Prenatal diagnosis is to test for birth diseases or conditions in an unborn child

such as chromosome abnormalities

single gene disorders and multigenic diseases. Through a variety of techniques

we can check the diseases or conditions of fetus before it is born. At present some new techniques provide chance for prenatal diagnosis

for example

fetal free DNA

comparative genomic hybridization (CGH)

sequencing and imaging

meanwhile some difficulties give us challenge. A growing spectrum and complex genetic mechanism of fetal disease become challenges for prenatal diagnosis and fetal therapy. Further improvements in molecular techniques

etoscopic equipment

intrauterine surgical technique

and gene therapy would promote the development of prenatal diagnosis and fetal medical science.