The sex ratio in anencephaly

  title={The sex ratio in anencephaly},
  author={Judy Timson},
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… 
3 Citations

Sex ratio in spina bifida and anencephaly

Timson's (1969, 1970) three locus model for the determination of anencephaly and spina bifida is examined, and it is concluded that observed population incidences of these conditions do not fit the

Risk factors, organ weight deviation and associated anomalies in neural tube defects: A prospective fetal and perinatal autopsy series.

This prospective fetal autopsy series to study the rate and distribution of NTD, analyze the reproductive factors and risk factors, note any associated anomalies and evaluate the organ weights and their deviation from normal.

Periconceptional folic acid supplementation and sex difference in prevention of neural tube defects and their subtypes in China: results from a large prospective cohort study

FA supplementation successfully reduces the prevalence of NTDs in both male and female infants, although it is found a significantly greater decrease in anencephaly and total N TDs in females than in males.



The sex ratio in spina bifida

It is shown that the well known excess of females in spina bifida children is statistically significant when they are compared with the general population and their sibs and when all the children in these families are considered they appear to have a sex ratio very similar to that general population.

Anencephaly, spina bifida and hydrocephaly

It is supposed that the result of an investigation with respect to congenital malformations might be that exogenous moments could exercise influence in case of certain deformities, but not of the serious ones as described in this treatise.

The Genetics of the Major Central Nervous System Malformations, Based on the South Wales Sociogenetic Investigation

A preliminary report is given of a family study from South Wales based on 424 index patients with spina bifida and 361 with anencephaly, that is about 8 times the normal population incidence in South Wales.

Incidence and Family Aggregation of Major Congenital Malformations of Central Nervous System

This paper reports relevant data on a series of patients from the Southampton area with major congenital malformations of the central nervous system, indicating that environmental factors such as season of birth and social class are important.

Congenital Malformations of the Central Nervous System

The intervening years have added little to the authors' knowledge of the aetiology of the malformations, but the effectiveness of preventive measures against other causes of infant death before and after birth has enormously altered their relative contribution to the total deaths.


  • A. Searle
  • Medicine, Biology
    Annals of human genetics
  • 1959
1. The incidence of anencephaly in Singapore was determined from hospital records for 1953–56 inclusive. Sixty‐eight cases were found in 88,069 births, or 0.77 per thousand.

Statistical Review of England and Wales

  • Economics
  • 1956

Anencephalus, Spina Bifida, and Hydrocephalus

This communication describes the findings of this investigation, with the exception of data relevant to the association with maternal age and parity, which is reported separately (Ingalls, Pugh, and MacMahon, 1953).