Maternal Hypothyroidism in Early Pregnancy and Infant Structural Congenital Malformations

Table 2

Presence of congenital malformations in infants whose mothers reported the use of thyroxin in early pregnancy (𝑛=23259) and in all infants born (𝑛=1567736).

Malformation	Number with thyroxin	Total number	OR/RR	95% CI
Any relatively severe malformation	730	48 012	1.06	0.98–1.14
Any chromosome anomaly	59	2927	1.18	0.91–1.53
Down syndrome	42	1911	1.25	0.92–1.69
Excluding chromosome anomalies
Neural tube defects	7	725	0.81	0.33–1.68^#
Other CNS malformations	22	1118	1.60	1.05–2.44
Severe eye malformations	6	577	0.84	0.34–1.74^#
Severe ear malformations	4	277	1.03	0.28–2.63^#
Choanal atresia	7	161	3.14	𝟏.𝟐𝟔--𝟔.𝟒𝟕^#
Orofacial clefts	40	2740	1.01	0.79–1.38
Cardiovascular defects	245	15891	1.05	0.92–1.19
Septal defects	171	10974	1.04	0.94–1.28
Oesophageal atresia	9	444	1.38	0.63–2.62^#
Small gut atresia	3	390	0.54	0.11–1.58^#
Anal atresia	16	588	1.85	𝟏.𝟎𝟎--𝟏.𝟖𝟓^#
Pyloric stenosis	11	1095	0.74	0.41–1.33
Abdominal wall defects	5	412	1.28	0.42–2.98^#
Diaphragmatic hernia	8	365	1.56	0.67–3.08^#
Hypospadias	70	4508	1.05	0.82–1.32
Severe kidney malformations	16	873	1.32	0.81–2.17
Pes equinovarus	28	2115	0.93	0.64–1.35
Poly- or syndactyly	38	3065	0.93	0.60–1.14
Limb reduction defects	13	826	1.13	0.65–1.96
Craniosynostosis	10	857	0.79	0.42–1.48

Odds ratio (OR) or risk ratio (RR marked^#) with 95% confidence intervals (95% CI). Bold text marks statistical significance.