The effect of Levothyroxine on pregnancy outcome of pregnant women with subclinical hypothyroidism and negative thyroid peroxidase antibody

Phase 2

• Conditions: Condition 1: Abortion. Condition 2: Preterm labor. Condition 3: Low birth weight. Condition 4: Intra uterine growth restriction. Condition 5: Premature rupture of membranes. Condition 6: Third trimester hemorrhage.; Spontaneous abortion; Preterm labour and delivery; Placenta previa, Premature separation of placenta [abruptio placentae]; O44 , O45; Disorders related to short gestation and low birth weight, not elsewhere classified; Slow fetal growth and fetal malnutrition; Premature rupture of membranes

• Registration Number: IRCT2013121214849N3
• Lead Sponsor: Shahid Beheshti University of Medical Sciences

Brief Summary

Context Currently, there is no consensus on universal thyroid screening and levothyroxine (LT4) treatment of pregnant women with subclinical hypothyroidism (SCH) who are negative for thyroid peroxidase antibody (TPOAb-). Objective We aimed to evaluate the benefits of LT4 treatment on pregnancy outcomes in SCH-TPOAb- women. Design This study was conducted within the framework of the Tehran Thyroid and Pregnancy Study. A single-blind randomized clinical trial was undertaken in pregnant women who were SCH-TPOAb-. Setting Prenatal care centers of the Shahid Beheshti University of Medical Sciences. Patients Using the thyrotropin (TSH) cut point of 2.5 mIU/L, 366 SCH-TPOAb- and 1092 euthyroid TPOAb- women were recruited. Intervention SCH-TPOAb- women were randomly assigned to two groups: group A (n = 183) who were treated with LT4 and group B (n = 183) who received no treatment. A total of 1,028 euthyroid TPOAb- women served as the control group (group C). Main Outcome Measure The primary outcome was the rate of preterm delivery. Results Using the TSH cutoff of 2.5 mIU/L, no significant difference in preterm delivery was observed between groups A and B [relative risk (RR): 0.86; 95% confidence interval (CI): 0.47 to 1.55; P = 0.61]. However, log-binomial model analysis based on a cut point of 4.0 mIU/L demonstrated a significantly lower rate of preterm delivery in LT4-treated women compared with those who received no treatment (RR: 0.38; 95% CI: 0.15 to 0.98; P = 0.04). Conclusions Despite no beneficial effect of LT4 therapy in reducing preterm delivery in SCH-TPOAb- women with a TSH cut point of 2.5 to 4 mIU/L, LT4 could precisely decrease this complication using the newly recommended cutoff =4.0 mIU/L.

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Last Update Posted: 11 September 2018

Recruitment & Eligibility

• Status: Complete
• Sex: Female
• Target Recruitment: 1600

Inclusion Criteria

pregnant women during the first 20 weeks of pregnancy.

Exclusion Criteria

contraindication of Levothyroxine use include: patients with severe cardiovascular diseases such as coronary heart failure, history of myocardial infarction, uncontrolled hypertension

Study & Design

• Study Type: interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Abortion. Timepoint: Up to 20 weeks of pregnancy (In cases that intervention begins in first trimester). Method of measurement: Checklist.;Preterm labor. Timepoint: 20 to 37 weeks of pregnancy (within 1 to 6 months after intervention). Method of measurement: Checklist.;Low birth weight. Timepoint: After birth (5 to 7 months after intervention). Method of measurement: Checklist.;Intra uterine growth restriction. Timepoint: 5 to 7 months after intervention. Method of measurement: Checklist.;Premature rupture of membranes (PROM). Timepoint: 5 to 7 months after intervention. Method of measurement: Checklist.;Third trimester hemorrhage. Timepoint: Third trimester (2 to 5 months after intervention). Method of measurement: Checklist.;TSH level of newborn at birth (day 3 to5 births). Timepoint: 3 to 5 days after birth (5 to 7 months after intervention). Method of measurement: Immunoradiometric assay (IRMA).