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Infertility Causes and Treatment Options

Contributor Mark D. Hornstein, MD
8 minute read
A concerned couple searches the Internet together.

Content warning: Discussion of pregnancy, fertility, infertility, childbirth, and miscarriage.

Infertility is a common, often treatable disease. But it can come as a shock to people trying to conceive for the very first time. People put so much hope and energy into tracking and planning each cycle that eventually, negative pregnancy tests begin to feel like personal attacks. And the idea of needing — and seeking — support may be scary.

Mark D. Hornstein, MD, is a Mass General Brigham reproductive endocrinologist and the director of reproductive endocrinology in the Center for Infertility and Reproductive Surgery at Brigham and Women’s Hospital. In this article, he answers common questions about infertility, including what it is, why it happens, and describes treatment options.

What is infertility?

“The American Society for Reproductive Medicine (ASRM) defines infertility as the inability to conceive a child after 1 year of unprotected intercourse in a female younger than 35, and after 6 months in women 35 and older” says Dr. Hornstein.

At this point, couples are encouraged to seek fertility support from their primary care provider (PCP) or obstetrician-gynecologist (OB-GYN).

Why do doctors use age 35 as a gauge? “Like most things in biology, this is a continuum,” explains Dr. Hornstein. “Your fertility doesn’t plummet as soon as your 35th birthday, but in population-based studies, we begin to detect a drop at age 35. I often explain to my patients that the ovary doesn’t know if you’re 34 years and 364 days old versus 35 years old. But 35 is a pretty good cutoff.” 

For people assigned male at birth (AMAB), Dr. Hornstein explains, age-related infertility is a bit different. “People assigned female at birth (AFAB) are born with all the eggs they will have for their entire life, and they lose those eggs throughout their reproductive lifespan. But people AMAB are constantly making sperm. Sperm production and numbers decline, but they decline less sharply, and at an older age.”

What causes infertility?

Infertility can happen for many reasons — but sometimes, it can’t be explained. That said, some common reasons include (but are not limited to):

  • Conditions affecting the ovulation or the ovaries, blocked or damaged fallopian tubes, or the uterus
  • Conditions affecting the testicles, ejaculation, or sperm quality or count
  • Hormone disorders such as thyroid disease, polycystic ovary syndrome, or low testosterone levels
  • Diminished ovarian function, or egg number or quality
  • Acquired conditions such as scarring, endometriosis or uterine fibroids
  • Overweight or obesity, or extreme weight gain or loss
  • Smoking
  • Alcohol use

What is secondary infertility?

According to Dr. Hornstein, you can struggle with infertility after a successful first pregnancy. It’s so common that there’s a term for it: secondary infertility.

“We see it often, and it doesn’t surprise us,” Dr. Hornstein explains “It’s well-known that patients who have no trouble getting pregnant the first time can have a problem the second time. We help them the same way we would if they’d never been pregnant in the first place, because the same factors come into play.”

What causes secondary infertility?

There are many reasons people struggle with secondary infertility. “It may have been that they were lucky the first time,” explains Dr. Hornstein. “But there are things that can happen in pregnancy that can affect fertility. Cesarean sections could affect the uterus. They usually don’t, but they can. Infections associated with labor aren’t that unusual, and they can cause tubal damage.”

One major cause of secondary infertility is age. “It takes 9 months from conception for a person to deliver a baby,” Dr. Hornstein says. “Let’s say they breastfeed for another 12 months. It’s almost 2 years from when they first got pregnant—and that’s assuming they’re ready to get pregnant right away. Let’s say they wait another year. Now it’s 3 years later. Three years is a long time, reproductively. Hormones could be very different at age 38 than they were at age 35.”

There’s a much more widely accepted idea that infertility is a disease and should be treated as a disease. It is defined as a disease by the Americans with Disabilities Act. It’s not a failure on the part of the individuals.

Mark D. Hornstein, MD
Reproductive Endocrinologist
Mass General Brigham

Why is it difficult to talk about infertility?

Not long ago, infertility was a secret often kept between patients and their partners, and maybe one or two other people for support. Many people expressed feelings of guilt and shame when they struggled to conceive. Often, they blamed themselves and struggled in silence.

Today, Dr. Hornstein says, this is changing. He attributes this, in part, to social media. “Many people will share their infertility stories on social media. And I think because of that, it’s now pretty well-recognized that this is a common problem,” he explains. “There’s a much more widely accepted idea that infertility is a disease and should be treated as a disease. It is defined as a disease by the Americans with Disabilities Act. It’s not a failure on the part of the individuals.”

How is infertility diagnosed and treated?

If you need fertility treatment, an easy first step is to talk to your primary care provider or OB-GYN. They can help you better understand what’s happening. And they can guide you on a path toward the right specialist if necessary.

“At Brigham and Women’s Hospital, you’d see myself or one of my 9 superb colleagues,” says Dr. Hornstein. “We’ll take a history and if it’s appropriate, we’ll initiate an evaluation, and we’ll treat you. We even offer virtual appointments.”

Dr. Hornstein recommends seeking fertility support sooner, rather than later, if you wish to have children. “Don’t wait too long,” he says. “If a person comes to me at 43, their options are much, much more restricted from the get-go than a person who is 33. It’s inevitable. That doesn’t mean the 43-year-old person won’t be successful. It does mean the range of options I can offer them, and the success of those options, will be different.”

Is IVF my only infertility treatment option?

Many patients have come to think of in-vitro fertilization (IVF) as synonymous with fertility treatment. But as Dr. Hornstein explains, this isn’t the case.

“We don’t use IVF in every patient. In fact, it’s probably a minority of our patients,” he says. “So even if you don’t want IVF, you should still be evaluated, learn the appropriate treatment options, and go from there.”

What makes infertility care at Mass General Brigham different?

“Many infertility practices effectively only treat infertility,” says Dr. Hornstein. “At the Center for Infertility and Reproductive Surgery, we believe reproductive surgery has a role. We treat many types of reproductive problems. We treat and help manage endometriosis. We treat fibroids. We treat adrenal disorders. And we find what works for you. We have lots of tools at our disposal—and we’re comfortable using them.”

That’s not all that sets Mass General Brigham apart. According to Dr. Hornstein, there’s an unparalleled sense of cohesion within his team and among his colleagues. “Some of us have greater expertise in certain areas of reproductive medicine than others. We funnel patients appropriately to the care team that is best for their particular care and we communicate very well.”

Finally, the team at the Center for Infertility and Reproductive Surgery provides specialized care to patients who are struggling with other complex medical problems. “We care for patients at extremes of body weight. We have a very strong cancer program. And we have an excellent fertility preservation program, not only for people who are undergoing chemotherapy or radiation or surgery, but also for individuals who may want to choose fertility preservation for other reasons.”

Mark D. Hornstein, MD


Reproductive Endocrinologist