To assess live birth after embryo transfer according to an individual's ERA results as opposed to routine protocol for frozen embryo transfer (FET) cycles.

It has been proposed, that the receptivity status of the endometrium shifts among individual women and that repeated implantation failure is ascribable to an endometrial factor in up to 25%. The endometrial receptivity analysis (ERA) is a diagnostic method that was developed based on the unique genomic signature of the endometrium during the window of implantation and classifies the endometrium as receptive, pre-receptive or post-receptive to guide embryo transfer.

The purpose of this assessor-blind, randomized clinical study is to determine whether live birth from vitrified/thawed euploid embryo transfer is improved when transfer is timed according to endometrial receptivity analysis (ERA) results.

Approximately 800 women (n=400 in each arm) will be enrolled according to the inclusion/exclusion criteria among patients of Shady Grove Fertility. Participants will undergo a standard in vitro fertilization (IVF) cycle, followed by preimplantation genetic screening (PGS) provided a high quality blastocyst is available. Participants with at least one PGS normal (euploid) embryo will be randomized (assigned by chance, like the flip of a coin) to one of two study groups. Women in both study arms will then undergo ERA testing and neither the patients nor their treating physicians will know to which group the women have been assigned to, or the ERA testing results. Up until this point there is no difference between the study and control group. The investigational aspect of this trial is described as follows: If the participant is assigned to the study arm, the single, euploid, frozen embryo transfer (FET) during the subsequent cycle will be performed at the time indicated by the ERA test results. If she is in the control arm, the embryo will be transferred according to our standard FET protocol.

Patients enrolling in the study will receive PGS and ERA free of charge.

Inclusion Criteria:

1. Signed informed consent
2. Female age between 30 and 40 years and deemed likely by her physician, based on ovarian reserve testing, to produce at least one euploid blastocyst via one IVF/intracytoplasmatic sperm injection (ICSI) cycle
3. Having ≥ 1 euploid embryo available for embryo transfer
4. Standard eligibility criteria to undergo IVF and FET at Shady Grove Fertility Center.

Exclusion Criteria:

1. Known uterine factor impacting the endometrium
2. Use of surgically aspirated sperm for fertilization
3. Presence of any clinically relevant systemic disease that contraindicates assisted reproductive technology.
4. Since the subject last had a live birth (if any), there have been more than two embryo transfers that have not resulted in ongoing pregnancy
5. Body mass index >40 kg/m2 at screening
6. Recurrent pregnancy loss, defined as two or more clinical pregnancy losses without live birth
7. Planned testing of embryos for single gene disorder(s) or structural chromosome rearrangements
8. Currently breast feeding, pregnant, or contraindication to pregnancy

Only biological female subjects will be recruited for this study as an evaluation of the endometrium requires a uterus to be present and therefore this is only possible in the biological female sex.

Results of the ERA analysis will not be disclosed to the patient or the physician or the outcome assessor, nor will the study arm to which the patient was assigned, though the patient/physician may be able to intuit assignment to the ERA arm based on the frozen embryo transfer time that she is assigned. The date and time of embryo transfer will be provided by the investigator/research team.