Interpretation of Controversial Teratogenic Findings of Drugs Such As Phenobarbital

Table 1

Characteristics of mothers.

Maternal variables	Case mothers				Control mothers
	without		with		without		with
	phenobarbital treatment				phenobarbital treatment
	(𝑁=22,694)		(𝑁=149)		(𝑁=37,942)		(𝑁=209)
	no.	%	no.	%	no.	%	no.	%
Quantitative
Maternal age (yr)
24 or less	10,876	47.9	69	46.3	17,882	47.1	112	53.6
25–29	7,106	31.3	48	32.2	12,823	33.8	62	29.7
30 or more	4,712	20.8	32	21.5	7,237	19.1	35	16.7
Mean ± S.D.	25.5±5.3		25.7±5.5		25.5±4.9		25.0±4.8
Birth order
1	10,636	46.9	72	48.3	18,095	47.7	114	54.6
2 or more	12,058	53.1	77	51.7	19,847	52.3	95	45.4
Mean ± S.D.	1.9±1.1		1.7±0.9		1.7±0.9		1.6±0.9
Categorical
Unmarried	1,264	5.6	5	3.4	1,462	3.9	9	4.3
Employment status
Professional	1,882	8.3	19	12.7	4,335	11.4	18	8.6
Managerial	4,931	21.7	37	24.8	10,076	26.6	58	27.7
Skilled worker	6,291	27.7	38	25.5	11,624	30.6	66	31.6
Semiskilled worker	3,835	16.9	34	22.8	5,744	15.1	39	18.7
Unskilled worker	1,492	6.6	11	7.4	1,843	4.9	16	7.7
Housewife	2,122	9.4	6	4.0	2,034	5.4	4	1.9
Others	2,141	9.4	4	2.7	2,286	6.0	8	3.8