Appropriately Grown Baby With Multiple Congenital Abnormalities: A Case Report

Devangi Thakkar, BMEdSci, MBBS; Narendra Aladangady, MBBS, MRCP, FRCPCH

Disclosures

Medscape J Med. 2008;10(9):210 

In This Article

Discussion

Trisomy 18 (also known as Edwards syndrome) was first described in 1960 by Edwards and colleagues.[1] Among liveborn children, trisomy 18 is the second most common autosomal trisomy after trisomy 21 (Down syndrome).[2] Pont and coworkers[2] estimated the prevalence of trisomy 18 as 1.29/10,000 live births. Although, there is no racial predilection,[3] females are 3 times more likely to be affected than males. Like Down syndrome, the incidence increases with advancing maternal age. Full trisomy 18 is responsible for 95% of Edwards syndrome cases, and mosaicism and translocations are responsible for the remainder of cases.[4]

Prenatal screening for trisomy 18 between 10 and 13 weeks, using a combination of pregnancy-associated plasma protein A and beta-human chorionic gonadotropin, has a detection rate of 60% and a false-positive rate of 0.1%.[5] Since most cases of Edwards syndrome have characteristic and detectable structural abnormalities, routine prenatal ultrasonography may suggest the possibility that the fetus is affected. Common anomalies in fetuses with Edwards syndrome include persistent abnormal position of fetal fingers (89%), choroid plexus cysts (43%), 2-vessel umbilical cord (40%), cardiac defects (37%), intrauterine growth retardation (29%), omphalocele (20%), neural tube defects (9%), cystic hygroma or lymphangiectasia (14%), abnormalities of amniotic fluid volume (12%), and renal defects (9%). Prenatal diagnosis with amniocentesis testing (at 14 to 16 weeks of gestation) for a chromosomal disorder is 99.5% accurate; with chorionic villus sampling (at 10-13 weeks of gestation) accuracy increases to 96% to 98%.[6]

Advances in prenatal diagnostics have greatly improved the possibility of early detection of chromosomal anomalies. This has allowed an opportunity to plan and thus improve perinatal care but also offers the option to terminate the pregnancy for cases in which the prognosis is likely to be very poor. Therefore, it is important for both healthcare providers and families to have accurate and detailed knowledge of survival, disease course, and quality of life so that they can make fully informed decisions regarding care.

Patients with Edwards syndrome usually have abnormalities of most body systems and organs ( Table ). Abnormalities may include growth deficiency, feeding and breathing difficulties, developmental delays, and mental retardation. Various gastrointestinal and genitourinary tract abnormalities have also been described.[4,7]

Definitive diagnosis of Edwards syndrome is by detection of a complete or partial trisomy of chromosome 18 using conventional cytogenetic studies. However, chromosomal analysis can be done using FISH, which gives a rapid provisional result. Various physical anomalies can be confirmed and investigated further using echocardiography, magnetic resonance imaging for cranial anomalies, barium studies for gastrointestinal anomalies, ultrasonography for genitourinary anomalies, and skeletal radiography for skeletal anomalies.[4]

The natural history of Edwards syndrome is one of limited survival. Approximately 68% of the fetuses with an in utero diagnosis of trisomy 18 die before delivery, [7] 30% die in the first month, 50% die within 2 months, and 90% by 1 year.[8]The remaining 10% are mentally retarded.[8] The high mortality rate is usually due to the presence of cardiac and renal malformations, feeding difficulties, sepsis, and apnea caused by CNS defects.[4]

When a diagnosis is confirmed, a detailed discussion with the parents is essential. It is likely to be a difficult time for them, and they will require social support and counseling, including a risk assessment for future pregnancies.

Several ethical issues arise when Edwards syndrome and other serious congenital anomalies are discussed. The issue of the child's best interest is probably the most important. Only 10% of children survive beyond 1 year of life, and they are all mentally retarded, usually with serious physical disabilities. Is surgery for cardiac deformities ethical when it will not change the ultimate prognosis? The answer to the question is probably not, since the surgery is not likely to improve the child's quality of life. In practice, however, the situation is extremely difficult to deal with. Ideally, decisions should result from a joint partnership between parents and healthcare staff.

The other issue that arises is a consideration of the economics of care in determining life and death issues. It is true that health care resources are limited and have to be considered on a social level. Economic considerations include costs to the health service, the parents, social services, and society in general. However, although economic considerations are important, they should not be the main driving force behind decision-making on whether to institute medical treatment.[9]

The statistics and ethical arguments help to explain why treatment for patients with this syndrome is invariably palliative and focuses on quality of life for the infant. Infections are treated appropriately, nasogastric tubes or gastrostomies are used for improved nutrition when required, cardiac abnormalities are treated medically, and referrals are made when necessary to physiotherapists and occupational health workers.[3,4]

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