The technology

Proov Confirm (MFB Fertility) is designed to confirm ovulation across the implantation window. It measures pregnanediol‑3a‑glucuronide (PdG) in the first morning urine during the luteal phase of the menstrual cycle. PdG is a hormone marker released after ovulation that supports implantation.

Proov Confirm is a disposable lateral flow test strip, which has a test area and a control area. The urine sample is applied to the strip by dipping. The sample moves by lateral flow into the test area, and then into the control area. The test area contains PdG-specific reagents on it which detect hormone metabolites in urine. The control area contains antibodies that are an internal control for proper assay function. The technology is intended for use outside the body (in vitro diagnostic use) and provides qualitative results, with a single red line indicating a positive result and 2 red lines indicating a negative result for PdG in urine.

A Proov Confirm test result can be read by eye or paired with an optional smartphone application that provides quantitative results of the test. The smartphone application is used as a logging tool that provides test reminders, results, and an ovulation insight report at the end of the testing period. A Proov Confirm pack contains 5 tests. The first test is used early in the menstrual cycle to establish a baseline, and the result is expected to be negative. The remaining 4 tests are used during the key implantation window, which takes place on days 7 to 10 after peak fertility. Users track their peak fertility either by using a luteinising hormone (LH) test, a fertility tracking device, or cervical mucus production.


The technology provides non-invasive monitoring of luteal phase health in natural cycles. It is an over-the-counter product that does not need a GP or hospital visit. The company says that Proov Confirm detects elevated PdG levels across the full implantation window to confirm that hormone levels are sustained, indicating successful ovulation and promoting the highest chance of pregnancy. The company also claims that Proov Confirm can help prevent early miscarriages caused by low progesterone levels, through detection of a luteal phase defect. There is no published evidence to support this claim.

Current care pathway

Standard care involves offering people having investigations for infertility a blood test to measure serum progesterone in the mid-luteal phase of their cycle to confirm ovulation. In the case of an irregular menstrual cycle, blood tests may need to be done later in the cycle and repeated weekly thereafter until the next cycle. A clinical expert noted that in certain instances, ovulation detection could include repeated examination for an LH peak, and repeated ultrasound examination.

The following publication has been identified as relevant to this care pathway: NICE's guideline on fertility problems: assessment and treatment.

Population, setting and intended user

Proov Confirm is intended to be used to confirm ovulation for people who are trying to conceive. Proov Confirm can be used at home and in primary care settings, including GPs.


Technology costs

The cost of Proov Confirm is £24.99 per pack (excluding VAT) per month of testing. A Proov Confirm pack contains 5 tests. The smartphone application is free to download.

Costs of standard care

Based on the national schedule of NHS costs for 2020 to 2021, the average cost of a clinical biochemistry (progesterone blood test category) pathology service is £1.85.

Resource consequences

The technology is not currently used in the NHS. It would be used as an alternative to standard care in a primary care setting or at home. The technology costs more than standard care but if adopted could result in earlier or more accurate detection of ovulation disorders. The company claims that providing the product for use in the NHS will reduce healthcare costs by diagnosing ovulation disorders that lead to infertility and early miscarriages, reducing the need for fertility treatments such as in vitro fertilisation (IVF). There is very limited published evidence to support these claims.