The difference between downregulation and direct stimulation
Disease description:
Recently, I saw online that there are two methods to promote ovulation: down-regulation and direct stimulation. What are the differences between down-regulation and direct stimulation?
Doctor's answer (1)
Dr. Zhang Lu
In assisted reproductive technology, downregulation and direct ovarian stimulation are two different treatment strategies primarily used during controlled ovarian hyperstimulation. The main differences between downregulation and direct ovarian stimulation are as follows:
1. Function and objective: Downregulation mainly aims to suppress the growth of dominant follicles, prevent spontaneous ovulation, and promote synchronous development of multiple follicles to obtain a sufficient number of high-quality oocytes. In contrast, direct ovarian stimulation involves directly promoting follicular maturation and ovulation by controlling cell differentiation.
2. Definition: Downregulation typically involves the use of either long-acting or short-acting GnRH agonists or antagonists. Its primary purpose is to inhibit the hypothalamic-pituitary axis, reduce endogenous LH levels, prevent premature LH surges, avoid spontaneous ovulation, and ensure synchronous follicular development, thereby improving the quantity and quality of retrieved mature oocytes. The downregulation phase generally lasts 7–14 days until an optimal suppressed state is achieved, after which ovulation-inducing medications are initiated. Direct ovarian stimulation involves administering FSH or other ovulation-stimulating drugs early in the menstrual cycle to stimulate the simultaneous development of multiple follicles. This method does not involve a downregulation phase.
3. Applicable populations: Not all women require downregulation treatment. For example, women who have good ovarian reserve, a normal uterine environment, and are relatively young usually can undergo direct ovarian stimulation.
4. Treatment methods and side effects: Downregulation may require administration of downregulation injections, whereas direct ovarian stimulation may involve using high doses of ovulation-inducing medications. Direct ovarian stimulation might increase the risk of conditions such as ovarian hyperstimulation syndrome.
