Detailed inform­a­tion and a list of ref­er­ences can be found in Chapter 2.8 of the Fer­ti­PRO­TEKT book, “Indic­a­tions and fertility pre­ser­va­tion methods for onco­lo­gic­al and non-onco­lo­gic­al disorders”, which can be down­loaded free of charge.

Turner syndrome is a genetic disorder (inherited disease) in which there is a loss of an X chro­mo­some or a lim­it­a­tion of its function. Women with Turner syndrome often have smaller stature and mal­form­a­tions of the kidneys, heart and major blood vessels. The latter may be the cause of a life-threat­en­ing tear in the aorta (aortic dis­sec­tion and aortic rupture).

Women with Turner syndrome have a reduced number and quality of oocytes. The con­sequence of this is that fertility is often very limited at an early stage.  The severity of Turner syndrome depends on the genetic dia­gnost­ic findings. Patients, in whom not all cells are affected (mosaic form), have a less pro­nounced appearance.

risks of a pregnancy in turner syndrome patients

Pregnancy in women with Turner syndrome is asso­ci­ated with increased risks for the mother and child. This must be con­sidered when con­sid­er­ing fertility preservation.

+ Obstetric risks for mother and child

The risk of life-threat­en­ing rupture of the aorta (aortic dis­sec­tion and aortic rupture) is sig­ni­fic­antly increased during pregnancy in patients with Turner syndrome. The event itself and the timing cannot be predicted. Risk factors, in addition to high blood pressure which commonly occurs in Turner syndrome, are diseases of the blood vessels and heart. The risk of a woman with Turner syndrome dying in pregnancy as a result of a tear in the aorta is 2%. It is therefore 150 times higher than in healthy pregnant women.

During pregnancy, women with Turner syndrome also have a greatly increased risk of hyper­ten­sion. Severe com­plic­a­tions occur in more than half these cases: pre-eclampsia, eclampsia and HELLP syndrome. The risk of gest­a­tion­al diabetes and an under­act­ive thyroid are also increased.

+ Infant chro­mo­somal abnor­mal­it­ies and miscarriages

In the few cases where women with Turner syndrome become pregnant with their own eggs, there is an increased risk of mis­car­riage or faulty genes (chro­mo­somal abnor­mal­it­ies). This also applies to women with Turner syndrome who become pregnant with donor eggs. The pos­sib­il­ity of prenatal diagnosis should be discussed due to the increased risk.

Approach if fertility pre­ser­va­tion is considered

Invest­ig­a­tion, risk coun­selling and monitoring

Every woman with Turner syndrome who is con­sid­er­ing a pregnancy should be informed in detail about the risks. This coun­selling should be carried out by:Jede Frau mit Turner-Syndrom, die eine Schwanger­schaft in Betracht zieht, muss eingehend über die Risiken aufgeklärt werden. Diese Aufklärung sollte erfolgen durch:

  • a car­di­olo­gist (a spe­cial­ist in con­gen­it­al heart disease)
  • a prenatal spe­cial­ist and obstet­ri­cian from a spe­cial­ized centre
  • a human geneticist.

The patient should be monitored closely for addi­tion­al risk factors and pre-existing diseases before the final decision about a pregnancy is made. During pregnancy, close mon­it­or­ing by a team of experts in a spe­cial­ist centre is necessary.

Estim­a­tion of the ovarian reserve

If a pregnancy is possible in principle, the choice of fertility pre­ser­va­tion method in Turner syndrome patients depends on the indi­vidu­al ovarian reserve. Factors that indicate the presence of egg cells are shown in the following table. Complex measures such as the freezing of ovarian tissue or eggs should be justified by the sim­ul­tan­eous presence of several of these pre­dict­ive factors.

+ Pre­dict­ive factors for the presence of egg cells in turner syndrome patients

  • Mosaic Turner syndrome
  • Normal FSH level
  • Normal AMH level
  • Spon­tan­eous onset of puberty
  • Spon­tan­eous onset of menstrual bleeding (menarche)
  • Normal antral follicle count, AFC

Fertility pre­ser­va­tion methods

+ egg cell donation with or without surrogacy

For a woman with Turner syndrome, egg cell donation is a way of reducing the risk of faulty genetic material. If she carries the pregnancy herself, the obstetric risk, including car­di­ovas­cu­lar risk, remains. In this respect, an egg donation with surrogacy is con­sidered as safer altern­at­ive outside Germany in Turner syndrome patients.

Egg donation is pro­hib­ited in Germany!

+ Fertility pro­tec­tion in the true sense: freezing of egg cells (oocyte cryo­p­reser­va­tion) and ovarian tissue (ovary cryopreservation)

If the patient wishes to retain her own fertility, then her age is con­sidered an important criterion. It enables better assess­ment of the indi­vidu­al capacity for pregnancy, so that an active approach can be con­sidered, espe­cially in patients from 14 to 16 years of age. Active measures are not usually used before this. On the other hand, it should be con­sidered whether freezing of ovarian tissue in very young girls who still have a favour­able egg cell reserve is jus­ti­fi­able and reas­on­able. After 14 to 16 years of age, more elaborate measures of fertility pre­ser­va­tion such as cryo­p­reser­va­tion of eggs or ovarian tissue should be carried out, taking into account the AMH value, the cycle reg­u­lar­ity and presence of other favour­able pre­dict­ive factors.

Despite the possible solutions, Turner syndrome is not only a difficult situation for fertility pre­ser­va­tion in repro­duct­ive medicine. Real­ist­ic­ally, tech­niques using own egg cells are pos­sib­il­ity, espe­cially for patients with Turner’s mosaisicm. Turner syndrome also means a high risk of illness with poten­tially life-threat­en­ing con­sequences for a pregnant woman. Therefore it is very important that the patient receives balanced, clear and open inform­a­tion about this complex situation. Turner’s syndrome is con­sidered by the American pro­fes­sion­al society, ASRM, as a reason to advise against pregnancy and to recom­men­ded surrogacy instead.