Table 2 Characteristics of Transient and Permanent Congenital Hypothyroidism

Sex

Male

222 (52.4 %)

116 (53.2 %)

0.838

Female

202 (47.6 %)

102 (46.8 %)

Birth Weight (g)^a

2912.8 ± 629.1 (N = 418)

2931.1 ± 666.7 (N = 216)

0.733

Height^a

48.8 ± 3.9 (N = 407)

48.5 ± 4.0 (N = 198)

0.475

Parental consanguinity^a

Absent

182 (44.7 %)

118 (60.8 %)

< 0.001*

Present

225 (55.3 %)

76 (39.2 %)

Age at start of treatment (day)

25.19 ± 25.14

26.39 ± 22.34

0.583

Initial LT4 dose (µg)

41.77 ± 22.59

39.36 ± 22.07

0.232

TSH level at first measurement

Age at measurement (days)

5.58 ± 5.72

5.14 ± 3.88

0.346

TSH concentration level (mIU/L)

mean ± SD (Median, IQR)

28.33 ± 47.62 (6.70, 5.00–19.60)

11.43 ± 25.27 (5.65, 5.00–8.73)

< 0.001*

TSH level at second measurement

Age at measurement (days)

14.25 ± 9.98

14.65 ± 8.58

0.664

TSH concentration level (mIU/L)

mean ± SD (Median, IQR)

25.00 ± 39.55 (8.20, 5.20–20.42)

13.8 ± 24.56 (7.10, 5.00–12.63)

< 0.001*

Season^a

Spring

87 (21.4 %)

48 (23.4 %)

0.849

Summer

98 (24.1 %)

46 (22.4 %)

Autumn

124 (30.5 %)

58 (28.3 %)

Winter

98 (24.1 %)

53 (25.9 %)

Method of delivery^a

Normal vaginal delivery

194 (46.7 %)

113 (57.4 %)

0.014*

Cesarean section

221 (53.3 %)

84 (42.6 %)

Family history of CH^a

Absent

306 (74.6 %)

145 (74.4 %)

0.942

Present

104 (25.4 %)

50 (25.6 %)

Serum TSH concentrations by each visit (mIU/L)^a

mean ± SD (Median, IQR)

First visit (confirmatory venous TSH, Initial TSH)

34.51 ± 31.51 (20.00, 10.50–55.30)

N = 259

21.12 ± 21.98 (12.95, 8.33–23.35)

N = 124

< 0.001

Second visit

13.92 ± 27.22 (4.48, 1.04–12.00)

N = 201

8.86 ± 15.99 (2.90, 1.47–8.27)

N = 85

0.052

Third visit

5.68 ± 12.19 (2.38, 0.92–5.41)

N = 198

4.51 ± 9.77 (1.77, 0.49–3.40)

N = 71

0.467

Fourth visit

4.89 ± 9.18 (2.59, 1.00–5.00)

N = 191

3.43 ± 4.19 (2.10, 1.20–4.48)

N = 67

0.212

Fifth visit

4.23 ± 7.76 (2.00, 0.80–5.35)

N = 181

2.79 ± 1.95 (2.44, 1.36–3.65)

N = 64

0.023*

Sixth visit

4.48 ± 9.04 (2.50, 1.28–4.43)

N = 174

3.32 ± 2.44 (2.94, 1.68–4.29)

N = 64

0.122

Seventh visit

4.80 ± 6.96 (2.90, 1.50–5.43)

N = 170

3.08 ± 2.40 (3.06, 1.28–3.84)

N = 56

0.006*

Eight visit

5.09 ± 9.33 (2.57, 1.36–4.70)

N = 179

3.39 ± 3.47 (2.90, 1.51–4.27)

N = 49

0.049*

Ninth visit

6.17 ± 14.68 (2.83, 1.24–5.28)

N = 144

3.03 ± 1.41 (3.39, 1.96–3.83)

N = 44

0.013*

Tenth visit

8.09 ± 38.14 (2.60, 1.20–5.10)

N = 155

3.25 ± 1.42 (3.23, 2.01–4.47)

N = 40

0.424

LT4 dose by end of each year (µg/kg)^a

First year

4.69 ± 2.38 (N = 221)

4.48 ± 2.73 (N = 79)

0.521

Second year

4.36 ± 2.24 (N = 198)

3.82 ± 2.43 (N = 68)

0.097

Third year

3.99 ± 1.99 (N = 180)

3.37 ± 2.32 (N = 46)

0.072