Estimates of sex ratio at birth in Viet Nam, 1998–2007.

aEstimates published in the annual Surveys of Population Change, Labour Force and Family Planning (General Statistics Office, Hanoi) except for 1999 (computed from the 2000 survey data).bComputed by the first author from the 2006 and 2007 annual survey data files.cData for the survey of births in health centres conducted in 2007 and 2008 by the General Statistics Office and the Ministry of Health.dOnly available for the first trimester.