Fetal umbilical cord oxygen values and birth to placental weight ratio in relation to size at birth
Fetal umbilical cord oxygen values and birth to placental weight ratio in relation to size at birth
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DOI：
10.1067/mob.2001.116686
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发表时间：
2001-09-01
影响因子：
9.8
通讯作者：
Richardson, B
中科院分区：
文献类型：
--
作者：
Lackman, F;Capewell, V;Richardson, B
目的：我们的目的是研究胎儿氧合与胎儿和胎盘发育之间的调节联系。我们测定了一家大型三级医院足月分娩人群的脐带血氧饱和度、氧摄取分数和出生胎盘重量与出生时大小的比值。研究设计：使用安大略省伦敦市圣约瑟夫保健中心的计算机化围产期数据库，获取1990年1月至1999年12月期间所有足月、单身、活产婴儿的脐带气体、pH值、出生体重、胎盘重量和其他选定信息(N=27,043)。由脐带血氧饱和度数据计算血氧饱和度，用先前推导的经验公式计算脐带血氧饱和度数据；从脐带血氧饱和度数据计算氧摄取值分数。根据新生儿生长标准将出生体重分为以下5种出生体重类型：胎儿生长受限，90%和小于或等于97%；大于胎龄，97%。结果：临界胎儿生长受限和胎儿生长受限组的新生儿脐静脉和动脉血氧饱和度和血氧饱和度均低于适宜胎龄组的相应值。反之，胎龄偏大组和胎龄偏大组的新生儿脐静脉血氧分压和血氧饱和度均高于胎龄组适宜值，而动脉血氧饱和度和血氧饱和度无明显变化。因此，临界胎儿生长受限组和胎儿生长受限组的婴儿氧摄取值逐渐高于适合胎龄组的值，而临界大胎龄组和大胎龄组的婴儿氧摄取值保持不变。临界胎儿生长受限组和胎儿生长受限组新生儿出生体重与胎盘重量不成正比，出生体重与胎盘重量比值呈递减趋势。相反，出生体重与胎盘重量成正比，在交界处出生体重与胎盘重量成正比，出生年龄大，胎龄大，出生与胎盘重量比与适合胎龄组的婴儿相比没有变化。结论：我们得出结论：从巨大儿到生长受限婴儿的整个出生体重范围内，胎儿氧合与出生时的大小有关；这一结论支持氧气作为胎儿生长的主要决定因素。然而，在这些队列人群中，胎儿氧合和代谢率或生长之间的联系存在差异，这可能与潜在的病因过程有关。
OBJECTIVE: Our purpose was to examine regulatory linkages between fetal oxygenation and fetal and placental growth. We determined umbilical cord Po-2 and oxygen saturation, fractional oxygen extraction, and birth to placental weight ratio values in relation to size at birth for a large tertiary hospital population delivering at term.STUDY DESIGN: The computerized perinatal database of St Joseph's Health Care London, London, Ontario, was used to obtain the umbilical cord gases, pH, birth weight, placental weight, and other selected information for all term, singleton, liveborn infants between January 1990 and December 1999 (N = 27,043). Oxygen saturation values were calculated from the umbilical cord Po-2 and pH data with a previously derived empirical equation; fractional oxygen extraction values were calculated from the umbilical cord oxygen saturation data. Size at birth was divided into the following 5 birth weight categories using neonatal growth standards: fetal growth restriction, 90% and less than or equal to 97%; large for gestational age, > 97%.RESULTS: Infants in the borderline fetal growth restriction and fetal growth restriction groups had umbilical vein and artery Po-2 and oxygen saturation values that were stepwise lower than respective values for infants in the appropriate for gestational age group. Conversely, infants in the borderline large for gestational age and large for gestational age groups had umbilical vein Po-2 and oxygen saturation values that were stepwise higher than respective appropriate for gestational age group values; infants in these groups showed no change in arterial Po-2 and oxygen saturation values. Therefore infants in the borderline fetal growth restriction and fetal growth restriction groups had fractional oxygen extraction values that were stepwise higher than the appropriate for gestational age group value, whereas values for infants in the borderline large for gestational age and large for gestational age groups remained unchanged. Birth weight was disproportional to placental weight for infants in the borderline fetal growth restriction and fetal growth restriction groups when compared with that of the infants in the appropriate for gestational age group, with the birth to placental weight ratio values stepwise decreased. Conversely, birth weight was proportional to placental weight for infants in the borderline large for gestational age and large for gestational age groups with the birth to placental weight ratio values thus unchanged when compared with that of the infants in the appropriate for gestational age group.CONCLUSION: We conclude that fetal oxygenation is related to size at birth across the entire range of birth weights as studied at term from macrosomic to growth-restricted infants; this conclusion supports oxygen as a primary determinant of fetal growth. However, there are differences in the linkage between fetal oxygenation and metabolic rate or growth for these cohort groups that may relate to underlying etiologic processes.