Dennis Lo, also called Yuk Ming Dennis Lo, is a professor at the Chinese University of Hong Kong in Hong Kong, China. In 1997, Lo discovered fetal DNA in maternal plasma, which is the liquid component of a pregnant woman's blood. By 2002, Lo distinguished the DNA differences between pregnant women and their fetuses, enabling scientists to identify fetal DNA in pregnant women's blood. Lo used his discoveries to develop several non-invasive and prenatal genetic tests, including tests for blood group status and Trisomy 21, also called Down's Syndrome. Lo's discovery of fetal DNA in maternal plasma lessened the risks to pregnant women and fetuses during prenatal testing, and it enabled early identification of potential genetic mutations in developing fetuses.

The National Association for Down Syndrome, or NADS, is an organization that was founded in 1960 by Kathryn McGee in Chicago, Illinois, to support people with Down syndrome and their families in improving their quality of life. Originally named the Mongoloid Developmental Council, NADS is one of the oldest organizations serving people with Down syndrome and their families in the United States. According to NADS, Down syndrome is a genetic condition that occurs in one in every seven hundred ninety-two people and that causes delays in physical and intellectual development. Members of NADS work to provide information, resources, and access to services and programs for families with Down syndrome, educate the public, address social policy issues and challenges, and facilitate advocacy efforts within the Down syndrome community. For over sixty years, NADS has helped support individuals born with Down syndrome, one of the most common genetic disorders, in the US to find acceptance, develop their capabilities, and work toward independence.

In the late 1990s researchers Yuk Ming Dennis Lo and his colleagues isolated fetal DNA extracted from pregnant woman’s blood. The technique enabled for more efficient and less invasive diagnoses of genetic abnormalities in fetuses, such as having too many copies of chromosomes. Lo’s team published their results in 1997’s “Presence of Fetal DNA in Maternal Plasma and Serum.” The results led to developments of clinical tests that can access fetal genetic information and detect genetic abnormalities before birth without the significant risks that can potentially harm the fetus associated with invasive genetic testing techniques.

Noninvasive fetal aneuploidy detection technology allows for the detection of fetal genetic conditions, specifically having three chromosomes, a condition called aneuploidy, by analyzing a simple blood sample from the pregnant woman. Dennis Lo and Rossa Chiu researched methods of detection of aneuploidies in the early twenty-first century. Their research has been specifically applied to three trisomies, trisomy twenty-one known as Down syndrome, trisomy eighteen known as Edwards Syndrome, and trisomy thirteen known as Patau Syndrome. Prior to the ability to detect fetal DNA in a pregnant woman’s blood, physicians performed amniocentesis or chorionic villus sampling, two techniques that increase the risk of spontaneous abortion. Noninvasive detection of trisomy twenty-one, eighteen, and thirteen technology allows for a more accurate and safer detection of those conditions than methods available before.

On 1 July 1976, the US Supreme Court decided in the case Planned Parenthood v. Danforth that provisions of a Missouri law regulating abortion care were unconstitutional. That law, House Bill 1211, restricted abortion care by requiring written consent for each abortion procedure from the pregnant woman as written consent of the woman’s husband if she was married, or the written consent of her parents if she was unmarried and younger than eighteen. House Bill 1211 also required that physicians make efforts to preserve the lives of aborted fetuses. Following the passage of House Bill 1211 in 1974, two physicians and Planned Parenthood of Central Missouri challenged the law. Following the decisions by several lower courts, the US Supreme Court ruled on the case. The US Supreme Court struck down parts of a law that violated the US Constitution and the prior court case Roe v. Wade, and in doing so, they expanded access to abortion care in the US.

The extraembryonic membranes that surround and originate from the embryos of vertebrates such as birds, reptiles, and mammals are crucial to their development. They are integral to increasing the surface area of the uterus, forming the chorion (which in turn produces the placenta) and the amnion, respectively. The amnion will ultimately surround the embryo in a fluid-filled amniotic cavity. This amniotic fluid, which cushions and protects the fetus and helps prevent the onset of labor, is sampled in amniocentesis to screen for genetic diseases.

Amniocentesis is a test used for prenatal diagnosis of inherited diseases, Rh incompatibility, neural tube defects, and lung maturity. Normally performed during the second trimester of a pregnancy, this invasive procedure allows the detection of health problems in the fetus as early as fifteen weeks gestation. Although amniocentesis does carry some significant risks, the medical community commonly accepts it as a safe and useful procedure.