Associations between severe and notifiable respiratory infections during the first trimester of pregnancy and congenital anomalies at birth: a register-based cohort study

Table 2 Rate of congenital anomalies according to type of infection during the first trimester of pregnancy and odds ratios for association^a

	n/N (%)	OR (95% CI)	Adjusted OR (95% CI)^b
Major congenital anomalies
Acute respiratory infection
No	15,486/1441327 (1.07)	Ref	Ref
Yes	22/1547 (1.42)	1.33 (0.88, 2.03)	1.33 (0.88, 2.02)
Influenza
No	15,612/1450187 (1.08)	Ref	Ref
Yes	4/399 (1.00)	0.94 (0.35, 2.5)	0.95 (0.36, 2.54)
High-risk infections^c
No	15,630/1452026 (1.08)	Ref	Ref
Yes	1/129 (0.78)	0.71 (0.10, 5.20)	0.72 (0.1, 5.27)
Cleft lip and palate
Acute respiratory infection
No	2222/1441327 (0.15)	Ref	Ref
Yes	1/1547 (0.06)	0.43 (0.06, 2.91)	0.43 (0.06, 2.9)
Influenza
No	2239/1450187 (0.15)	Ref	Ref
Yes	1/399 (0.25)	1.62 (0.22, 11.66)	1.68 (0.23, 12.18)
High-risk infections^b/
No	2240/1452026 (0.15)
Yes	0/129 (0)
Selected cardiovascular anomalies^d
Acute respiratory infection
No	1724/1441327 (0.12)	Ref	Ref
Yes	7/1547 (0.45)	3.79 (1.80, 7.99)	3.64 (1.73, 7.66)
Influenza
No	1739/1450187 (0.12)	Ref	Ref
Yes	1/399 (0.25)	2.10 (0.3, 14.86)	2.04 (0.29, 14.42)
High-risk infections^c
No	1745/1452026 (0.12)
Yes	0/129 (0)
All major cardiovascular anomalies (ICD AM Q20–25)
Acute respiratory infection
No	7671/1441327 (0.53)	Ref	Ref
Yes	14/1547 (0.90)	1.70 (1.00, 2.89)	1.68 (0.99, 2.84)
Influenza
No	7745/1450187 (0.53)	Ref	Ref
Yes	2/399 (0.50)	0.95 (0.24, 3.75)	0.95 (0.24, 3.78)
High-risk infections^c
No	7758/1452026 (0.53)	Ref	Ref
Yes	1/129 (0.78)	1.45 (0.20, 10.45)	1.41 (0.19, 10.26)

BOLD type indicates p < 0.05
^aOnly first trimester analysis is included in the Table 2. We have kept infections in 2nd/3rd trimester in analyses as a separate group, but they are not shown in the table. Results of 2nd/3rd trimesters are presented in the supplementary tables (S4, S5 and S6)
^bAdjusted for maternal age group at delivery, smoking during pregnancy, remoteness of area of residence, quartile of socioeconomic status based on area of residence, previous pregnancy, country of birth, hospital of delivery, the number of weeks pregnant at first antenatal visit, Indigenous status, hypertension, and diabetes
^cTORCH and other known causes of congenital anomalies
^dAs per Australian reporting - Abeywardana S & Sullivan EA 2008. Congenital anomalies in Australia 2002–2003. Birth anomalies series no. 3 Cat. no. PER 41. Sydney: AIHW National Perinatal

ISSN: 1471-2393