Endometrial Receptivity And IVF Success

Of all the fertility treatments that are currently available, In vitro fertilization (IVF) is probably the most well-known assisted reproductive technology (ART) method. The process takes 4-6 weeks to complete and involves fertilizing a woman’s eggs outside of the body before transferring the healthy embryos into the uterus. A variety of factors can impact success during the process, and in particular, endometrial health is a major issue, especially for women who’ve struggled with failed embryo transfers in previous IVF rounds, having an endometrial receptivity analysis.

What is the endometrium?

The endometrium is the inner lining in the uterus that is shed every month during menstruation. Once a girl begins puberty, hormones cause the lining to thick every month in preparation for pregnancy. If an egg isn’t fertilized and implantation does not occur, the endometrium is shed and the process repeats until menopause. During pregnancy, the endometrium is the main contact point for not only fertilization, but for the exchange of fluids and nutrients once the placenta forms.

Endometrium quality

Research has shown that an optimal endometrial thickness range exists that supports embryo implantation and sustains a pregnancy to achieve a live birth. Studies have shown that for an embryo transfer, the ideal range is between 8-14mm regardless of whether fresh or frozen eggs are used during the fertilization process. As a result, individuals with endometrial thicknesses outside this range may experience IVF failure. For women who have experienced repeated failed transfer attempts, undergoing endometrial receptivity analysis may be necessary.

What does testing do?

Endometrial receptivity analysis (ERA) is a test designed to measure the thickness of the uterine lining specifically. Additionally, the exam is designed to improve precision and timing in an IVF round. All ART treatments rely on proper timelines to create the perfect series of events that will result in not only a positive pregnancy test result, but ideally lead to a successful live birth. The ERA determines when the endometrium is at optimal thickness to support implantation after embryo transfer. When the measurement is determined, the transfer procedure can be scheduled.

What to expect

ERA is usually performed in individuals with either a history of miscarriages or documented previous failed IVF attempts. Like other fertility treatment steps, timing matters for this exam. Usually women will be prescribed either oral or injection medications to boost endometrial growth. During that time, patients will return to the fertility center to undergo several transvaginal ultrasounds and blood exams. Once the ideal timeline is reached, doctors may perform biopsies to verify endometrial quality and result in a rating of either receptive or non-receptive. If the results are not good, the embryo transfer may be delayed and hormone doses increased to improve chances for the next cycle.

The bottom line

Not all IVF participants will be encouraged to undergo ERA. Women with a history of miscarriages or failed IVF attempts should speak with a fertility specialist about having an ERA performed to fine tune the embryo transfer window and ideally increase success rates.