As China pushes for a baby boom, a leading reproductive health expert has said that one in eight couples has trouble getting pregnant after a year of trying.

The country’s infertility rate is now 10 to 15 percent, according to Li Yuan, the director of the reproductive health center at Beijing Chaoyang Hospital. Li discussed infertility at a press conference on Sunday for the 30th anniversary of China’s first baby born through in vitro fertilization.

According to official statistics, infertility in China rose from 3 percent in 1992 to 12.5 percent in 2012, while a paper published in the journal Fertility and Sterility in October found a 15.5 percent infertility rate. The study surveyed more than 18,500 couples countrywide in 2010 and 2011, and found that just over half of those who had failed to achieve pregnancy after a year had sought medical help. Another study that followed sperm bank donors also found significant declines in sperm count and quality between 2008 and 2014.

Infertility alarms China’s policymakers as the world’s most populous country faces labor shortages and growing health care demands due to its aging population. Though the government has now abolished the one-child policy, the birth rate has not increased as much as expected. Last year saw around 17 million births — 630,000 fewer than in 2016. Experts say that demand for assisted reproductive technology far outpaces supply.

Liu Mofang, a researcher from the Chinese Academy of Sciences, told Sixth Tone that delayed pregnancy is a major factor in rising infertility rates. “Nowadays, many people focus more on their careers and choose to have children after the age of 35 — especially the well-educated,” she said.

Unhealthy lifestyles and increased stress may also play a part, Liu said, as smoking and drinking can cause hormone imbalances that impact fertility. Alcohol and tobacco consumption are high among Chinese men. Longer working hours and higher stress in China’s breakneck economy could also increase infertility, Liu added.

Social pressure to have a child doesn’t help. In a catch-22, nearly 80 percent of infertile couples are under moderate to severe psychological pressure, according to Li, the doctor — and a major source of stress is anxiety about conceiving.

However, China’s infertility rate is not exceptionally high in a global context. Past research has found that infertility rates in the U.S. are also around 15 percent.

Yet medical infertility is only one factor among the myriad reasons why so few Chinese families are jumping at the opportunity to have a second child. Many families that have had two children report anxieties over financial pressures, child safety, and elderly care, and women worry that having a second child will set back their career progression.

Editor: Qian Jinghua.

(Header image: Medical staff examine an ultrasound at a hospital in Guiyang, Guizhou province, Dec. 22, 2017. Yan Minglei/IC)