Smith G N, Frey K A, Johnson T R
Am Fam Physician. 1986 Feb;33(2):215-20.
Decision making in obstetrics is based on accurate knowledge of fetal gestational age. Menstrual dating based on the last menstrual period is an accurate method for estimating gestational age. Other reliable indicators are fundal height, quickening, the date that the fundus reaches the umbilicus and the date that fetal heart tones are first auscultated. Combinations of these data approach the reliability of menstrual dating. Biochemical assays are useful in early pregnancy. Ultrasound is indispensable when the clinical situation is questionable.
产科决策基于对胎儿孕周的准确了解。根据末次月经推算孕周是估算孕周的准确方法。其他可靠指标包括宫高、胎动初觉、宫底到达脐部的日期以及首次听诊到胎心音的日期。这些数据的综合使用接近月经孕周推算的可靠性。生化检测在孕早期很有用。当临床情况存疑时，超声检查必不可少。
