Abstract：
OBJECTIVE: We aimed to perform a systematic review and meta-analysis addressing the efficacy of levothyroxine therapy in pregnant women with subclinical hypothyroidism considering most recent evidence and subgroups of interest for clinical practice.
METHODS: PubMed, Embase, and Cochrane Central were searched from inception for randomized controlled trials (RCTs) comparing levothyroxine with placebo or no intervention in pregnant women with subclinical hypothyroidism. We used a random-effects model and conducted subgroup analyses based on thyroid peroxidase antibody status, thyroid stimulating hormone levels, fertility treatment, and recurrent miscarriage.
RESULTS: We included 11 RCTs comprising 2,749 pregnant women with subclinical hypothyroidism. Patients treated with levothyroxine (1,439; 52.3%) had significantly lower risk of pregnancy loss (risk ratio 0.69; 95% confidence interval 0.52-0.91; p < 0.01; 6 studies). However, there was no significant association between levothyroxine and live birth (risk ratio 1.01; 95% confidence interval 0.99-1.03; p = 0.29; 8 studies). No statistically significant interaction was observed across subgroups (p > 0.05).
CONCLUSIONS: Levothyroxine replacement therapy for subclinical hypothyroidism during pregnancy may decrease pregnancy loss when early prescribed. Nevertheless, further investigation is needed in patients with thyroid stimulating hormone above four milliunits per liter, especially when associated with recurrent miscarriage or infertility.
METHODS: PubMed, Embase, and Cochrane Central were searched from inception for randomized controlled trials (RCTs) comparing levothyroxine with placebo or no intervention in pregnant women with subclinical hypothyroidism. We used a random-effects model and conducted subgroup analyses based on thyroid peroxidase antibody status, thyroid stimulating hormone levels, fertility treatment, and recurrent miscarriage.
RESULTS: We included 11 RCTs comprising 2,749 pregnant women with subclinical hypothyroidism. Patients treated with levothyroxine (1,439; 52.3%) had significantly lower risk of pregnancy loss (risk ratio 0.69; 95% confidence interval 0.52-0.91; p < 0.01; 6 studies). However, there was no significant association between levothyroxine and live birth (risk ratio 1.01; 95% confidence interval 0.99-1.03; p = 0.29; 8 studies). No statistically significant interaction was observed across subgroups (p > 0.05).
CONCLUSIONS: Levothyroxine replacement therapy for subclinical hypothyroidism during pregnancy may decrease pregnancy loss when early prescribed. Nevertheless, further investigation is needed in patients with thyroid stimulating hormone above four milliunits per liter, especially when associated with recurrent miscarriage or infertility.
摘要：
目的：我们的目的是进行一项系统评价和荟萃分析，探讨左甲状腺素治疗对亚临床甲状腺功能减退孕妇的疗效，并考虑最新证据和对临床实践感兴趣的亚组。
方法：PubMed，Embase,和CochraneCentral从一开始就在亚临床甲状腺功能减退症孕妇中比较了左甲状腺素与安慰剂或无干预的随机对照试验(RCTs).我们使用随机效应模型，并基于甲状腺过氧化物酶抗体状态进行亚组分析，促甲状腺激素水平,生育治疗,和复发性流产。
结果：我们纳入了11项随机对照试验，包括2,749例亚临床甲状腺功能减退症孕妇。接受左甲状腺素治疗的患者（1,439;52.3％）妊娠丢失的风险显着降低（风险比0.69;95％置信区间0.52-0.91;p<0.01;6项研究）。然而,左旋甲状腺素与活产之间无显著关联(风险比1.01;95%置信区间0.99-1.03;p=0.29;8项研究).在各亚组之间没有观察到统计学上显著的相互作用(p>0.05)。
结论：妊娠期间亚临床甲状腺功能减退症的左甲状腺素替代治疗可以减少妊娠丢失。然而，甲状腺刺激激素高于每升4毫单位的患者需要进一步调查，特别是当与复发性流产或不孕症相关时。
方法：PubMed，Embase,和CochraneCentral从一开始就在亚临床甲状腺功能减退症孕妇中比较了左甲状腺素与安慰剂或无干预的随机对照试验(RCTs).我们使用随机效应模型，并基于甲状腺过氧化物酶抗体状态进行亚组分析，促甲状腺激素水平,生育治疗,和复发性流产。
结果：我们纳入了11项随机对照试验，包括2,749例亚临床甲状腺功能减退症孕妇。接受左甲状腺素治疗的患者（1,439;52.3％）妊娠丢失的风险显着降低（风险比0.69;95％置信区间0.52-0.91;p<0.01;6项研究）。然而,左旋甲状腺素与活产之间无显著关联(风险比1.01;95%置信区间0.99-1.03;p=0.29;8项研究).在各亚组之间没有观察到统计学上显著的相互作用(p>0.05)。
结论：妊娠期间亚临床甲状腺功能减退症的左甲状腺素替代治疗可以减少妊娠丢失。然而，甲状腺刺激激素高于每升4毫单位的患者需要进一步调查，特别是当与复发性流产或不孕症相关时。
