Table 3.

Advisory committee-confirmed clinically major birth defects^a

Birth defect/s	Maternal age, years	Pregnancy outcome	Gestational age,b weeks	Duration of IM IFNβ-1a exposure during pregnancy (weeks)	Confounding factors	Temporally attributed to IM IFNβ-1a exposure?
Hypospadias	35	Live birth	34.1	4.1	–	No
Hypospadias	27	Live birth	40.1	3.4	–	No
Hypospadias	36	Live birth	36.6	6.0	–	No
Down syndrome	35	Live birth	38.4	4.1	Advanced maternal age	No known causec
Down syndrome	39	Stillbirth	32.4	6.1	Advanced maternal age	No known causec
Marcus Gunn syndrome	32	Live birth (twin)	31.4	1.3	–	No
Marcus Gunn syndrome	30	Live birth	39.4	2.6	–	No known causec
Amniotic band syndrome	29	Live birth	27.9	5.6	–	Unknown
Bilateral hearing loss	33	Live birth	39.1	2.0	–	Unknown
Sensory hearing loss	34	Live birth	38.1	1.0	–	No
Club feet	36	Live birth	37.1	4.1	–	Unknown
Diaphragmatic hernia	26	Live birth	41.0	18.3	–	Unknown
Hydronephrosis	22	Live birth	33.1	0.6	–	No
Interrupted aortic arch and esophagus	32	Live birth	39.9	3.9	–	Unknown
Pyloric stenosis	36	Live birth	39.3	4.3	–	Unknown
Spina bifida	28	Elective abortion	23.4	5.0	–	Unknown
Trisomy 8 mosaicism	30	Elective abortion	22.1	4.0	–	Unknown

IFNβ-1a interferon beta-1a, IM intramuscular

^aConfirmed clinically major birth defects in live births and fetal losses > 20 weeks’ gestation

^bGestational age at identification of the birth defect

^cGeneticist coded the defect as a defect with a known cause; therefore, temporality may be irrelevant. Shaded rows represent birth defects clustered in cases of ≥ 2