Important terms on the topic of a desire for children and the Ritex Kinderwunsch conception lubricant

Acrosome Reaction

In order to get into the ovum, the sperm must first break down the protective embryonic membrane. In order to do this, the sperm releases certain enzymes – this process is called an acrosome reaction.¹ The acrosome reaction is triggered by proteins in the jelly coat of the ovum as well as by the hormone progesterone, which is emitted by the ovum. Since a sperm can only perform the acrosome reaction once, it is very important for fertilisation that it only be triggered near to the ovum.


Fertilisation occurs when a healthy sperm meets a healthy ovum and can penetrate through the ovum wall. This requires both the acrosome reaction and the hyperactivation of the sperm. The chromosomes from the sperm and the ovum merge into a new set of chromosomes, which completes fertilisation of the ovum. The cell division of the fertilised ovum (also called a zygote) starts approximately 24 hours following fertilisation.


Chemotaxis refers to the navigation of cells or organisms along chemical signposts, so-called attractants. The hormone progesterone, which is emitted by cells surrounding the ovum, presumably serves as an attractant for sperm. There is evidence that men whose sperm do not react to progesterone are infertile. However the sperm react not only to progesterone, but also to other partly foreign substances and mixtures of substances. It is known that everyday chemicals with a (coincidental) hormonal-effect of the natural attractants and messengers on the sperm.4


An ovum carries the female genetic information that is necessary to conceive a child. With a diameter of between 0.11 and 0.14 mm, it can just about be seen with the naked eye. The (immature) ova are already present in the ovaries at birth.  In a sexually mature, healthy woman, several ova mature each cycle for fertilisation, but usually only one ovum is actually released. 

A woman has about 6 days per cycle during which she is fertile: 4 days before ovulation (as sperm can survive for up to 4 days in the vaginal tract), the day of ovulation itself and one day after ovulation (as the ovum remains in the fallopian tube for approx. 24 hours and is therefore accessible to the sperm). The highest probability for fertilisation is on the day of ovulation.


Fertility starts when a man or a woman becomes sexually mature. While a man retains his fertility even into old age, a woman’s fertility is limited to the time of the menopause (from about the age of 50). Statistically, a woman is most fertile between the ages of 20 and 25. From the age of 30, a woman’s fertility drops rapidly. As a rule of thumb, a woman aged 35 years is only half as fertile as a woman aged 25 years and a woman aged 40 years is only half as fertile as a woman aged 35 years.6 Due to individual factors, fertility in both men and women can deviate significantly from the average.

Hormone-like substances

Hormone-like substances or chemicals with a hormonal effect imitate the effect of the body’s hormones or impair their function. Studies show that approximately 30% of the most frequently occurring hormone-like substances (e.g. certain parabens and phthalates) can interfere with sperm function. It is therefore assumed that the generally observed decrease in fertility in industrialised countries is also attributable to the prevalence of hormone-like substances.4


This is the hyperactivation of sperm. The swimming behaviour of sperm depends, among other things, on the concentration of the hormone progesterone. The higher its concentration, the faster and straighter the sperm swims. Above a certain concentration, the sperm becomes hyperactive (i.e. swims forwards at maximum speed) and the acrosome reaction is triggered. Both hyperactivation and the acrosome reaction are necessary for fertilisation.

DNA integrity

An important prerequisite for the procreation of a healthy child is the integrity of the genetic information from the sperm and ovum, which is also referred to as “DNA integrity”. We are particularly referring to the sperm’s DNA integrity, as this possibly comes into contact with lubricants introduced from outside (external). The fertile/fertilised egg, on the other hand, moves only into the uterus and therefore does not come into contact with external lubricants.

The study of DNA integrity is important because the functionality of a sperm is not related to the integrity of the genetic information: it is therefore possible that apparently normal sperm carry damaged genetic information and are therefore unsuitable for the procreation of a healthy child.7

In vitro

The imitation and investigation of organic processes under laboratory conditions is referred to as “in vitro” (in contrast, the investigation of processes in living organisms is referred to as “in vivo”). In vitro studies are usually carried out in order to be able to specifically investigate individual processes, which is often not possible due to the complex conditions in vivo.


Preservatives are used to kill pathogens such as viruses, bacteria, fungi, etc. As with many lubricants, it is also necessary to use preservatives so that they do not spoil quickly. The problem with many preservatives is that they can also exert a damaging effect on sperm, which limits the speed of movement or the life span of the sperm.


See vaginal lubrication.


The motility of sperm is the ability of sperm to move by itself. Progressive motility is referred to when the sperm move in a specific direction.


This is the external appearance of the sperm, i.e. the shape of the head, the flagellum, etc. Changes in the morphology can, for example, lead to limitation of sperm movement.

Non-fertile days

Each woman is only able to become pregnant on the fertile days per cycle. Therefore, all other days during the cycle are referred to as non-fertile or infertile days.


Osmolality, or osmotic pressure, indicates in this context whether fluid is withdrawn from or added to a cell as a result of the environment. For sperm, this value is particularly important, as both too high and too low osmolality lead to the sperm becoming inactive or even dying off.²


Orgasm is also referred to as a climax during sexual intercourse and for men usually produces an ejaculation. In women, an orgasm produces a variety of reactions, such as contractions of the uterus and the release of various sex hormones. Although, in contrast to the male ejaculation, the female orgasm is not necessary for conception, it’s assumed that it does improve the likelihood of conception.

pH value

The pH value indicates whether an environment is acidic, neutral or alkaline. Studies have shown that sperm display the best activity within a pH range of 7.2 to 8.5.5 Vaginal pH is generally constant at about 4 and is therefore significantly too acidic for sperm. However, during fertile days, the vaginal pH value increases to approximately 7, so that it becomes a sperm-friendly environment.


A sperm carries the male genetic information that is necessary to conceive a child. A sperm is approx. 0.06 mm long and is therefore significantly smaller than an ovum. It is made up of a head, midsection and tail/flagellum. Sperm are produced in the seminiferous tubules of the testicles from sexual maturity until old age. A man can produce up to 100 million sperm every day. That’s over 1,100 sperm every second.


According to WHO guidelines from 2010, the following standard parameters are considered “normal” in a spermiogram:

  • Ejaculate volume 1.4-1.7 ml
  • Sperm count greater than 39 million
  • Progressive motility in at least 32% of the sperm
  • Normal morphology in 3.0-4.0% of the sperm
  • Proportion of living sperm of at least 50%

However, recent studies suggest that the average sperm count in industrialised countries is now below these levels.

Vaginal lubrication

Vaginal lubrication, also called vaginal moisture, facilitates, among other things, the penetration of the penis during sexual intercourse. The amount of lubrication depends on several factors such as sexual arousal, diet, well-being and/or stress and hormone status. A lack of lubrication can lead to sexual intercourse being uncomfortable for both partners and reduce the likelihood of reaching orgasm. There is also the risk for the woman of injury to the mucous membrane of the vaginal, thereby increasing the risk of an infection in the vaginal area.8


The higher the viscosity of a liquid, the thicker it is. Sperm move best in the viscosity of the cervical mucus on the fertile days.³ If the viscosity is higher, the sperm are slowed down and require more energy for movement. If the viscosity is lower, then the sperm begin to “wriggle” which also consumes more energy than normal.


For vitality, the number or percentage of living sperm is the factor considered.

Cervical mucus

Cervical mucus is located in the cervix and during infertile days serves as a barrier for the uterus against germs but also against other foreign bodies, e.g. sperm. On fertile days, however, the cervical mucus changes its consistency significantly and becomes permeable to sperm. For this reason, it is also possible to indicate the fertile days with the help of the cervical mucus: If you can draw out threads that are 6-15 cm longwith the cervical mucus (“spinnability”), the woman is in her fertile days.


  1. Konservierungsstoffe, Pestizide, UV-Blocker und Co.: Wie Alltagschemikalien die Spermienfunktion beeinträchtigen, C. Schiffer, A. Müller, T. Stünker, Jahresbericht 2014 Forschungszentrum CAESAR
  2. Role of seminal osmolarity in the regulation of human sperm motility, M. Rossato et al., international journal of andrology, 25:230–235 (2002)
  3. Spermatozoa scattering by a microchannel feature: an elastohydrodynamic model, T.D. Montenegro-Johnson et al., royal society open science
  4. Aktenzeichen XY gelöst: Die Progesteronwirkung auf menschliche Spermien, T. Strünker et al., Jahresbericht 2010 Forschungszentrum CAESAR
  5. Effect of vaginal lubricants on sperm motility and chromatin integrity: a prospective comparative study, A. Argwal et al., fertility and sterility Vol 89 2008
  6. Problematik und Wahrscheinlichkeit einer Schwangerschaft, J.-C. Spira, Gynäkologie 2008
  7. Human sperm DNA integrity in normal and abnormal semen samples and its correlation with sperm characteristics, A.C. Varghese, Blackwell Verlag GmbH 2009
  8. To Lube or Not to Lube: Experiences and Perceptions of Lubricant Use in Women With and Without Dyspareunia, S. Boyer and C.F. Pukall, journal of sexual medicine 2011