Duryea Elaine L, McIntire Donald D, Leveno Kenneth J
Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX.
Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX.
Am J Obstet Gynecol. 2015 Aug;213(2):231.e1-5. doi: 10.1016/j.ajog.2015.04.038. Epub 2015 Apr 30.
The objective of the study was to examine the rate of preterm birth in the United States using 2 different methods of gestational age assignment and determine which method more closely correlates with the known morbidities associated with preterm birth.
Using National Center for Health Statistics data from 2012 United States birth certificates, we computed the rate of preterm birth defined as a birth at 36 or fewer completed weeks with gestational age assigned using the obstetric estimate as specified in the revised birth certificate. This rate was then compared with the rate when gestational age is calculated using the last menstrual period alone. The rates of neonatal morbidities associated with preterm birth were examined for each method of assigning gestational age.
The rate of preterm birth was 9.7% when the obstetric estimate is used to calculate gestational age, which is significantly different from the rate of 11.5% when gestational age is calculated using the last menstrual period alone. In addition, the neonates identified as preterm by obstetric estimate were more likely to qualify as low birthweight (54% vs 42%; P < .001) and suffer morbidities such as need for assisted ventilation and surfactant use than those identified with the last menstrual period alone. That is to say obstetric estimate is more sensitive and specific for preterm birth by all available markers of prematurity.
The preterm birth rate is 9.7% vs 11.5% and more closely correlates with adverse neonatal outcomes associated with preterm birth when gestational age is assigned using the obstetric estimate. This method of gestational age assignment is currently used by most industrialized nations and should be considered for future reporting of US outcomes.
本研究的目的是使用两种不同的孕周确定方法来检查美国的早产率，并确定哪种方法与已知的早产相关发病率更密切相关。
利用美国国家卫生统计中心2012年出生证明的数据，我们计算了早产率，早产定义为孕周为36周或更少的分娩，孕周根据修订后的出生证明中规定的产科估计来确定。然后将该比率与仅使用末次月经计算孕周时的比率进行比较。针对每种孕周确定方法，检查与早产相关的新生儿发病率。
使用产科估计计算孕周时，早产率为9.7%，这与仅使用末次月经计算孕周时的11.5%有显著差异。此外，通过产科估计确定为早产的新生儿比仅通过末次月经确定的新生儿更有可能符合低出生体重标准（54%对42%；P<.001），并且更有可能出现诸如需要辅助通气和使用表面活性剂等疾病。也就是说，就所有可用的早产标志物而言，产科估计对早产更敏感、更具特异性。
当使用产科估计确定孕周时，早产率为9.7%对11.5%，并且与早产相关的不良新生儿结局更密切相关。这种孕周确定方法目前被大多数工业化国家使用，未来美国的结果报告应考虑采用这种方法。
