China After blocking a suspicious woman at the Port of Fu Tian, customs officers discovered that she had hidden a bra in her bra with blood tubes bearing the name of the pregnant woman.

The middle-aged woman was arrested in July 2017 while walking through a security screening room in Fuzhou port, on the border between Shenzhen City and Hong Kong.

Four days later, customs officers continued to block a woman from wearing a heavy backpack, filled with pregnant women's blood tubes. 203 blood tubes were wrapped in plastic bags, some of them started to spoil due to the heat. Hong Kong officials said the woman admitted to being paid 100-300 yuan ($ 14-42) to transfer sensitive items to the special zone.

At La Ho port, another Hong Kong entry point, customs officers in February discovered a 12-year-old girl hiding 142 blood samples in a backpack. "The students who cross the border usually carry nothing but books, stationery and snacks, so their bags look neat. However, we find her backpacks so full that they can be flung. out, should have checked it, "an employee at the port explained.

Blood transfusions of pregnant women from mainland China to Hong Kong have increased sharply in the past three years. Blood samples are sent to specialized clinics to check fetal DNA, to help prospective parents know the sex of their baby.

China's one-child policy makes sex selective abortion common, in the hope of having a son. The condition leaves 12 million girls born between 1970 and 2017, according to research published in May by National University of Singapore.

Although the policy was partially relaxed in 2015, many couples still did not want to have many children because of economic issues, so it was necessary to know the sex of the fetus. China's population and family planning law has banned the sex check of the fetus since 2002, to prevent gender imbalance. However, many people still send blood samples to Hong Kong to test to avoid the ban.

The National Health and Family Planning Commission of China in 2017 banned the transfer of human blood from territory. However, Hong Kong allows importing blood samples, as long as they are not suspected of containing contagious and licensed substances.

Couples can find dozens of companies offering sex testing services in Hong Kong on social networking site Weibo. A company representative said that "women can start testing at 6-7 weeks of pregnancy" and only needs to send a blood sample, along with an ultrasound test that proves that the fetus has reached the appropriate stage.

Pregnant women are advised to hide blood tubes inside stuffed animals or packed snack boxes to avoid being detected, then send them straight to Hong Kong by mail. "We are no longer hiring manual transfer services because of the high risk. The government has recently been disrupting our operations," the company representative added.

The company has more than 380,000 followers on Weibo, for a fee of 3,500 yuan ($ 490) for the service and returns the result after about a week. The test is done in a laboratory located in a remote area in Hong Kong.

To check the sex of the fetus, the laboratory conducts a non-invasive prenatal test (NIPT). "Previously, women had to be 4-5 months pregnant to determine the sex of the baby. But with NIPT, they only need 10 weeks to know it," said Tom Shakespeare, English sociologist, said.

According to him, this technique has a strong impact on sex selective abortion, adding that "aborting a 10-week-old fetus is much easier than 18 weeks".

NIPT is the "brainchild" of Dennis Lo, professor of clinical chemistry at Chinese University of Hong Kong. He began by looking for an alternative to amniocentesis and chorionic villi sampling, two invasive test methods used to check for chromosomal abnormalities in the fetus. "Both of these have the potential for a small miscarriage, so I wonder if there is a safer method to check for genetic disorders," the professor said.

During the study, he demonstrated the mother's DNA presence in the mother's plasma, presented in an article published in the medical journal The Lancet in 1997. It took him another 10 years to develop. NIPT development, a test that helps detect chromosomal abnormalities.

Professor Lo's test, which has an accuracy rate of 99%, was put into use by biotechnology company Sequenom in 2011 in the US, then quickly became popular. This technique completely changes prenatal testing, ensuring safety for both pregnant women and their babies.

"About 7 million women conduct NIPT tests every year worldwide," said Professor Lo. The market is expected to reach $ 3.9 billion in 2019, with an annual growth rate of 13.5%, according to research firm MarketsandMarkets.

NIPT is extremely popular in China, where the age of giving birth to women is increasing. However, while most countries allow parents to know the sex of their children thanks to this test, mainland Chinese doctors are forced to keep information hidden, helping to further advance the medical testing industry that is now on the rise in Hong Kong.

Laboratories in Hong Kong are only allowed to test blood samples transferred by a licensed physician. However, many facilities ignore the rule, said Kwok Ka-Ki, a member of the Hong Kong legislature and a doctor.

Hong Kong has become a "destination" for Chinese women who want to know their children's gender in advance. Artwork: CNN

"The Department of Health can 'catch' them by impersonating customers, but officials have not done it even once. The government wants to ignore it for fear of harming the large medical testing industry. strong Hong Kong ", he explained.

As of September, the Hong Kong Department of Health has investigated a total of 53 cases involving the import of blood samples from China without a license. However, no investigation has led to prosecution, the department's spokesman said, citing "insufficient evidence", adding that any complaint with Hong Kong laboratories would transferred to the Medical Laboratory Technician Council.

"This is most likely just the tip of the iceberg. Based on the number of medical laboratories providing sex check services in Hong Kong, there must be dozens of cases of transfusion gonorrhea every day." , Congressman Kwok commented.

Besides fetal gender, the NIPT test causes a number of other dilemmas. In addition to helping detect genetic disorders, this technique could in the future detect the risk of pre-eclampsia, premature birth, and illness of the child.

"If we find out that a child will have diabetes when he is 40 years old, or have cancer, should we tell the mother and then burden her even before the baby is born? ? ", Professor Lo said.