LUF Syndrome & Infertility

In a normal, healthy fertile woman, when ovulation occurs, the mature ovarian follicle will rupture and release eggs within 38 hours of the increase in luteinizing hormone (LH). However, in a very small percentage of women, the follicle goes through the luteinization process, but doesn’t rupture post the midcycle LH surge.

A very difficult diagnosis

This particular occurrence is known as luteinized unruptured follicle syndrome or LUF. The increase in progesterone secretion brings about secretory changes in the endometrium. But obviously, unless an oocyte is released, there can be no pregnancy. This also means the cycles are regular.

In addition the Day 21 Progesterone levels (hormonal studies), findings in an endometrial biopsy and the basal body temperature curve will also be consistent with ovulation. This is exactly what makes the diagnosis very difficult . The only way it can be done is by doing serial vaginal ultrasound scans – these are done to track ovulation.

The scans show that even though the follicle matures, the dominant follicle doesn’t rupture. Since the follicle doesn’t rupture, there is no free peritoneal fluid around the time of ovulation; these indicators are used to establish the diagnosis of luteinized unruptured follicle syndrome. The condition is also known as the "trapped egg syndrome".

A "silent" problem

Luteinized unruptured follicle syndrome is more common in women who have endometriosis. In most instances, the diagnosis is made when patients are being monitored for follicle tracking using serial ultrasound scans. Since LUF has no signs or symptoms, it’s called a silent problem and it’s not uncommon to miss its early diagnosis either.

Treating LUF

Since the luteinizing hormone is the one that induces follicular rupture, Human Chorionic Gonadotropin (hCG) injection can be given to treat LUF. This injection is given intramuscularly, in the dose of 10,000 IU; at this point, the lead follicle reaches a diameter of 18-20 mm. Ovulation can be documented using ultrasound. After this injection, it takes around 36- 40 hours for the oocyte to be released. Insemination/intercourse should then be timed accordingly.

In case it still doesn’t take place, it’s possible to increase the hCG injection dosage. If ovulation doesn’t occur even with the increased of 20000 IU, IVF then becomes the best solution.

So, what’s next?

At the Malpani Infertility Clinic we don’t make a diagnosis of LUF in a natural cycle, simply because the diagnosis doesn’t change your treatment option. If you are infertile, it means that the sperm and eggs aren’t meeting. Logically, the next step is to do an IUI. In this procedure, an HCG injection is given to induce ovulation. This is how IUI automatically helps patients with LUF.

Not happy with the attention you are getting from your IVF clinic? Need more information? Please send me your medical details by filling in the form that I can guide you!

Authored by : Dr Aniruddha Malpani, MD and reviewed by Dr Anjali Malpani.