When you’re ready to start a family and you’re not becoming pregnant, it can be frustrating and overwhelming. Even when you’ve done everything you can to plan for pregnancy, such as having regular intercourse, tracking your fertile window and taking prenatal vitamins, it might not happen right away.

Chantel Cross, M.D., a reproductive endocrinologist and infertility specialist with the Johns Hopkins fertility center at the Johns Hopkins Health Care & Surgery Center at Green Spring Station, explains what factors might be affecting your ability to get pregnant and when to consider getting help.

What is infertility?

Infertility is defined as the inability to conceive. For women with male partners, this is after one year of unprotected sex when under age 35 and after six months for women 35 and older. For women in same-sex partnerships, infertility is defined as the inability to conceive after 12 months of donor inseminations when under age 35 and after six months of inseminations for women 35 and older. From 12% to 15% of couples have trouble getting pregnant.

“The majority of people will become pregnant within the first 12 months of trying to conceive with regular unprotected intercourse,” says Cross. “After six months to a year of trying — depending on a woman’s age — we recommend that a couple comes in for an infertility evaluation. At that point, it’s more likely that there’s a problem preventing pregnancy. And if you’re a woman over 40 trying to conceive, we always suggest a consultation with a reproductive specialist.”

What causes infertility?  

Both men and women may have health conditions that affect their ability to create a pregnancy. The infertility evaluation may help determine the cause of infertility. However, for about one-third of couples who are infertile, the cause is unknown.

Infertility in Women

Common causes of infertility in women include:

• Fallopian tube obstruction. Blocked or scarred fallopian tubes that prevent sperm from reaching the egg are a frequent cause of infertility. A history of pelvic infections, sexually transmitted diseases or endometriosis increases your risk for fallopian tube obstruction.
• Ovulation disorder. Sometimes women don’t ovulate regularly, which is the process of the ovaries releasing eggs for fertilization. Infrequent or missing periods may be a sign of polycystic ovary syndrome (PCOS), hormonal imbalances, stress or a low body weight. Obesity can also lead to ovulation problems.
• Uterine abnormalities. Some conditions make it difficult for a fertilized egg (embryo) to attach to the uterine wall. Uterine fibroids (noncancerous growths on the uterine wall), scar tissue, endometrial polyps or an abnormally shaped uterus can decrease the chances of pregnancy.

Infertility in Men

Common causes of infertility in men include:

• Sperm disorders. A man may have a low sperm count, or the sperm may be abnormally shaped. Sometimes sperm have low motility, which means they have trouble moving quickly or efficiently toward the egg. Although rare, some men don’t have any sperm in their semen (azoospermia).
• Varicoceles. Swollen veins in the scrotum are a common cause of male infertility. Blocked veins may increase the temperature in the scrotum, which can make it too hot for sperm to thrive. Varicoceles can lead to a low sperm count.
• Poor sperm delivery. Premature ejaculation, retrograde ejaculation (semen goes backward into the body), erectile dysfunction or blockages in the testicles can all reduce the chances that healthy sperm will make it to the egg.

Infertility Risk Factors

For both men and women, a variety of risk factors can make it harder to get pregnant:

• Age. Women can’t conceive after their menstrual cycles stop, which is usually sometime when their age is in the 40s or 50s. Men produce sperm throughout their lives, but women are born with a set number of eggs that decreases with age.

• Body weight. A very low or high body weight can impact fertility in both men and women. Aim for a healthy body mass index (BMI) of 18 to 25.
• Cancer treatments. Treatment such as surgery, chemotherapy, radiation therapy or hormone therapy can reduce fertility in men and women.
• Lifestyle choices: Heavy drinking, drug abuse or smoking can affect both partners’ fertility. In addition, health authorities, including the Centers for Disease Control and Prevention, advise women not to engage in these activities during pregnancy.
• Underlying health conditions: Conditions such as diabetes, kidney disease or even chronic stress can make it harder for couples to get pregnant.

How does age affect fertility in women?

You’ve probably heard the phrase, “your biological clock is ticking.” This refers to a woman’s fertile window.

“At birth, you have about 1 million eggs but naturally lose hundreds of thousands of them by the time you reach puberty,” says Cross. “Your body continues to lose eggs no matter what you do. And the rate at which women lose eggs accelerates around the age of 37.”

The quality of eggs stored in the ovaries also declines over time. “The eggs you’re born with are naturally paused in the process of dividing their DNA,” Cross explains. “They complete that process, or ripen, when you ovulate them 20 to 40 years later. The longer eggs are stuck in the mid-division stage, the more likely that process will go wrong — creating eggs with the wrong number of chromosomes. That results in not becoming pregnant, experiencing miscarriages or having babies with genetic syndromes due to chromosomal abnormalities.”

The bottom line: The quality and number of eggs a woman has decreases throughout her lifetime and egg loss accelerates around the age of 37, which makes it more difficult to become pregnant.

What’s an infertility evaluation?

If you’re having trouble conceiving, an infertility specialist may be able to help. The first step is to schedule an infertility evaluation for both partners. This multipart assessment includes:

• Physical examination and a careful review of your medical history
• Blood work to check ovulation (for women), hormone levels and thyroid function, and to make sure no sexually transmitted diseases are present
• Imaging exams to check the woman’s uterus and fallopian tubes
• Semen analysis to evaluate the health of the man’s sperm

Do I need infertility treatment?

Treatment options depend on the results of the infertility evaluation. If your doctor uncovers a medical issue affecting fertility, such as fibroids or varicoceles, fertility might be restored by treating the underlying issue with medicine or surgery.

Other fertility treatments include:

• Ovulation induction. Oral, topical or injectable medications improve ovulation patterns or may encourage more than one egg to be released each month, increasing the likelihood of conceiving. This treatment can help women who don’t ovulate regularly.
• Intrauterine insemination (IUI). A small catheter deposits good quality sperm directly into a woman’s uterus when she’s ovulating. IUI eliminates the need for sperm to swim up the vaginal canal to fertilize the egg, which increases the chances of pregnancy. Most women combine ovulation induction with IUI.
• In vitro fertilization (IVF). During this procedure, one or more eggs are removed from the ovaries and fertilized with sperm in a laboratory. The doctor chooses the embryo that has the greatest chance of success and transfers it to the uterus, where it may implant and create a pregnancy. Any remaining embryos can be frozen and used in future IVF cycles.

Each type of fertility treatment comes with its own risks and benefits. The treatments also vary greatly by cost and invasiveness. Every couple and their journey to start a family is unique, so talk to your doctor about your options.