From the Research
An estrogen level of 75 pg/mL is generally considered too low for a frozen embryo transfer (FET) in a medicated IVF cycle, and increasing the estrogen dose may be necessary to achieve optimal endometrial development and implantation success. For optimal endometrial development and implantation success, estrogen levels should typically reach at least 150-200 pg/mL before progesterone is introduced 1. If your level is only 75 pg/mL, your reproductive endocrinologist would likely increase your estrogen supplementation or extend the duration of estrogen therapy before proceeding with transfer. Common estrogen medications include oral estradiol (Estrace) at 2-6 mg daily, estradiol valerate injections (10-20 mg every 3-5 days), or transdermal estrogen patches (0.1-0.2 mg patches changed every other day). The goal is to achieve adequate endometrial thickness (typically 7-9 mm) with a trilaminar pattern and sufficient estrogen levels to support implantation. Low estrogen levels may result in inadequate endometrial development, potentially reducing the chances of successful embryo implantation. Your doctor should monitor your levels and adjust medication accordingly before proceeding with the transfer.
Some key points to consider:
- The optimal endometrial preparation protocol for FET is still a topic of debate, and more research is needed to determine the best approach 2, 3.
- The timing of FET and the use of progesterone supplementation can also impact success rates 4, 5.
- Increasing the estrogen dose during FET cycles may not necessarily improve pregnancy rates, despite achieving thicker endometrium 1.
- The clinical pregnancy rates were similar between the increased-dose and fixed-dose groups, suggesting that the optimal estrogen dose may vary from patient to patient 1.
It's essential to work closely with your reproductive endocrinologist to determine the best course of treatment and adjust your medication regimen as needed to achieve optimal estrogen levels and endometrial development.