Ignite Creation Date:
2025-12-24 @ 5:20 PM
Ignite Modification Date:
2025-12-25 @ 2:56 PM
Study NCT ID:
NCT07257250
Status:
RECRUITING
Last Update Posted:
2025-12-17
First Post:
2025-11-20
Is NOT Gene Therapy:
False
Has Adverse Events:
False
Brief Title:
Levothyroxine Treatment and IVF Outcomes in Women With Subclinical Hypothyroidism: A Target Trial Emulation
Sponsor:
Mỹ Đức Hospital
Organization:
Study Overview
Official Title:
Effectiveness of Levothyroxine Treatment on In Vitro Fertilization and Pregnancy Outcome in Women With Subclinical Hypothyroidism and Infertility: A Target Trial Emulation
Status:
RECRUITING
Status Verified Date:
2025-12
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
LESI
Brief Summary:
Subclinical hypothyroidism (SCH) is defined by elevated thyroid-stimulating hormone (TSH) with normal free thyroxine (fT4) levels. It affects approximately 5-7% of women of reproductive age and may negatively influence outcomes of assisted reproductive technology (ART). During controlled ovarian stimulation, rising estradiol increases thyroxine-binding globulin and thyroid hormone requirements. These physiological changes, combined with increased metabolic demand in early pregnancy, may worsen SCH and contribute to adverse outcomes such as miscarriage, preterm birth, and hypertensive disorders of pregnancy.
Although levothyroxine (LT4) is routinely used to treat overt hypothyroidism, evidence for its benefit in SCH, especially among infertile women undergoing In Vitro Fertilization (IVF) or Intra-Cytoplasmic Sperm Injection (ICSI) with frozen embryo transfer (FET), remains inconclusive. Some trials and meta-analyses have shown reductions in miscarriage and neonatal mortality, while others have found no improvement in ART or obstetric outcomes.
This study aims to evaluate the effectiveness of levothyroxine therapy on IVF/FET outcomes and subsequent pregnancy results in women with subclinical hypothyroidism and infertility. This retrospective cohort study will emulate the target trial to evaluate whether LT4 treatment, titrated to achieve a pre-transfer TSH \< 2.5 mIU/L, improves implantation, live birth, and obstetric outcomes compared with expectant management.
Although levothyroxine (LT4) is routinely used to treat overt hypothyroidism, evidence for its benefit in SCH, especially among infertile women undergoing In Vitro Fertilization (IVF) or Intra-Cytoplasmic Sperm Injection (ICSI) with frozen embryo transfer (FET), remains inconclusive. Some trials and meta-analyses have shown reductions in miscarriage and neonatal mortality, while others have found no improvement in ART or obstetric outcomes.
This study aims to evaluate the effectiveness of levothyroxine therapy on IVF/FET outcomes and subsequent pregnancy results in women with subclinical hypothyroidism and infertility. This retrospective cohort study will emulate the target trial to evaluate whether LT4 treatment, titrated to achieve a pre-transfer TSH \< 2.5 mIU/L, improves implantation, live birth, and obstetric outcomes compared with expectant management.
Detailed Description:
This study is a target trial specified (a randomized controlled trial between the Intervention (Exposed) Group and the Control (Unexposed) Group).
* Intervention (Exposed) Group: Women treated with levothyroxine 25-50 µg/day initiated before the planned FET, titrated every 2-4 weeks to achieve TSH \< 2.5 mIU/L before transfer.
* Control (Unexposed) Group: Women managed expectantly without thyroid medication (Before 2020, LT4 use was at the discretion of clinicians; since 2020, the Reproductive Endocrinology Unit has standardized treatment for most SCH patients)
The target trial is emulated using observational data of infertile women aged 18-45 years diagnosed with subclinical hypothyroidism, defined as TSH 4.2-\<10 mIU/L and FT4 0.92-1.68 ng/dL, undergoing IVF/ICSI followed by FET in My Duc Hospital and My Duc Phu Nhuan Hospital (Ho Chi Minh City, Vietnam), using routinely collected medical records from January 1, 2019, to December 31, 2024.
* Intervention (Exposed) Group: Women treated with levothyroxine 25-50 µg/day initiated before the planned FET, titrated every 2-4 weeks to achieve TSH \< 2.5 mIU/L before transfer.
* Control (Unexposed) Group: Women managed expectantly without thyroid medication (Before 2020, LT4 use was at the discretion of clinicians; since 2020, the Reproductive Endocrinology Unit has standardized treatment for most SCH patients)
The target trial is emulated using observational data of infertile women aged 18-45 years diagnosed with subclinical hypothyroidism, defined as TSH 4.2-\<10 mIU/L and FT4 0.92-1.68 ng/dL, undergoing IVF/ICSI followed by FET in My Duc Hospital and My Duc Phu Nhuan Hospital (Ho Chi Minh City, Vietnam), using routinely collected medical records from January 1, 2019, to December 31, 2024.
Study Oversight
Has Oversight DMC:
False
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?: