The occurrence of multiple births has risen significantly over the past two decades. This trend can be attributed mainly to the fact that a large portion of women having babies are now over the age of thirty, which increases the likelihood of conceiving multiples. Additionally, the use of fertility medications and treatments has contributed to this rise. There are two primary types of multiples: identical (monozygotic) and fraternal (dizygotic).
What Are Identical (Monozygotic) Multiples?
Identical multiples arise from a single fertilized egg and are genetically identical. Often referred to as identical twins, these multiples share the same sex and look alike.
How Are Identical Multiples Formed?
The formation of identical multiples is considered a random event and is not influenced by factors such as age, race, or family history. Identical twins occur in approximately 3 to 4 out of every 1,000 live births.
What Are Fraternal (Dizygotic) Multiples?
Fraternal multiples, on the other hand, are the result of multiple eggs being fertilized by different sperm. These multiples can be of different genders and are not genetically more similar than regular siblings.
How Are Fraternal Multiples Created?
Fraternal multiples are the most common type of multiples, often occurring as a result of fertility treatments. The increase in fraternal births can also be linked to older maternal age, as women today are having children later in life. Other factors that increase the likelihood of fraternal multiples include a higher body mass index (BMI), recent discontinuation of hormonal birth control, and having had multiple previous pregnancies.
What About Higher-Order Multiples?
Higher-order multiples (triplets, quadruplets, etc.) can be a combination of identical and fraternal types. For instance, triplets could result from one fertilized egg that splits into three, making them genetically identical. Alternatively, triplets might occur when one of two fertilized eggs divides, resulting in two identical siblings and one fraternal sibling. Similar scenarios apply to quadruplets and other multiple births.
If you’re interested in exploring fertility options or considering at-home insemination, you might want to check out Make A Mom, which offers a unique reusable insemination method. You can also learn more about how at-home insemination works on their page, How It Works. For those in need of sperm donation, Vegas Pregnancy provides a free sperm donor matching service in Las Vegas. Additionally, for a comprehensive overview of in vitro fertilization, the Mayo Clinic is an excellent resource.
For more insights on this topic, you can also read our blog post on Make A Mom featured in Business Insider. If you’re looking for expert opinions, Modern Family Blog covers various aspects of family planning and fertility.
In summary, multiple births can occur due to various factors, including maternal age and fertility treatments. Understanding the differences between identical and fraternal multiples can help prospective parents navigate their options.