system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A patient present for her first antenatal visit after performing a home pregnancy test and gives a last menstrual period of about 8 weeks ago. She says she is not entirely sure of her dates, however because she has a long history of irregular menses. Which of the following is the most accurate way of dating the pregnancy?
assistant
The correct answer is  Dating of pregnancy crown rump length is measured from the top of the head to the bottom of the buttocks excluding limbs CRL between 9 and 11 weeks is the most accurate method of dating CRL in cm + 6.5 gives a rough estimate of gestational age in weeks refer pgno:476 Sheila textbook of obstetrics 2 nd edition