Letter: Antenatal diagnosis via amniocentesis.
D000649:Amniocentesis / Q000009:adverse effects*; D004562:Electrocardiography; D005260:Female; D005318:Fetal Heart; D006801:Humans; D008722:Methods; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014427:Twins; D014463:Ultrasonography