M. Fukuda et al., HEALTHY AND ATRETIC FOLLICLES - VAGINOSONOGRAPHIC DETECTION AND FOLLICULAR-FLUID HORMONE PROFILES, Human reproduction, 10(7), 1995, pp. 1633-1637
The health status of human preovulatory follicles was prospectively st
udied by non-invasive transvaginal ultrasound. Daily ultrasound scans
were performed from the time when the follicle measured 15 mm in diame
ter until formation of corpus luteum or oocyte retrieval, Based on the
ultrasound scans two types of follicles were defined: type A follicle
s showed a cloud visualized as a cone projecting into the follicular f
luid with the base of the cone positioned on the follicle wall, A ligh
t spot seen at the tip of the cloud in the majority of scans was presu
med to be the oocyte-cumulus complex, Type B follicles showed an echo
free space without a cloud, Two groups of infertility patients were st
udied: Group I received intrauterine insemination; 106 patients underg
oing a total of 263 cycles (188 spontaneous cycles and 75 clomiphene c
itrate cycles), Group II received in-vitro fertilization (IVF); 22 pat
ients undergoing a total of 52 cycles (31 spontaneous cycles and 21 cl
omiphene cycles), In the first group, the ovulatory potential of the f
ollicle is associated with the ultrasound characteristics. From the IV
F patients the follicular fluid was harvested and assessed for the fre
e concentration of the following steroids: oestradiol, progesterone, t
estosterone and androstendione, The endocrine health status of the fol
licle was associated with the ultrasound characteristics of the follic
le, In patients of group I, 288 type A follicles ovulated out of a tot
al of 298 follicles (97%), None of the type B follicles ovulated (0/14
), In patients of group II, oocytes were obtained in 79% of the type A
follicles (50/63), whereas 7% of the type B follicles yielded an oocy
te (1/14). The follicular fluid hormone profile showed significantly l
ower free oestradiol, free oestradiol/testosterone ratio and oestradio
l/androstenedione ratio and higher free testosterone and free androste
nedione in type B follicles compared to type A follicles, The hormone
status and the high oocyte recovery rate suggest that type A follicles
are healthier than type B follicles, which seem to have undergone atr
etic changes, It is concluded that non-invasive transvaginal ultrasoun
d with a good degree of accuracy predicts the health status of preovul
atory follicles. Healthy follicles have a cloud with a light spot at t
he tip, whereas almost all atretic follicles lack this characteristic.