Scan dating becomes progressively less accurate and should be utilized only up to 20 weeks' GA:
■ US measures the size of the fetus, not the gestational age.
■ Biologic variation in size increases as gestation advances.
If FHTs are not auscultated by 11 weeks' GA, an ultrasonic evaluation should be performed to document a viable intrauterine pregnancy.
Scan dating is useful up to 20 weeks' GA when menstrual data is unreliable or conflicts with clinical findings.
Was this article helpful?
Far too many people struggle to fall pregnant and conceive a child naturally. This book looks at the reasons for infertility and how using a natural, holistic approach can greatly improve your chances of conceiving a child of your own without surgery and without drugs!