EPF activity was very high at the early pregnant stage, gradually decreased with the continuance of gestation, faded out at 6 months of gestation and basically disappeared at 10 weeks before delivery.

• 在孕早期EPF活性较高,随孕期延长活性逐渐下降,至孕6个月活性渐趋消失,分娩前10周基本消失。