What can affect fertility treatment success?

Creighton Likes, III, MD

Obstetrics and Gynecology

For those who are considering fertility treatment, what can be done to make it more likely to succeed? Fertility specialist Creighton Likes III, MD, explained what can affect fertility treatment – and what can’t.

How is infertility treated?

After a thorough evaluation, there are oftentimes medications that can be used or patients are encouraged to do Intrauterine insemination (IUI) and in vitro fertilization (IVF), which are two common fertility treatments.

IUI is an office procedure in which a prepared sperm specimen is placed into a catheter and inserted through a woman’s vagina and cervix into her uterus near the time of ovulation. If needed, IUI can be combined with medication that improves the chances of ovulation and increases the number of eggs that are released.

IVF involves using medication to control the timing of egg ripening and to increase the chance of collecting multiple eggs during one cycle. Eggs are retrieved through a minor outpatient surgical procedure. The eggs and sperm are sent to a lab to be combined, and those that result in embryos are placed in the uterus or frozen for future use.

How successful is fertility treatment?

According to the Centers for Disease Control and Prevention (CDC), about 2% of babies in the U.S. are born through IVF and other assisted reproductive technologies.

The latest reports, from 2020, show that about 50% of procedures in women ages 35 and under resulted in a live birth. For women ages 40 and older, 7.6% resulted in a live birth.

Can a tilted uterus affect treatment success?

“A lot of patients are told they have a tilted uterus,” Dr. Likes said. “Most uteri are tilted one way or the other, which is not a concern. The most common way to tilt is toward the belly, which is called anteverted.  The other way is retroverted, so it tilts back towards the tailbone.”

Can the shape or condition of your uterus impact a successful implantation?

Shape can sometimes impact fertility. A uterine cavity typically looks like an upside-down triangle. The cervix is at the bottom and tubes are at the top. An arcuate uterus has a subtle dip at the top. If it dips below a certain depth, it’s called a septate uterus and that can cause trouble with recurrent pregnancy loss.

“If you have two or more pregnancy losses, have your uterine cavity evaluated for a septate uterus or other conditions,” Dr. Likes said. “We find that 15–20% of the time in women who have two more losses, they have a septate uterus, which can be corrected with an outpatient surgical procedure.”

The condition of the uterus absolutely matters which is why uterine evaluations are done before any embryo transfer. A typical uterine evaluation involves a 3D saline ultrasound. “This is a vaginal ultrasound, where we put sterile saline in the uterine cavity, which slightly distends it, and we take a 3D image,” Dr. Likes explained. “If there are any polyps, fibroids or adhesions in the uterine cavity, we’ll take care of it surgically first and then do the transfer.”

Is there a correlation between age and success with implantation?

Age absolutely impacts fertility, but Dr. Likes said he’s seen successful treatment among patients up to age 40 and beyond.  However, age is still the biggest predictor of fertility.

“As long as we’re optimizing the implantation of the uterine lining for the transfer, the age-related issues may actually be decreased if we’re transferring a normal chromosome embryo, even at age 40. If it’s a good quality embryo, the success rate should be high.”

Can your BMI affect fertility treatment success?

Body mass index can impact fertility treatment success, which is why you might have to reach a certain BMI to receive treatment.

“For treatments that do not involve IVF, there usually isn’t a BMI cutoff,” Dr. Likes said. “Some providers might choose to have a BMI cutoff because higher BMIs not only have a decreased chance of success, but they have the potential for higher pregnancy complications. Typically, patients will see a maternal fetal medicine specialist to go over those complications so that they’re aware of them prior to conceiving.

“However, for IVF we do have a BMI cutoff – it’s 40 or lower. The reason is twofold. One, we do our IVF retrievals in our procedure room versus a major operating room. So, for safety reasons, we use the BMI of 40. We also know that higher BMIs correlate to a lower success rate of IVF. I’m not saying that someone with a BMI of 42 can’t get pregnant. It’s just a matter of overall success.”

What else can affect fertility treatment success?

To improve your chances of a successful treatment, Dr. Likes offered these tips:

• Take a prenatal vitamin. Women should take a prenatal vitamin with at least 400–800 mcg of folic acid for at least three months before conception to reduce the risk of spina bifida and central nervous system abnormalities. Men should take a multivitamin to optimize sperm function.
• Limit your use of alcohol, tobacco, caffeine and drugs. Both partners should refrain from, or severely restrict, using alcohol, tobacco, caffeine or other drugs while trying to conceive or during pregnancy.
• Have blood tests. Both partners should have prenatal blood tests, including those for HIV/AIDS, hepatitis B and C, rapid plasma reagin (RPR) for syphilis, rubella titer (German measles immunity) and a blood type evaluation.
• Get immunized. Women should be immunized against rubella at least one month before they start trying to have a family.
• Decrease your stress. Physical and emotional stress has long been implicated as factors in a couple’s ability to conceive, but we now have more solid evidence for their role. Stress raises levels of cortisol, one of the major metabolic hormones from the adrenal glands that can influence the way other hormones are produced and metabolized.
• Stop smoking. Numerous studies have shown that smoking can have adverse effects on fertility. In women, smoking decreases in vitro fertilization (IVF) and intrauterine insemination (IUI) pregnancy rates by approximately half. Smoking also increases miscarriage rates. In men, smoking decreases sperm function and impairs fertilization.