Participating in the study

This study is for previous or current users of the OvuSense and OvuFirst devices. To help you to decide whether to take part in the study please see the OvuSense Participant Information Sheet (PDF, 121kB).

If, after reading the participant information sheet, you decide to complete the questionnaire, please access the questionnaire here.

Your questionnaire responses will be submitted to viO HealthTech (the company owning and selling OvuSense). viO HealthTech will provide your questionnaire data to the OvuFAST research team for this research study. viO HealthTech may also use your data (please contact support@ovusense.com if you wish to know more about how viO HealthTech will use your data).

What does this study aim to do?

We are interested in finding ways to identify when ovulation occurs, and to understand when and why the timing of ovulation differs between women. In this new study we will utilise the OvuSense intra-vaginal temperature sensor or OvuFirst wearable fertility monitor to better understand the patterns of temperature change and how these relate to the timing of ovulation. 

In this study, we will use data on women who have chosen to use the OvuSense or OvuFirst devices. We will use their temperature data to identify different menstrual cycle patterns. We aim to evaluate whether basal body temperature measured vaginally every 5 minutes overnight (i.e. “continuous” measurement rather than just one measure each morning) may enable more accurate prediction of ovulation, compared to temperature charts that informed current guidelines. We also aim to evaluate whether ovulation can be predicted more than one day in advance, such that ‘timed intercourse’ need not be acute. We will explore whether device effectiveness varies by subgroups of women (e.g. with or without regular menstrual periods).

Who is doing this study?

This study will be carried out by researchers at the MRC Integrative Epidemiology Unit at the University of Bristol, a leading centre for research into women’s reproductive health and for analysing complicated data with lots of repeat measurements (such as the repeat OvuSense/OvuFirst temperature data).

Research team

• Dr Louise Millard (Principal Investigator), Senior Lecturer in Health Data Science
• Prof Tom Gaunt, Professor of Health and Biomedical Informatics
• Prof Deborah Lawlor, Professor of Epidemiology

Why vaginal temperature data?

Timing of the fertile window (the 6 days ending on the day of ovulation) varies across women and across cycles, even in women with regular menstrual periods. A woman’s resting core body temperature changes across the menstrual cycle due to changes in progesterone levels. Typically, basal body temperature (lowest resting body temperature) exhibits a biphasic pattern, increasing at ovulation and remaining high until menstruation. Women have used measures of their temperature to aid conception or as a form of contraception for centuries. Currently, women using this method typically use a temperature chart, measuring their basal body temperature once each day when they wake, and this pattern is also seen in core body temperature measurements. UK (NICE) and international guidelines do not recommend using such temperature charts because previous research suggests that ovulation prediction using them is not accurate, and acutely timed intercourse may cause stress.

OvuSense is a device worn vaginally overnight. It predicts ovulation one day in advance using core body temperature measured every 5 minutes. Since it was first marketed in 2013, OvuSense has been used by over 15,000 women in the US and Europe.