Gestational Age Specific Thyroid Function Reference Range

Gestational Age Specific Thyroid Function Reference Range in Hong Kong

It has been well accepted that maternal thyroid dysfunction has adverse affects on both mothers and fetuses. However, the dramatical changes during pregnancy make the interpretation of thyroid function test (TFT, i.e. free triiodothyronine [FT3], free thyroxine [FT4] and thyrotropin [TSH]) very difficult. Previous studies have shown that the level of thyroid hormones differs from non-pregnant population and varies from gestational ages. Moreover, studies have shown the agreement among different instrument platforms was quite low. This study is aimed to determine gestational age specific TFT reference ranges of the local pregnant population for all available platforms currently used under Hospital Authority and Department of Health.

Study Overview

• Status: Completed
• Conditions: Pregnancy; Thyroid; Reference Values

• Study Type: Observational
• Enrollment (Actual): 599

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 50 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

• Sampling Method: Probability Sample

Study Population

Hong Kong women

Description

Inclusion Criteria:

• Pregnant women receiving pregnancy and postnatal care in the Department of Obstetrics & Gynaecology, Prince of Wales Hospital, Hong Kong

Exclusion Criteria:

• 1. Previous history of thyroid dysfunction (hypothyroidism or hyperthyroidism);
• 2. Autoimmune disease, particularly those receiving corticosteroid or immunosuppressant: e.g. systemic lupus erythematosus;
• 3. Disease associated with thyroid dysfunction: e.g. molar pregnancy

Study Plan

How is the study designed?

Design Details

• Observational Models: Ecologic or Community
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
pregnant women; pregnant women in Hong Kong

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of free triiodothyronine (FT3) during pregnancy	gestational FT3 level	At the time of booking for antenatal visit (1st trimester), oral glucose tolerance test (24-32 weeks), admission for delivery (3rd trimester) and a gestational age assigned randomly.
Change of free thyroxine (FT4) during pregnancy	gestational FT4 level	At the time of booking for antenatal visit (1st trimester), oral glucose tolerance test (24-32 weeks), admission for delivery (3rd trimester) and a gestational age assigned randomly.
Change of thyrotropin (TSH) during pregnancy	gestational TSH level	At the time of booking for antenatal visit (1st trimester), oral glucose tolerance test (24-32 weeks), admission for delivery (3rd trimester) and a gestational age assigned randomly.

Collaborators and Investigators

• Sponsor: Chinese University of Hong Kong
• Investigators: Principal Investigator: Wing Hung Tam, MD, Chinese University of Hong Kong

Study record dates

Study Major Dates

• Study Start (Actual): July 2, 2014
• Primary Completion (Actual): April 30, 2016
• Study Completion (Actual): April 30, 2016

Study Registration Dates

• First Submitted: August 21, 2018
• First Submitted That Met QC Criteria: September 6, 2018
• First Posted (Actual): September 10, 2018

Study Record Updates

• Last Update Posted (Actual): September 10, 2018
• Last Update Submitted That Met QC Criteria: September 6, 2018
• Last Verified: September 1, 2018

More Information

Terms related to this study

• Keywords: Pregnancy; Thyroid; Reference values
• Additional Relevant MeSH Terms: Endocrine System Diseases; Thyroid Diseases
• Other Study ID Numbers: CUHK_TMP00159

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided
• IPD Plan Description: To be confirmed.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No