The effect of amniocentesis and drainage of amniotic fluid on lung development in Macaca fascicularis.

Amniocentesis and withdrawal of amniotic fluid was performed on pregnant monkeys (Macaca fascicularis) at two stages in development, either between 47 and 64, or between 85 and 95 days gestation. After birth the lungs of each infant monkey were studied using precise morphometric techniques, and compared with those in a control group of animals. The lungs after amniocentesis had alveoli of normal maturity but reduced in number and increased in size, features which both reduce the relative area for gas exchange. There was also a reduction in the number of respiratory airways. These changes occurred regardless of the time of amniocentesis, the amount of fluid removed and even if the membranes were simply punctured with no fluid removal. There is some evidence to suggest that similar sublethal effects may be present in human infants after maternal amniocentesis.