After ejaculation, sperm have to be able to swim through the cervix to reach the Fallopian Tube where fertilization of the egg occurs. However, the interactions of sperm and cervical mucus that allow this migration are often disrupted in fertility patients. It is thought that at least a third (if not more) of subfertile couples have some disruption of sperm-cervical mucus interactions that limit sperm transport to the tubes.The importance of normal cervical mucus in natural reproduction is widely recognized. For most of a woman’s cycle the cervical mucus is a thick gel and hostile to sperm, with a low pH and a structure that stops sperm transport by the presence of closely spaced microfibers. During ovulation however, the cervical mucus becomes more alkaline (higher pH), and the fibers align in parallel with an expanded distance between them. This allows the sperm to swim through the mucus. Normally, the volume of daily cervical mucus also increases 5 fold at ovulation. Cervical mucus is a hydrogel of 90% water, and its primary function appears to be bathing sperm in a fluid medium to protect them during transport. The presence of sugar-proteins in the gel that holds the water is controlled by hormone changes at ovulation (especially the presence of estrogen). These sugars increase the mucus gel’s capacity to hold water, expand fiber spacing, and allow sperm migration. Taken together, these changes permit sperm to rapidly swim through the cervix and proceed to the Fallopian Tube for fertilization.
In women with poor sperm-cervical mucus interaction, there is a reduction in cervical mucus fiber spacing making sperm migration difficult, a primary cause of which in many women may be inadequate water in the gel. This may be caused by advancing age (with low grade hormonal disruptions) and following the use of fertility medication such as clomiphene citrate (CC or clomid). CC is a widely prescribed fertility drug. In fact, it has become increasingly used as a first line therapy for couples with fertility issues. With easy internet access, many women are also taking CC without doctor oversight. Estimates are that 40% of couples with fertility problems utilize CC at some point for the woman. Although its widespread use has helped many couples conceive, it does cause significant problems with vaginal dryness and cervical production production and function. Specifically, numerous studies have shown that CC causes decreases in: volumes of cervical mucus; quality of cervical mucus (“egg-white like appearance”) and sperm penetration into cervical mucus. In fact, women on CC are seven times more likely to have “hostile” cervical mucus that is difficult for sperm to penetrate than are women not on the medication.
Women on CC also have an increased prevalence of vaginal dryness, which can cause pain at intercourse and decrease enjoyment for the man (which can decrease sperm counts). Many women on CC (which is already making them prone to poor sperm-cervical mucus penetration) are therefore also using lubricants that can harm sperm such as KY, Astroglide and Replens. These women may be creating a vaginal environment that limits sperm transport. Pre~Seed “sperm-friendly” Intimate Moisturizer can replenish vaginal moisture without harming sperm. A clinical trial is also planned to evaluate the effect of Pre~Seed on sperm and cervical mucus interactions, especially for women on Clomid.
Dr. JE Ellington, recipient of the 2003 International Young Andrologist Award for her research in sperm-Fallopian Tube physiology invented Pre~Seed through her work with infertile couples.