Relationship of constructed follicular growth patterns in stimulated cycles to outcome after IVF.

The growth patterns of 827 follicles have been constructed from ultrasound measurements made between day -7 and day -2 of the follicular phase (oocyte aspiration = day 0) as a part of the routine treatment of 107 in-vitro fertilization (IVF) patients. A distinctive pattern of growth which was characterized by rapid early growth and a later growth consistent with the 'conceptual pattern' of growth described by Zegers-Hochschild (1984) for natural cycles was shown to be highly correlated with a delivered pregnancy outcome. Every cycle where a delivered pregnancy resulted (n = 9) produced one or more follicles with this pattern of growth (11/69 follicles, 16%). In contrast, only 20% (20/98) of cycles with any other outcome (abnormal pregnancy, no pregnancy, no embryo formed) appeared to have a follicle conforming to this pattern (27/758 follicles, 3.6%). These observations suggest that the follicle growth pattern, with particular emphasis on the rate of early growth, may be a highly predictive indicator of the quality of follicle development and the subsequent pregnancy potential of the oocyte contained within.