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Table 3 Summary of binary outcomes between pregnant women with subclinical hypothyroidism treated with and without levothyroxine in randomized controlled trials and observational studies, expressed as risk ratios (RR) with 95% confidence intervals (CI)

From: Levothyroxine and the risk of adverse pregnancy outcomes in women with subclinical hypothyroidism: a systematic review and meta-analysis

 

Observational studies

Randomized controlled trials

Outcomes

No. of studies

Risk ratio

(95% CI)*

No. of studies

Risk ratio

(95% CI)

Fetal

 Intrauterine growth restriction

2

1.06 (0.59 to 1.90)

0

NA

 Placenta abruption

2

1.06 (0.81 to 1.38)

3

0.93 (0.01 to 101.99)

 Spontaneous abortion

1

0.46 (0.12 to 1.84)

3

0.44 (0.03 to 6.83)

 Pregnancy loss (still births and

spontaneous abortions)

4

0.81 (0.62 to 1.05)

6

0.51 (0.25 to 1.05)

Perinatal

 Postpartum hemorrhage

2

1.16 (1.06 to 1.27)

1

0.33 (0.06 to 1.89)

 Premature rupture of membranes

3

0.94 (0.52 to 1.70)

0

NA

 Preterm delivery

3

0.82 (0.13 to 4.98)

4

0.72 (0.39 to 1.35)

 Preterm labour

2

1.05 (0.56 to 1.97)

0

NA

 Still birth

4

0.75 (0.39 to 1.42)

0

NA

Neonatal

 APGAR under 7 at five minutes

2

0.24 (0.00 to 68,937.70)*

1

0.66 (0.11 to 3.95)

 Low birth weight

3

0.55 (0.03 to 11.63)

2

0.86 (0.00 to 3722.22)

 Neonatal death

1

0.37 (0.02 to 6.83)

1

0.33 (0.01 to 8.13)

  1. NA –non-applicable
  2. *There were no events in the levothyroxine exposed groups