Microcephaly

Smallness of the cranium is one of the commonest findings in severe mental defect. Ashby and Stuart (1933 and 1934) found a correlation between brain weight and mental age of +0.15, but they regarded this as part of the more general positive correlation of +0.24 which they observed between body weight and mental age. In discussing this subject elsewhere (Hilliard and Kirman, 1957), Crome and Kirman have taken a more definite stand on this matter in so far as idiocy and imbecility are concerned and regard reduced brain weight, which is so often associated with a small cranium, as one of the major factors in reduced intelligence. Crome (1957) found marked reduction in size to be the commonest abnormality in brains of low-grade defectives.

An update on cardiovascular malformations in congenital rubella syndrome

BACKGROUND

Congenital rubella syndrome (CRS) has long been characterized by the triad of deafness, cataract, and cardiovascular malformations (CVMs). While initial reports identified patent ductus arteriosus (PDA) as the primary CVM in CRS, the exact nature of the CVMs found in CRS has not been well established.

METHODS

We searched the English literature from 1941 through 2008 to identify studies that used cardiac catheterization or echocardiography to evaluate the CVMs in CRS.

RESULTS

Of the 121 patients in the 10 studies with catheterization data, 78% had branch pulmonary artery stenosis, and 62% had a PDA. In 49% of cases, both branch pulmonary artery stenosis and PDA were present, whereas isolated branch pulmonary artery stenosis and isolated PDA were found in 29 and 13% of cases, respectively. Of the 12 patients in the 10 studies with echocardiographic data, PDA was more common than branch pulmonary artery stenosis, but this finding is greatly limited by the small numbers of patients and limitations of echocardiography. Although published studies of CVMs in CRS have in general reported PDA as the CVM phenotype most commonly associated with CRS, among CRS cases evaluated by catheterization, branch pulmonary artery stenosis was actually more common than PDA. Moreover, although the combination of branch pulmonary artery stenosis and PDA was more common than either branch pulmonary artery stenosis or PDA alone, isolated branch pulmonary artery stenosis was twice as common as isolated PDA.

CONCLUSION

Among children with suspected CRS, clinical evaluations for the presence of CVMs should include examinations for both branch pulmonary artery stenosis and PDA.

How many subjects are needed in a longitudinal birth cohort study?

One of the first decisions that needs to be taken when planning a birth cohort concerns the size of the study. This in turn will depend on the research questions to be answered and thence whether environmental exposures and outcomes are measured on a continuum or as dichotomous variables. Here we describe ways in which different birth cohorts have addressed this issue and explore the advantages of smaller detailed studies over larger less-detailed studies.

Noninherited risk factors and congenital cardiovascular defects: current knowledge: a scientific statement from the American Heart Association Council on Cardiovascular Disease in the Young: endorsed by the American Academy of Pediatrics

Prevention of congenital cardiovascular defects has been hampered by a lack of information about modifiable risk factors for abnormalities in cardiac development. Over the past decade, there have been major breakthroughs in the understanding of inherited causes of congenital heart disease, including the identification of specific genetic abnormalities for some types of malformations. Although relatively less information has been available on noninherited modifiable factors that may have an adverse effect on the fetal heart, there is a growing body of epidemiological literature on this topic. This statement summarizes the currently available literature on potential fetal exposures that might alter risk for cardiovascular defects. Information is summarized for periconceptional multivitamin or folic acid intake, which may reduce the risk of cardiac disease in the fetus, and for additional types of potential exposures that may increase the risk, including maternal illnesses, maternal therapeutic and nontherapeutic drug exposures, environmental exposures, and paternal exposures. Information is highlighted regarding definitive risk factors such as maternal rubella; phenylketonuria; pregestational diabetes; exposure to thalidomide, vitamin A cogeners, or retinoids; and indomethacin tocolysis. Caveats regarding interpretation of possible exposure-outcome relationships from case-control studies are given because this type of study has provided most of the available information. Guidelines for prospective parents that could reduce the likelihood that their child will have a major cardiac malformation are given. Issues related to pregnancy monitoring are discussed. Knowledge gaps and future sources of new information on risk factors are described.

Gregg's congenital rubella patients 60 years later

BACKGROUND

In 1941, a Sydney ophthalmologist, Norman McAlister Gregg, correctly identified the link between congenital cataracts in infants and maternal rubella early in pregnancy. Fifty of Gregg's subjects with congenital rubella, born in 1939-1944, were reviewed in 1967 and again in 1991. We reviewed this cohort in 2000-2001, 60 years after their intrauterine infection.

METHODS

The subjects underwent full clinical assessment, plus pathology tests, an ophthalmological and cardiological review (including electrocardiography and echocardiography) and HLA histocompatibility testing.

RESULTS

Since they were first seen in 1967, 10 have died (cardiovascular causes [4], malignant disease [4], AIDS [1], and hepatitis C-related cirrhosis [1]). All surviving men came for review (19) and 13 women (eight women declined). Echocardiography showed mild aortic valve sclerosis in 68%. The prevalence of diabetes (22%), thyroid disorders (19%), early menopause (73%) and osteoporosis (12.5%) was increased compared with the Australian population; 41% had undetectable levels of rubella antibodies. The frequency of HLA-A1 (44%) and HLA-B8 (34%) antigens was increased, and the haplotype HLA-A1, B8, DR3, said to be highly associated with many autoimmune conditions, was present in 25%.

CONCLUSIONS

This cohort of people with congenital rubella has illuminated our understanding of viral teratogenesis.

Prenatal determinants of motor disorders

Cerebral palsies (CP) are the commonest childhood motor disorders, originating in early childhood as a result of interference in the developing brain. Identifying prenatal factors in CP is a challenge because there is a considerable period of time (years) between the causal event(s) and diagnosis. Four fascinating "natural" situations provided a unique opportunity to identify and measure prenatal exposures in relation to motor disorders, thus establishing the unequivocal role of some factors. However, the majority of studies determining adverse reproductive effects of environmental factors require a retrospective case-control approach, which present considerable problems. Studies based on the Western Australian CP register suggest that prenatal factors singly or in complex sequences are more common as causes than those occurring perinatally or postnatally. In future, better diagnosis of motor disorders, use of sophisticated scientific techniques to identify markers of neuronal development and the accurate linkage of these findings to clinical patterns of motor dysfunction are required.

Tumour induction by transplacental infection with polyoma virus of the F1 generation of Wistar rats

Intravenous polyoma virus inoculation into pregnant Wistar rats resulted in transplacental infection of the foetus, causing tumours and hydronephroses. Cyclosporin A reduced these effects significantly.

A fifty-year follow-up of congenital rubella

50 patients with congenital rubella, born in 1939-43, were reviewed in 1967. Here we report their outcome in 1991. Since 1967, there have been 7 deaths (3 cardiovascular, 3 malignant disease, 1 AIDS). 40 had full clinical assessment. The prevalence of diabetes mellitus is similar to that in 1967: 4 of the 5 reported diabetic then, remain so, and there is 1 new case. 1 subject has malignant melanoma and 3 have died from cancer. Although the incidence of malignant disease is not increased, the death rate is (standardised mortality rate 6.0, 95% CI 1.24-17.57). Longer follow-up will be required to confirm this observation.

Laboratory diagnosis of rubella: past, present and future

Fifty years ago in New South Wales the late Sir Norman Gregg [1] described congenital cataracts in 78 babies, 67 of whose mothers had had clinical rubella in early pregnancy; he concluded that the disease in the mother caused the abnormality in the baby. Gregg [1–3] and Swan [4, 5] and their colleagues reported that deafness, heart disease and microcephaly were also major components of the congenital rubella syndrome. The need to prevent this tragic outcome stimulated intensive work on laboratory diagnosis and vaccine development, leading to the isolation of rubella virus in 1962 and then to methods for antibody detection. These complementary advances established the two traditional pillars of virological diagnosis and opened the way to immunization, with the result that some countries are now on the verge of eliminating a disease which for over 100 years was regarded as no more than a mild and harmless exanthem of childhood.

Teratogens associated with congenital contractures in humans and in animals

An evaluation of over 350 patients in a study of congenital contractures of the joints (arthrogryposis) included a review of family, pregnancy, and delivery histories for teratogenic exposures. Fifteen out of the total 350 patients studied had a possible teratogenic exposure: an infectious agent (viral or bacterial), maternal drug or toxin ingestion, chronic maternal neurologic or muscular illness, or a direct physical insult such as a structural uterine anomaly. Literature was reviewed for all human and animal cases reported with congenital contractures of the joints with an associated teratogenic insult. Those findings are discussed here.

VIRAL AND DRUG HAZARDS IN PREGNANCY

Should pregnant mothers be immunized against smallpox? Poliomyelitis?

What is the incidence of fetal loss or major congenital anomalies if a pregnant woman contracts rubella? Poliomyelitis? Rubeola? Mumps? Or varicella? Is there a relationship to the time of the infection during pregnancy and congenital anomalies?

Is there a higher fetal mortality associated with the use of the sulfonylurea drugs for pregnant diabetic mothers?

Are progesteroids harmless to the fetus when given to a pregnant woman? Anti-thyroid drugs? Thiazides?

WEST INDIAN BABIES WITH MULTIPLE CONGENITAL DEFECTS

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