Are there differences between the left and right ovaries? Do they affect IVF in Thailand?

2024-05-27 20:56:49，浏览量： 36次

 

The human body isn't entirely symmetrical, much like how the left and right sides of the face aren't perfectly alike, the heart usually tilts to the left, and hair grows in different patterns. The important reproductive organs in women—the ovaries—also exhibit differences between the left and right sides. What does this asymmetry mean for the ovaries? Are there differences between the eggs produced by ovulation from the left ovary compared to those from the right? Is ovulation bilateral or alternating each month? Today, Dr. Nathan Zhang from IVF USA will answer these questions and discuss the significance of these answers for fertility and assisted reproductive treatments.

 

There are indeed physiological differences between the two ovaries, with the right ovary usually having a higher ovulation rate than the left. A study by the European Society of Human Reproduction and Embryology found that regardless of whether women were fertile or infertile, 55% of ovulations occurred from the right ovary. Why is this the case? One reason is that the venous drainage systems of the right and left ovaries are slightly different. The venous drainage of the right ovary goes directly to the inferior vena cava, while the blood supply from the left ovary first goes to the left renal vein and then to the inferior vena cava. Due to the shorter path on the right side, the right ovary is more active.

 

Additionally, while the basic endocrine environment of both ovaries is similar, physiological differences control the growth pattern of follicles and the side of ovulation. The side of ovulation typically depends on the length of the previous menstrual cycle. The formation of dominant follicles—those that ultimately mature into eggs and ovulate—is more likely to occur in the ovary with lower progesterone levels during the follicular phase. At this stage, follicle-stimulating hormone (FSH) produced by the pituitary gland promotes the development of several follicles, one of which will become the dominant follicle.

 

In addition to the more frequent ovulation from the right ovary, studies have also found that oocytes ovulated from the right ovary exhibit significantly better reproductive potential. This may be due to the action of the corpus luteum. The corpus luteum is the empty shell left behind after the egg is ovulated from the follicle, and it becomes a temporary gland that secretes estrogen and testosterone. In the right ovary, the corpus luteum enhances the output of these hormones, making these oocytes more likely to be fertilized.

 

This has also been validated in reproductive treatments. A recent study of nearly 800 patients undergoing IVF or ICSI-IVF found that the right ovary outperformed the left ovary in multiple indicators. The study found that the number of follicles over 10mm in diameter retrieved from the right ovary on the day of retrieval was 6.5, compared to 6.1 from the left ovary; the number of oocytes retrieved from the right side was 3.6, compared to 3.0 from the left side; the fertilization rate from the right side was 79.9%, compared to 74.6% from the left side; and the average number of top-quality embryos available for transfer on the day of transfer was 1.39 from the right side, compared to 0.73 from the left side. These results indicate a significant statistical difference in the response of the left and right ovaries of IVF patients with healthy ovaries.

 

The study further found that short-cycle ovulation tends to alternate between the ovaries, while long-cycle ovulation occurs randomly. This makes prediction complex but also highlights the flexibility and diversity of the ovulation mechanism.

Dr. Nathan Zhang from IVF USA emphasizes that the success rate of IVF is not only closely related to the age and ovarian condition of women but also closely related to the doctor's medication regimen, drug combinations, dosage, and laboratory proficiency. Currently, IVF USA provides services such as American egg freezing, American IVF, and third-party assisted reproduction to those in need, with operations extending beyond the United States to include IVF and egg freezing in Japan, Thailand, Mexico, Taiwan, Hong Kong, and other regions, closely collaborating with top IVF doctors worldwide. If you are in need of egg freezing or IVF, feel free to consult IVF USA. Our expert team, including Dr. Nathan Zhang, will provide you with professional guidance and high-quality services to help you achieve your dreams of parenthood.