Introduction
Transvaginal Ultrasound is currently the gold standard for assessing follicular growth. With the introduction of pelvic ultrasound in the 1980s, non-invasive assessment of ovarian morphology became possible. With advances in technology in particular that of TVS, ultrasound has replaced laparotomy and X-Ray pelvic pneumogynaecography in the diagnosis of PCOS.1 The static B scanners of the mid 1960s allowed visualization of ovarian enlargement as well as of cysts > 1 cm in diameter.2 The poor resolution of the ultrasound equipment used in the early 1970s, permitted visualization of the ovarian outline only. However, the use of a single dimension may lead to false positive results when the full bladder compresses the ovary or false negative results when the ovaries are spherical in shape. There after the development of grey scan equipment in the 1970s and real time sector scanners in the 1980s, improved resolution and for the first time, follicles or cysts < 1 cm could easily be recognized.3 In 1981, Swanson et al. described PCO as enlarged and rounded with a mean volume of 12 cm3 and containing an increased number of small follicle (2 – 8 mm) encircling the ovarian cortex.4 In 1985, new criteria based on TA ultrasound required 10 or more cysts of 2 – 8 mm in diameter arranged peripherally around an echodense stroma.5 These criteria have remained in widespread use even after the introduction of TVS, a decade later. Ultrasound studies have demonstrated that approximately 20% of young women have polycystic ovaries.
Materials and Methods
Place of study
Infertility clinic of department of Gynaecology & Obstetrics of SSKM and IPGMER, Kolkata.
Exclusion criteria
Patients with co-morbidities.
Patients with secondary infertility.
Debilitated or moribund patients.
Patients under Contraceptives.
Primary infertility due to other causes.
Menopause.
Unmarried subject.
The main outcome measures were changes in the ovarian parameters and follicle status with age and following clomiphene therapy.
Methodology
The patients were examined thoroughly in the infertility clinic of the same hospital. Full history was taken with special reference to menstrual history and treatment history. General survey was done with special reference to body weight, excess body hair, hirsuitism, any pelvic mass, etc.
Transvaginal ultrasonography was done – baseline folliculometry (before treatment with clomiphene) and post treatment folliculometry.
Before Application of Clomiphene: Study of ovarian size, volume and development of follicles followed by rupture, if any, with alternate day transvaginal ultrasonography was done. Study started from Day 9 of menstrual cycle.
Application of Clomiphene: 100 mg orally daily from Day 3 to Day 7 for 1 cycle.
After Application of Clomiphene: Similar alternate day transvaginal sonography to observe changes, if any, in the same parameters, starting from Day 9 of the same cycle in which clomiphene was given.
Operational definitions
Transvaginal Ultrasonography
Toshiba Xario Model ultrasonography machine was used. It is performed by a registered medical sonologist. Preparation of the patient: Patients need to empty the urinary bladder before transvaginal sonography. During the sonogram, the patient lies on the examination table in supine position with knees flexed. Gel is applied on the vaginal probe and then covered by a condom. The gel helps elimination of the formation of air pockets between the transducer and the organ examined. The sonographer introduces a probe into the patient’s vagina and presses the transducer against the part examined, moving from one area to another as necessary to view the uterus and ovaries. Sonography usually is a painless procedure. However, one may experience some discomfort as the sonographer guides the transducer. Transvaginal imaging utilizes a higher frequency imaging achieving better resolution of the ovaries. 6
3 – D Ultrasound
To avoid the difficulties in outlining or measuring ovarian size, 3 – D ultrasound has been proposed using a volumetric probe (9) or a manual survey of the ovary. 3 – D ultrasound has been used to measure ovarian and stromal volumes providing information that is not available from 2 – D ultrasound. Data can be transferred to a computer and analysed later. 7
Results
Volume of the ovary with age (average of rt. & lt. ovaries)
The volume of the ovary decreases after 30 years. So 30 years has been taken as the cut off age. The decrease in volume indicates a fall in ovarian reserve and number of eggs. No significant difference was found between the right & left ovaries.
Table 1
Change in the volume of ovaries with age
|
Age range |
No. of patients |
Vol. of ovary (average of rt. & lt. ovaries) |
|
19- 20 yrs. |
7 |
8.87 cc |
|
21 – 30 yrs. |
28 |
8.83 cc |
|
30-36 yrs. |
15 |
5.32 cc |
|
Total |
50 |
|
Table 2
Volume of the ovary before & after clomiphene therapy
The change in volume is usually insignificant. However, in the present study, the volume change is significant as we have included several cases of PCOD. In these cases, there is a rise of ovarian volume due to Clomiphene therapy.
Table 3
Length of the ovary before & after Clomiphene therapy (average of rt. & lt. ovaries)
The change of length is significant with Clomiphene therapy.
Table 4
Breadth of the ovary before & after Clomiphene therapy (average of rt. & lt. ovaries)
There was no significant change with Clomiphene therapy.
Table 5
Total number of follicles in both ovaries before & after Clomiphene therapy
In PCOD cases, many follicles are small & immature and may be ≥ 10 in number. In the present study, significant follicles were taken to be > 10 mm in maximum dimension. Folliculometry was done from day 9, on alternate days till rupture of follicles if any. If no follicles ruptured, measurements were continued till day 21. Unruptured follicles became atretic.
No. of follicles before Clomiphene = 7.50 follicles.
No. of follicles after Clomiphene = 8.00 follicles
Discussion
Age changes in ovarian volume as measured by Trans vaginal Sonography (TVS)
The volume of the ovary decreases with age. However, this is not just a perimenopausal feature. In the present study, a gradual decrease in ovarian volume was observed between the ages of 19 and 36 years, the average ovarian volume dropping from 8.87cc to 5.32cc. A sharp decline in ovarian volume has been found after the age of 30 years. Ovarian volume was unrelated to patient weight. In present study each ovary was measured in three dimensions and ovarian volume was calculated using the prolate ellipsoid formula (Length X Height X Width X 0.523). It supports the work of E. J. Pavlik et al, who found a statistically significant decrease in ovarian volume in each decade of life from age 30 to age 70.8 They have set the upper limit of normal for ovarian volume at 20 cm3 in pre-menopausal women and 10 cm3 in post-menopausal women.
No significant difference was found between the volumes of right & left ovaries. The ovarian volume varied from 5.32 cc to 8.87 cc with an average of 7.67 cc. This tallies with the data of Farzana et al.9
Most of the couples attending the infertility clinic at the Dept. of Gynecology, I.P.G.M.E.&R. were referred cases from other institutions. They had already spent a considerable amount of time and money over various modalities of treatment with no results. The mental pressure on the concerned couples was considerable and they had come to this referral centre with a lot of hope. All previous investigations were reviewed to prevent unnecessary duplication of test.
In humans therefore, oocytes are established in the ovary before birth, and may by dormant awaiting initiation for up to 50 years.10
The oocyte in a follicle is in the stage of a primary oocyte. The nucleus of such an oocyte is called a germinal vesicle. Meiosis I is completed just prior to ovulation which results in the formation of the mature Graafian Follicle. Meiosis II is completed around fertilization forming the mature ovum.11, 12
The mean diameter of the dominant follicle is 20mm before ovulation, the mean volume 3.0 ml, and the growth rate of follicles 1-3mm/24 hr. Ovulation occurred within 24 hrs of the LH peak and within 48 hours of the blood estrogen peak.
Advancing female age is one of the “greatest enemies” of fertility. This contrasts the most males who can father children for their entire lives. If one graphs female age against declining fertility, there is a direct relationship which cultivates in the menopause.13, 14
The human ovaries become unresponsive to gonadotropins38 with advancing age and their function declines, so that sexual cycles disappear (menopause).This unresponsiveness is associated with and probably caused by a decline in the number of primodial follicles,which becomes precipitous at the time of menopause .
Causes of infertility in the present study – All the cases were due to failure of ovulation. However, none of the cases were due to primary ovarian failure (total absence of follicles). Follicles were formed in all cases, with or without the use of clomiphene. In most cases, the infertility was due to inadequate growth of the follicle, absence of dominant follicle, failure of rupture and premature atresia.
The present study addressed the problem of anovulation. The cases were followed up in a particular cycle by transvaginal ultrasonography to assess the number & size of the maturing follicles up to ovulation. This was done both before and after administration of clomiphene.
The use of clomiphene citrate for induction of ovulation
Clomiphene citrate (CC) is an synthetic, non-steroidal oestrogen antagonist drug which has been in use since the 1970’s. It binds to both oestrogen receptor α and β. It induces gonadotropin secretion in women by blocking oestrogenic feedback inhibition of pituitary. The amount of LH / FSH released at each secretory pulse is increased. In response, the ovaries enlarge and ovulation occurs if the varies are responsive to gonadotropins. Antagonism of peripheral action of oestrogen results in hot flushes. The endometrium and cervical mucus may be modified.
Clonmiphene is useful in women with oligomenorrhoea and amenorrhoea with intact hypothalamo – pituitary – ovarian axis. If the patient is anovulatory, CC is often used before diagnostic procedures continue. Some authorities prefer to initiate treatment with 50 mg once daily 5 days starting from the 5th day of the cycle. Treatment was given monthly. If 1 – 2 months treatment did not result in conception, the daily dose was doubled for 2 – 3 cycles up to a maximum of 200 mg/day.
In the present study, clomiphene alone was used with similar results. Similar findings have been reported by Nasrullah, et al.15
Nausea, vomiting, vasomotor flushes, bloating sensation were the adverse effects of clomiphene citrate therapy in few cases of this study.
Changes in the ovary after clomiphene therapy
Increase in ovarian dimensions & volume after treatment with Clomiphene as measured by TVS.
In the previous sections it was seen that the ovarian volume gradually decreases over the lifetime of the individual. The decline was specialy rapid after the age of 30 years. Clomiphene therapy increased the ovarian volume due increased secretion of pituitary gonadotropins. This increase was due to both increased folliculogenesis and an increase in the ovarian stroma.
Thus clomiphene compensates for the age changes in the ovary and brings about a greater chance of conception even in the ageing ovary.
In the present study, the size of the ovary increased after clomiphene therapy in all three axes (length, breadth & height). The average length increased from 3.61cm to 3.76cm, the breadth from 2.05cm to 2.14cm, and the height from 2.04cm to 2.05cm. While the individual axial lengths showed a modest increase, the volume increased from 8.16cm to 8.89cm. Similar work has been carried out by Goswami et al in 1988,16 and Fossum et al in 1990.17 Measurments of the ovaries in younger age groups are also available from the data of Haber et al in 1994.18
Change in total number of follicles before and after treatment with Clomiphene as measured by TVS: It is not economically feasible to carry out sonographic folliculometry in several cycles for each patient. Therefore, one or at the most two cycles may be selected for the purpose. In any particular cycle, folliculometry was done on alternate days from day 9 till rupture. If there is no evidence of rupture, the study was carried out till day 21. This study is expensive because it has to be done both before and after clomiphene therapy.
In the present study, the number of ovarian follicles ranged from 0 to 12 before stimulation with clomiphene and from 1 to 13 after stimulation.
Previous workers have divided such cases into three groups based on the sum of ovarian follicles in both ovaries – inactive (< 5 follicles), normal (5 – 15 follicles) and polycystic like ovaries (> 15 follicles). The number of follicles present before stimulation was found to be a better predictor of outcome than ovarian volume or age alone. Patients with inactive ovaries were found to have a poor response to IVF treatment (Tomas et al). 19
Solutions after failure of treatment of infertility
Despite all efforts, some couples are not benefited by infertility therapy. For these cases there remain the options of assisted reproduction measures, surrogate pregnancy and adoption.
The future
The future of reproductive technology is opening up at a rapid rate. Selective culture of embryos, screening for birth defects at the primodrial stage and genetically engineered fetuses are looming on the horizon. The womb and the mother’s lap may be replaced by culture solutions and incubators. The role of the individual parents in conceiving a child is likely to decrease with unknown consequences for the child. A compromise will have to be made between conception of perfect children and parental and child bonding. The challenges of the future are likely to bring forth unique solutions to the age old process of natural childbirth and rearing.
Conclusion
The present study has shown that the ovarian reserve declines with age. Both the size of the ovary and the number of follicles are gradually reduced after the second decade. The decline however is abrupt after the age of 30. The increased latency of meiosis in the developing ovarian follicle predisposes it to various disruptive influences. It would therefore seem to be a wise idea to contemplate the completion of one’s family by the third decade. In the present study, we have studied the dimensions of the ovary across the ages of 19 – 36 years. The gradual decline in ovarian function was evident on transvaginal sonography (TVS). The effect of clomiphene was dramatic, with recruitment of follicles and an increase in size of one or more dominant follicles.
