Prenatal
diagnosis and prenatal screening are aspects of prenatal care that focus on
detecting anatomic and physiologic problems with the zygote, embryo, or fetus
as early as possible, either before gestation even starts (as in
preimplantation genetic diagnosis) or as early in gestation as practicable.
They use medical tests to detect problems such as neural tube defects,
chromosome abnormalities, and gene mutations that would lead to genetic
disorders and birth defects. The screening focuses on finding problems among a
large population with affordable and noninvasive methods, whereas the diagnosis
focuses on pursuing additional detailed information once a particular problem
has been found, and can sometimes be more invasive. Screening can also be used
for prenatal sex discernment. Common testing procedures include amniocentesis,
ultrasonography including nuchal translucency ultrasound, serum biomarker
testing, or genetic screening. In some cases, the tests are administered to
determine if the fetus will be aborted, though physicians and patients also
find it useful to diagnose high-risk pregnancies early so that delivery can be
scheduled in a tertiary care hospital where the baby can receive appropriate
care.
In
the present book, fifteen typical literatures about prenatal diagnosis
published on international authoritative journals were selected to introduce
the worldwide newest progress, which contains reviews or original researches on
medical science, cryobiology, obstetrical procedures, human pregnancy, reproduction,
ect. We hope this book can demonstrate advances in prenatal diagnosis as well
as give references to the researchers, students and other related people.