Related Experiment Videos
Fecundability of female twins
K Christensen1, O Basso, K O Kyvik
1Danish Twin Registry, Odense University Medical School, Denmark.
Epidemiology (Cambridge, Mass.)
|March 21, 1998
Summary
Female twins do not have different fertility rates compared to singletons. This study found no evidence of reduced fecundability in female twins, even those with a male co-twin.
Area of Science:
- Reproductive biology
- Human embryology
- Twin studies
Background:
- Animal studies suggest prenatal hormonal interactions between fetuses of unlike sexes can impact female fertility.
- The potential effects of in-utero exposure to a co-twin's hormones on female reproductive capacity require further investigation in humans.
Purpose of the Study:
- To investigate whether the fecundability (ability to conceive) of female twins differs from that of singletons.
- To determine if the sex of a co-twin influences the fecundability of female twins.
Main Methods:
- A questionnaire survey of 12,681 female twins born in Denmark (1953-1976).
- An interview survey of 760 female singleton controls born in Denmark (1953-1966).
- Comparison of pregnancy outcomes and time to conception between female twins (monozygotic, dizygotic same-sex, dizygotic unlike-sex) and singleton controls.
Main Results:
- No significant differences in fecundability or time to pregnancy were observed among monozygotic, dizygotic same-sex, and dizygotic unlike-sexed female twins.
- Initial observations of shorter time to pregnancy in twins compared to singletons were attributed to data collection artifacts.
- No evidence of reduced fecundability was found in female twins, irrespective of their co-twin's sex.
Conclusions:
- Female twins do not exhibit altered fecundability compared to singletons.
- Prenatal exposure to a co-twin of the opposite sex does not appear to reduce female fecundability.
- Findings do not support the hypothesis of inter-twin hormonal interactions affecting female fertility in humans.