Abstract：
BACKGROUND: Optimal management of fetuses diagnosed as small for gestational age based on an estimated fetal weight of <10th percentile represents a major clinical problem. The standard approach is to increase fetal surveillance with serial biometry and antepartum testing to assess fetal well-being and timing of delivery. Observational studies have indicated that maternal rest in the left lateral position improves maternal cardiac output and uterine blood flow. However, maternal bed rest has not been recommended based on the results of a randomized clinical trial that showed that maternal rest does not improve fetal growth in small-for-gestational-age fetuses. This study was conducted to revisit this question.
OBJECTIVE: This study aimed to determine whether maternal bed rest was associated with an increase in the fetal biometric parameters that reflect growth after the diagnosis of a small-for-gestational-age fetus.
METHODS: A retrospective study was conducted on fetuses who were diagnosed as small for gestational age because of an estimated fetal weight of <10th percentile for gestational age. The mothers were asked to rest in the left lateral recumbent position. Fetal biometry was performed 2 weeks after the diagnosis. All fetuses before entry into the study had a previous ultrasound that demonstrated an estimated fetal weight of >10th percentile. To assess the response to bed rest, the change in fetal biometric parameters (estimated fetal weight, head circumference, abdominal circumference, and femur length) after the recommendation of bed rest was computed for 2 periods: (1) before the diagnosis of a weight of <10th percentile vs at the time of diagnosis of a weight of <10th percentile and (2) at the time of diagnosis of a weight of <10th percentile vs 2 weeks after maternal bed rest. For repeated measures, proportions were compared using the McNemar test, and percentile values were compared using the Bonferroni Multiple Comparison Test. A P value of <.05 was considered significant. To describe changes in the estimated fetal weight without bed rest, 2 control groups in which the mothers were not placed on bed rest after the diagnosis of a small-for-gestational-age fetus were included.
RESULTS: A total of 265 fetuses were observed before and after maternal bed rest. The following were observed in this study: (1) after 2 weeks of maternal rest, 199 of 265 fetuses (75%) had a fetal weight of >10th percentile; (2) the median fetal weight percentile increased from 6.8 (interquartile range, 4.4-8.4) to 18.0 (interquartile range, 9.5-29.5) after 2 weeks of bed rest; (3) similar trends were noted for the head circumference, abdominal circumference, and femur length. In the groups of patients who were not asked to be on bed rest, a reassignment to a weight of >10th percentile at a follow-up examination only occurred in 7 of 37 patients (19%) in the Texas-Michigan group and 13 of 111 patients (12%) in the Colorado group compared with the bed rest group (199/265 [75%]) (P<.001).
CONCLUSIONS: Patients who were prescribed 2 weeks of bed rest after the diagnosis of a fetal weight of <10th percentile had an increase in weight of >10th percentile in 199 of 265 fetuses (75%). This increase in fetal weight was significantly higher than that in the 2 control groups in which bed rest was not prescribed. This observation suggests that bed rest improves fetal growth in a subset of patients.
OBJECTIVE: This study aimed to determine whether maternal bed rest was associated with an increase in the fetal biometric parameters that reflect growth after the diagnosis of a small-for-gestational-age fetus.
METHODS: A retrospective study was conducted on fetuses who were diagnosed as small for gestational age because of an estimated fetal weight of <10th percentile for gestational age. The mothers were asked to rest in the left lateral recumbent position. Fetal biometry was performed 2 weeks after the diagnosis. All fetuses before entry into the study had a previous ultrasound that demonstrated an estimated fetal weight of >10th percentile. To assess the response to bed rest, the change in fetal biometric parameters (estimated fetal weight, head circumference, abdominal circumference, and femur length) after the recommendation of bed rest was computed for 2 periods: (1) before the diagnosis of a weight of <10th percentile vs at the time of diagnosis of a weight of <10th percentile and (2) at the time of diagnosis of a weight of <10th percentile vs 2 weeks after maternal bed rest. For repeated measures, proportions were compared using the McNemar test, and percentile values were compared using the Bonferroni Multiple Comparison Test. A P value of <.05 was considered significant. To describe changes in the estimated fetal weight without bed rest, 2 control groups in which the mothers were not placed on bed rest after the diagnosis of a small-for-gestational-age fetus were included.
RESULTS: A total of 265 fetuses were observed before and after maternal bed rest. The following were observed in this study: (1) after 2 weeks of maternal rest, 199 of 265 fetuses (75%) had a fetal weight of >10th percentile; (2) the median fetal weight percentile increased from 6.8 (interquartile range, 4.4-8.4) to 18.0 (interquartile range, 9.5-29.5) after 2 weeks of bed rest; (3) similar trends were noted for the head circumference, abdominal circumference, and femur length. In the groups of patients who were not asked to be on bed rest, a reassignment to a weight of >10th percentile at a follow-up examination only occurred in 7 of 37 patients (19%) in the Texas-Michigan group and 13 of 111 patients (12%) in the Colorado group compared with the bed rest group (199/265 [75%]) (P<.001).
CONCLUSIONS: Patients who were prescribed 2 weeks of bed rest after the diagnosis of a fetal weight of <10th percentile had an increase in weight of >10th percentile in 199 of 265 fetuses (75%). This increase in fetal weight was significantly higher than that in the 2 control groups in which bed rest was not prescribed. This observation suggests that bed rest improves fetal growth in a subset of patients.
摘要：
背景：根据估计的胎儿体重<10百分位数，对被诊断为小于胎龄的胎儿进行最佳管理是一个主要的临床问题。标准方法是通过连续生物测量和产前测试来增加胎儿监测，以评估胎儿的健康状况和分娩时机。观察性研究表明，产妇在左侧卧位的休息可以改善产妇的心输出量和子宫血流量。然而,根据一项随机临床试验的结果显示,产妇休息不能改善小于胎龄胎儿的胎儿生长,因此不建议产妇卧床休息.这项研究是为了重新审视这个问题。
目的：本研究旨在确定产妇卧床休息是否与胎儿生物特征参数的增加有关，这些参数反映了在诊断为小于胎龄儿后的生长情况。
方法：对因估计胎儿体重<胎龄10%而被诊断为小于胎龄的胎儿进行了回顾性研究。要求母亲以左侧卧位休息。诊断后2周进行胎儿生物测定。所有胎儿在进入研究之前都有先前的超声检查,其显示估计的胎儿体重>10百分位数。为了评估卧床休息的反应，胎儿生物特征参数的变化(估计的胎儿体重，头围,腹围,和股骨长度）在建议卧床休息后计算了两个时期：（1）在诊断前体重<10百分位数与诊断时体重<10百分位数；（2）在诊断时体重<10百分位数与产妇卧床休息2周后。对于重复的措施，使用McNemar检验比较比例，和百分位值使用Kruskal-Wallis检验进行比较。P值<.05被认为是显著的。为了描述在没有卧床休息的情况下估计胎儿体重的变化，包括2个对照组，其中母亲在诊断出小于胎龄儿后未卧床休息。
结果：产妇卧床前后共观察到265例胎儿。在本研究中观察到以下内容:(1)产妇休息2周后,265个胎儿中的199个（75％）的胎儿体重>10百分位数；（2）胎儿体重中位数从6.8增加（四分位距，4.4-8.4)至18.0(四分位数间距，9.5-29.5）卧床休息2周后；（3）头围的趋势相似，腹围,和股骨长度。在没有被要求卧床休息的患者组中，与卧床休息组(199/265[75%])相比,Texas-Michigan组37例患者中的7例(19%)和Colorado组111例患者中的13例(12%)在随访检查中体重>10%(P<.001)。
结论：在诊断为胎儿体重<10百分位数之后被规定卧床休息2周的患者，在265例胎儿中的199例（75%）体重增加>10百分位数。胎儿体重的增加显着高于未规定卧床休息的2个对照组。这一观察结果表明，卧床休息可以改善一部分患者的胎儿生长。
目的：本研究旨在确定产妇卧床休息是否与胎儿生物特征参数的增加有关，这些参数反映了在诊断为小于胎龄儿后的生长情况。
方法：对因估计胎儿体重<胎龄10%而被诊断为小于胎龄的胎儿进行了回顾性研究。要求母亲以左侧卧位休息。诊断后2周进行胎儿生物测定。所有胎儿在进入研究之前都有先前的超声检查,其显示估计的胎儿体重>10百分位数。为了评估卧床休息的反应，胎儿生物特征参数的变化(估计的胎儿体重，头围,腹围,和股骨长度）在建议卧床休息后计算了两个时期：（1）在诊断前体重<10百分位数与诊断时体重<10百分位数；（2）在诊断时体重<10百分位数与产妇卧床休息2周后。对于重复的措施，使用McNemar检验比较比例，和百分位值使用Kruskal-Wallis检验进行比较。P值<.05被认为是显著的。为了描述在没有卧床休息的情况下估计胎儿体重的变化，包括2个对照组，其中母亲在诊断出小于胎龄儿后未卧床休息。
结果：产妇卧床前后共观察到265例胎儿。在本研究中观察到以下内容:(1)产妇休息2周后,265个胎儿中的199个（75％）的胎儿体重>10百分位数；（2）胎儿体重中位数从6.8增加（四分位距，4.4-8.4)至18.0(四分位数间距，9.5-29.5）卧床休息2周后；（3）头围的趋势相似，腹围,和股骨长度。在没有被要求卧床休息的患者组中，与卧床休息组(199/265[75%])相比,Texas-Michigan组37例患者中的7例(19%)和Colorado组111例患者中的13例(12%)在随访检查中体重>10%(P<.001)。
结论：在诊断为胎儿体重<10百分位数之后被规定卧床休息2周的患者，在265例胎儿中的199例（75%）体重增加>10百分位数。胎儿体重的增加显着高于未规定卧床休息的2个对照组。这一观察结果表明，卧床休息可以改善一部分患者的胎儿生长。
