Final answer:
During the first trimester, genetic screening can be done through tests like NIPT and NT ultrasound. Between 15-19 weeks, amniocentesis can be performed for more detailed analysis.
Step-by-step explanation:
In the first trimester of pregnancy, genetic screening can be performed through a variety of tests. One common test is called noninvasive prenatal testing (NIPT), which involves a blood test to analyze the fetus's DNA and check for chromosomal abnormalities, such as Down syndrome. Another test that can be done during this time is the nuchal translucency (NT) ultrasound scan, which measures the thickness of the back of the fetus's neck and can help identify the risk of certain chromosomal conditions.
Between 15-19 weeks of pregnancy, a test called amniocentesis can be performed. This involves extracting a small amount of amniotic fluid from the uterus and analyzing it for genetic disorders, chromosomal abnormalities, and neural tube defects. It can provide more detailed information than the tests done in the first trimester. However, amniocentesis is an invasive procedure and carries a small risk of miscarriage.