Wenstrom K D
Department of Obstetrics and Gynecology, University of Iowa Hospitals and Clinics, Iowa City.
Obstet Gynecol Clin North Am. 1992 Jun;19(2):397-408.
In summary, fetal pulmonary development occurs in three phases. Hypoplasia results when an interruption occurs in or before the canalicular stage. Factors necessary for normal lung growth include sustained adequate amniotic fluid volume and normal fetal breathing movements. Pulmonary hypoplasia is most likely to occur with a very early rupture of membranes (less than 22 weeks) and with persistent oligohydramnios. Lack of sustained breathing movements and failure of modulation of ductal flow are strongly associated. Ultrasound measurement of fetal lung length may eventually be useful in monitoring intrauterine pulmonary development. Limb contractures resulting from prolonged oligohydramnios are examples of deformation-type defects. Their presence correlates most strongly with the length of the latent period (time from ROM to delivery) and the degree of oligohydramnios. Most contractures of this type are readily reversible. Early amnion rupture sequence, presumed to result from rupture of only the amnion in the first trimester, is associated with multiple severe fetal deformations. It usually occurs sporadically, with a minimal recurrence risk.
总之，胎儿肺发育分为三个阶段。当在小管期或小管期之前发生中断时，就会导致肺发育不全。正常肺生长所需的因素包括持续充足的羊水量和正常的胎儿呼吸运动。肺发育不全最有可能发生在胎膜过早破裂（少于22周）和持续性羊水过少的情况下。缺乏持续的呼吸运动与导管血流调节失败密切相关。超声测量胎儿肺长度最终可能有助于监测子宫内肺发育情况。长期羊水过少导致的肢体挛缩是变形型缺陷的例子。它们的出现与潜伏期（从胎膜破裂到分娩的时间）的长短和羊水过少的程度相关性最强。大多数这种类型的挛缩很容易逆转。早期羊膜破裂序列，推测是由于孕早期仅羊膜破裂所致，与多种严重胎儿畸形有关。它通常是散发性发生，复发风险极小。
