New study sheds light on long-term survival of children with trisomy 13 and 18

TORONTO – For years, health-care providers have debated the effectiveness and ethics of medical interventions for children with trisomy 13 and trisomy 18, a pair of severe genetic conditions that can affect multiple organ systems. Half of babies with these conditions die within the first days to weeks of life; however, a small percentage survives beyond one year and rarely much longer. Due to the shortened lifespan associated with these conditions, many clinicians have historically avoided surgery in this patient population, in part because of uncertainty about the potential for benefit.

New research led by The Hospital for Sick Children (SickKids) and the Institute for Clinical Evaluative Sciences (ICES) has found that while early mortality is the most common outcome for children with trisomy 13 and 18, the children who survive live much longer than previously described.  In this study, 10 per cent of children with trisomy 13, and 13 per cent of children with trisomy 18, survived for a decade or more. Among those who had surgery, one-year post-operative survival was around 70 per cent. The study is published in the July 26 online edition of JAMA.

In the population-based, retrospective cohort study, researchers evaluated 174 children with trisomy 13 and 254 with trisomy 18, who were born in Ontario from April 1991 to March 2012. They found:

• Among the 44 children with trisomy 13 who were alive at six months, 51 per cent were alive at 10 years;
• Among the 40 children  with trisomy 18 who were alive at  six months, 60 per cent were alive at 10 years;
• Fewer than 25 per cent of children with trisomy 13 and 18 underwent surgical procedures;
• Babies typically underwent their first surgeries at about 92 days (trisomy 13) and 205 days (trisomy 18) following birth;
• Interventions ranged from minor procedures to drain fluid from the eardrum, to complex cardiac repairs;
• One-year post-operative survival among children with trisomy 13 was 70.7 per cent;
• One-year post-operative survival for those with trisomy 18 was 68.6 per cent.

“Our findings show that more than half of children who survived six months actually lived 10 years or more. Long-term survival is more common than was previously expected and some of these children went on to have a range of different surgeries,” says the study’s senior author, Dr. Astrid Guttmann, Staff Paediatrician and Associate Senior Scientist at SickKids, and Chief Science Officer and Senior Scientist at ICES. She notes that the high post-operative survival in those who underwent procedures may be attributed to the fact that these children were older, healthier and therefore more likely to be considered candidates for surgical intervention.

“Further research should help health-care providers better understand the detailed clinical characteristics of children with trisomy 13 and 18 who have surgery. It should also assess important outcomes that go beyond survival, including quality of life of the child and family,” Guttmann says. Evaluating the potential for surgical benefit is important, she explains, since some health-care providers have historically been reluctant to offer potentially-risky treatment options like surgery to children with these conditions. This was often due to the fact that babies with trisomy 13 and 18 may be more vulnerable because of low birth weight and problems with multiple organ systems, and the benefits of surgical interventions were unclear.

“Health-care providers and families should work together to develop an individualized care plan in the best interest of the child. Decisions about whether to perform procedures should be based on several factors, including the child’s current clinical status, the family’s goals and values, as well as the genetic diagnosis,” says lead author Dr. Katherine Nelson, Staff Paediatrician with the Paediatric Advanced Care Team (PACT) at SickKids and PhD student at the University of Toronto.

While previous studies have described survival among children with trisomy 13 and 18, the new research is the first large cohort study to examine long-term survival and surgeries in this population. The paper does not explore quality of life among children with trisomy 13 and 18.

Trisomy 13 and 18 are caused by an extra copy of the 13th or 18th chromosome, and are associated with problems with the heart, brain and other organs, as well as severe developmental delays and characteristic hand and foot anomalies. Trisomy 13 and 18 occur in eight to 15 per 100,000 live births.

Guttmann is also Associate Professor of Paediatrics and Health Policy, Management and Evaluation at the University of Toronto.

The study is funded by ICES and the Norman Saunders Complex Care Initiative through SickKids Foundation.  

This paper is an example of how SickKids is contributing to making Ontario Healthier, Wealthier and Smarter.