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The Effects of Maternal Age, Parity, and Sex of the Twins on Twin Perinatal Mortality. A Population Based Study

Published online by Cambridge University Press:  01 August 2014

H. Rydhström*
Affiliation:
Department of Obstetrics and Gynecology, University of Lund, Sweden
*
Department of Obstetrics and Gynecology, University Hospital, S-221 85 Lund, Sweden

Abstract

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The aim of this study on all twin births in Sweden between 1973 and 1985 was to evaluate the effect of maternal age, parity, and sex on twin perinatal mortality (PNM), by using national data held at the Medical Birth Registry, National Board of Health and Welfare, Stockholm. Zygosity in this study was estimated by the Hardy-Weinberg formula. In all, 22,374 twins were born; 972 (4.3%) of these died perinatally. The relative risk for perinatal death (after standardization for maternal age, parity, and like sex) decreased significantly during the study period, and reached its lowest value (0.3) in 1983. Maternal age was not associated with PNM, while women having their first delivery had a significantly higher PNM than the rest of the parturients. The MZ twinning rate increased fom 0.36% during 1973-76, to 0.40% during 1977-81 and 0.44% during 1982-85 (trend analysis: χ2 = 40.1, p < 0.001). After stratification for year of delivery and birthweight, like-sexed twins had a significantly higher PNM than unlike-sexed twins (odds ratio, OR = 1.25, 95% confidence interval, CI = 1.02-1.54). Males had a significantly higher PNM than females in like-sexed pairs (OR = 1.39, 95% CI = 1.16-1.66), and in unlike-sexed pairs (OR = 1.46, 95% CI = 1.01-2.10). MZ twins had a significantly higher estimated PNM than DZ ones (OR = 1.31, 95% CI = 1.02-1.67).

Type
Research Article
Copyright
Copyright © The International Society for Twin Studies 1990

References

REFERENCES

1.Armitage, P (1971): Statistical Methods in Medical Research. Oxford: Blackwell Scientific Publications, pp 363-93.Google Scholar
2.Boklage, CE (1987): Race, zygosity and mortality among twins: Interaction of myth and method. Acta Genet Med Gemellol 36:275288.Google Scholar
3.Bressers, WMA, Eriksson, AW, Kostense, PJ, Parisi, P (1987): Increasing trend in the monozygotic twinning rate. Acta Genet Med Gemellol 36:397408.Google ScholarPubMed
4.Butler, NR, Alberman, ED (1969): British Perinatal Mortality Survey. Second Report: Perinatal problems. Edinburough: Livingstone.Google Scholar
5.Campbell, DM, MacGillivray, I (1988): Outcome of twin pregnancies. In MacGillivray, I, Campbell, DM, Thompson, B (eds): Twinning and Twins. Chichester: John Wiley & Sons, pp 179206.Google Scholar
6.Dunn, PM (1965): Some perinatal observations in twins. Develop Med Child Neurol 7:121–34.Google Scholar
7.Farell, AGW (1964): Twin pregnancy: A study of 1000 cases. S Afr J Obstet Gynecol, 2:2835.Google Scholar
8.Having a Baby in Europe. Public Health in Europe 26 (1985). Copenhagen: WHO.Google Scholar
9.Karn, MN (1953): Twin data: A further study of birth weight, gestation time, maternal age order of birth, and survival. Ann Eugenics 17:233248.Google Scholar
10.Klein, JK (1964): Perinatal mortality in twin pregnancy. Obstet Gynecol 23:738744.Google Scholar
11.Källén, B (1988): Epidemiology of Human Reproduction. Boca-Raton, FL: CRC Press, pp 960.Google Scholar
12.Lee, K, Fergson, RM, Corpuz, M, Gartner, LM (1988): Maternal age and incidence of low birthweight at term: A population study. Am J Obstet Gynecol 158:8489.Google Scholar
13.MacGillivray, I, Campbell, DM (1988): Management of twin pregnancies. In MacGillivray, I, Campbell, DM, Thompson, B (eds): Twinning and Twins. Chichester: John Wiley & Sons, pp 111143.Google Scholar
14.Mantel, N (1959): Statistical aspects of the analysis of data from retrospective studies of disease. J Nat Cancer Inst 22:719.Google Scholar
15.Miettinen, OS (1974): Simple interval estimation of risk ratio. Am J Epidemiol 100:515-16.Google Scholar
16.Newton, W, Keith, L, Keith, D (1984): The Northwestern University Multihospital Twin Study. IV: Duration of gestation according to fetal sex. Am J Obstet Gynecol 149:655658.Google Scholar
17.Population Changes. Official Statistics of Sweden. Statistical Reports 1973-85 (19741986). Stockholm: Civiltryck Ltd.Google Scholar
18.Potter, EL (1963): Twin zygosity and placental form in relation to the outcome of the pregnancy. Am J Obstet Gynecol 87:566–7Google Scholar