Ultrasound monitoring of ovulation
At the beginning of menstruation, there are small follicles of 3-5mm in the ovary. As the menstrual cycle progresses, the dominant follicle appears in one ovary and gradually increases in size, forming the dominant follicle, while the other small follicles gradually shrink. The growth rate of the dominant follicle is about 1-2mm per day, and the maximum growth rate of the follicle in the natural cycle is 2-3mm per day before ovulation, and the mature follicle is 18-22mm in diameter. Lv Hongtao, Department of Obstetrics and Gynecology, Shandong Qianfo Mountain Hospital
Specific methods of ovulation monitoring by B-ultrasound.
The monitoring usually starts 5 days before ovulation, for example, on the 28th day of menstruation is the 8th or 9th day of menstruation. The maximum average diameter of the follicle is less than 10mm, check once every 3 days. The maximum average diameter of the follicle is about 10mm-15mm, check once every 2 days. For follicles with maximum average diameter greater than 15mm, check once a day until ovulation or the start of the next menstrual cycle.
Criteria for determining follicular maturity.
①The maximum follicle diameter is more than 20mm, and the maximum follicle diameter before ovulation ranges from about 17mm-24mm.
②The follicles are full in shape and round or ovoid with thin and clear inner walls.
(③The ovaries are shifted to the ovarian surface and are not covered by ovarian tissue on one side and protrude outward.
④If an oval mound is present, ovulation is imminent.
Determination of ovulation.
①Dominant follicle disappears: the original anechoic area becomes smaller or disappears.
(ii) Blood body formation: the anechoic area in the ovarian cortex becomes a mixed echogenic area with poorly defined borders, irregular morphology and a slightly thicker inner wall than the follicular wall.
(③) Follicular fluid outflow and fluid accumulation visible in the rectal uterine trap.
(iv) Synchronous thickening of the endometrium, greater than 8 mm, with hyperechogenicity of the endometrium in the secretory phase, showing the “three-line sign”.
Ovulation abnormalities.
(1) Small follicle ovulation: the dominant follicle ovulates at a maximum average of less than 18mm.
(ii) follicular failure: no dominant follicle is seen in both ovaries.
(iii) Luteinized unruptured follicle syndrome: the dominant follicle does not ovulate even though its average diameter is greater than 28 mm.
(④Polycystic ovaries: manifested by enlarged ovaries with more than ten follicles of different sizes without dominant follicles.
This article is authorized by Dr. Hongtao Lu.