Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2005 Jan:19 Suppl 1:8-9.
doi: 10.1111/j.1365-3016.2005.00609.x.

Factors influencing twins and zygosity

Affiliations
Review

Factors influencing twins and zygosity

Gary V D Hankins et al. Paediatr Perinat Epidemiol. 2005 Jan.

Abstract

Zygosity is influenced by many factors. Monozygotic twins occur spontaneously in approximately 1 in 250 births and are felt to increase twofold with ovulation induction techniques. Monozygotic twinning also increases in proportion to the number of blastocysts transferred during in vitro fertilisation. In contrast, dizygotic twinning appears to be influenced by race, genetic factors, maternal age, fertility enhancing drugs, folic acid supplementation, and maternal nutritional status.

PubMed Disclaimer

Similar articles

Cited by

LinkOut - more resources