Follicular study

Ovulation was initially monitored by conventional methods like BBT, mid luteal serum progesterone and urinary LH.

Nowadays, USG is used for follicular monitoring for both natural and stimulated cycles.

1. Follicular Study/Monitoring Prepared by Dr Vrishit Guided by Prof. Dr Dharmraj

2. Ovulation was initially monitored by conventional methods like BBT, mid luteal serum progesterone and urinary LH. Nowadays, USG is used for follicular monitoring for both natural and stimulated cycles.

3. Follicular monitoring Vital component of IVF/IUI assessment and timing Employs a simple technique of assessing ovarian follicles on regular intervals, and documenting the pathway of ovulation.

4. W H Y TO MONITOR ? To evaluate if the dose being used is optimal To adjust the dose of the drug as some patients are hyperresponsive and some are poor responders To find optimal time for ovulation induction To time IUI To avoid exessive stimulation and prevent OHSS and multiple pregnancy

5. H O W TO MON I TOR ? By ultrasound, color doppler , power doppler - morphological growth of follicles By estradiol alone- indicates functional activity of follicles By both TVS –accepted method at all infertility clinics

6. Pathophysiology : Journey to ovulation begins during late luteal phase of prior menstrual cycle, when certain 2-5 mm sized healthy follicles form a population, from which dominant follicles is to be selected for next cycle This process is called 'recruitment ' . Usual number of such follicles may be 3-11, which goes on decreasing with advancing age .

7. During Day 1-5 of the menstrual cycle, a second process of 'follicular selection' begins, when among all recruited follicles, certain growing follicles of size 5-10 mm are selected, while rest of the follicles regress or become atretic .

8. During Day 5-7 of the menstrual cycle, a process of 'dominance' begins, when a certain follicle of 10 mm size takes the control and becomes dominant. This also suppresses the growth of the rest of the selected follicles, and in a way, is destined to ovulate. This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation .

9. *** One important learning point in this regard is, "largest follicle on day 3 of the cycle, may or may not be a dominant follicle in the end. Process of dominance begins late, when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant".

10. Almost nearing ovulation, rapid follicle growth takes place, and follicle starts protruding from the ovarian cortex, attains a crenated border, and it literally explodes to release the ovum, along with some antral fluid.

11. U l t r as ou n d m o n i t o r i n g i n i ndu c e d cyc l e s , and predicting success of IVF Most of the IVF studies are conducted after induction of ovaries with help of ovulation inducing agents like Clomiphene citrate. In such induced cycle, primary determinants of success are: ovarian volume antral follicle number ovarian stromal blood flow

12. Ovarian volume is easy to measure, although not a good predictor of IVF outcome. a low ovarian volume does not always lead to anovulatory cycle. But, it's important to recognize a polycystic ovarian pattern and differentiate it from post-induction multicystic ovaries. Follicles arranged in the periphery forming a 'necklace sign', echogenic stroma , and more than 20 follicles of less than 9 mm size, signify a polycystic pattern in induced cycle. While, follicles in the center as well as the periphery, are seen in normal induced multicystic

13. Antra l follicl e number Antral follicle number of less than three, usually signify possible failure of assisted reproductive therapy (ART).

14. Ovaria n stroma l bloo d flow has been recommended as a good predictor of ART success. Increased peak systolic velocity (>10 cm/sec) is one of such parameters which has been advocated.

15. SIGNIFICANCE: Helps in prediction of impending ovulation and optimal timing for: hCG administration, ntercourse , donor or husband insemination egg collection If not ovulating can be treated with ovulation induction agents.

16. Ultrasoun d follicular monitoring Serial USG follicular monitoring is started from day 7 or 8 of the cycle But in case of gonadotrophins we start scanning from 6 th day of stimulation.

17. Assessin g th e follicular maturity T he follicles normally grow at a rate of 2- 3 mm / day in a stimulated cycle. Definitive size of the follicle which confirms the maturity of oocytes is still controversial. A follicle measuring 18—20 mm has been found to contain a mature oocyte . Follicular size is measured by taking mean of 2 or 3 largest perpendicular diameters of each follicle .

18. When to administer gonadotropins ? Although, its a matter of choice, based on experience of individual IVF specialists, there are certain parameters which may be considered. Minimal criteria suggested is a follicle size of atleast 15 mm, and serum estradiol level of 0.49 nmol /L. Better prospects are at follicle size of 18 mm, and serum estradiol level of 0.91 nmol /L. Random hCG administration should be avoided 3 , to prevent a risk of ovarian hyperstimulation syndrome (OHSS).

19. Predictin g th e ris k o f OHSS If there are more than 4 follicles larger than 16 mm or more than 8 follicles larger than 12 mm It is best not to give hCG so as to prevent OHSS and high order multiple births.

20. OHSS Is a complication of ovarian stimulation treatment for IVF. Rarely, may occur as a spontaneous event in pregnancy

21. OHS S syndrom e consist s of Weight gain Increase in abdominal circumference Ascites Pleural effusion Intravascular volume depletion with hemoconcentration oliguria

22. Role of radiologist Familiarity with OHSS helps in avoiding the incorrect diagnosis of ovarian cystic neoplasm Appropriate management can be timely done OHSS has a significant risk for miscarriage in early phase after IVF(< 10 days after oocyte retrieval)

23. F o lli c u l a r do p p l e r f l o w s t ud i e s A mature follicle shows vascularity in atleast ¾th of the follicular circumference and PSV is 10 cm/sec. At this time LH surge starts and This is the right time to give hCG trigger

24. P r e d i c t o r s o f po o r o v a r i a n r es p o n s e are : Ovarian volume <3 cc < 3 antral follicles Ovarian RI > 0.6 Ovarian PSV < 5 cm / sec Suggest poor ovarian response & Higher doses of gonadotropins will be required for stimulation.

25. Ovulation trigger The end point of any ovulation induction protocol is to indentify the best time for triggering ovulation. In a gonadotrophin In in clomiphene Leading follicle is 18 – 20 mm in diameter Leading follicle is 20 – 22 mm in size

26. Suggestive of ovulation Disappearance of the follicle Presence of free fluid in the cul-de-sac. Presence of hyperechoic , smooth secretary endometrium .

27. Baseline, prior to initiating gonadotropin stimulation. Ovary with antral follicles

28. Stimulation day 5,showing recruited follicles measuring 10–12mm

29. Stimulati o n da y 9 , s howin g ov a r y wit h g r owing follicles

30. Thank You