More Boys Born Than Girls
New Report
Documents Total Gender Ratios At Birth From 1940 to 2002
For Immediate Release:
June 14,
2005
Contact: CDC
National Center for Health Statistics Press Office(301) 458-4800
E-mail: nchsquery@cdc.gov
Trend Analysis of the
Sex Ratio at Birth in the United States.NVSR Volume 53, Number 20. 18 pp. (PHS)
2004-1120 View/download PDF
1.4 MB
For the 63d year in a
row, the number of boys born in the United States outnumbers births of girls
-– in 2002, 94,232 more boys than girls were born. This is the central finding
of a new Centers for Disease Control and Prevention (CDC) report that
examines total sex ratios at birth for over six decades. The total sex ratio
is the number of male births divided by female births times 1,000. Other
findings of the report are:
Since
1940, an average of 91,685 more male babies have been born each year than
females, a total of 5,776,130 over that 63-year period.
The
highest sex birth ratio occurred in 1946 (1,059 male births per 1,000
females) while the lowest occurred in 1991 and again in 2001 (1,046 male
births per 1,000 females).
There
were three major trends in sex birth ratios over this period: a significant
decline between 1942 and 1959; a significant increase between 1959 and 1971;
and another significant decline between 1971 and 2002.
Combining
all the years studied, older mothers (40 to 44 years of age and 45 years and
over) have the lowest total sex birth ratios (1,038 and 1,039, respectively)
and mothers 15 to 19 years of age had the highest sex birth ratio (1,054).
The
more children a woman has the more likely she is going to give birth to an
equal number of boys and girls.
For
all available years combined, Chinese mothers (1,074) and Filipino mothers (1,072)
had the highest differences between the number of boys born compared with girls,
whereas non-Hispanic black mothers (1,031) and American Indian mothers (1,031) had the
lowest.
The report, “Trend
Analysis of the Sex Ratio at Birth in the United States,” was prepared by
CDC’s National Center for Health Statistics (NCHS) and is available at the
CDC/NCHS Web site (www.cdc.gov/nchs).