To evaluate whether the measurement of urinary estrone glucuronide and luteinizing hormone (LH) concentrations with an at-home device is correlated with serum hormone levels within a natural cycle frozen embryo transfer protocol.

The hypothesis is that home urinary monitoring can reliably detect the LH surge and serve as a trigger for timing the FET. Results of this study may ultimately lead to change in clinical practice by reducing the number of clinic visits for serum monitoring, offering a more convenient, time and cost saving method of detection of LH surge. If the proposed protocol were feasible and widely accepted by patients, this would prompt the wide adoption of a less invasive but equally as effective FET protocol.

A prospective multi-center cohort study evaluating the anticipated utility of the Mira device for detection of the LH surge, in natural cycle frozen embryo transfer protocols. All patients scheduled for undergoing natural cycle frozen embryo transfers at The Ottawa Fertility Centre (Ottawa, Ontario, Canada) and Olive Fertility Centre (Vancouver, British Columbia, Canada) with the ability to provide informed consent for participation will be eligible for inclusion. Each individual patient may only be included once in the study.

The objective of the proposed study is to evaluate whether the use of home urinary testing of quantitative estradiol metabolites and LH can be used to accurately predict ovulation and serve as a trigger for the gold standard of serum LH monitoring in a natural cycle protocol for frozen embryo transfer (FET). Its anticipated that this at home device will provide a reliable alternative to daily bloodwork, thereby reducing the number of daily visits for serum monitoring and also increased satisfaction and quality of life with the implementation of their use within these cycles.

Estrone glucuronide (E3G) and Pregnanediol-3-Glucoronide (PdG) are the major metabolites of estradiol (E2) and progesterone that can be measured in the urine. Similarly, LH is another hormone that is commonly measured during natural cycle FET cycles and can also be quantified in the urine. Urinary E3G, LH and PdG measurement are commercially available with an FDA and CE registered home device called the Mira Fertility Tracker ("Mira"). Correlation between the serum hormones and their respective urinary metabolites has been established but the efficacy of monitoring urinary E3G and LH has not been demonstrated in the context of natural cycle FET.

Therefore the study will take place within a true natural cycle protocol, whereby ovulation occurs spontaneously and is not triggered with exogenous hormones. Patients meet to discuss the approach to FET with their physician prior to proceeding with treatment. Patients are considered to be candidates for natural cycle protocol if they have regular menstrual cycles, ranging in length between 27-35 days and no luteal phase concern (i.e. significant luteal phase spotting, or evidence of a short luteal phase).

Inclusion Criteria:

• All patients scheduled for a natural cycle frozen embryo transfer
• Agree to participate in the research study

Exclusion Criteria:

• There are no exclusions

Participants that are presenting for a natural cycle frozen embryo transfer at The Ottawa and Olive Fertility Centre's