Waldenström U, Axelsson O, Nilsson S
Department of Obstetrics and Gynecology, Falu Hospital, Sweden.
Acta Obstet Gynecol Scand. 1991;70(1):17-20. doi: 10.3109/00016349109006171.
In order to study the benefit of sonographic dating, 277 women with irregular periods and 264 women with a scanty last bleeding had gestational age and estimated day of delivery (EDD) estimated from both last menstrual period (LMP) and measurement of fetal Biparietal Diameter (BPD) in the second trimester. For the women with irregular periods, the two estimates differed by more than 7 days for 51.6%, and more than 14 days for 25.6%. Corresponding figures for women with a scanty last bleeding were 44.3% and 21.6%, respectively. In general, the BPD estimates were better than the LMP estimates (P = less than 0.001) in predicting day of delivery, especially when the differences between the estimates exceeded 7 days. For women with irregular periods, post-term pregnancies decreased, from 20.2% according to the LMP estimate to 2.5% according to the BPD estimate. Corresponding figures for women with a scanty last bleeding were 16.7% and 4.5%, respectively. According to the LMP estimate, 64.8% of the women with irregular periods and 69.3% of the women with a scanty last bleeding gave birth within +/- 14 days of EDD. Corresponding figures for the BPD estimate were 83.6% and 88.3%, respectively. The conclusion is that sonographic dating of pregnancies among women with irregular periods and women with a scanty last bleeding substantially improve the accuracy of term prediction.
为了研究超声孕周测定的益处，对277名月经周期不规律的女性和264名末次月经量少的女性，在孕中期通过末次月经日期（LMP）和胎儿双顶径（BPD）测量来估算孕周和预计分娩日期（EDD）。对于月经周期不规律的女性，两种估算方法相差超过7天的占51.6%，相差超过14天的占25.6%。末次月经量少的女性相应比例分别为44.3%和21.6%。总体而言，在预测分娩日期方面，BPD估算优于LMP估算（P＜0.001），尤其是当估算值之间的差异超过7天时。对于月经周期不规律的女性，过期妊娠率从根据LMP估算的20.2%降至根据BPD估算的2.5%。末次月经量少的女性相应比例分别为16.7%和4.5%。根据LMP估算，月经周期不规律的女性中有64.8%、末次月经量少的女性中有69.3%在EDD的±14天内分娩。根据BPD估算，相应比例分别为83.6%和88.3%。结论是，对月经周期不规律和末次月经量少的女性进行超声孕周测定可显著提高预产期预测的准确性。
