Turner Syndrome is a chromosomal condition exclusively affecting females, resulting from the complete or partial absence of one of the two X chromosomes. This genetic difference leads to a range of physical and medical characteristics, varying significantly among individuals. A common concern for individuals with Turner Syndrome and their families is fertility and the possibility of pregnancy.
How Turner Syndrome Affects Fertility
The primary impact of Turner Syndrome on fertility stems from its effect on ovarian development and function. Females with Turner Syndrome commonly experience gonadal dysgenesis, a condition where the ovaries do not develop properly or degenerate prematurely. This leads to a significantly reduced number of ovarian follicles, which are the structures that contain and release eggs.
The rapid loss of these ovarian follicles often results in premature ovarian insufficiency (POI) or premature ovarian failure. In many cases, the ovaries may cease to function effectively even before puberty or early in adulthood. This absence of proper ovarian function prevents spontaneous puberty, regular menstruation, and natural ovulation, making natural conception rare. While a small percentage of individuals with mosaic Turner Syndrome (where some cells have a typical chromosomal makeup) may experience some ovarian function or even spontaneous pregnancy, this is not common.
Medical Options for Conception
Medical advancements offer pathways for individuals with Turner Syndrome to become pregnant. The most common method is in vitro fertilization (IVF) using donor eggs. In this process, a donor egg is fertilized with sperm in a laboratory, and the resulting embryo is transferred into the uterus. Success rates for donor egg IVF in individuals with Turner Syndrome are comparable to other women undergoing the procedure, ranging from approximately 24-47%.
Less common or experimental options also exist. Oocyte cryopreservation, or egg freezing, may be an option for some individuals with mosaic Turner Syndrome who still have ovarian function, allowing them to preserve their own eggs for future use. Ovarian tissue cryopreservation, which involves freezing ovarian tissue containing immature eggs, is another promising, albeit still experimental, technique. This procedure is primarily considered for individuals who may experience ovarian insufficiency before puberty. Consulting with fertility specialists is important to determine the most suitable and safe options.
Health Considerations During Pregnancy
Pregnancy for individuals with Turner Syndrome carries specific health considerations that necessitate specialized medical care and monitoring. Cardiovascular complications are a primary concern, as individuals with Turner Syndrome have a higher predisposition to heart conditions such as bicuspid aortic valve and coarctation of the aorta. Aortic dissection, a tear in the body’s main artery, is a serious and potentially life-threatening risk, with estimates suggesting a risk of 1% or higher during pregnancy.
Other potential health issues during pregnancy include an increased risk of hypertension, gestational diabetes, and kidney problems. Close monitoring by a multidisciplinary team, including a high-risk obstetrician and a cardiologist, is important throughout the pregnancy. Pre-conception counseling is also advised to thoroughly assess individual risks and plan for appropriate care. While donor eggs are typically used, if an individual with Turner Syndrome conceives with their own eggs, there is an increased risk of chromosomal abnormalities in the fetus.