Heterogeneity of neural tube defects in Europe: the significance of site of defect and presence of other major anomalies in relation to geographic differences in prevalence.

In the period 1980-1987, neural tube defects were two to three times more prevalent in populations covered by EUROCAT registries in the United Kingdom and Ireland (UKI) than in Continental Europe and Malta (CEM). 1864 NTD cases in a total population of 580,000 births in UKI and 455 cases in a population of 380,000 births in CEM were analysed to find if there were differences in the ratio of prevalence rates between UKI and CEM according to site of the defect and association with non-central nervous system (CNS) anomalies. The prevalence rate ratio was high for anencephaly with accompanying spina bifida, iniencephaly, and upper spina bifida, and low for encephalocele, lower spina bifida, and anencephaly without other neural tube defects. There was a greater female excess for anencephaly with accompanying spina bifida, iniencephaly, and upper spina bifida than for other defects in both geographic areas. There was a female excess for encephalocele in UKI but a male excess in CEM. Certain sites (anencephaly with accompanying spina bifida, iniencephaly, and encephalocele) were more likely to have accompanying non-CNS anomalies. The prevalence rate ratio of multiply malformed NTD was in general lower than for isolated NTD but showed the same pattern by site. The prevalence rate ratio was high for multiply malformed anencephaly with accompanying spina bifida, iniencephaly, and upper spina bifida. The sex ratio was similar between isolated and multiply malformed cases when site of the defect is taken into account. It is concluded that the geographic prevalence pattern and sex ratio differ according to site of NTD but do not differ substantially according to whether NTD is isolated or associated with non-CNS anomalies.

The impact of supportive intervention after second trimester termination of pregnancy for fetal abnormality.

The reactions of women who had had a termination of pregnancy for fetal abnormality in the second trimester have been studied retrospectively using a semi-structured questionnaire. The severity of the grief reaction was measured and the outcome at 6 months was compared with the findings from a previous study in South Wales which had led to the introduction of skilled support from genetic fieldworkers and formal genetic counselling after the termination. Of the 69 women interviewed, 55 (80 per cent) experienced an acute grief reaction and 17 (25 per cent) had not resolved their grief 6 months after the termination, compared with 37 (77 per cent) and 22 (46 per cent) out of 48 respectively in the previous study. Fifty-seven (83 per cent) women had found the fieldworker's intervention useful or very useful, some describing her support as essential. An association between poor resolution of the grief reaction with increasing maternal age and with poor perceived support from partners was noted. Improved follow-up support and counselling have lessened the adverse emotional consequences and support should therefore be offered to all women undergoing termination for fetal malformation.

PIP: The reactions of women who had undergone a termination of pregnancy for fetal abnormality in the 2nd trimester have been studied retrospectively using a semistructured questionnaire. The severity of the grief reaction was measured and the outcome at 6 months compared with the findings from a previous study in South Wales which had led to the introduction of skilled support from genetic fieldworkers and formal genetic counseling after the termination. Of the 69 women interviewed, 55 (80%) experienced an acute grief reaction and 17 (25%) had not resolved their grief 6 months after the termination, compared with 37 (77%) and 22 (46%) of 48, respectively, in the previous study. 57 (83%) women has found the fieldworker's intervention useful or very useful, some describing the support received as essential. An association between poor resolution of the grief reaction with increasing maternal age and with poor perceived support from partners was noted. Improved followup support and counseling have reduced the adverse emotional consequences, and support should thus be offered to all women undergoing pregnancy termination for fetal malformations.

Factors affecting employability among young adults with spina bifida and hydrocephalus.

A sample of 98 young adults with spina bifida were interviewed. None had severe learning difficulties. All were resident in S. Wales or the West of England. Only a third were in open competitive employment, mainly of a clerical nature. Their incomes fell well below average British earnings. Comparing those in work with the unemployed showed they differed significantly according to intelligence, academic qualifications, continence, behaviour, overall disability score and place of residence. The non-discriminating factors are listed and the implications of the findings discussed.

Maternal serum alpha-fetoprotein screening for open neural tube defects in twin pregnancies.

Data on maternal serum alpha-fetoprotein (AFP) levels at 13-24 weeks' gestation in 46 twin pregnancies with open neural tube defects (22 with anencephaly, 24 with open spina bifida) and 169 unaffected twins were used to estimate the detection and false-positive rates associated with different cut-off levels. Using the conventional cut-off level of 2.5 multiples of the median (MoM) for unaffected singleton pregnancies of the same gestation and laboratory, the detection rate in twins was 99 per cent for anencephaly and 89 per cent for open spina bifida, with a false-positive rate of 30 per cent. Using a 5.0 MoM cut-off level to maintain a similar false-positive rate to that found among singleton pregnancies at 16-18 weeks' gestation (about 3 per cent), the detection rate was 83 per cent for anencephaly and 39 per cent for open spina bifida. Estimates are provided of the odds of having an affected twin pregnancy given a positive AFP result as well as the odds for individual women with a raised AFP level.

Relationship between fetal adrenal morphology and anterior pituitary function.

A comparative study of adrenal morphology between normal fetuses and those with anencephaly or congenital adrenal hyperplasia (CAH) was performed in order to examine the hypothesis that fetal adrenal mass and structure are adrenocorticotrophin (ACTH)-dependent throughout gestation. Combined adrenal weight in 102 normal fetuses was used to establish a reference range for the gestational ages of 15-27 weeks. During this period, mean adrenal weight showed a 6-fold linear increase. In 38 anencephalic fetuses of similar gestation age, adrenal weight was below the normal range and did not show a rise. Three fetuses with CAH (18, 22 and 30 weeks gestation) had adrenal weights considerably above the normal range. Adrenal cortical thickness was significantly increased in CAH fetuses, largely as a consequence of cell hypertrophy, whereas decreased cortical thickness in the anencephalic group represented cellular hypoplasia. Conspicuous secretory granules in the cytoplasm was the electron-micrographic feature of the adrenal gland in the 22-week fetus with CAH. These observations are consistent with close dependency of fetal adrenal growth and development upon fetal pituitary function from an early age, mediated primarily through ACTH.

Interstitial deletion of 17p11.2: case report and review.

A child with mental retardation and multiple congenital abnormalities, including brachycephaly, an unusual facies, brachydactyly, clinodactyly and bilateral talipes valgus, was found to have a small interstitial deletion of the short arm of chromosome 17. The clinical features and cytogenetic observations are compared with those in previously reported cases.

Medical and social service provision for families of children with NTD.

The supply of services to the families of children with spina bifida participating in the South Wales longitudinal study was reviewed. Initially general information and contact with other mothers were the commonest needs; as the children grew older the need for practical, material and financial help took priority. Parents were, generally, very satisfied with support provided by hospital staff with whom they had frequent, regular contact. Contact with health visitors and social workers was considered insufficient and unsatisfactory. Mothers of more severely disabled children were most likely to receive visits, but some saw none and contact with the social services decreased as the children got older. The locally organised parents association (SWASBAH) was able to provide information, financial assistance, holiday accommodation, and contact with others in a similar position; all of which were common, but otherwise inadequately met, needs. Despite improvements, particularly in financial benefits, over the course of the study, at 18 years parents appeared largely unsupported as they faced major changes in their children's lives. Throughout the study support from SWASBAH and the interviewer appeared to far outweight the statutory, non-medical, support.

Prenatal diagnosis of congenital adrenal hyperplasia: reliability of amniotic fluid steroid analysis.

The concentration of 170H-progesterone was measured in amniotic fluid samples collected from 55 mothers who had previously had a child with congenital adrenal hyperplasia due to 21-hydroxylase deficiency. In eight pregnancies the levels of 170H-progesterone were raised; the parents elected to terminate in four and examinations of the fetus confirmed the diagnosis of congenital adrenal hyperplasia. In each case, the affected sib was a salt loser. The remaining four affected pregnancies proceeded to term and each infant had salt losing 21-hydroxylase deficiency. All 47 infants predicted to be unaffected were normal at birth. However, an increased plasma concentration of 170H-progesterone was documented in a male non-salt loser at three months of age. Prenatal diagnosis of congenital adrenal hyperplasia by amniotic fluid steroid analysis is reliable only for the salt losing variant of 21-hydroxylase deficiency. Of the affected sibs in this study, 20% died during infancy in a salt losing crisis. This simple and rapid prenatal test is sufficiently reliable to predict the group of infants most at risk in early infancy.

Homozygous paracentric inversion 12 in a mentally retarded boy: a case report and review of the literature.

A mentally retarded male was found to be homozygous for a paracentric inversion of the long arm of chromosome 12(inv(12)(q21.1q23.2]. His parents, who are first cousins, and his phenotypically normal younger brother are inversion heterozygotes. Homozygous structural rearrangements are discussed and cases of paracentric inversions, including a further nine previously unpublished, are reviewed.

Amniotic fluid steroid levels and fetal adrenal weight in congenital adrenal hyperplasia.

The concentration of 17-OH-progesterone was determined in second trimester amniotic fluid collected from 58 pregnancies at risk for fetal 21-hydroxylase deficiency. The prediction was incorrect in 1 male nonsalt-loser who had an increased plasma 17-OH-progesterone concentration at 3 months of age. All 11 infants predicted to be affected were salt-losers. The adrenals from 2 affected fetuses available for study were significantly enlarged in comparison with adrenal size in 84 normal fetuses from 15 to 26 weeks' gestation. Amniotic fluid steroid analysis reliably predicts the fetus with 21-hydroxylase deficiency most at risk in early infancy. There is no evidence from this study to indicate that ACTH is not the main trophic factor for fetal adrenal growth and steroidogenesis.

The fathers of children with spina bifida.

Health, employment, marital outcome and involvement with the child, of fathers with spina bifida (IF) and with "normal" controls (CF), were analysed at intervals from birth to 18 years. By 10 years IF had poorer reported health than did CF. By 18 years IF had more specific health problems, many being psychosomatic in nature, than CF or index and control mothers. This pattern was also reflected in the GHQ scores; IF had a significantly higher incidence of symptoms than CF. Practical involvement of IF and CF was generally little different but at 18 years 30% of IF were still involved in their child's "personal care". Employment and income amongst IF and CF did not differ in the early years. By 18 years, significantly more IF were claiming invalidity benefit, while they were also more likely to be the family's only wage-earner. Our evidence suggests that IF suffered surprisingly severely as a result of emotional strain. Both the psychological and practical problems could be alleviated to the benefit of all family members.

Should women at high risk of neural tube defect have an amniocentesis?

As part of an investigation into the practical problems of a maternal serum alphafetoprotein (AFP) neural tube defect (NTD) screening programme carried out in Mid Glamorgan, South Wales, between 1977 and 1979, obstetricians were recommended to refer women with high risk pregnancies directly for counselling, high resolution ultrasonography, and amniocentesis without first carrying out serum screening. Out of 15 687 pregnant women one-third attended too late to be screened. A total of 637 was classed as high risk, mostly at greater risk than 1 in 50 because of a previously affected pregnancy or an affected close relative. Compliance with recommended procedure was relatively low as many were screened. There were 10 pregnancies with a recurrence of NTD, of which one was not tested at all, two were not detected (one closed meningocele and one closed iniencephalic), and seven were detected and the pregnancies terminated. All the latter, as well as the iniencephalic, would have been detected from a serum AFP determination and a high resolution ultrasound scan alone. It is concluded that these investigations are sufficient for high risk pregnancies and that amniocentesis is not really cost effective or necessary unless either of these investigations is abnormal. As numbers in this study were small it is suggested that these conclusions should be tested in a larger study.

The apparently declining prevalence of neural tube defect in two counties in South Wales over three decades illustrating the need for continuing action and vigilance.

Neural tube defects, anencephaly and spina bifida (including encephalocele) have been the major malformation problem in South Wales. Births of affected offspring of residents of Mid and South Glamorgan between 1956 and June 1985 were ascertained from various sources. To these were added terminations following prenatal diagnosis and affected spontaneous abortions of 16 weeks gestation or more since 1973. Variable fluctuation in prevalence occurred between 1956 and 1965. Since then there has been an accelerating decline in the birth prevalence of NTD but especially of anencephaly in both counties. When abortions and terminations are taken into consideration the decline until 1984, though still present, is much slower and is virtually non-existent now. The need for continuing NTD pregnancy screening and prenatal diagnosis followed by selective abortion is stressed. It is suggested that genetic counselling health education to improve maternal nutrition preconceptional counselling and population folic acid supplementation should be extended to prevent these defects.

Possible personality problems among 10-year-old spina bifida children.

Forty-four 10-year-old spina bifida children and 52 non-disabled controls completed the Rogers Personal Adjustment Inventory and their teachers assessed their school behaviour on the Bristol Social Adjustment Guide. Spina bifida children and the controls had similar school adjustment scores but the former appeared to have significantly more emotional problems on the Rogers Inventory suggesting that they have private worries not revealed by characteristic behaviour in school. Factors associated with apparent emotional upset are considered and implications for support discussed.

Three new cases of oculodentodigital (ODD) syndrome: development of the facial phenotype.

Three new cases of oculodentodigital (ODD) syndrome are reported. The clinical features are discussed and the development of the characteristic facial appearance is illustrated. Conductive deafness is reported in one of our cases and has been reported in six previous cases. It is suggested that it is a feature of the syndrome which is amenable to treatment.

Sequelae and support after termination of pregnancy for fetal malformation.

A retrospective study examined the reactions to the termination of pregnancy for fetal malformation and the follow up services that were available. Women resident in Mid Glamorgan who had had a termination between 1977 and 1981 because of positive findings after midtrimester prenatal diagnostic tests for neural tube defect or chromosome abnormalities were interviewed at home using a semistructured interview schedule. Three retrospective internal comparison groups were formed from those women who had also had a spontaneous abortion, previous stillbirth, or neonatal death or previous termination for medicosocial reasons early in pregnancy. Of the 48 women interviewed, 37 (77%) experienced an acute grief reaction after the index pregnancy was ended. This reaction was akin to that documented after stillbirth or neonatal death. Twenty two women (46%) remained symptomatic six months after the pregnancy had been ended, some requiring psychiatric support, compared with no such reaction after spontaneous abortion or termination for medicosocial reasons. All the women who had previously had a stillbirth or neonatal death were visited at home either by the general practitioner or by the midwife after that event but such follow up was limited to only eight of the study group after termination for fetal malformation. The findings suggest that support is inadequate for these patients and that improved follow up and counselling services may lessen the adverse sequelae of termination for fetal malformation.

Can we afford screening for neural tube defects? The South Wales experience.

Clinical and financial gains and losses accruing from five different options for screening for open neural tube defects were estimated, based principally on the results of detailed monitoring of inputs and outcomes and of process costs in the South Wales Anencephaly and Spina Bifida Study. As well as estimating the overall clinical costs of a screening service it was shown that if the prevalence, including terminations, of open neural tube defects is between 1.25 and five per 1000 births the financial cost of avoiding the birth of a seriously handicapped child who would survive for more than 24 hours is in the range 9000 pounds- 54000 pounds depending on the option adopted and the prevalence of the condition in the target population. Prevalence is the biggest determinant of cost. The data should provide a basis for assessment and discussion of resource priorities in the National Health Service.