Theory of obstetrics: an epidemiologic framework for justifying medically indicated early delivery.
Theory of obstetrics: an epidemiologic framework for justifying medically indicated early delivery.
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DOI：
10.1186/1471-2393-7-4
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发表时间：
2007-03-28
影响因子：
3.1
通讯作者：
Joseph, K S
中科院分区：
文献类型：
--
作者：
Joseph, K S
背景：现代产科面临着一个严重的悖论。产科实践越来越多地以经验证据为基础进行干预，但这种干预没有理论基础。产科围产期死亡模型显示，死亡率随着妊娠期的增加呈指数下降，而医学上指示的引产和剖腹产的时间增加导致早产率上升和早产率下降。其他问题包括胎龄特异性生长受限模式之间的脱节（整个妊娠期不变）和胎龄别围产期死亡率（随着持续时间的增加指数下降）和交叉围产期死亡率曲线的悖论（吸烟者的低出生体重婴儿的新生儿死亡率低于非吸烟者的低出生体重婴儿）。胎儿处于危险的方法是一个因果模型，带来了连贯性的各种围产期现象。根据这一公式，妊娠并发症（如先兆子痫）、引产/剖宫产、分娩、显示小于胎龄儿和死亡显示出一致的发病模式。危险胎儿的提法也为医学上指示的早期分娩提供了理论依据，这是现代产科的基石。它允许治疗所需数量的概念化（例如，对于紧急剖腹产在预防胎盘脱垂和胎儿心动过缓引起的围产期死亡中低至2）和计算需要治疗的边缘数（即，为防止一例围产期死亡而需要进行的额外医学指示引产/剖腹产的次数）。来自美国的数据显示，1995- 1996年至1999-2000年期间，引产/剖腹产率增加了45.1%.，妊娠≥ 28周的单胎妊娠围产期死亡率下降了0.31%.。需要治疗的边缘人数为145人（45.1/0.31），显示1999-2000年有145例引产/剖腹产（相对于1995- 1996年）在妊娠≥ 28周的单胎妊娠中，预防了1例围产期死亡。危险胎儿的方法，其重点是发病率的措施，提供了一个连贯的观点围产期的现象。它还提供了一个理论上的理由，为医学指示的早期分娩和调和产科理论和产科实践之间的当代鸿沟。
BACKGROUND: Modern obstetrics is faced with a serious paradox. Obstetric practice is becoming increasingly interventionist based on empirical evidence but without a theoretical basis for such intervention. Whereas obstetric models of perinatal death show that mortality declines exponentially with increasing gestational duration, temporal increases in medically indicated labour induction and cesarean delivery have resulted in rising rates of preterm birth and declining rates of postterm birth. Other problems include a disconnection between patterns of gestational age-specific growth restriction (constant across gestation) and gestational age-specific perinatal mortality (exponential decline with increasing duration) and the paradox of intersecting perinatal mortality curves (low birth weight infants of smokers have lower neonatal mortality rates than the low birth weight infants of non-smokers).DISCUSSION: The fetuses at risk approach is a causal model that brings coherence to the various perinatal phenomena. Under this formulation, pregnancy complications (such as preeclampsia), labour induction/cesarean delivery, birth, revealed small-for-gestational age and death show coherent patterns of incidence. The fetuses at risk formulation also provides a theoretical justification for medically indicated early delivery, the cornerstone of modern obstetrics. It permits a conceptualization of the number needed to treat (e.g., as low as 2 for emergency cesarean delivery in preventing perinatal death given placental abruption and fetal bradycardia) and a calculation of the marginal number needed to treat (i.e., the number of additional medically indicated labour inductions/cesarean deliveries required to prevent one perinatal death). Data from the United States showed that between 1995-96 and 1999-2000 rates of labour induction/cesarean delivery increased by 45.1 per 1,000 and perinatal mortality decreased by 0.31 per 1,000 total births among singleton pregnancies at > or = 28 weeks of gestation. The marginal number needed to treat was 145 (45.1/0.31), showing that 145 excess labour inductions/cesarean deliveries in 1999-2000 (relative to 1995-96) were responsible for preventing 1 perinatal death among singleton pregnancies at > or = 28 weeks gestation.SUMMARY: The fetuses at risk approach, with its focus on incidence measures, provides a coherent view of perinatal phenomena. It also provides a theoretical justification for medically indicated early delivery and reconciles the contemporary divide between obstetric theory and obstetric practice.