MacGregor S N, Tamura R K, Sabbagha R E, Minogue J P, Gibson M E, Hoffman D I
Obstet Gynecol. 1987 Sep;70(3 Pt 1):344-8.
Inaccuracies in gestational age assignment based on published crown-rump length data were noted in patients with known ovulation dates. In this study, we tested the hypothesis that crown-rump length data derived from pregnancies with known ovulation dates differ from those of menstrually timed pregnancies. Seventy-two previously infertile women with known dates of ovulation had crown-rump length measurements from 35-79 days postovulation. We transformed the data to menstrual age (gestational age) by adding 14 days to the date of ovulation and compared our crown-rump length values with those of two previous reports. At corresponding crown-rump length values, the gestational ages from our data differed from those in the previous studies. We suggest using crown-rump length dating curves based on ovulation-timed pregnancies because crown-rump length data derived from menstrually dated pregnancies underestimate true gestational age.
在已知排卵日期的患者中，发现根据已发表的头臀长度数据确定的孕周存在不准确之处。在本研究中，我们检验了这样一个假设：来自已知排卵日期妊娠的头臀长度数据与月经周期计时妊娠的头臀长度数据不同。72名先前不孕且已知排卵日期的女性在排卵后35至79天进行了头臀长度测量。我们通过在排卵日期上加14天，将数据转换为月经龄（孕周），并将我们的头臀长度值与之前两份报告中的值进行比较。在相应的头臀长度值下，我们数据中的孕周与之前研究中的不同。我们建议使用基于排卵计时妊娠的头臀长度孕周计算曲线，因为来自月经周期计时妊娠的头臀长度数据低估了实际孕周。
