Content area
Full Text
In 1990, Austrian chemist Carl Djerassi, who discovered the synthetic progestin used in the first birth control pill, expressed concern about existing contraceptive methods and predicted fertility awareness and family planning through biochemical measurement of endogenous hormones at home.1 Today, multiple fertility monitors are available that provide couples with accurate biochemical measurement of the fertile window to plan or avoid pregnancy, without potential side effects associated with other contraceptive methods. In this article, we review two new hormone-based personal fertility monitors that can be used for contraception.
Fertility monitoring involves biochemical identification of the fertile period and avoidance of intercourse, or use of other precautions, during this brief stage. The current understanding of the menstrual cycle is that an ovum in wo men of reproductive age is released once per cycle and is typically fertilizable for 12-24 hours, whereas sperm are typically viable for three to five days. In a series of studies by the World Health Organization in the 1970s, measurable changes in serum estradiol levels were found to signal the onset of potential fertility, and surges in luteinizing hormone levels were confirmed as the best predictor of impending ovulation.2 Subsequently, rising urine levels of estrone-3-glucuronide were found to correlate with rising serum estradiol levels and potential fertility,3 whereas surges in urine levels of luteinizing hormone accurately predicted impending ovulation. These findings showed that serum samples were no longer needed.
How do fertility monitors work?
The measurement of estrone-3-glucuronide and luteinizing hormone levels in urine to identify the fertile period was the premise in the development of two family-planning devices that first came to market about 10 years ago. The Persona monitor (Swiss Precision Diagnostics GmbH, Switzerland) was marketed for contraception; although currently available only in Europe, the device may be purchased in North America via the Internet. The second device was marketed for assistance in achieving pregnancy; it is distributed as Clearblue Easy and Clearplan Easy in North America and Europe (Swiss Precision Diagnostics GmbH) and as Clearview Primera in Japan (Mitsui Pharmaceuticals Inc., Japan). Using the same technology to indicate fertility, the Persona and Clearblue Easy fertility monitors use a urine-based test strip with antibodies to estrone-3-glucuronide and luteinizing hormone that detect elevated concentrations of these compounds.
Differences exist between the user...