Table 1.

Maternal and cord estrogen and AFP levels and their associations with birth weight

MeanMedianRangeCrude r (P)Adjusted*r (P)Mean birth weight (g)*
Quartile 1Quartile 2Quartile 3Quartile 4
Estradiol (pg/mL)
    10th week2,6872,305632-9,0900.08 (0.26)0.08 (0.30)3,0382,8422,9873,088
    29th week21,75420,6007,390-38,0000.11 (0.11)0.16 (0.03)2,9222,9503,0153,095
    Delivery31,41931,9003,960-67,3000.12 (0.10)0.20 (0.001)2,9202,9523,0033,095
    Cord5,9074,325554-41,300−0.15 (0.04)−0.06 (0.44)2,9923,0083,0402,944
Estriol (ng/mL)
    10th week5.75.05.0-18.50.13 (0.07)0.14 (0.07)
    29th week91.085.831.4-3010.21 (0.004)0.29 (0.0001)2,8392,9873,0193,155
    Delivery239.421835.4-7070.25 (0.001)0.41 (0.0001)2,7812,9803,0573,151
    Cord2,1262,050725-3,8600.16 (0.03)0.15 (0.049)2,8813,0423,0732,978
AFP (ng/mL)
    10th week12.18.72.8-3800.001 (0.98)−0.04 (0.58)2,9553,0393,0002,980
    29th week283.9261.087-723−0.003 (0.96)0.07 (0.34)2,9872,9962,9143,075
    Delivery203.0185.047.8-954−0.03 (0.70)0.07 (0.38)2,9762,9632,9793,055
    Cord96,50391,05022,300-327,000−0.24 (0.001)−0.16 (0.04)3,0982,9852,9922,909
  • * Adjusted for age, parity, length of gestation, smoking status, years of education, pre-pregnancy height and weight, weight gain, and weeks of gestation at the time of measurement.

  • A 5.0 ng/mL was assigned for 157 (80.9%) women with undetectable levels. The mean birth weight according to quartile of estriol level was not calculated.