Distribution of the incidence of anencephaly in Japan

Abstract

Distributions of the incidence of anencephaly in Japan were obtained using nationwide data on fetal and postnatal deaths of individuals with anencephaly during 1969–71. Higher incidences of anencephaly occurred in the urbanized and industrialized areas and lower values in the comparatively sparsely populated highlands. Population size and variance of incidence show a negative association. The distribution of the incidence seems to be binomial, and expected incidences based on binomial distribution indicated good agreement with weighted mean incidences in populations with different sizes. The rate of first cousin marriages among the parents of anencephalic patients is 1.86 per cent, a value not significantly different from the value of general population, 2.13 per cent. It seems that the inheritance of anencephaly is not related to a specific number of recessive genes.     

The sex ratio in anencephaly

It is shown that the well known excess of females in anencephalic births is statistically significant when compared with (a) the general population and (b) their normal sibs.There is also a statistically significant difference between the sex ratio of anencephalic births and that of spina bifida births which suggests that there is a definite difference in the genetic component of their aetiology.These results are discussed with reference to the genetics of anencephaly and spina bifida and a genetic model of the inheritance of the genetic component of anencephaly is given. The significance of a possible cytoplasmic factor is also considered.     

Extremely high prevalence of neural tube defects in a 4-county area in Shanxi Province, China

BACKGROUND: In the past, northern China's Shanxi Province has reported the highest incidence of neural tube defects (NTDs) in the world. However, little is known about the epidemiology of NTDs in this area in recent years. METHODS: Data were collected from a population-based birth defects surveillance system in 4 counties that captures information on all live births, stillbirths of at least 20 weeks' gestation, and pregnancy terminations at any gestational age resulting from prenatal diagnosis of a birth defect. We also surveyed mothers of NTD case patients to determine their use of folic acid before and during early pregnancy. RESULTS: During 2003, 160 NTD cases were identified among 11,534 births (NTD birth prevalence = 138.7/10,000 births). The rates of anencephaly, spina bifida and encephalocele were 65.9, 58.1, and 14.7 per 10,000, respectively, and a female predominance was observed among anencephaly cases (male-to-female relative risk [RR], 0.49; 95% confidence interval [CI], 0.30-0.79), but not among spina bifida (RR, 0.90; 95% CI, 0.55-1.45) and encephalocele (RR, 1.03; 95% CI, 0.40-2.69) cases. The percentages of pregnancy termination following prenatal diagnosis of anencephaly, spina bifida, and encephalocele were 50%, 41.8%, and 35.3%, respectively. NTD birth prevalence tended to be higher among mothers aged <20 or > or =30 years (P = .06) and was markedly associated with lower levels of maternal education (P < .001). Among 143 NTD mothers, only 6 (4.2%) used folic acid supplements during the periconceptional period. CONCLUSIONS: The NTD birth prevalence rate in the study area is among the highest worldwide. Folic acid deficiency may be one important risk factor.     

Epidemiological studies of neural tube defects in Newfoundland

A 9-year survey of neural tube defects in Newfoundland showed (1) evidence for secular variation, with a peak in 1980, but no general downward trend as seen in some other populations; (2) significant geographic variation which did not correlate with hardness or nitrate content of the lake water; (3) a tendency for the proportion of females among anencephalic births to increase with increasing frequency of anencephaly among geographic regions. This supports previous evidence for a female-specific contribution to the causes of increased liability to neural tube defect.     

SEIZURE PROBLEMS IN 250 CEREBRAL PALSIED ADULTS

Seizures occurred at some time in 81 (or 32 per cent) of an unselected, consecutive series of 250 cerebral palsied persons between the ages of 16 and 52 years, an incidence similar to that reported by other investigators in groups of cerebral palsied persons who were mainly children.The incidence of seizures of any kind after 16 years of age in the present series was 10 per cent as compared with 0.5 per cent in the general population. Half of the 10 per cent had more than six convulsions despite drug therapy, and the other half had fewer than six.Of thirty-six who had convulsions in the neonatal period, only four had seizure problems as adults, even though most showed moderate to severe physical handicap after age 16.Data on the small group of paraplegics in the present study, all spastics, were in accord with reports by other investigators with regard to decreased incidence of seizures in cerebral palsied patients with normal upper extremities. Of the thirteen (5 per cent of the 250) whose seizure problems continued to be clinically significant in adult life, ten had had frequent seizures in childhood. Eight were hemiplegic. There appeared to be no relationship between the severity of physical handicap and the incidence of seizures after age 16.     

Experimental protein malnutrition during gestation and breeding performance of squirrel monkeys,Saimiri sciureus

The report summarizes our four year experience with the breeding of squirrel monkeys, a New World species used widely in experimental research. Breeding squirrel monkeys in captivity has hitherto been considered capricious, with success in most instances not exceeding 50%. By a combination of hand picking the animals, housing in a harem-type situation with one male to several females, and sound nutrition, a success rate of 85–91% live births to number of pregnancies has been achieved. The rate of stillbirths and abortions in the group maintained on a well-balanced diet did not exceed 10% of the total pregnancies. This compares favorably with any successful breeding program with Old World monkeys, whose reproductive physiology is relatively well understood. It is clear from our studies that adequate quantities of proteins are essential for optimum reproduction. Among the pregnant animals maintained on a diet containing about 50% of their normal requirements of protein (8% calories from a protein source), the incidence of abortions increases significantly. In this group, the rate of abortions to total pregnancies ranges from 40.5 to 61.5%. The females maintained on a protein deficient diet during pregnancy are so protein hungry that an extruded fetus is a welcome food and no time is lost in devouring all of the placenta and the fetus. This type of cannibalism has never been observed among the mothers maintained on a high protein regimen.     

Results of cytogenetic examinations in 255 married couples with a history of infertility]

The results of cytogenetic examination carried out in 255 couples with a history of infertility have been analysed. Chromosomal aberrations have been detected in 15 examinations (6.7%) with predominance of translocations (mutual - 3.6%; Robertson' - 1.3%). Identified aberrations have been noted in 9 women and 6 men. The obtained results have been analysed in relation to the number of abortions, dead and live newborn babies with inherited abnormalities. It was found that the incidence of chromosomal aberrations increases with the number of the spontaneous abortions in anamnesis. Such aberrations have also been more frequent in the families in which spontaneous abortions have been accompanied by other fertility disorders.     

Neural-tube defects: importance of a history of abortion in aetiology.

The overall incidence of anencephaly and spina bifida (ASB) in 69,056 pregnancies was 4.7/1000 births. ASB was more common (8.4/1000 births) among children of mothers who had had two or more abortions, but the increased risk was confined to spina bifida. A history of abortion was more common in older women and women of higher parity, but this was not matched by a similar increase in the incidence of ASB. The incidence of ASB was related to social class, but the prevalence of previous abortions was similar in all classes. The results suggest that expectant mothers with a history of two or more abortions have an increased risk of producing a child with spina bifida. The abortions are considered to be a manifestation of previous abnormal conceptions rather than the primary cause.     

Experimental production of anencephalic monsters by chick embryo microsurgery. Initial observations

42 hour-old chick embryos are operated by microsurgical means. The encephalon, which is normally closed at this stage, is reopened and the incision extended to the level of 2nd or 3rd somites. The experimental embryos are anencephalic. Their comparison with a spontaneous anencephalus shows a large morphological similarity. These first experiments confirm the hypothesis by which anencephaly is a direct consequence of the failure of neural tube closure.     

Sex ratio and mortality in a laboratory colony of the common marmoset (Callithrix jacchus).

In a retrospective study sex ratio and mortality were analysed in a captive colony of common marmosets (Callithrix jacchus). Seven hundred and thirty-five infants in 294 litters (20 singletons, 119 twins, 140 triplets, 14 quadruplets) out of 57 breeding females were evaluated. The sex ratio at birth was 0.95 males:1.0 females. The frequency of males and females, as well as the sex composition of twins and triplets confirm the assumption of dizygotic twinning in the common marmoset. According to age at death, 9 categories were differentiated, with perinatal mortality being the highest. Once early infancy had passed the probability of a common marmoset infant of our colony reaching childhood is nearly 95%. Sixty per cent of all liveborn infants survived beyond 18 months. Mortality of infants at birth from primiparous mothers did not differ from that of pluriparous females, nor did the survival rate of infants with the filial generation the respective female had reached (F1 to F6). Females with a high ratio of triplets and quadruplets had a lower reproductive success than females with a majority of singleton or twin deliveries. Differential mortality between males and females was not observed. The frequency of stillbirths was not strongly related to parity, but was to litter-size. Most stillborn babies were seen in sets of quadruplets, most abortions in singletons. A normal socialization in a stable social environment, as well as not pairing the animals before they are fully adult, are considered important factors in good breeding success and infant survival.     

Relationship of physiological factors to placental retention in dairy cattle

Various physiological and environmental factors were examined for possible association with retention of the fetal membranes in a herd experiencing a high incidence of this problem. Data were collected on 116 multiparous and primiparous cows during the first lactation of the trial and 57 multiparous cows during the second lactation of the trial. No mineral or heavy metal deficiencies or toxicities were detected in the herd and injections of selenium and/or vitamins A, D and E during the prepartum period were not beneficial. Also, no common disease entity could be found in this herd. Placental retention rates observed were 28% and 42% in the first and second lactations, respectively, of this study. The incidence of retained placenta was higher in cows giving birth to twins or male calves, and following abortions, stillbirths or placental retention at the previous parturition. Seasonal effects varied, with a higher retention rate in the warm season in the first lactation and in the cold season in the second lactation. Factors examined that did not show a statistically significant relationship to the placental retention rate included: blood serum vitamin A and β-carotene concentrations; age or lactation number; calf birth weight; presence of serum antibodies to leucosis or chlamydia; incidence of milk fever or ketosis; and services per conception, days open and gestation length of the pregnancy prior to retention. Cows with retained placenta subsequently had longer postpartum intervals to first ovulation and more uterine infections, foot problems and mastitis than cows without retained placenta.     

Legalized Abortion in Japan

The enactment of the Eugenic Protection Act in Japan was followed by many changes. The population explosion was stemmed, the birth rate was halved, and while the marriage rate remained steady the divorce rate declined. The annual total of abortions increased until 1955 and then slowly declined. The highest incidence of abortions in families is in the 30 to 34 age group when there are four children in the family. As elsewhere abortion in advanced stages of pregnancy is associated with high morbidity and mortality.There is little consensus as to the number of criminal abortions. Reasons for criminal abortions can be found in the legal restrictions concerning abortion: Licensing of the abortionist, certification of hospitals, taxation of operations and the requirement that abortion be reported. Other factors are price competition and the patient''s desire for secrecy.Contraception is relatively ineffective as a birth control method in Japan. Oral contraceptives are not yet government approved. In 1958 alone 1.1 per cent of married women were sterilized and the incidence of sterilization was increasing.     

A FIVE-YEAR STUDY OF PREMATURITY

To get a comprehensive picture of prematurity and neonatal death or survival, all factors on the maternal and fetal records that might be pertinent were recorded. This information, having to do with factors such as age, gravida of the mother, blood group incompatibility, period of gestation, weight at birth, type of delivery, medication and anesthesia administered to the mother, is presented in tabular form.In the study of perinatal mortality it was noted that failure to establish normal pulmonary ventilation is the most common cause of death in the neonatal period. Maternal history of relative infertility, that is, previous abortions, stillbirths and premature deliveries, was the most impressive finding in the stillborn series.In the follow-up study of premature infants who survived the neonatal period, 8.5 per cent were found to be severely handicapped. In four cases the handicap was due to congenital anomalies, in two others probably to infection, leaving 12 with complications possibly ascribable to prematurity. Six of these had retrolental fibroplasia as a major handicap. In seven, mental retardation was the presenting problem. Most of the handicapped children had multiple handicaps, which included spasticity, delayed motor development, strabismus, etc. The incidence of the necessity for corrective measures for feet and legs appeared relatively high.In general, survivors compared favorably with the rest of the childhood population. Complications and twinning were associated inordinately often.     

EFFECTIVENESS OF ANTACIDS IN REDUCING DIGESTIVE DISTURBANCES IN PATIENTS TREATED WITH PREDNISONE AND PREDNISOLONE

To appraise the efficiency of complemental antacid administration in preventing and reducing digestive disturbances during prolonged treatment with prednisone and prednisolone, 100 patients with active rheumatoid arthritis who were maintained on combined antacid and prednisone or prednisolone therapy for periods of one year or longer, were studied clinically and roentgenographically. Antacid therapy consisted of 300 mg. of dried aluminum hydroxide gel and 50 mg. of magnesium trisilicate taken with each 2.5 mg. dose of the steroids.Digestive symptoms, such as indigestion, heartburn, sour eructations, gnawing epigastric distress and the like, were experienced by 18 per cent of patients during treatment with prednisone or prednisolone combined with antacids. Among patients who had been maintained on the steroids without antacids beforehand, the incidence of digestive complaints was reduced from 38 per cent to 17 per cent by the addition of alkali therapy, and the severity of the distress decreased in others.Active peptic ulcers were detected roentgenographically in three of the 100 patients. In two instances the ulcers were asymptomatic and in two instances they were considered as reactivations of previously healed lesions. The incidence of active ulcers in this series was substantially lower than that reported by several investigators among patients treated with prednisone and prednisolone without the concomitant administration of alkalis. The size of dosage and individual susceptibility appeared to be important factors in the development of digestive disturbances from steroids.Results of the study indicated that the complemental use of antacids with each divided dose of steroid is highly effective in reducing the frequency and severity of digestive symptoms during prednisone and prednisolone administration. The low incidence (3 per cent) for roentgenographically demonstrable active lesions in the series suggests that the addition of acid-neutralizing agents during prolonged treatment with these steroids may afford at least partial protection against the development and reactivation of peptic ulcers.     

Parental HLA compatibility, fetal wastage and neural tube defects: evidence for a T/t-like locus in humans

To test the hypothesis that a locus in or near the human major histocompatibility complex (HLA) contributes to both involuntary fetal loss and neural tube defects (NTD), we evaluated sharing of antigens of the HLA-A, HLA-B, or HLA-DR loci of couples who had three or more first-trimester spontaneous abortions or who had a child with an NTD (myelomeningocele or anencephaly). HLA-A antigen sharing was increased in couples with three or more spontaneous abortions and in couples who had an anencephalic fetus, when compared with couples who had three or more pregnancies and no fetal loss. Increased sharing of antigens at the HLA-A and B loci was not seen in the entire group of couples with children with myelomeningocele, but was found in the subgroup of 36 couples whose child had a lumbar myelomeningocele. An increase in HLA-DR sharing was not seen in any group or subgroup when compared with the control couples. Among the aborting couples, increased sharing was not restricted to the couples who had no term pregnancies, but was also found in the couples whose fetal losses occurred after one or more normal term pregnancies. These results are consistent with the hypothesis that a locus on the HLA-A side of the HLA-DR locus contributes to some fetal loss and susceptibility to NTD. This model is proposed as an alternative to the hypothesis that the maternal immune response to paternal major histocompatibility complex (MHC) antigens is the basis for increased HLA sharing in couples with fetal wastage.     

Comparison of infertility rates in communities from boron-rich and boron-poor territories

As a part of a large-scale work aimed at studying the health effects of boron (B) in residents of a country with the world’s largest supply, developmental effects of B are presented. Spontaneous abortions, stillbirths, and congenital malformations in addition to early infant mortality were questioned in the field by home visits. Although the number of families so far ascertained is rather small, the rates related to spontaneous abortions and stillbirths from high B exposure vs low B exposure subpopulations revealed no differences of significance, providing no evidence that B affects human development adversely.     

Wallerian degeneration in rabbit tibial nerve: changes in amounts of the S-100 protein

Abstract— —A soluble protein (S-100) which is unique to the nervous system was measured in rabbit tibial nerve at 0, 3, 7, 14, 21, and 28 days of degeneration. Amounts of S-100 in the degenerated peripheral segment of the transected nerve fell progressively during degeneration to 2 per cent of that measured in the corresponding portion of nerve taken from control rabbits 28 days postoperatively. Total soluble proteins increased 42 per cent during this time. Levels of S-100 and total soluble proteins remained unchanged in non-degenerated nerve segments from experimental and control rabbits. Correlations of amounts of S-100 measured in the study reported here with cellular changes demonstrated by other investigators to characterize Wallerian degeneration in peripheral nerve suggest that the S-100 protein is localized primarily in axons rather than in Schwann cells or myelin.     

Livestock production in central Mali: Reproductive performance and reproductive wastage in ruminants in the agro-pastoral system

Results of a 7-yr field study and a 3-yr slaughterhouse study into reproductive performance and reproductive wastage of ruminants in central Mali are reported. Cattle had delayed age at first puberty (40), long calving intervals (644) and produced few young (3.02) per lifetime. Goats and sheep first conceived at about 11 mo, had shorter parturition intervals (298 and 280 d) but also produced few young (2.64 and 1.92) per lifetime. Conceptions showed a strong seasonality in cattle and mainly occurred during and shortly after the short rainy season. Seasonality was less marked in small ruminants, but most females conceived before the rains. However, maximum litter sizes were associated with late-rain and post-rain conceptions. Early embryonic wastage did not appear to be a major problem but abortions, stillbirths and heavy preweaning mortality were sources of loss of reproductive potential. Additionally at a secondary (government controlled) abattoir, 15.0 % of cows, 31.7 % of goats and 20.0 % of sheep that were slaughtered were found to be pregnant.     

Variation in the incidence of congenital malformations in spontaneous abortions,stillbirths and artificially interrupted pregnancies

Summary The study describes the nation wide rate of stillbirths and the incidence of mal-development in a series of spontaneous and induced abortions in Great Britain. Special reference is made to CNS malformations. Comparative study of these various types of births revealed that the incidence of maldevelopment is higher in induced abortion and in spontaneous abortion than in total or in stillbirths respectively. CNS malformations showed a higher frequency in stillbirths than in that of spontaneous abortions.

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Zusammenfassung Dies Arbeit betrifft die Rate von Totgeburten in ganz England und die Mißbildungshäufigkeit in einer englischen Serie von spontanen und induzierten Aborten. Auf die Mißbildungen des Zentralnervensystems wird besonders Bezug genommen. Ein Vergleich der verschiedenen Arten von Geburten hat ergeben, daß die Häufigkeit von Mißbildungen bei induzierten Aborten und bei Spontanaborten höher ist als insgesamt bzw. bei Totgeburten. Mißbildungen des Zentralnervensystems waren bei Totgeburten häufiger als bei Spontanaborten.