TABLE 1

Characteristics of Singleton Births at ≥37 Weeks’ Gestation

2004–2008 (n = 20 708), %a2010–2015 (n = 24 897), %aP
Maternal age, y<.0001
 <258.56.8
 25–<3555.558.4
 ≥3536.034.7
Race and/or ethnicity<.0001
 White59.946.8
 African American10.510.4
 Hispanic5.45.3
 Asian American13.315.6
 Other or unknown10.922.0
Insuranceb<.0001
 Private81.880.8
 Medicaid13.516.1
 Other4.73.1
Parity >052.951.1.0002
Vaginal delivery65.170.8<.0001
Diabetesc3.95.3<.0001
Hypertensionc9.510.4.002
Male infant50.451.0.18
  • —, not applicable.

  • a Percentages do not always add to 100 because of rounding.

  • b Missing: n = 9.

  • c Combination of gestational and prepregnancy or chronic.