Increased pregnancy rate with use of the Clearblue Easy Fertility Monitor

Fertil Steril. 2007 Feb;87(2):329-34. doi: 10.1016/j.fertnstert.2006.05.054. Epub 2006 Oct 30.


Objective: To determine the effect on pregnancy rates through use of the Clearblue Easy Fertility Monitor (CEFM) in women trying to conceive.

Design: Prospective study, in which volunteers were randomly assigned either to use or not to use the CEFM. All participants could also use other aids to conception. Data were self-reported by volunteers using daily diaries, supplied and collected by mail.

Setting: Home use, under conditions normally experienced by over-the-counter purchasers of the marketed device.

Patient(s): Women who were trying to conceive; 653 (CEFM 305, control 348) provided evaluable information.

Intervention(s): CEFM was used for two cycles.

Main outcome measure(s): Cumulative pregnancy rates over two cycles of use.

Result(s): The cumulative pregnancy rate for 2 cycles was significantly higher in the CEFM group (22.7%) compared with the control group (14.4%). More women who had been trying to conceive for <6 months became pregnant than women who had been trying to conceive for >6 months (odds ratio: 2.67). Previous pregnancy and younger age of partners were also significant prognostic factors, but use of other aids to conception was not. After adjustment for other factors, CEFM use remained a significant factor affecting the chance of conceiving within two cycles (odds ratio: 1.89). CEFM users found the device to be easy/very easy to use (90%) and convenient/very convenient (80%).

Conclusion(s): Use of the CEFM increases the likelihood of getting pregnant during the first two cycles of use compared with its nonuse, in women who had been trying to conceive for up to 2 years.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Equipment Failure Analysis
  • Female
  • Humans
  • Ovulation Detection / instrumentation*
  • Ovulation Detection / statistics & numerical data*
  • Pregnancy
  • Pregnancy Outcome / epidemiology*
  • Pregnancy Rate*
  • Self Care / instrumentation*
  • Self Care / statistics & numerical data*
  • Treatment Outcome
  • United Kingdom / epidemiology