A varicocele is an enlargement of the veins within the loose pouch of skin holding the testicles, known as the scrotum. This condition is similar to a varicose vein that can occur in the legs, and it affects 15% to 20% of the adult male population. The primary concern for many couples is whether a varicocele can cause birth defects in a child.
Understanding Varicocele
A varicocele forms when the valves inside the testicular veins, which are part of the pampiniform plexus, malfunction. These valves normally ensure that blood flows one-way, from the testicles back toward the heart. When the valves fail, blood pools in the veins, leading to their abnormal enlargement and twisting.
This pooling of blood is often more common on the left side due to anatomical differences in the venous drainage system. The stagnation of blood can elevate the temperature around the testicles, which are designed to function a few degrees cooler than the rest of the body. While many men with a varicocele experience no symptoms, others may notice a feeling of heaviness, a dull ache, or visible, twisted veins.
Varicocele and Genetic Integrity
Varicocele does not cause congenital birth defects or structural abnormalities in a developing fetus. The condition’s impact is not on the fetal development process itself but rather on the quality of the paternal genetic material before conception. The elevated scrotal temperature and poor blood flow resulting from the varicocele lead to an increase in harmful chemicals called reactive oxygen species (ROS).
This state, known as oxidative stress, damages the sperm’s genetic material. Specifically, it causes high levels of Sperm DNA Fragmentation (SDF), which means there are breaks or nicks in the strands of DNA contained within the sperm head. Although this damage affects the integrity of the sperm’s DNA, it typically does not result in the major structural birth defects that concern most parents.
Impact on Conception and Fertility
The compromised DNA integrity and altered testicular environment have consequences for reproductive outcomes. Varicocele is the most frequent alteration found in men presenting with infertility, affecting 35% to 40% of those cases. The condition can negatively impact basic semen parameters, often leading to a reduced sperm concentration (oligozoospermia), poor sperm movement (asthenozoospermia), and abnormal sperm shape (teratozoospermia).
High levels of SDF are particularly concerning because they are associated with adverse outcomes even when using assisted reproductive technologies (ART). Embryos derived from sperm with fragmented DNA may have lower implantation rates and are less likely to develop normally. Furthermore, male partners with a varicocele and high SDF levels have been linked to an increased risk of recurrent miscarriage in their female partners.
Treatment and Management Strategies
Treatment for varicocele is typically considered when the condition causes pain, is associated with testicular shrinkage, or is contributing to male factor infertility. Non-surgical management options include wearing supportive underwear or using over-the-counter anti-inflammatory drugs to alleviate discomfort. However, these approaches do not resolve the underlying anatomical issue.
For men with impaired semen quality or high SDF, surgical or interventional repair is often recommended. Procedures like microsurgical varicocelectomy or percutaneous embolization aim to block the affected veins, redirecting blood flow to healthy pathways. The goal of these interventions is to improve sperm parameters, reduce sperm DNA fragmentation, and enhance the chances of achieving a successful pregnancy.