Posted under Fertility Treatment by Dr. Suchetana Sengupta

Understanding Turner Syndrome and Conception Options

This is a guide to conception for people with turner syndrome. Explore the article to understand what are the options available for becoming pregnant for people with turner syndrome

What is Turner Syndrome

• Turner syndrome is the most common chromosome aneuploidy (presence of abnormal number of chromosomes in a cell) in women.
• It is the only monosomy (a form of aneuploidy with the presence of only 1 chromosome from a pair) compatible with live birth.
• Second most common genetic condition associated with subfertility, but not related with maternal age.

Genetic behind Turner syndrome

• It present classically as monosomy X(45,X0) having full sets of autosome and 1 X chromosome.
• Other presents as mosaism (having some normal karyotype 45XX & some45X0).The degree of mosaism decides the clinical presentation of the syndrome.

Clinical presentation seen in Turner syndrome

Turner affects multiple organ system as 1 x chromosomes het inactivated .in mosaic variety some of the gene escape the inactivation process(SHOX gene, responsible for short height) and lead the phenotypic presentation.

• Short height is the main presentation with webbed neck.
• Deafness
• Ptosis, low set ear, widely placed nipple
• Cubitus valgus(forearm is angled out from body)
• V.S abnormalities
• Renal abnormalities
• Fragile bones, diabetes mellitus, Hypertension etc.
• Ovary-mostly present with primary amenorrhea (no menstruation during puberty) in 45,X0,the mosaic variety present with spontaneous menarche(start of menstruation) but soon all the follicles undergo rapid destruction resulting in premature ovarian failure(premature menopause.
• Uterus-In 45 X0 uterus remain rudimentary (not attaining adult size) where as in the mosaic variety where spontaneous menstruation starts ,it may be of normal size
• Infertility-due to premature ovarian failure. The accelerated atresia of the ovarian follicles even before natural age of menarche due to inactivation of BMP15 gene which prevents the follicular destruction in normal condition.
• In the mosaic variety where there is some amount of ovarian activity ,there the proportion of normal cell control the loss.so when we measure the AMH to see the ovarian reserve ,we need to correlate with the karyotype and pubertal development. Turner presents with high FSH, LH and low Estrogen level due to this ovarian failure.

what are the conception options for people with turner syndrome?

Now coming to the part of how to conceive if you have turner syndrome. 

Spontaneous pregnancy

Is noted in 8% of cases but mostly miscarry .there is evidence of increased miscarriage (30-45%) due to poor oocyte quality and suboptimal uterine growth.

Artificial reproductive technique:

1. Patients with some ovarian activity –

We can do multiple cycle oocyte pooling (stimulating ovary for consecutive cycle to create a good pool of eggs) and then to do IVF/ICSI.

2. Premature ovarian failure-

These are the patients where already the follicles has been exhausted. Here the way to fertility is by donor eggs and pregnancy rate is 27.5%.with donor oocyte

·         the miscarriage rate is same as general population

·         hypertensive disorders and renal problems are more if the turner

·         ,preterm labour   woman is carrying the embryo herself.

The next step of treatment depends on the size of uterus, if it is rudimentary then patient will need help from surrogacy .Surrogacy is also needed for patients with turner who are medically unfit(aortic valve aneurysm) for pregnancy .With a normal sized uterus we can do uterine endometrium preparation by giving exogenous hormone followed by embryo transfer.

3.  Fertility preservation:-

mature oocyte freezing / embryo freezing / ovarian tissue freezing.

Councelling and checks  before undergoing for pregnancy

• Screening for optimizing end organs before trying for pregnancy is necessary to ensure women’s health first as turner is associated with several cardiovascular, ranal, maetabolic complications.
  • height, weight, BMI
  • Target B.P-Systolic B.P should be less than <
  • 140 &120 mm of hg in cases where the aortic valves of heart are involved (tricuspid and aortic respectively.)
  • Check kidney by usg
  • Other blood to check for D.M, Thyroid function test, Lipid profile, iver function test
  • Check for tricuspid and bicuspid valve to see aneurysm.
  • DEXA scan to see the bones.
  • Angiogram-to see the coarctation of aorta/any aortic valve (aortic diameter >35mm is a contraindication for pregnancy) aneurysm.it decides wheather the woman can opt for pregnancy or not due to her own health’s condition.
• Karyotype- to see 45,X0 /45XX,45XO.The karyotype denotes which pathway to be followed for parenthood as turner presents with different phenotype according to their karyotype.
• Though it is a genetic disorder there is no risk of passing from mother to fetus.
• Patients information is the key of any treatment and whatever the way be tfor conception(spontaneous /ART ) all patients should be informed
• Pregnancy with turner associated with pre-eclampsia and hypertension, preterm labour (short stature)
• More incidence of cesarean section
• After birth neonatal outcome are reassuring.
• All pregnancy should be seen by integrated care by consultant obstetrician, anaesthetist, neonatologist, radiologist with proper hospital based antenatal, intrapartum (during delivery) care.

CONCLUSION:-

• Diagnosis of turner at earliest by karyotype ( from different tissue),blood for FSH,LH ,Estrogen and AMH to understand the needed approach for fertility
• Though this is a genetic disorder it doesn’t pass from mother to fetus and unrelated to mother’s age.
• 2^nd most common genetic condition to cause infertility. Premature ovarian failure is the cause.
• Turner itself affects many organ system and so as there are unique complications associated with pregnancy.
• Proper integrated pre pregnancy counselling & end organ assessment and with help of assisted reproductive technique and evidence base antenatal care fertility is very much achievable.

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About the author

The author, Dr. Suchetana Sengupta is a Fertility Consultant at Care IVF Kolkata. For an appointment with the doctor, call +91-33-66-398-600. You can also book a Skype Consultation here.