Various studies have suggested the superiority of LOD outcomes over other treatments, including the use of CC for ovulation induction and pregnancy (
7-
9). However, resistance to CC is recognized as the most important indication of LOD (
5,
6). The evaluation of AMH as a factor affecting the success of interventional treatment with LOD was questionable until recently, when some researchers reported a reduction in AMH after PCOS treatment (
3). Other researchers evaluated the role of LOD in reducing AMH more precisely and suggested that the serum level of this hormone is beneficial in the diagnosis of PCOS (
10).
In our study, a significant reduction was observed in the serum levels of AMH three and six months after LOD compared to preoperative levels. However, Farzadi et al. found no significant correlation between LOD and reduced serum levels of AMH in Iranian women (
11). Amer et al., in a study of 29 women with PCOS at the mean age of 28.4 years, observed a significant reduction in AMH plasma levels three months after LOD compared to preoperative levels. However, the mean hormone levels showed a slight increase six months after the intervention, but in general, they were lower than the pre-interventional levels (
12). Elmashad found similar results in a study on 20 women with the mean age range of 27.4 years (
13). A study by Köninger et al. found that during pregnancy, the serum levels of AMH decrease, which is due to the inhibition of ovarian function. Moreover, AMH does not indicate ovarian reserve during pregnancy and does not appear to be related to the gestational age, but its levels are lower in pregnant women aged 35 or over (
14). In our study, pregnancy occurred in six (20%) patients after LOD and although the mean serum level of AMH decreased by the third month of surgery, no statistically significant difference was observed, which can be due to the low sample size.
Researchers have shown the increased serum testosterone level during PCOS and its decrease after treatment with LOD (
3,
15). Elmashad proved the association between this hormone and AMH in PCOS and the reduction of serum testosterone levels one week after LOD (
13). During LOD, the holes developed in the ovarian stroma destroy androgen-producing tissues, leading to the decreased production of testosterone and increased FSH level. Meanwhile, inflammatory factors such as insulin-like growth factor-1 in response to tissue destruction caused by surgical site damage, the effect of FSH on folliculogenesis, and increased blood flow to the ovarian tissue can facilitate gonadotropin entry (
16). In the present study, serum testosterone levels decreased three months after LOD compared to preoperative levels, but it was not statistically significant. The level of the hormone after six months was even higher than before the surgery (
Tables 2 and
3). The results of this study are similar to Elmashad’s study in the third month while contrary results were observed in the sixth month.
According to Hendricks et al., there are conflicting reports about the changes in testosterone levels after LOD in cases of ovulation compared to individuals without ovulation. The lack of reduction or a slight reduction in testosterone levels can be associated with high levels of its initial levels or low levels of tissue damage during LOD (
17). In the study by Amer et al., testosterone levels were seen in ovulation cases, but the P value was not significant (
12). In our study, testosterone levels three and six months after LOD had statistically significant decreases in women with ovulation compared to the other group. Also, in pregnant women, a significant decrease was observed in the serum levels of testosterone three months after LOD compared to the non-pregnant group. The results of our study are consistent with previous studies (
12,
17) in terms of non-significant reduction in serum testosterone levels after LOD in patients without ovulation and patients who did not become pregnant.
As noted above, an increase in the serum levels of AMH during PCOS has been reported in various studies. Along with increased AMH, the small follicles count also increased in these individuals (
18). The destruction of AMH-producing tissues and antral follicles may occur following LOD (11), which leads to their decreases. Recent studies suggest a positive correlation between serum levels of AMH and antral follicular count in ultrasound (
19). Serum levels of AMH are provided by granulosa cells of 2 to 9 mm (60%) follicles that are counted as AFC in ultrasound. The evaluation of the serum level of AMH is even more sensitive than AFC because it reflects small and pre-antral follicles (less than 2 mm in diameter), which are difficult to see in ultrasound. Therefore, the serum level of AMH is a more accurate marker than AFC for developing follicles (
3). Ultrasonographic studies showed a significant decrease in AFC after three months and six months of LOD. In both groups of pregnant and non-pregnant women, the number of antral follicles decreased, but there was no significant difference between the two groups.
5.1. Conclusions
Polycystic ovary syndrome is one of the causes of infertility in women. In patients with clomiphene resistance, LOD intervention can induce successful ovulation and pregnancy. In patients who ovulated after ovarian drilling, i.e., had a successful operation, AMH and AFC showed a significant reduction, but this did not apply to serum testosterone levels and DHEAS. Therefore, it may be possible to use postoperative changes in the levels of AMH and AFC as markers to predict the success rate of ovarian drilling in PCOS.