from Knaus-Ogino . . .

think backwards, count forward

The Austrian gynecologist Hermann Knaus first demonstrated at a gynecologist's congress in Leipzig 90 years ago that in the monthly cycle of a woman there are specific times when she can become pregnant. He was able to show that each month women have fertile and infertile days. 

Around the same time, the Japanese Kyusaku Ogino made the same discovery. It was a sensation.

Until then, people believed that women could become pregnant at any time!

Ogino examined the ovaries as part of gynecological operations. Knaus discovered the laws through physiological experiments. In 1923, Ogino published that ovulation was related to the subsequent menstruation and not to the previous one. Knaus contributed essential findings on the duration of ovum fertility and the ability of sperm to fertilize.

The Knaus-Ogino method is based on the assumption that the duration of ovum fertilization is only ten hours . At the same time it is assumed that sperm has a maximum lifespan of three days and the luteal phase after ovulation lasts exactly 14 days (+/– 2 days).Therefore, the time frame with the highest likelihood for a pregnancy is limited to a few days each month. Assuming the woman has a relatively regular cycle.

Before the Knaus-Ogino method can be used safely, the woman first needs to count and document the number of days from one menstruation to the next for about a year. Then the average cycle duration will be calculated. This way the highest probability for the time of ovulation can be determined. However, the aggregated 12-month data doesn't document any patterns arising from the documentation.


to cylceduc®

count backward, plan forward

With cycleduc® the Knaus-Ogino method becomes more granular, because all cycles, longer or shorter, are visible and show the complete range of cycle variations as well as cycle rhythms.

The big advantage of cycleduc® is that no averages are formed and they are not used to predict a possible future ovulation.

Basically, every day in a woman's cycle is documented individually. In the first step, the only distinction is between days of bleeding (red) and days without bleeding (white). In the second step, at the end of each cycle, the potentially fertile days of that cycle are marked in color (green) after counting backwards (15 days). This is repeated cycle by cycle.

Each cycle image allows individual conclusions about interpretation: regular or irregular cycles can occur, as can patterns in the variation of cycle lengths that follow a certain rhythm. Visually, the women can be given an intended frame around the green crosses, which can be narrow or wide or follow a zigzag pattern. This visual approach enables a very easy-to-understand yet meaningful, self-based prediction of fertile days.

Clear advantage: Women receive an increasingly accurate cycle picture, which enables a more and more precise prediction of the fertile and infertile days as well as the beginning of the coming menstruation.

Natural methods – an overview

Why did we decide on precisly this method after Knaus-Ogino instead of other choices of natural family planning (NFP)?

Considering the ethnological point of view – including cultural and religious ones – we consider the possibilities of the NFP to be limited. Especially the symptothermal method is unsuitable, since there is no guarantee that women can carry out both vaginal examinations (cervical mucus) and temperature measurements in a protected space. 
Outside the western world the female body is still considered taboo in many places. The fertile times in the cycle can be determined woman through this this kind of body observation, but it requires learning self-observation and cycle evaluation correctly. This is precisely where we see the problem of acceptance and feasibility due to the social and personal situation of many women and girls worldwide.
The birthcontrol chain also serves as a female menstrual calendar. A flexible ring is pushed over the drops in one direction once a day. However, the woman has no overiew of her individual cycle history, but only the standard model which may or may not fit her cycle. If her cycle differs her prediction is not safe and the Pearl index rises. 

The Pearl Index measures the safety of a contraceptive method. Its value is mainly calculated theoretically. Therefore, data on the Pearl Index can vary. For example, the Pill has a value between 0.1 and 0.9. The Pearl Index of a condom is between 2 and 12. The NFP has 0.4 to 1.8, but only in combination with total celibacy during fertile days. The Pearl Index for the Knaus-Ogino-method is 9, while intercourse without contraception is 85.