Amniocentesis can screen for SMA, but it cannot detect whether SMA is a heterozygous deletion or a pure deletion, and further genome sequencing is needed to target the causative gene for SMA. SMA is spinal muscular atrophy, with progressive, symmetrical proximal limb-dominant generalized flaccid paralysis with myasthenia as the main clinical manifestation, belonging to autosomal recessive genetic disease, the parents are the carriers of the abnormal gene, no clinical symptoms, and no disease. The main function of amniocentesis is to exclude whether the fetus has any chromosomal hereditary disease, so amniocentesis can be used to exclude SMA. However, whether SMA is a heterozygous deletion or a pure and homozygous deletion requires further genome sequencing for the SMA-causing gene, and the father and mother of the fetus need to undergo the relevant chromosomal gene sequencing at the same time.