Park Hyun-tae, Professor of Obstetrics and Gynecology at Korea University Anam Hospital
The number of infertility patients in South Korea continues to rise. According to the National Health Insurance Service (NHIS), 300,401 people were diagnosed with infertility in 2024 — 108,358 men and 192,043 women — a 31.4% increase from 2020. Analysts attribute the surge to expanded government support for infertility treatment combined with increasingly delayed marriage and childbirth, driving more couples to seek medical help.
Park Hyun-tae, a leading infertility specialist and professor of obstetrics and gynecology at Korea University Anam Hospital, said, "One of the biggest reasons infertility patients are increasing so rapidly in Korea is the expansion of government support for infertility treatment." He added, "Patients who previously hesitated due to cost now visit infertility clinics as soon as they have difficulty conceiving, so more cases are being captured in the statistics." He also noted that "the rising ages of first marriage and first pregnancy are also important factors."
On the evening of the 4th at 9:30 p.m., Professor Park will appear on Seoul Economic TV's program "Now, the Specialist" to discuss the causes of infertility, advances in in vitro fertilization (IVF) technology, and prevention methods.
Age: The Decisive Variable in Infertility
The most critical factor in infertility is a woman's age. Professor Park explained, "Women have the best fertility before age 35. It gradually declines after 35, and by 40, the natural conception success rate drops to around 5% per ovulation cycle." He said, "The natural conception success rate is highest in the late 20s to early 30s, generally estimated at 20–25% per ovulation cycle." He added, "From age 46, the chance of natural conception should be considered virtually zero."
On why fertility declines with age, he explained, "The number of eggs decreases, the rate of chromosomal abnormalities in each egg rises, and the internal function of eggs also deteriorates. Both quantity and quality decline."
Men can also experience declining fertility with age, but the pattern differs from women. Professor Park said, "For women, there is a clear point when pregnancy becomes impossible with menopause, but for men, it is not a complete 'shutdown.'" He added, "However, sperm quality can deteriorate with age, and there is significant individual variation depending on lifestyle habits and chronic diseases."
Couples Over 40 Should Seek Infertility Care Immediately
When should couples visit an infertility clinic? Women under 35 should see a doctor if they have not conceived after one year of regular intercourse. For women aged 35 to 40, the threshold is six months. Women over 40 should seek care immediately. Professor Park emphasized, "Beyond age, those with a history of ovarian or uterine surgery, irregular menstruation, or chemotherapy should seek evaluation right away."
Infertility diagnosis differs between men and women. For men, the basic tests are a semen analysis examining sperm count and quality, and a hormone test. For women, hormone tests and ovarian function assessments are performed according to the menstrual cycle, and ultrasound is used to check the condition of the uterus and ovaries. A hysterosalpingography using contrast dye is also conducted to examine the uterus and fallopian tubes.
PCOS and Endometriosis: Key Infertility-Causing Conditions
Setting aside the age variable, it is essential to check for diseases that cause infertility. For women, polycystic ovary syndrome (PCOS), endometriosis, uterine fibroids, and a history of pelvic inflammatory disease are among the leading conditions. Professor Park explained, "PCOS causes ovulation disorders, and endometriosis can adversely affect ovarian function and embryo implantation." He noted, "If menstruation is irregular or there is severe menstrual pain that does not respond to painkillers, it should be regarded as a high-risk sign for infertility and warrants a medical consultation."
The degree to which uterine fibroids cause infertility depends on their location. Fibroids located inside the uterus at the implantation site can cause infertility. For men, varicocele — enlarged blood vessels above the testicles — is considered the leading infertility-causing condition.
IVF Success Rates Now Reach Up to 50%
Infertility treatment varies depending on the cause and the patient's age. Some patients attempt natural conception by timing ovulation, while others proceed to intrauterine insemination (IUI) or IVF. In some cases, IVF is necessary from the outset.
IVF outcomes have improved compared to the past. Professor Park said, "For women under 35, the average IVF success rate has risen to 45–50%." He added, "However, success rates remain significantly lower for women in their early 40s and beyond." He explained that the IVF success rate for women aged 40–41 is slightly above 10%, declining further thereafter.
He cited advances in cryopreservation and embryo culture technologies as key drivers of improved IVF outcomes. Professor Park said, "The technology for freezing and thawing embryos and eggs has improved dramatically, and we can now culture embryos more stably for longer periods to select higher-quality embryos." He added, "Preimplantation genetic testing (PGT), which screens for chromosomal or genetic abnormalities at the embryo stage, can also be helpful for certain patients."
He also discussed egg freezing, which has drawn increasing attention recently. Professor Park said, "Cryopreservation technology has advanced to a point where frozen-thawed eggs show little difference from fresh eggs." He noted, "The most critical cases are women whose ovarian function is expected to decline due to chemotherapy or radiation therapy." He added, "For women facing ovarian surgery or those delaying pregnancy for social reasons, freezing eggs at a young age can help preserve fertility."
Professor Park stressed that awareness of age is paramount for infertility prevention. He said, "You should not assume you can easily conceive later just because of what you see on TV or hear from people around you. If you have family plans, you should act as soon as possible."
Regarding lifestyle habits, he said obesity, smoking, processed meats, and refined carbohydrates can have negative effects. Conversely, a Mediterranean diet rich in oily fish, olive oil, leafy greens, berries, and nuts can be beneficial. At least 150 minutes of exercise per week is recommended, but excessively intense exercise can actually cause menstrual irregularities or reduced sperm quality.
Professor Park said, "There is clearly a 'window' for women. Before 35 is the best time, and before 37, it is worth actively considering fertility preservation including egg freezing." He advised that while depression and burnout are common during infertility treatment, patients should not lose hope.
Severe Menstrual Pain Could Signal Infertility Risk, Even for Young Women [Park Hyun-tae, Professor of Obstetrics and Gynecology, Korea University Anam Hospital]