Characteristics Study
Waller et al. [32] Stott-Miller et al. [46] Watkins et al. [58]
Ethnicity/race Cases No.
(%)		 Non-Hispanic white 6230 (60.8)
Black 1047 (10.2)
Hispanic 2394 (23.4)
Other 555 (5.4)
Missing 23 (0.2) 		White 1674 (80)
Black/African American 51 (2)
American Indian/Alaska Native 73 (4)
Asian 121 (6)
Hawaiian/Pacific Islander 10 (1)
Hispanic/Latino 167 (8)
Other 2 (0) 		59% white
41% others
Controls No.
(%)		 Non-Hispanic white 2439 (60)
Black 487 (12)
Hispanic 952 (22.8)
Other 203 (5)
Missing 11 (0.3) 		White 13617 (77)
Black/African American 722 (4)
American Indian/Alaska Native 419 (2)
Asian 1073 (6)
Hawaiian/Pacific Islander 72 (0)
Hispanic/Latino 1682 (10)
Other 6 (0) 		55% white
45% others
Recruitment

sources 		Case National Birth Defects
Prevention Study (NBDPS)
population in 8 states:
Arkansas, Iowa, Massachusetts,
New Jersey, Georgia,
California, Texas, and New York		 Birth Certificate in Washington state Metropolitan Atlanta
Congenital Defects Program
Control Birth certificates of 8 states:
Arkansas, Iowa, Massachusetts,
New Jersey, Georgia, California,
Texas, and New York		 Birth Certificate in Washington state Hospitals registered with
the Atlanta Birth Defects Risk
factor Surveillance study
Inclusion criteria Case Live birth
Fetal death
Pregnancy termination 		Live birth with
(ICD-9 diagnostic codes):
749 (CP) or 749.1 (CL) or 749.2 (CLP) 		Live birth
Fetal death
Pregnancy termination
Control Live birth
(randomly selected
without malformations)		 Live birth
(random sample without
diagnosis of orofacial)		 Live birth
(stratified random sample
without malformations)
Exclusion criteria Case Chromosomal abnormalities,
diabetes 		Chromosomal abnormalities,
diabetes 		Chromosomal abnormalities,
diabetes
Control Diabetes Diabetes Diabetes
Response rate of
maternal interview
for weight
and height information		 Case 71.4% N/A N/R
Control 67.9% N/A N/R

N/R = not reported; N/A = not applicable, CL = cleft lip; CP = cleft palate; CLP = cleft lip with or without palate.