Table 1. The response rates of the mothers, fathers, and children for each survey item.
1st trimester | 2nd/3rd trimester | Birth | ||||
n | % | n | % | n | % | |
Mother (100,778 pregnancies) | ||||||
Questionnaire and interview about drug use | 99,300 | 98.5 | 97,969 | 97.2 | ||
Medical record transcription | 100,611 | 99.8 | 100,778 | 100 | ||
Blood | 89,434 | 88.7 | 96,098 | 95.4 | 94,985 | 94.3 |
Urine | 89,190 | 88.5 | 96,341 | 95.6 | ||
Hair | Xa | |||||
Father (51,402 with pregnant partners) | ||||||
Questionnaire | 50,014 | 97.3b | ||||
Blood | 49,661 | 96.6b | ||||
Child (n = 101,779) | ||||||
Medical record transcription | 101,779 | 100 | ||||
Cord blood | 88,009 | 87.3c | ||||
Blood | Xa |
aWe have not yet evaluated the data.
bBetween the mother’s early pregnancy and 1 month after delivery, we distributed a questionnaire to fathers, and collected blood from them.
cResponse rate of 100,778 pregnancies.