Kullinger Merit, Wesström Jan, Kieler Helle, Skalkidou Alkistis
Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
Center for Clinical Research, Västmanland County Hospital, Västerås, Sweden.
Acta Obstet Gynecol Scand. 2017 Jan;96(1):86-95. doi: 10.1111/aogs.13034. Epub 2016 Nov 13.
Gestational age is estimated by ultrasound using fetal size as a proxy for age, although variance in early growth affects reliability. The aim of this study was to identify characteristics associated with discrepancies between last menstrual period-based (EDD-LMP) and ultrasound-based (EDD-US) estimated delivery dates.
We identified all singleton births (n = 1 201 679) recorded in the Swedish Medical Birth Register in 1995-2010, to assess the association between maternal/fetal characteristics and large negative and large positive discrepancies (EDD-LMP earlier than EDD-US and 10th percentile in the discrepancy distribution vs. EDD-LMP later than EDD-US and 90th percentile). Analyses were adjusted for age, parity, height, body mass index, smoking, and employment status.
Women with a body mass index >40 kg/m had the highest odds for large negative discrepancies (-9 to -20 days) [odds ratio (OR) 2.16, 95% CI 2.01-2.33]. Other factors associated with large negative discrepancies were: diabetes, young maternal age, multiparity, body mass index between 30 and 39.9 kg/m or <18.5 kg/m , a history of gestational diabetes, female fetus, shorter stature (<-1 SD), a history of preeclampsia, smoking or snuff use, and unemployment. Large positive discrepancies (+4 to +20 days) were associated with male fetus (OR 1.80, 95% CI 1.77-1.83), age ≥30 years, multiparity, not living with a partner, taller stature (>+1 SD), and unemployment.
Several maternal and fetal characteristics were associated with discrepancies between dating methods. Systematic associations of discrepancies with maternal height, fetal sex, and partly obesity, may reflect an influence on the precision of the ultrasound estimate due to variance in early growth.
尽管早期生长的差异会影响可靠性，但孕周是通过超声以胎儿大小作为年龄的替代指标来估算的。本研究的目的是确定与末次月经日期估算的预产期（EDD-LMP）和超声估算的预产期（EDD-US）之间差异相关的特征。
我们确定了1995年至2010年瑞典医学出生登记册中记录的所有单胎分娩（n = 1201679例），以评估母体/胎儿特征与大的负差异和大的正差异（EDD-LMP早于EDD-US且差异分布在第10百分位数以下与EDD-LMP晚于EDD-US且差异分布在第90百分位数以上）之间的关联。分析针对年龄、产次、身高、体重指数、吸烟和就业状况进行了校正。
体重指数>40kg/m²的女性出现大的负差异（-9至-20天）的几率最高[比值比（OR）2.16，95%可信区间2.01-2.33]。与大的负差异相关的其他因素包括：糖尿病、年轻的产妇年龄、多产、体重指数在30至39.9kg/m²或<18.5kg/m²之间、妊娠期糖尿病史、女胎、身材较矮（<-1标准差）、子痫前期病史、吸烟或使用鼻烟以及失业。大的正差异（+4至+20天）与男胎（OR 1.80，95%可信区间1.77-1.83）、年龄≥30岁、多产、未与伴侣同住、身材较高（>+1标准差）和失业相关。
几种母体和胎儿特征与预产期估算方法之间的差异相关。差异与母体身高、胎儿性别以及部分肥胖之间的系统性关联，可能反映了早期生长差异对超声估算精度的影响。
