Conceiving naturally after having a child through in vitro fertilization, or another fertility treatment, is not as uncommon as people might think.

Danyela Thurston remembers all too well when her urge to have a baby kicked into high gear. She’d been married to her husband for about three years, and it was as if a switch flipped on.

“At 32 it was ‘game on,’” she said. “There was this rage to have a baby.”

Thurston said she was a force to be reckoned with — taking her temperature, charting her cycle … She did this for a year. But when the couple didn’t get pregnant they sought help from a fertility clinic.

Thurston was diagnosed with what she described as “old eggs.” Meaning they required more hormones than she produced in order to drop from the ovaries. Thurston was told she had a 10 percent chance of getting pregnant.

After much consideration, the couple decided to use in vitro fertilization (IVF) and a donor egg. Nine months later, Thurston gave birth to a healthy baby.

But just seven weeks later, something remarkable happened. Thurston became pregnant on her own.

“I was elated and horrified,” she said with a chuckle.

To have a child via IVF and then get pregnant naturally is not as uncommon as people may think.

One report out of France was based on surveys from 2,000 couples. The findings showed that roughly 17 percent who had a child because of IVF also eventually ended up conceiving naturally.

Read more: ‘Sperm radar’ technique could help fertility research »

So what causes a woman, who’s been diagnosed with fertility issues, to suddenly get pregnant on her own?

One theory floating around is that women who are around babies somehow experience improved fertility.

The fertility experts that Healthline spoke to said a successful pregnancy involves many factors. But the notion that being around babies is enough to help a woman with known fertility issues become pregnant isn’t a theory they prescribe to.

“There is zero evidence of this, other than anecdotes,” Dr. Paula Amato, Oregon Health & Science University School of Medicine associate professor of obstetrics and gynecology, told Healthline.

A successful pregnancy in the face of infertility is no small feat, she added. Infertility is caused by a number of different issues, and to get at the root cause a couple must endure a battery of tests.

This includes looking at sperm count and analyzing hormone levels, among other procedures, before any diagnosis can be made.

Once the barriers to pregnancy are defined, methods are introduced to encourage implantation of an egg. After the treatments are in place, a lot comes down to a mix of science and luck.

“It’s really a numbers game for the most part,” she said.

Having said that, Amato noted that having a successful pregnancy — with or without medical intervention — is always an encouraging mark for future pregnancies.

“Having a child in the past is a good prognostic sign,” she said.

Couples trying to conceive naturally, but haven’t had success, can choose from a lengthy list of fertility treatments. These include artificial insemination, surrogacy, fertility medication, and donor eggs.

IVF is one of the most popular procedures. According to the Centers for Disease Control and Prevention (CDC), in 2014 more than 70,000 babies were born with the help of fertility treatments.

Dr. Eric Surrey is the chief medical officer at the Colorado Center for Reproductive Medicine, one of the top fertility clinics in the United States, according to Parents magazine. He said it’s not impossible that a couple who conceived via IVF can get pregnant again without such treatment.

However, he agreed with Amato that there isn’t evidence to support the theory that being around babies can help.

Rather, Surrey noted, a lot depends on the root cause of the infertility, and more importantly, the age of the mother.

“If you take away everything, the single greatest predictor [of pregnancy] is female age,” he told Healthline.

Surrey said as a general rule, couples that are experiencing infertility shouldn’t wait too long to seek treatment. That’s because infertility doesn’t follow the same path for all people. What may work for one couple may not produce the same outcome for another.

“There is rarely a single problem,” he said. “Everyone is different.”

Thurston’s scenario is a perfect example.

Amato noted that getting pregnant less than two months after giving birth is very rare. But in her own practice she has seen patients who conceived naturally after IVF.

“It happens, but it’s not happening in the majority of the cases,” she said.

For Thurston, she believes that the IVF treatment somehow affected her ability to conceive naturally.

“All of that stimulation in my system just amped things up,” she said. “It did something.”

Thurston may be right. That second pregnancy turned out to be twins.