Association Between Isolated Maternal Hypothyroxinemia and Adverse Maternal and Infant Outcomes.

AIM: The current meta-analysis aims to assess the incidence of isolated maternal hypothyroxinemia (IMH) and its impact on pregnancy complications and adverse pregnancy outcomes. METHODS: PubMed, Embase, Web of Science, and Cochrane databases were searched until November 15, 2024. Cochrane, a risk-of-bias assessment tool, was used to evaluate the quality of literature; R Studio and Stata 15.0 were employed for data analysis and publication bias assessment. RESULTS: In total, 22 cohort studies were analyzed, with a sample size of 33,1640 cases, including 16 390 IMH patients. The meta-analysis revealed that the prevalence of IMH was 5.7% (95% CI: 3.5, 8.4%). Compared to pregnant women with normal thyroid function, the prevalence of gestational diabetes mellitus (GDM) in IMH patients was 1.12% (95% CI: 1.01,1.24), macrosomia was 1.41% (95% CI: 1.12, 1.65), preterm birth was 1.26% (95% CI: 1.12, 1.41), and preeclampsia/eclampsia was 1.26% (95% CI: 1.12, 1.41) (p < 0.05). CONCLUSIONS: Patients with IMH have an elevated risk of GDM, preeclampsia, eclampsia, preterm birth, and macrosomia relative to normal pregnant women. It is anticipated that future studies will further confirm the complications related to pregnancy in patients with IMH.