In theory, anything that increases your chance of ovulating more than one egg at a time will increase your chances of having multiples. This includes things like age, being taller, and eating a diet high in protein. Let’s dig into that some more.
DZ pregnancies refer to twins that are created from two different eggs becoming fertilized at the same time. Whether that is from hyper ovulation (releasing multiple eggs at once) or fertility treatments, this results in fraternal twins.
MZ pregnancies, on the other hand, occur when one egg is fertilized and splits into two, identical embryos. This results in identical twins.
So what can affect your odds of having multiples?
Twins in the family
Many scientists argue that hyperovulation can run in a woman’s family resulting in a higher rate of twins. A male cannot contribute to the release of an egg so, therefore, cannot affect the ovulation status of his partner. A father can, however, pass down the genetic factor of hyperovulation to his daughters who may be more likely to conceive twins in the future.
Fertility Medications / Treatments
There are many reasons why people experience infertility and choose to undergo fertility treatments to conceive children. Some fertility medications can cause hyperovulation, increasing the chances that a woman may carry a set of dizygotic (DZ) twins. According to the Mayo Clinic, these are a few examples of common medications, and what they do:
Clomiphene citrate (Clomid). Stimulates ovulation by causing the pituitary gland to release certain hormones.
Injections that stimulate the ovary to produce multiple eggs. Used to improve a woman’s insulin resistance when this is the suspected cause of infertility.
Letrozole (Femara). Works similarly to Clomiphene, but is used mostly in women under the age of 39 who have Polycystic Ovarian Syndrome (PCOS).
Another type of fertility treatment that can affect the chance of conceiving multiples is In-vitro Fertilization (IVF). This process includes taking eggs from a woman’s body, sperm from a man’s body, and fertilizing them in a medical lab. After fertilization, the product becomes an embryo and the patient chooses how many embryos to transfer into the uterus in hopes of implantation. If the patient transfers two or more embryos at one time, the odds of a multiple pregnancy increase.
Certain health conditions
Some argue that certain health conditions or statuses can lead to an increased rate of conceiving twins, specifically obesity. Obesity is defined as having a Body Mass Index (BMI) over 30. Although this may be true, there is not much scientific evidence to back it up. In fact, studies show that being overweight or obese increases the risk for pregnancy complications including gestational diabetes and preterm labor. Be sure to discuss the ideal diet and level of activity during pregnancy, and while trying to conceive, with your healthcare provider.
Age and Past Pregnancies
Advanced Maternal Age (AMA) is associated with an increased chance of conceiving twins. This also goes hand in hand with parity which refers to the number of previous pregnancies a woman has had. The more pregnancies a woman has undergone, and the higher her age, the greater chance that she will have twins in future pregnancies.
It is worth mentioning that some people share stories that encourage certain behaviors in order to increase the chances of conceiving twins. Although these have not been backed by science, they have been told for many years and are interesting to discuss! Here are some common ones:
Eating extra dairy: Some say the protein in dairy can increase the odds of conceiving twins.
Increasing folic acid: This nutrient is essential during pregnancy because it reduces the risk for life-threatening conditions such as Spina Bifida in babies. However, some claim that taking folic acid before becoming pregnant may help you have multiples.
Sweet Potatoes: These may contain nutrients that increase your odds of twinning
Eat Cassava: Sometimes referred to as yucca, is a root vegetable that is believed by some to induce hyperovulation.
Drinking Bourbon before conceiving: This beverage has high levels of phytoestrogen.
Good, Old Fashioned Luck!
Ultimately, many twin pregnancies are the result of luck. Even if a woman has a family history of hyper ovulation, is of advanced maternal age, and is taking fertility medications, the conception of twins comes down to her body’s ovulation during that cycle and the success of implantation.