LONDON – Hypertensive complications are seen in more than one-third of pregnant women with Turner’s syndrome undergoing fertility treatment, according to the results of a longitudinal retrospective study performed in Finland, Denmark, and Sweden.
Of 106 women with Turner’s syndrome who conceived after oocyte donation between 1992 and 2011, 35% had hypertensive complications and 20% had preeclampsia. Although there were no maternal deaths, life-threatening complications occurred in four (3.3%) women. This included a case of aortic dissection.
"We think it’s very important to have a centralized cardiovascular assessment before pregnancy," Dr. Anna Hagman of Sahlgrenska Hospital, Gothenburg, Sweden, said on behalf of the study team at the annual meeting of the European Society of Human Reproduction and Embryology. This should include echocardiography and magnetic resonance imaging, looking for specific cardiac abnormalities known to affect women with Turner’s syndrome.
Turner’s syndrome is caused by an aberration of the X chromosome and affects around one in 2,500 women. It is associated with increased cardiovascular (CV) morbidity and mortality, which raises concern for women who may want to try to conceive either spontaneously or via assisted conception methods. Women with the condition typically are of short stature and almost all (95%–99%) are infertile. Oocyte donation may offer one of their best chances for becoming pregnant.
For the study, medical data from fertility clinics, antenatal clinics, and hospitals where women had been treated or delivered their baby between 1992 and 2011 in Finland and Denmark, or between 2003and 2011 in Sweden, were examined.
The 45,X karyotype was observed in 44% of the women and 9% had a known cardiac defect before pregnancy. Just under half (49%) of women had a CV exam within the 2 years prior to becoming pregnant, and 29% had a CV exam during their pregnancy.
Single embryo transfer was performed in 70% of the cases and the multiple birth rate was 7%; 15% of women conceived twice after two oocyte donations during the study period. The median follow-up time was 4 years, but ranged from 0.3 to 19 years.
There were 122 deliveries studied in total and 131 neonates, of which 18 were twins. Among the single births, the rate of preterm delivery, defined as before 37 weeks’ gestation, was 8%, with 9% of children having low birth weight (less than 2,500 g). Perinatal mortality was 0.8%. Congenital defects were seen in 3.8% of the children.
"Neonatal outcomes were reassuring for singletons," Dr. Hagman said at the annual meeting of the European Society of Human Reproduction and Embryology, later noting that the team "recommends single-embryo transfer."
This is because greater risks for mother and child were seen after twin births. Hypertensive complications occurred in 50% of women and around two thirds (67%) of twins were delivered prematurely. Almost three quarters (72%) had a low birth weight and perinatal mortality was approximately 11% for twin births.
Dr. Hagman suggested that pregnancy should be avoided in women with Turner’s syndrome if there is CV disease or other severe health problems exist. Thyroid, renal, and liver tests should be performed, she advised, as well as testing for diabetes.
"All pregnancies must be carefully monitored," Dr. Hagman advised. The blood pressure should be kept below 140/90 mm Hg and echocardiography, MRI, or both performed two to three times during pregnancy.
The study’s findings have recently been published (Hum. Reprod. 2013;28:1598-09).
The study was funded by a variety of sources, including: the Gothenburg Medical Society, grants from the ALF agreement at the Sahlgrenska University Hospital, Gothenburg, Sweden; Hjalmar Svensson Foundation; the Nordic Federation of Societies of Obstetrics and Gynecology Nordic Fund; Finnish Society of Paediatric and Adolescent Gynecology; Liv och hälsa Foundation in Finland; and MSD Finland, Norway, and Denmark. No conflict of interest was reported.