc.2016.06.005
ISSN: 17012163
Original Language: English