Reproductive Life Events of Twins with Opposite Sex

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Shayesteh Jahanfar


Introduction: It is hypothesized that androgens are transferred between fetuses across membranes, and have shown that female fetuses in female-male twin pairs have higher concentrations of serum testosterone than female fetuses in female-female pairs.  The question is whether or not this hormonal transfer has any impact on adult reproductive life events.

Objective: The study objective was to test the hypothesis that females from female-female twins and females from female-male twins differ with respect to reproductive life events.

Design and method:  We conducted a cross sectional study using volunteer female twins aged 15 and above from two settings of Malaysian and Iranian twin registries.

Result: Female-female twins had a higher frequency of congenital abnormality and hirsutism than male-female twins. Other reproductive events were not found to be statistically significantly different between the two groups.

Conclusion: Our study was distinctive in comparing specific reproductive events among females from female-male twins compared with female-female twins.  Our results indicates that hormonal transition from male to female in a female-male gestation cannot be a valid explanation for reproductive ill health during adulthood. 

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How to Cite
JAHANFAR, Shayesteh. Reproductive Life Events of Twins with Opposite Sex. Medical Research Archives, [S.l.], v. 6, n. 2, feb. 2018. ISSN 2375-1924. Available at: <>. Date accessed: 23 mar. 2018. doi:
Research Articles


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