NORMAL AMNIOTIC-FLUID INDEX BY GESTATIONAL WEEK IN A CHINESE POPULATION

Objective: To construct an ultrasonography-based gestation-specific am niotic fluid index (AFI) curve in a Chinese population. Methods: Routi ne obstetric ultrasonography examinations were performed in 5496 norma l pregnancies (more than 95% first births) in five obstetric ultrasoun d laboratories in Central-South China from January 1, 1992, to Decembe r 31, 1993. A gestation-specific AFI curve was constructed and compare d with previous studies. Results: The gestational ages of the patients included in this study ranged from 16 to 40 weeks. The gestation-spec ific AFI showed patterns similar to those observed previously, with th e median being 72 mm at 16 weeks, increasing to 119 mm at 26 weeks, an d then gradually declining to a median of 91 mm at 40 weeks. However, the absolute value of AFI in this Chinese population was consistently and substantially lower than values reported in previous studies in po pulations with mixed parities. Conclusion: Different standards of AFI are needed for different populations. (Obstet Gynecol 1998;92:237-40. (C) 1998 by The American College of Obstetricians and Gynecologists.)