Screening and subsequent management for thyroid dysfunction pre‐pregnancy and during pregnancy for improving maternal and infant health

Background Thyroid dysfunction pre‐pregnancy and during pregnancy (both hyper‐ and hypothyroidism) is associated with increased risk of adverse outcomes for mothers and infants in the short‐ and long‐term. Managing the thyroid dysfunction (e.g. thyroxine for hypothyroidism, or antithyroid medication for hyperthyroidism) may improve outcomes. The best method of screening to identify and subsequently manage thyroid dysfunction pre‐pregnancy and during pregnancy is unknown. Objectives To assess the effects of different screening methods (and subsequent management) for thyroid dysfunction pre‐pregnancy and during pregnancy on maternal and infant outcomes. Search methods We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (14 July 2015) and reference lists of retrieved studies. Selection criteria Randomised or quasi‐randomised controlled trials, comparing any screening method (e.g. tool, program, guideline/protocol) for detecting thyroid dysfunction (including hypothyroidism, hyperthyroidism, and/or thyroid autoimmunity) pre‐pregnancy or during pregnancy with no screening, or alternative screening methods. Data collection and analysis Two review authors independently assessed eligibility of studies, extracted and checked data accuracy, and assessed the risk of bias of included studies. Main results We included two randomised controlled trials (involving 26,408 women) ‐ these trials were considered to be at low risk of bias. Universal screening (screening all women) versus case finding (screening only those at perceived increased risk) in pregnancy for thyroid dysfunction One trial (4562 women) compared universal screening with case finding for thyroid dysfunction. Before 11 weeks' gestation, women in the universal screening group, and 'high‐risk' women in the case finding group had their sera tested for TSH (thyroid stimulating hormone), fT4 (free thyroxine) and TPO‐Ab (thyroid peroxidase antibody); women with hypothyroidism (TSH > 2.5 mIU/litre) received levothyroxine; women with hyperthyroidism (undetectable TSH and elevated fT4) received antithyroid medication. In regards to this review's primary outcomes, compared with the case finding group, more women in the universal screening group were diagnosed with hypothyroidism (risk ratio (RR) 3.15, 95% confidence interval (CI) 1.91 to 5.20; 4562 women; GRADE: high quality evidence), with a trend towards more women being diagnosed with hyperthyroidism (RR 4.50, 95% CI 0.97 to 20.82; 4562 wome