Skip to main content
. Author manuscript; available in PMC: 2012 Apr 1.
Published in final edited form as: Obstet Gynecol. 2011 Apr;117(4):892–897. doi: 10.1097/AOG.0b013e3182102adf

Table 1.

Characteristics of mothers with and without twins, US Census data, 1980

Variable Mothers
without twins		 Mothers of
twins		 Mothers of
twins at first
birth
Number 835,218 13,595 6,224
No. of children, mean (sd) 2.0 (0.9) 3.2 (1.1) 2.7 (1.0)
Age at first birth, years (sd) 23.3 (4.3) 23.3 (4.2) 24.1 (4.2)
Age at first marriage, years (sd) 20.3 (3.4) 20.4 (3.5) 20.9 (3.5)
White, % (sd) 90.4 (29.8) 88.1 (32.4) 88.5 (32.5)
Any college education, % (sd) 35.6 (17.9) 35.6 (17.8) 38.2 (18.1)
Divorced, % (sd) 12.6 (3.3) 13.1 (3.3) 13.2 (3.3)