P-662 Effect of rescue-dose progesterone in patients with low serum progesterone levels on the day of embryo transfer in frozen embryo transfer cycles
Authors: Bhatnagar A , Bhatnagar V 
Published: July 2024

Study question

What is the effect of rescue-dose progesterone in patients with low serum progesterone on the day of embryo transfer in frozen embryo transfer cycles?

Summary answer

In patients with low serum progesterone on the day of embryo transfer, rescue dose progesterone results in significantly higher clinical pregnancy rates.

What is known already

Frozen embryo transfer (FET) has become more common lately with many centers utilizing hormone replacement therapy (HRT) to electively plan embryo transfer with improved compliance rates. Serum progesterone level on the day of embryo transfer is a very simple, useful investigation which can be used as a predictor of clinical outcomes. Patients with lower progesterone levels (&lt;5ng/ml) are associated with lower clinical pregnancy and ongoing pregnancy rates. Progesterone levels of &gt; 10ng/ml are considered optimal by various studies. There is limited data on the efficacy of progesterone supplementation in patients with low progesterone levels.

Study design, size, duration

This study was conducted to assess the effect of rescue dose progesterone in patients with low serum progesterone levels on the day of embryo transfer in patients with HRT-FET cycles. This was a retrospective study and data was collected from prospectively maintained records of patients undergoing treatment at Miracles IVF and fertility center, Gurgaon, India between December, 2021 to November, 2023.

Participants/materials, setting, methods

All were HRT-FET cycles with vaginal progesterone supplementation of 800 mg/day. Serum progesterone levels were done on day of embryo transfer and if 5-10 ng/ml, rescue dose progesterone (100 mg intramuscular) was given. Single blastocyst embryo transfer was done.

Inclusion criteria: 1.Age 25-35 years, 2.Endometrial thickness &gt;7.5mm on day of start of progesterone.

Exclusion criteria: 1.Transfer day progesterone &lt;5ng/ml, 2. BMI &gt; 30, 3. Previously failed embryo transfer

The primary outcome was clinical pregnancy rate.

Main results and the role of chance

A total of 121 patients underwent 165 cycles during the study period with 93 patients included in the study after fulfilling the inclusion and exclusion criteria. 35 patients (37.6%) received rescue dose progesterone (RD group) and remaining 58 patients (62.4%) received no rescue dose (NRD group) as per their serum progesterone levels. All these patients were followed as per protocol and serum bhcg was done after 14 days of embryo transfer. Patients with positive values were monitored till positive clinical pregnancy. Biochemical pregnancy rates were 20 out of 35 (57.1%), 35 out of 58 ( 60.3%) and 55 out of 93 ( 59.1%) in RD group, NRD group and overall respectively. Clinical pregnancy rates were 18 out of 35 (51.4%), 34 out of 58 ( 58.6%) and 52 out of 93 ( 55.9%) in RD group, NRD group and overall respectively. RD group had significantly improved outcomes in terms of clinical pregnancy rates which were comparable to NRD group

Limitations, reasons for caution

Limitations, reasons for caution: Ours was a single center retrospective study with limited sample size. Though, our study revealed comparable outcome between the two groups but large volume multicenter studies are needed for making conclusive recommendations.

Wider implications of the findings

This study provides an insight into the role of serum progesterone levels on the day of embryo transfer. Rescue progesterone dosage for patients with sub-optimal serum progesterone levels may help in achieving similar clinical pregnancy rates and improving overall outcomes.

Trial registration number

not applicable