Recently, Ms. Wang has been preparing for pregnancy after two years of marriage. Together with her husband, she went to Zhenhai Maternal and Child Health Care Hospital in Ningbo for preconception counselling. Onsite blood sampling was undertaken as the doctor advised, and their blood sampling was then sent for genetic disease carrier screening through genetic testing at the Central Laboratory of Birth Defects Prevention and Control in Ningbo Women & Children’s Hospital. The lab has signed agreements with all county/district-level maternity and childcare hospitals in Ningbo, enabling genetic disease carrier screening to be accessible for all pregnant women.
During her preconception, Ms. Wang and her husband had taken a variety of gene tests related to genetic diseases. According to the test reports revealed weeks later, they were both found to be thalassemia gene carriers and hence sought assistance from Ningbo Central Laboratory of Birth Defects Prevention and Control.
Thalassemia is an autosomal recessive genetic disease. A quarter of children born to thalassemia carrying parents will be healthy, half of them have thalassemia minor (just like their parents), and another quarter develop thalassemia major. Symptoms range from fatigue, growth issues, increased rate of infection and can result in the patient requiring blood transfusions.
According to their test results, Li Haibo, the lab's director, offered them two solutions: one is to receive third-generation IVF to ensure a healthy baby, and the other is to get pregnant naturally but constantly monitor the fetus through prenatal diagnosis. If the fetus is diagnosed as having thalassemia intermedia or thalassemia major, the pregnancy should be terminated.
The couple went with the second option. Mrs. Wang is pregnant now; and fortunately, according to constant prenatal monitoring, the fetus has proved to be among the 50% of fetuses with thalassemia minor (the same as the parents).
Testing positive is actually quite normal, as Director Li explained, because about 70% of people carry various pathogenic genes, usually without any symptoms or signs. However, if both members of a couple carry with the same type of disease-causing gene, their child is much more likely to bear the genetic disease. It can be seen that genetic disease carrier screening is of great necessity.
In fact, the number of terminated pregnancies due to lab-confirmed birth defects is substantial across Ningbo. In 2019, 2,774 pregnant women received birth defect prevention test, and 313 pregnancies diagnosed as abnormal had been terminated. The corresponding figures were 2,232 and 317 in 2020, 1,990 and 300 in 2021 respectively.
The Central Laboratory of Birth Defects Prevention and Control was set up in Ningbo in 2018 to reduce birth defects. Up to now, a comprehensive technical system has been established, including experiment platforms of prenatal screening during pregnancy, cytogenetic diagnosis, tandem mass spectrometry, and other experiment platforms of neonatal genetic metabolic diseases. It also includes high-throughput sequencing and gene chip platforms, covering the whole cycle of intervention measures for the prevention and treatment of birth defects.
Furthermore, the central lab leverages the service and quality control networks in relation to the healthcare of local women and children, signing agreements with all county/district-level maternity and childcare hospitals on birth defect prevention. Such wide-range cooperation also includes assistance and guidance on personnel training, technical guidance, information management, and quality control. The full coverage of genetic disorder screening will greatly improve regional comprehensive prevention and control of birth defects in Ningbo.
Reporter: Cheng Xin
Correspondent: Ma Dieyi
Translators: Mei Jie, Lü Chang
Proofreaders: Huang Dawang, Paul Maybrow