Hostname: page-component-7479d7b7d-rvbq7 Total loading time: 0 Render date: 2024-07-08T08:30:40.700Z Has data issue: false hasContentIssue false

Changing Trends in Twinning*

Published online by Cambridge University Press:  01 August 2014

R. Goswami
Affiliation:
Department of Genetics, The University Campus, Bhopal 462026, India
H.K. Goswami*
Affiliation:
Department of Genetics, The University Campus, Bhopal 462026, India
*
Department of Genetics, Bhopal University, Bhopal, 462026, India

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Birth statistics (on 13,887.943 births) from 11 Indian States indicate a fall in the dizygotic twinning rate and a rise in the monozygotic twinning rate over the decade between 1982 and 1991. These figures seem to reverse the trend of the period 1960-1982. One plausible explanation is offered by the age-data on mothers, which indicate that twins of different sex are more frequently born to mothers above the age of 35. Since extensive family planning measures have reduced the upper age-limit of mothers, the birth-rate of twins of different sex has also fallen. Due to the increased proportion of twins of the same sex, Weinberg's differential method will therefore report a decline in the dizygotic twinning rate, wherever the mean age of mothers has fallen (i.e. most mothers do not reproduce after the age of 35).

Type
Research Article
Copyright
Copyright © The International Society for Twin Studies 1993

Footnotes

*

This data was presented at the 7th International Congress on Twin Studies, held in Tokyo from 22-25 June, 1992.

References

REFERENCES

1. Bulmer, MG (1970): The Biology of Twinning in Man. Oxford, Clarendon Press.Google Scholar
2. Chen, CJ, Lin, TM, Chang, C, Cheng, YJ (1987): Epidemiological characteristics of twinning rates in Taiwan. A Ge Me Ge 36:335342.Google Scholar
3. Derom, C, Vlietinck, R, Derom, R, Van den Berghe, H, Thiery, M (1987): Increased monozygotic twinning rate after ovulation induction. Lancet 1:12361238.CrossRefGoogle ScholarPubMed
4. Elwood, JM (1978): Maternal and environmental factors affecting twin births in Canadian cities. Br J Obst Gynaecol 85:351358.CrossRefGoogle ScholarPubMed
5. Eriksson, AW, Bressers, WMA, Kostense, PJ, Pithanen, KJ, Mielke, JH, Jorde, LB, Tas, RFJ, Fellman, JO (1988): Twinning rates in Scadinavia, Germany and The Netherlands during years of privation. A Ge Me Ge 37:277297.Google Scholar
6. Goswami, HK (1970): Frequency of consanguineous marriages in Madhya Pradesh. A Ge Me Ge 19:486490.Google Scholar
7. Goswami, HK (1970): Studies on twins IV: twinning in Madhya Pradesh. A Ge Me Ge 19:465471.Google ScholarPubMed
8. Goswami, HK (1983): Genetics and public health: some considerations in an Indian context. In Goswami, HK (ed): Genetics and Public Health. Ranchi Catholic Press.Google Scholar
9. Goswami, HK (1987): Twinning and inbreeding in India: the fraternal component. A Ge Me Ge 36:343347.Google ScholarPubMed
10. Goswami, HK, Wagh, KV (1975): Twinning in India. A Ge Me Ge 24:347350.Google Scholar
11. Parisi, P, Gatti, M, Prinzi, G, Caperna, G (1983): Familial incidence of twinning. Nature 304:626628.Google Scholar
12. Philippe, P (1991): Twinning in susceptible mothers. A Ge Me Ge 40:269289.Google Scholar
13. Sarkar, SS, Sarkar, J (1967): Twin studies in India. Transactions of the Bose Research Institute 30:235238.Google Scholar