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Sex ratio of twins in a southeastern Brazilian population

B. Beiguelman; H.O. Villarroel-Herrera

Departamento de Genética Médica, Faculdade de Ciências Médicas, UNICAMP, Caixa Postal 6111, 13081 Campinas, SP, Brasil

ABSTRACT

The sex ratio of 1,150 twin births (363 MM, 407 MF and 380 FF pairs) was compared to that of 272,644 single births from the city of Campinas, State of São Paulo, Brazil. These births referred not only to live but also to stillborn children. The sex ratio of the twins (97.1 males per 100 females) was significantly lower than that of the singletons (106.3 males per 100 females)

Keywords: Sex ratio; Southeastern; Brazilian; population.

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