Table 2.

Pregnancy characteristics of cases and controls

CharacteristicsCases, N (%)*Controls, N (%)*
Birth rank of index child
    First138 (43.4%)139 (43.9%)
    Second102 (32.1%)99 (31.2%)
    Third+78 (24.5%)79 (24.9%)
Type of delivery
    Vaginal259 (81.2%)272 (86.3%)
    Cesarean60 (18.8%)43 (13.7%)
Length of pregnancy
    Normal257 (81.3%)255 (81.2%)
    Premature25 (7.9%)9 (2.9%)
    Overdue34 (10.8%)50 (15.9%)
Spotting/cramping/abnormal vaginal bleeding during pregnancy67 (21.1%)37 (11.9%)
Number of pregnancies
    Previous pregnancies3.1 (1.6)3.2 (1.6)
Stillbirths/miscarriages/abortions0.4 (0.9)0.4 (0.8)
Living infants2.6 (1.3)2.7 (1.3)
Number of prenatal visits13.3 (4.1)13.5 (4.8)
Index child birth weight (lbs)7.4 (1.4)7.5 (1.1)
Age at index child birth (y)
    Paternal29.0 (5.9)29.0 (6.4)
    Maternal26.2 (5.2)26.2 (5.2)
  • * Percentage of respondents to each question (excluding unknowns).

  • Mean (SD).