Natural pregnancy after IVF: How 'subfertility' surprises moms like Chrissy Teigen

Celebrity supercouple Chrissy Teigen and John Legend have been very open about their struggles with infertility and how in vitro fertilization (IVF) helped them conceive their two children. So, even they were surprised in July to learn that Teigen was pregnant without the use of assisted reproductive technology (ART).

While uncommon, natural conception after IVF can occur. One study found that out of 2,134 couples who attempted ART, about 20% became pregnant on their own after treatment. Many couples that present for fertility care are subfertile, not infertile.

This nuance is important:

• Infertility occurs when couples cannot conceive on their own. Either the woman or her partner has a health condition that makes natural conception impossible.
• Subfertility is when couples have a lower chance of conceiving on their own. A variety of conditions can contribute, including mild sperm deficiencies, ovulatory dysfunction, or tubal disease.

Couples with subfertility may go on to have healthy, successful pregnancies. However, some pregnancies, such as Teigen's, result in miscarriage. The couple announced that they had lost their baby, whom they had named Jack, in late September. According to the New York Times, it's unclear how far along Teigen was in the pregnancy.

I've asked Dr. Jennifer Shannon, an Ob/Gyn specialist who is in her second year of a Reproductive Endocrinology and Infertility Fellowship at UT Southwestern, to delve deeper into what we know about subfertility and share practical advice with patients who are trying to conceive.

The ART of fertility

Couples can feel rushed to conceive and may visit their doctor early for a fertility evaluation. While certain obvious concerns such as ovulatory dysfunction should be addressed right away, approximately 80% of couples likely will conceive within a year of trying on their own. The best way to optimize natural fertility is to increase how often the couple has intercourse.

However, ART is sometimes necessary to conceive. While the risks of ART are minimal, the emotional toll and costs can be significant. As Teigen expressed, her unsuccessful IVF was "devastating."

ART can be expensive, and results depend on the diagnosis and duration of infertility. Fortunately, Texas is one of a handful of states that requires insurers to offer coverage for IVF, though employers are not required to pay for coverage.

As you plan for pregnancy, it's important to consider specific factors that may affect your ability conceive. Let’s discuss these factors, and when to consider visiting a fertility specialist.

Conception challenges

If you and your partner are struggling to conceive, you’re not alone. Many conditions can make it difficult to become pregnant. About one-third of infertility cases are associated with a female factor, one-third are associated with a male factor, and the remaining one-third are either unexplained or associated with other causes.

A woman's age

Women are born with all the eggs they will ever have – about 1 million. Research shows that most women will have about 12% of their eggs left at age 30 and 3% at 40. Not only does the pool of available eggs decrease over time, but so does their quality. Diminished egg quality can affect pregnancy and miscarriage rates.

Further, many women are choosing to delay pregnancy. Your Ob/Gyn can assist you with evaluation of your ovarian reserve, and some women consider fertility preservation if they know they want to delay pregnancy.

Underlying health conditions

In men, genetic conditions can cause problems with sperm production and delivery. Health conditions, such as high blood pressure or diabetes can also reduce the likelihood of conception.

In women, the most common disorders are ovulatory dysfunction or tubal disease. However, other conditions such as fibroids, adenomyosis, and endometriosis can have a significant impact as well.

Cancer treatments such as radiation and chemotherapy, or overexposure to certain environmental factors such as alcohol or cigarette smoking can impair fertility in men and women. Prior to attempting conception, your Ob/Gyn can help optimize your general health.

Unspecified reasons

In a 2016 interview, Teigen said, “The big question was why this wasn’t working for us when I was young and he was healthy. I thought, 'people get pregnant by accident all the time. How does this happen?'” She's right – nearly half of all U.S. pregnancies are unplanned. However, up to 10% of subfertile couples are left without a cause, even after a thorough work up.