Turner's syndrome

TORONTO -- Egg donation has opened the door to the possibility of pregnancy in women with Turner's syndrome, but it also exposes them to some unexpected and possibly fatal cardiac risks.

"Few elective treatments in medicine today place seemingly healthy patients at risk of death. But in reproductive medicine, by allowing Turner's syndrome patients to achieve pregnancy through oocyte donation, we may be doing just that," Dr. Megan Karnis said at the annual meeting of the Society for Gynecologic Investigation.

Turner's syndrome, which affects women only, is caused by the complete or partial absence of one of the X chromosomes. Affected women experience a premature loss of oocytes, which usually results in infertility, explained Dr. Richard Reindollar, director of reproductive endocrinology at the Beth Israel Deaconess Medical Center, Boston.

"Only about 15% of patients have enough oocytes to go through puberty, and about 5% develop menstrual cyclicity, which usually stops in their 20s. About 1% of patients can achieve a spontaneous pregnancy, but there is a high miscarriage rate," he explained.

As a result, obstetricians rarely see pregnant women with Turner's syndrome and have little knowledge of their condition, which is also characterized by a high rate of cardiac abnormalities.

"It is estimated that 20%-30% of patients with Turner's syndrome have some associated cardiac malformation, although some studies suggest that the most common problem, which is bicuspid aortic valve, may actually occur in up to 50% of patients," said Dr. Karnis, a clinical fellow in obstetrics, gynecology, and reproductive endocrinology at Beth Israel Deaconess.

In addition, mitral valve prolapse occurs in about 25% of patients, and aortic dilation occurs in 5%. Ten percent of cardiac fatalities in Turner's syndrome patients occur in the absence of known risk factors.

The literature contains reports on at least 68 patients with Turner's syndrome who have died from aortic rupture or aortic dissection when they weren't pregnant.

"We are concerned that the increased cardiovascular demands of pregnancy might increase this risk and may not be safe for women with Turner's," Dr. Reindollar said.

In a survey of all 259 donor oocyte programs listed in the 1997 Society for Assisted Reproductive Technology report, Dr. Karnis and Dr. Reindollar found that less than 50% of patients with Turner's syndrome had been given cardiac screening before entering treatment.

Among the 123 programs that responded to the survey, 143 patients with Turner's syndrome had received donor oocytes, but only 71 (50%) of these patients had been given screening echocardiography, they reported.

Abnormal cardiac findings were reported in 6 of these 71 patients (8.4%), four of whom had aortic abnormalities. One of the six also had aortic dilatation, a bicuspid aortic valve, and aortic regurgitation.

Pregnancy was achieved in 99 patients, for a crude pregnancy rate of 60.9%, and 17 patients had multiple-gestation pregnancies.

One death, from an aortic rupture, was reported in a woman with Turner's syndrome who was awaiting donor oocyte treatment.

Dr. Karnis said that the incidence of pregnancy-related cardiac deaths is probably higher than the study showed.

"We know that in the literature, there have been two or three reported deaths during pregnancy in Turner's syndrome patients who have received donor oocytes. These deaths were not reported to us in the survey, so they must have occurred in the 53% of clinics that have not yet responded to us," she explained.

Dr. Karnis and Dr. Reindollar recommended that more thorough echocardiographic screening be done for patients with Turner's syndrome who wish to receive donated oocytes and that patients be carefully counseled about the risks they may be undertaking before attempting to get pregnant.

"Both physicians and patients should at least be cognizant of these risks and that these problems can occur even in patients with no identifiable risk factors," Dr. Reindollar said.

If the patient decides to take the risk, Dr. Reindollar recommends regular echocardiography, probably in every trimester.

"Many if not most women with Turner's syndrome who have died from spontaneous dissection and rupture have gone to the ER with a complaint and have been sent home with a misdiagnosis to die at home. These patients need to be aware that if they have any unusual symptoms that take them to the emergency room, even if they have negative screens, they should at least let the healthcare providers know what their risks are, and what to look for," he said.

COPYRIGHT 2001 International Medical News Group
COPYRIGHT 2001 Gale Group