While a woman’s chances of having twins are going to vary, there are several circumstances that could leave you buying two car seats instead of one.

Family History of Twins

If twins run in your family, your chances of getting pregnant with twins may be greater than a woman with no family history. But, there’s a catch.

“The paternal lineage doesn’t seem to increase the risk,” says Sara Twogood, MD, a board-certified OB GYN in Los Angeles and co-founder of Female Health Education and the online magazine Female Health Collective.

That means that if twins run on the mother’s side, you may have a greater chance of having twins. One reason for this may be hyperovulation. This is when the body releases two or more eggs during ovulation. The genes for this to occur can be inherited. Check your family history on your mother’s side to see if twins are a thing. If so, don’t be surprised if you’re conceiving twins down the road.

Fertility Treatments

Fertility treatments are also high on the list of factors that can increase a woman’s chances of having twins.

Twogood tells FamilyEducation enhancing treatments such as IVF, ovulation induction, and superovulation with fertility drugs like Clomid or Femara can increase the chance of twins.

If a woman undergoes in vitro fertilization (IVF), the likelihood of having fraternal twins increases. In this fertility treatment, doctors often place two fertilized embryos in the womb to enhance the chances of pregnancy, resulting in twins when both embryos successfully implant and develop.

For women under 35 using IVF, the probability of twin pregnancies is 12 percent, while women aged 35-37 have a 9 percent chance.

Another fertility procedure is intrauterine insemination (IUI), but it typically doesn’t raise the likelihood of having twins like IVF does. In IUI, doctors give women medications such as Clomid or Femara to stimulate ovary function, potentially leading to the production of multiple eggs. Doctors then directly insert sperm into the uterus to facilitate proximity to the egg. If two or more eggs fertilize and implant, it can result in the occurrence of twins.

Gonadotropins, especially follicle-stimulating hormone (FSH), stimulate egg follicle growth and play a frequent role in IUI and other fertility treatments, increasing the rate of twins by 30 percent.

Age

A woman’s age when she becomes pregnant can influence the likelihood of conceiving twins.

According to Twogood, ‘Age 35 years and older seem to have increased risk.’

At this age, women often release more than one egg during their reproductive cycle compared to younger women. This is attributed to hormonal changes occurring near menopause. If sperm fertilizes more than one egg, twins can result.”

Diet

A woman’s diet might heighten the likelihood of having twins. Research suggests that women who adhere to a dairy-free or vegan diet may increase their chances of having twins, potentially due to the growth hormones present in milk, influencing reproduction.

Some believe that yams could also enhance a woman’s chances of having twins. A study conducted in Nigeria, where the twinning rate is the highest globally, is based on the notion that yams contain a natural hormone, phytoestrogen, which may stimulate multiple ovulation, leading to twins

Height

Taller women’s likelihood of having twins is a subject of debate. According to one study, women with an average height of 5 foot 5 inches have a greater chance of experiencing multiple births compared to slightly shorter women.

Weight

Discussing strategies for conceiving twins, consider weight along with height.

“Obesity heightens the likelihood of having twins, and researchers are exploring other diet-related connections,” notes Twogood.

A 2005 study found higher twin likelihood in women with a BMI over 30 compared to lower BMI. However, intentionally gaining weight for twins is discouraged due to potential pregnancy complications.

Racial Background

A woman’s racial background may also play a role in her chances of conceiving twins. CDC statistics indicate that the rate of twin pregnancies is higher in African-American women than in white women. On the other hand, Asian and Hispanic women typically have lower rates of twin pregnancies compared to women in other ethnic groups.

Taking Supplements

Taking certain supplements may impact whether you’re buying one crib or two.

‘Some studies suggest that increasing amounts of folic acid may increase the risk of having twins,’ says Twogood.

Pregnant women are advised to take folic acid for baby’s brain development and to reduce neural tube effect risks.

Breastfeeding

Breastfeeding’s potential influence on the likelihood of having twins varies depending on the source. A 2006 study indicates that women who breastfeed have an 11 percent chance of having twins, compared to just one percent for non-breastfeeding women. It’s essential to note that women can conceive not only while breastfeeding but also with the possibility of having twins.

The Takeaway ( 8 Factors Having Twins)

When it comes to how to get pregnant with twins, it’s important to be aware of the 8 factors that may increase your chances having twins. Besides infertility treatments and genetics, there are other things like diet, height, and weight, that can also play a role. Understanding these and knowing your chances can help determine whether you’ll need one car seat or two! Learn more about the Day in the Life of a Mom with Twins.