Larsen John, Buchanan Philip, Johnson Sarah, Godbert Sonya, Zinaman Michael
Department of Obstetrics and Gynecology, George Washington University Medical Center, Washington, USA.
Int J Gynaecol Obstet. 2013 Dec;123(3):189-95. doi: 10.1016/j.ijgo.2013.05.028. Epub 2013 Sep 3.
To compare gestational age (GA) estimates in early pregnancy, determined by last menstrual period (LMP), human chorionic gonadotropin (hCG) concentration, ultrasound crown-rump length (Hadlock formula), and ovulation day (luteinizing hormone surge plus 1day).
Female volunteers seeking to conceive (at 5 US sites) collected daily early-morning urine for up to 3 menstrual cycles. Pregnant women underwent ultrasound dating scans. Conception cycle urine was quantitatively assessed for luteinizing hormone and hCG. Summary statistics for GA using each reference method were determined (n=131).
Correlation between GA determined by ultrasound and ovulation day was excellent (maximum difference 10days); however, pregnancies dated by ultrasound were 3days advanced. The difference between LMP estimates and estimates based on ovulation day or ultrasound was 9 and 12days, respectively. A uniform rise in hCG on each day of pregnancy was seen using all reference methods. The accuracy of hCG measurement in determining the week since conception was more than 93%.
Methods for establishing pregnancy duration vary in their accuracy and their GA estimates. The rise in hCG concentration in early pregnancy is uniform and therefore hCG levels provide the most accurate, early estimation of GA in single, viable pregnancies. ClinicalTrials.gov:NCT01077583.
比较通过末次月经日期（LMP）、人绒毛膜促性腺激素（hCG）浓度、超声头臀长度（哈德洛克公式）和排卵日（促黄体生成素高峰加1天）确定的孕早期孕周（GA）估计值。
（在美国5个地点）寻求受孕的女性志愿者连续3个月经周期每天清晨收集尿液。孕妇接受超声孕周扫描。对受孕周期尿液进行促黄体生成素和hCG的定量评估。确定使用每种参考方法得出的GA的汇总统计数据（n = 131）。
超声确定的GA与排卵日之间的相关性极佳（最大差异10天）；然而，超声确定孕周的妊娠提前了3天。LMP估计值与基于排卵日或超声的估计值之间的差异分别为9天和12天。使用所有参考方法均观察到孕期每天hCG呈均匀上升。hCG测量在确定受孕周数方面的准确性超过93%。
确定孕期的方法在准确性和孕周估计方面各不相同。孕早期hCG浓度呈均匀上升，因此hCG水平为单胎、活胎妊娠提供了最准确的早期孕周估计。ClinicalTrials.gov：NCT01077583。
