New research has demonstrated that over 95% of Down syndrome cases can now be detected in early pregnancy.

Led by Professor Fergal Malone; Professor and Chairman of the Department of Obstetrics and Gynaecology at RCSI and the Rotunda Hospital, Dublin; the First-Trimester and Second-Trimester Evaluation of Risk (FASTER) trial is one of the largest ever studies in pregnancy, with over 38,000 patients being recruited to evaluate various methods of screening for fetal abnormalities such as Down syndrome.

The results are published today (10 November 2005) as the lead article in The New England Journal of Medicine, the leading biomedical research journal in the medical world. They demonstrate that new ultrasound and blood tests are now widely available that can detect over 95% of cases of Down syndrome as early as 10 to 12 weeks gestation for all pregnant women.

Conducted at 15 US centres, and analysed at the RCSI, the FASTER trial set out to find the best way to screen pregnancies for a wide range of fetal abnormalities, such as Down syndrome.

Over 38,000 pregnant patients were provided with a range of ultrasound and blood screening tests at 10 to 13 weeks gestation, and again at 15 to 18 weeks gestation. The study’s conclusions indicated that first-trimester screening provided a detection rate of Down syndrome of up to 87%, and that other combinations of screening produced a detection rate of 96%.

Commenting on the results Professor Fergal Malone said: "This approach picks up over 95% of cases of Down syndrome, which is a huge step forward and provides reassurance to the vast majority of women in the very early stages of pregnancy. This study provides guidelines on how to perform this very efficient test, but also points out the technical challenges in performing the special ultrasound scans properly. Measurements that are off by even a fraction of a millimeter can lead to very inaccurate results."

According to Professor Malone this study has relevance for all women. "Down syndrome is one of the most common genetic causes of intellectual impairment and concern regarding this condition causes considerable anxiety for many pregnant women, especially amongst those aged 35 years and over. In Ireland today more and more older women are having babies. Age is a significant risk factor for Down syndrome. The traditional test for Down syndrome, CVS or amniocentesis, carries a small risk of miscarriage. This new research shows that the vast majority of women, both old and young, can avoid amniocentesis by using ultrasound and blood tests which pose no risk to the pregnancy and give reassurance to the patient early on."

The RCSI Professor continued: "Women who are interested in the reassurance that these tests can provide should be asking their doctors or midwives for early access to a combined ultrasound and blood test. Like many other obstetricians in Ireland, I have recently been offering this test to all patients during early pregnancy. Performing the ultrasound test on its own is no longer sufficient, and delaying until after 13 weeks is too late. International best practices would now suggest that all pregnant women, regardless of their age, should be offered the tremendous reassurance and advantages of these combination screening tests. Medical practice in Ireland will almost certainly evolve in the near future to come into line with this now internationally accepted standard."

Funded by the National Institutes for Health (NIH) for $15 million, the international collaborative FASTER trial was the biggest research grant ever awarded by the NIH in the field of obstetrics. Lasting over eight years, this study was led by Professor Malone while at Columbia University, New York, and subsequently at RCSI, Dublin upon his appointment there earlier this year.