Table 3 Absolute and relative risk of recurrent congenital anomaly in the second pregnancy for similar anomalies (i.e. from the same group) and dissimilar anomalies (i.e. from a different group), by congenital anomaly group/subtype in the first pregnancy

Isolated anomalies

5289

91

172 ^a

(134-210)

19.90 ^a

(15.46-24.39)

<0.0001

99

185 ^a

(146-225)

1.27 ^a

(1.00-1.55)

0.05

Nervous system

744

14

188

(112-315)

12.41

(7.30-21.10)

<0.0001

17

215

(132-348)

1.41

(0.87-2.29)

0.17

Neural tube defects

482

9

187

(97-355)

12.17

(6.31-23.47)

<0.0001

7

145

(69-301)

0.95

(0.45-1.98)

0.90

Anencephaly

207

3

145

(47-443)

9.33

(3.01-28.88)

0.0002

5

242

(100-572)

1.58

(0.66-3.79)

0.30

Spina bifida

241

4

166

(62-434)

10.70

(4.01-28.52)

<0.0001

2

Hydrocephalus

98

1

4

408

(154-1040)

2.67

(1.02-6.99)

0.05

Microcephaly

52

3

581

(186-1670)

37.33

(12.25-113.7)

<0.0001

2

Cardiovascular

2282

45

197

(147-264)

3.61

(2.68-4.85)

<0.0001

34

149

(107-208)

1.33

(0.95-1.86)

0.11

Ventricular septal defect (VSD)

966

23

238

(158-357)

4.32

(2.86-6.51)

<0.0001

15

155

(94-257)

1.38

(0.83-2.29)

0.22

Atrial septal defect (ASD)

165

6

365

(164-792)

6.56

(2.97-14.49)

<0.0001

2

Pulmonary valve stenosis

198

3

152

(49-463)

2.72

(0.88-8.40)

0.09

1

Coarctation of the aorta

122

3

247

(79-745)

4.42

(1.43-13.65)

0.01

1

Orofacial clefts

398

8

201

(101-397)

32.34

(15.98-65.43)

<0.0001

6

151

(68-332)

0.93

(0.42-2.06)

0.86

Cleft lip

103

1

3

291

(94-866)

1.80

(0.59-5.49)

0.30

Cleft lip and palate

154

5

325

(136-759)

51.44

(21.39-123.7)

<0.0001

1

Cleft palate

142

2

3

211

(68-636)

1.31

(0.43-4.01)

0.64

Digestive system

371

4

108

(41-284)

14.85

(5.53-39.85)

<0.0001

8

216

(108-426)

1.34

(0.67-2.67)

0.41

Oesophageal atresia

53

0

2

Diaphragmatic hernia

79

2

3

381

(123-1118)

2.36

(0.78-7.19)

0.13

Urinary

751

16

213

(131-345)

12.29

(7.50-20.15)

<0.0001

18

240

(151-378)

1.60

(1.01-2.52)

0.05

Cystic kidney disease

145

5

344

(144-800)

19.41

(8.16-46.20)

<0.0001

3

206

(67-621)

1.37

(0.45-4.20)

0.58

Limb

244

1

4

164

(62-429)

0.99

(0.37-2.63)

0.98

Musculoskeletal

47

0

4

858

(322-2094)

5.11

(1.98-13.22)

0.001

Syndromic anomalies

2072

59

285 ^a

(209-362)

33.63 ^a

(24.40-48.86)

<0.0001

52

253 ^a

(181-325)

1.74 ^a

(1.24-2.23)

0.004

Chromosomal syndromes

1073

29

271

(189-388)

8.74

(6.06-12.60)

<0.0001

18

170

(107-268)

1.24

(0.78-1.97)

0.35

Down syndrome

536

7

131

(62-272)

4.11

(1.96-8.62)

0.0003

8

149

(75-296)

1.09

(0.55-2.18)

0.80

Genetic syndromes and microdeletions

332

18

542

(344-845)

80.95

(49.98-131.1)

<0.0001

13

391

(228-663)

2.43

(1.43-4.15)

0.002

DiGeorge syndrome

61

1

4

657

(247-1635)

4.08

(1.57-10.6)

0.005

Stickler syndrome

7

3

4326

(1319-7928)

590.8

(236.7-1475.0)

<0.0001

0

Other syndromes, sequences, etc.

209

3

143

(46-435)

32.61

(10.44-101.9)

<0.0001

6

296

(134-643)

1.80

(0.82-3.98)

0.15

Other genetic anomalies

36

5

1389

(585-2952)

1929.5

(735.7-5060.4)

<0.0001

1

Multiple congenital anomalies

344

2

14

407

(242-677)

2.52

(1.50-4.22)

0.001

Any congenital anomaly

7362

150

204 ^a

(169-239)

23.75 ^a

(19.64-27.85)

<0.0001

151

204 ^a

(169-239)

1.40 ^a

(1.16-1.64)

0.001