When do twins occur

Some identical twins may be born with individual sets of membranes, which may lead to the mistaken assumption that the babies are fraternal.

One way to tell the difference is to have the twins DNA-tested. Identical twins share the same genetic information, while fraternal twins share around half.

The test can be done with a sample of cheek cells, collected painlessly. Other tests include blood group examinations.

Where to get help Your doctor Paediatrician Maternity hospital Things to remember Twins account for over 90 per cent of multiple births. To form identical or monozygotic twins, one fertilised egg ovum splits and develops into two babies with exactly the same genetic information. To form fraternal or dizygotic twins, two eggs ova are fertilised by two sperm and produce two genetically unique children.

Your likelihood of conceiving twins or more , BabyCentre, Inc. More information here. Give feedback about this page. Was this page helpful? Yes No. View all reproductive system - female. Related information. Content disclaimer Content on this website is provided for information purposes only.

Reviewed on: J Reprod Med. Mechanisms of twinning. Sex preference and lactation. Shur N. The genetics of twinning: from splitting eggs to breaking paradigms. University of Rochester Medical Center. Health Encyclopedia. Overview of Multiple Pregnancy.

Centers for Disease Control and Prevention. Blastocyst culture is associated with an elevated incidence of monozygotic twinning after single embryo transfer. Fertil Steril. Case report: Successful of a spontaneous quadruplet pregnancy. J Prenat Med. Fertility treatments and multiple births in the United States. N Engl J Med. Multiples: Twins, Triplets and Beyond. March of Dimes. Mechanisms of twinning: X. The male factor. Your Privacy Rights. To change or withdraw your consent choices for VerywellFamily.

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Odds of Higher-Order Multiples. Frequently Asked Questions What are the chances of having twins if they run in your family? How can I increase my chance of having twins? Was this page helpful? Thanks for your feedback! You might also want to ask if your hospital has cots that allow co-bedding where your babies sleep in a single cot , if this is appropriate and if you want your babies to sleep together.

If you have one baby in the hospital and one at home, you will need to think about splitting your time between the two. When you visit your baby in hospital, ask if you can bring their twin and if co-bedding is allowed during visits.

If you want to breastfeed and only one twin can feed effectively, you may need to express milk to feed the twin who is having trouble feeding. You may then need to put the twin who can feed on the breast to encourage milk production in order to get enough milk to feed both babies. Check if your hospital offers support from a community neonatal nurse, which would allow for you and your babies to leave hospital earlier, for example if your baby is still tube-fed.

When you go to clinics for follow-up appointments, it's a good idea to ask not to be booked into early morning appointments. Getting out of the house with two babies, particularly if one is unwell, can be difficult. For more information and support, visit Twins Research Australia. Learn more here about the development and quality assurance of healthdirect content. Birth rates for MZ twins are consistent among all races about 4 per ; but the incidence of DZ twinning varies among races 8 per , among Caucasians, 16 per among people of African descent, and 4 per among Asians.

A genetic predisposition or inherited characteristic for DZ twinning exists in some families, but the consistency of MZ twinning among all populations suggests that identical twinning is a random occurrence that is not influenced by genes. Read more on Twins Research Australia website. Read more on Better Health Channel website. There has been an overall increasing trend in multiple births in the last two decades in Australia. Attributed largely to the increased use of fertility drugs and assisted reproduction technology and the growing number of older mothers.

Get the facts you need about different types of twins. Read more on raisingchildren. If you are having twins, triplets or more, find out everything you need to know about your pregnancy, the birth, feeding and raising your babies. Learn more about labour complications. Pregnant with twins? Helping twins to understand the psychology of their relationship means going right back to conception. Image credit: CDC As of , there are on average around 16 sets of twins born per 1, births in the United States.

There are two types of twins Identical twins Identical twins come from a single egg that was fertilized by a single sperm, which then divided into two separate embryos very early in the pregnancy. They are no more related than regular siblings! Image from Wikimedia Are there factors that increase your odds of having identical twins? Are there factors that increase your odds of having fraternal twins? There are several things that can increase the odds of fraternal twins. Everyone has a chance of having twins.

More Information WA state twin registry: Twins run in my family. Below are a few that are especially relevant to this article: : Twins seem to run in my family. Does it have to do with our genetics? Is this true?

Do scientists know why this is? Does this increase our chances of having twins? References Hoekstra, Chantal et al. Steinman, G. Effect of diet and heredity on the human twinning rate.

Other useful papers Machin, G. Shur, N. Search Ask a Geneticist.