Sickle cell disease (SCD) is an inherited blood disorder where red blood cells adopt a rigid, crescent shape, leading to blockages and various health complications. Sickle cell trait (SCT) means a person is a carrier, having inherited one sickle cell gene and one normal gene, and rarely experiences symptoms. A man with SCD or SCT can certainly impregnate a woman. However, the primary consideration is not his physical capacity to conceive, but the genetic risks involved in family planning. Careful pre-conception planning is necessary to understand and manage the inheritance risk to the child.
Sickle Cell Disease and Male Fertility
The chronic nature of the disease can affect male reproductive health. The constant presence of sickled cells can lead to blockages in the small blood vessels supplying the testes, potentially causing testicular dysfunction and impaired sperm production. Studies show that men with SCD often exhibit lower sperm counts, reduced sperm motility, and an increase in abnormally shaped sperm compared to unaffected men.
Priapism, a prolonged and painful erection, is a common complication experienced by many men with SCD. This can cause long-term damage to erectile tissue, potentially leading to sexual dysfunction. Low levels of testosterone (hypogonadism) are also reported in about 25% of men with SCD, which can further affect fertility and libido. Despite these potential complications, SCD does not automatically result in sterility, and many men with the condition successfully father children.
Genetic Risk and Inheritance Patterns
The most important consideration for a couple pursuing conception is the probability of the child inheriting the condition. Sickle cell disease is inherited in an autosomal recessive pattern, meaning a child must receive an abnormal gene from both parents. The father’s genotype will be either SCD (HbSS) or SCT (HbAS), and the mother’s status is the determining factor for the child’s risk.
Father Has SCD
If the father has SCD and the mother is completely unaffected, all children will inherit the sickle cell trait and be carriers. If the mother is a carrier, there is a 50% chance the child will inherit SCD and a 50% chance the child will inherit SCT. In this pairing, no child will be completely unaffected.
Father Has SCT
If the father has the sickle cell trait and the mother is completely unaffected, none of the children will have SCD. The highest risk occurs when both parents are carriers. This results in a 25% chance of the child having SCD, a 50% chance of the child having SCT, and a 25% chance of the child being completely unaffected.
Pre-Conception Screening and Planning
Genetic screening for both partners is the essential first step in family planning due to the variable risks. A blood test, such as hemoglobin electrophoresis, determines if the woman is a carrier for the sickle cell gene or related hemoglobin disorders. If the father has SCD or SCT, the mother must be tested to calculate the precise risk to the child.
Following screening, consultation with a genetic counselor is highly recommended. Counselors specialize in explaining inheritance probabilities and helping couples make informed decisions based on their personal values. For couples at high risk of having a child with SCD, specialized reproductive options exist. These options provide diagnostic information, allowing the couple to prepare for the birth of a child with SCD or consider other choices:
- Preimplantation genetic diagnosis (PGD), performed with in vitro fertilization (IVF), tests embryos for SCD genes before transfer to the uterus.
- Prenatal diagnosis, such as chorionic villus sampling (CVS) or amniocentesis, can test the fetus for SCD early in the pregnancy.
Health Considerations for the Father
The father’s own health management is important during the conception process. Maintaining stable disease management is paramount, which includes adhering to prescribed medications and avoiding known triggers for painful crises. A man with SCD should discuss all current medications, including hydroxyurea, with his hematologist and a fertility specialist when planning conception.
Hydroxyurea, a common treatment for SCD, may reduce sperm concentration. The care team can advise on whether temporary discontinuation or adjustment of medication is necessary before attempting conception. The father having sickle cell disease does not increase the medical risk to the mother during pregnancy, but the mother will be monitored for typical high-risk factors.