Impact of Serum Progesterone Levels on Embryo Transfer Day on Clinical Pregnancy

Impact of Serum Progesterone Levels on Embryo Transfer Day on Clinical Pregnancy in Frozen-thawed Embryo Transfer Cycles Using Hormone Replacement Therapy: a Prospective Observational Study

Hypotheses:

We hypothesize that serum progesterone levels on the day of embryo transfer in HRT-FET cycles are positively associated with clinical pregnancy rates.

Aims:

To evaluate the relationship between serum progesterone levels on embryo transfer day and clinical pregnancy outcomes in frozen-thawed embryo transfer cycles using hormone replacement therapy (HRT).

Primary outcome:

To compare the incidence of clinical pregnancy outcome in those infertility patients undergoing frozen embryo transfer with caterized Progesterone level on the day of embryo transfer

Secondary outcomes:

Biochemical pregnancy rate. Implantation rate. Early pregnancy loss rate. Ectopic pregnancy rate.

Study Overview

• Status: Recruiting
• Conditions: Reproductive Issues

• Study Type: Observational
• Enrollment (Estimated): 370

Contacts and Locations

Study Locations

• China
  • Hong Kong, China
    • Recruiting
    • The Chinese University of Hong Kong
    • Contact: Chung PW Pui Wah, Jacqueline; Phone Number: 35051537; Email: jacquelinechung@cuhk.edu.hk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

All infertility patients undergoing FET at the Assisted Reproductive Technology Unit of the department of Obstetrics and Gynecology in the Prince of Wales Hospital

Description

Inclusion Criteria:

• Patients undergoing FET cycles
• Infertility patients aged >18 years old and < 42 years old
• BMI < 30 kg/m2
• Transfer of at least one good-quality embryo.

Exclusion Criteria:

• Severe endocrine disorders (e.g., thyroid dysfunction, premature ovarian failure).
• Severe uterine factors without treatment (severe endometriosis, extensive or subendometrial fibroid, uterine adherent, endometrial polyps)

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical pregnancy rate (CPR)	Rate of clinical pregnancy outcome in subjects undergoing FET	6 weeks of gestation and ultrasound scanning will be performed to confirm at least one gestational sac around 1 to 3 months after FET

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Biochemical pregnancy rate	Rate of biochemical pregnancy outcome in subjects undergoing FET	Up to 12 weeks
Implantation rate	Rate of implantation in subjects undergoing FET	Up to 12 weeks
Early pregnancy loss rate	Rate of early pregnancy loss in subjects undergoing FET	Up to 12 weeks
Ectopic pregnancy rate	Rate of Ectopic pregnancy in subjects undergoing FET	Up to 12 weeks

Collaborators and Investigators

• Sponsor: Chinese University of Hong Kong

Study record dates

Study Major Dates

• Study Start (Actual): January 20, 2026
• Primary Completion (Estimated): June 30, 2028
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: January 29, 2026
• First Submitted That Met QC Criteria: January 29, 2026
• First Posted (Actual): February 5, 2026

Study Record Updates

• Last Update Posted (Actual): May 11, 2026
• Last Update Submitted That Met QC Criteria: May 8, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 2025.875

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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