Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas.
Obstet Gynecol. 2014 Jul;124(1):16-22. doi: 10.1097/AOG.0000000000000345.
To generate birth weight curves based on the obstetric estimate of gestational age as specified in the revised 2003 U.S. birth certificate.
Using National Center for Health Statistics data from 2011, we constructed birth weight curves for neonates between 24 and 42 weeks of gestation. Curves were developed using the obstetric estimate of gestational age that is included in the revised 2003 U.S. birth certificate, which, when available, incorporates ultrasound dating information. Live-born singleton neonates between 500 and 6,000 g without malformations were included. These curves were compared with curves we generated using 1991 data on which the current national reference of Alexander and colleagues is based, a reference that used only last menstrual period to establish gestational age.
The 1991 curves were based on 3,684,778 U.S. live births and the 2011 on 3,252,011 births. Birth weight percentile values were greater from 28 to 36 weeks of gestation in the 1991 data set. That is, the birth weights for preterm neonates were overestimated when 1991 reference curves were used compared with the proposed 2011 reference. For example, in 1991, a birth weight of 2,000 g was at the 50th percentile between 31 and 32 weeks of gestation, whereas in 2011, a birth weight of 2,000 g now corresponds to the 50th percentile between 33 and 34 weeks of gestation.
Our revised reference curve for the United States provides an updated national reference for birth weight.
: II.
根据修订后的 2003 年美国出生证明中规定的产科估计孕周生成出生体重曲线。
利用国家卫生统计中心 2011 年的数据，我们为 24 至 42 周龄的新生儿构建了出生体重曲线。曲线是根据修订后的 2003 年美国出生证明中包含的产科估计孕周来制定的，当有超声日期信息时，该证明会将其纳入。包括 500 至 6000 克且无畸形的单胎活产新生儿。将这些曲线与我们使用当前基于 Alexander 等人的国家参考值的 1991 年数据生成的曲线进行比较，该参考值仅使用末次月经来确定孕周。
1991 年的曲线基于 3684778 例美国活产儿，2011 年的曲线基于 3252011 例活产儿。在 1991 年的数据集中，从 28 周到 36 周，体重百分位数的值更高。也就是说，与拟议的 2011 年参考值相比，使用 1991 年参考曲线会高估早产儿的出生体重。例如，在 1991 年，体重为 2000 克的新生儿在 31 至 32 周的第 50 个百分位，而在 2011 年，体重为 2000 克的新生儿现在对应 33 至 34 周的第 50 个百分位。
我们修订的美国参考曲线为出生体重提供了一个更新的国家参考值。
II 级。
