Cadaver study of the volume of the ovary in Bangladeshi women

Reproductive age, ovarian reserve and reproductive capability may be determined from the volume of the ovary. A cross-sectional, descriptive study was done in the Department of Anatomy, Dhaka Medical College, Dhaka, from January to December 2009, to see the variation in the volume of the ovary with age in Bangladeshi women. The study was performed on 140 post mortem human ovaries collected from 70 unclaimed female dead bodies which were in the morgue under examination in the Department of Forensic Medicine, Dhaka Medical College, Dhaka. The samples were divided into three age-groups including group A (10-13 years), group B (14-45 years) & group C (46-52 years). Group A is pre-menarche group, group B represents reproductive age and group C is post menopausal group. The length, breadth and thickness of each ovary were measured by using a slide calipers. Then the volume of each ovary was determined by the product of its length, breadth and thickness multiplied by 0.524, according to the Prolate ellipsoid formula. The mean volume of the right ovary was found higher than that of the left one in all age groups (p<0.001). The difference in mean volume of the ovary between group A & group B, group B & group C (p<0.001) and group A & group C (p<0.01) were also statistically significant. The volume of the ovary increases with age and then gradually starts to decrease from menopause.


Introduction
The human ovary is a dynamic organ which continually changes in size and activity through life, as an integral part of the hormonal changes in female through before, during and after her reproductive life 1 .Reproductive age, ovarian reserve, reproductive capability and prediction of response to induced ovulation or superovulationall these phenomena in modern reproductive medicine may be determined from measurement of the volume of the ovary 2, 3 .The accurate assessment of ovarian reserve will revolutionize the management of women requesting assisted conception or those who have had treatment for childhood cancer and those who are considering delaying a family for personal or professional reasons 4 .Ovarian morphology has become an important aspect of gynecological endocrinology, as volume is a crucial parameter to determine the extent of functional capability with hormonal integrity of the ovary 5 .Moreover, ovarian volume is an indicator of deviation from normal size and function to abnormal size and disease process like polycystic disease, tumour, ectopic pregnancy etc 6,7,8 .For example, van Nagell et al. (1995) 8 performed transvaginal scan on 8500 women without any symptom and defined an ovary as abnormal if its volume was >20 cm 3 in premenopausal and >10 cm 3 in postmenopausal women.Thus, we usually depend on the western data which come from the subjects of different races and geographic conditions as well as different measuring procedures.Ovarian function related clinical conditions such as infertility, nonneoplastic follicular cyst and ovarian malignancy are common in our country 9 and for perfect and complete evaluation of ovarian disease of Bangladeshi women, it is essential to establish an extensive data on the ovary of our own people 10 .Hence, the present study was aimed to see the variation in the volume of the ovary with age in Bangladeshi women and compare with that of western studies.It is expected that the findings of this study would help gynecologists, surgeons, sonologists and pathologists to adopt appropriate plan for diagnosis and treatment of the ovary.

Materials of the study:
A cross-sectional, descriptive type of study was designed and done in the Department of Anatomy, Dhaka Medical College, Dhaka, from January to December 2009, based on collection of 140 human ovaries from 70 unclaimed female dead bodies (age range 12-52 years) that were under examination in the Department of Forensic Medicine, Dhaka Medical College, Dhaka.All the samples were collected within 24-36 hours of death without any sign of putrefaction and taken from medicolegal cases excluding poisoning, any cutting or crushing injury to the ovary, ovary found in one side and diseased ovaries.

Methods:
The ovary was taken and its outer surface was dried with blotting paper.After isolation, the samples were divided into three age-groups: group A (10-13 years), group B (  At first, the length of the ovary was measured from its upper pole to the lower pole, then its breadth was measured at its maximum transverse diameter and the thickness was measured at the region of its maximum antero-posterior diameter, by using a slide calipers, according to Ahmed et al. ( 2007) 10 .Then the volume of each ovary was calculated which requires the measurement of the above three dimensions.
The Prolate ellipsoid formula is as follows: Volume = Length × Breadth × Thickness × 0.524 Statistical processing of data: All the data were recorded and processed; statistical analyses were done by using the SPSS 13.0 version.The comparison between right and left side was done by unpaired Student's 't' test and the comparison between different groups was done by One-way ANOVA.

Results
In the present study, the mean volume of the right ovary was found 2.66±0.23 cm 3 in group A (10-13 years), 5.95±1.37cm 3 in group B (14-45 years) and 0.83±0.20 cm 3 in group C (46-52 years).The mean volume of the left ovary was found 1.78±0.20 cm 3 in group A (10-13 years), 4.24±1.05cm 3 in group B (14-45 years) and 0.46±0.08cm 3 13 are lower than that of the present data.In most of the previous studies, the volume was recorded by using the ultrasound imaging, and that may naturally differ with the present study.However, in the present study, it was 14-45 years) & group C (46-52 years), according to Kumar & Malhotra (2008) 11 .Here, group A is pre-menarche age group, group B represents reproductive age group and group C is post menopausal age group (Table-I).

Table - I
: Grouping of the sample of the present study (n = 140)

Table -
II: Volume of right and left ovary in different age groupHealy (2008)18 stated that an average volume of ovary is 11 cm 3 in reproductively mature woman.The findings of Ivarsson, Nilsson & Persson 12 and Thatcher & Naftolin 14 are in agreement with the present study.In contrast, the findings of Higgins et al. 7 , Pavlik et al. 15 , Kupesic et al. 16 , Jonard, Robert & Dewailly 17 and Healy 18 are somewhat higher, and the findings of Forabosco et al.