Frequently Asked Questions About Twins
In the answers to the questions below, the following words are synonyms and may be used interchangeably:
- Identical Twin = monozygotic = MZ
- Fraternal Twin = dizygotic = DZ
For more information about these terms, see the Zygosity section.
Occurrence of Twins
- How often do twin births occur?
- Why did the number of twin births increase?
- Are there more male twins or female twins?
- I am a twin. Do I have an increased chance of having twins?
- Twins run in my family. Do I have an increased chance of having twins?
Appearance of Twins
- What factors are related to fraternal twinning?
- Does identical twinning run in families?
- Can identical twins look different?
- Do female identical twins appear more different than male identical twins?
- Can fraternal twins look so similar that they are mistaken for identical?
- Can a male/female twin pair be identical?
- Can twins appear to be different races?
Types of Twins
Medical Questions For Twins
- What is twin-to-twin transfusion syndrome?
- If my twin gets a disease, will I also get it?
- What causes some twin pairs to be born with very different birth weights?