Weil A, Schenk W, Ramzin M S
Z Geburtshilfe Perinatol. 1978 Dec;182(6):410-6.
Epidemiological data of 338 preterm deliveries (excluding multiple gestations) were compared with the same number of term deliveries. Both groups were matched for age and parity. In one third of the cases only, possible organic factors could be attented to preterm delivery. In the remaining patients the etiology was unknown e.g. "idiopathic". These results confirm the difficulty to identify the patient at risk for preterm delivery, especially in the nullipara.
对338例早产（不包括多胎妊娠）的流行病学数据与相同数量的足月分娩数据进行了比较。两组在年龄和胎次方面进行了匹配。仅在三分之一的病例中，可注意到早产的可能器质性因素。在其余患者中，病因不明，例如“特发性”。这些结果证实了识别早产风险患者的困难，尤其是初产妇。
