Female genital cosmetic surgery (FGCS) is a broad term, defined as the surgical alteration of the vulvovaginal anatomy (labiaplasty, vaginoplasty, perineoplasty, clitoral hoodectomy, hymenectomy, labia majora augmentation, and Gspot amplification) [1]. The most popular of the female genital cosmetic surgeries is labiaplasty [2]. In the last five years alone in the USA, the number of labiaplasties has seen a 53% increase [3]. Labiaplasty refers to the surgical reduction of the size of the labia minora. The labia minora contributes sensory and erectile tissue for sexual arousal and intercourse, functions of which require the labia minora to be 1 cm or more in size [4]. Classically, it is considered hypertrophy when the labia minora measure more than 4 cm [5].

Unfortunately, there presently exists no standardization of the procedures performed. Edge resection [6], wedge resection [7], W shaped resection [8], laser labiaplasty [9], de-epithelialization [10], composite reduction labiaplasty [11], custom flask labiaplasty [12], lambda laser nymphoplasty [13], and fenestration labiaplasty [14] are the most commonly used labia minora reduction techniques [6, 15]. A variety of techniques have also been described for vaginoplasty [16] and perineoplasty [17]. The ‘golden ratio’ is very commonly seen in nature, and it has long been proposed as a characteristic of beauty in nature and in artistic creations. The golden ratio has been used for years in breast and facial aesthetic surgeries [18], but we find that it has never been used previously in female genital cosmetic surgery. We started implementing the golden ratio in labiaplasty cases as of 2020. To detect the patient satisfaction and quality of life, specifically designed, validated and reliable patient-reported outcome measures (PROMs) must be used. The Female Sexual Function Index (FSFI) [19, 20] and the Female Genital Self-Image Scale (FGSIS) [21, 22] questionnaires allow the efficacy of surgery to be measured from the patient perspective. Our primary goal was: (1) to determine the golden ratio (inspired by Fibonacci) with a holistic approach to standardize genital harmony with a purely mathematical ratio other than existing classification systems [23, 24]. This analysis will identify the most optimal measures currently in use and provide guidance on the development of new female genital cosmetic procedure-specific measures, to assess whether the proportional phi ($\phi$) ratio is associated with an ideal labiaplasty; (2) to adapt the golden ratio applied in breast and facial aesthetics to genital aesthetic surgical procedures; (3) to determine the effect of the Freya approach Technique (FT) on patient satisfaction with preop-postop survey data. Our secondary goal was to evaluate the effects of a new mathematical, holistic and easily applicable version of the vulvar region, which has very common anatomical variations, instead of the existing classification methods.

This single-center retrospective cohort study was conducted at the Department of Obstetrics and Gynecology of a tertiary care center. The files of 151 women who underwent labiaplasty and/or vaginoplasty by a single operator (EO) between 2020 and 2022 were retrospectively reviewed. The number of patients who underwent both labiaplasty and vaginoplasty was 127 (77 women were operated with Classical Technique (CT) and 50 with FT). Those women who underwent surgery with the FT were defined as the FT group and those women who underwent the CT were defined as CT group. The flowchart of the FT group inclusion process is shown in Fig. 1. 29 women who underwent FT fulfill these criteria agreed to participate and were included in the study.

We created a control group of women (n: 77) who underwent the CT between 2020 and 2022 at a tertiary care center. The control group was matched on age, gravida, parity, comorbidity, obesity, and smoking status to women operated using the FT. We randomly selected 30 women who fulfilled the study criteria and agreed to participate in the study. A total of 59 labiaplasty + vaginoplasty cases who fulfilled these criteria agreed to participate and were included in the study. The groups consisted of 29 study women who underwent the FT and 30 comparison women who underwent the CT.

A total of 59 women were included in this study (29 FT, 30 CT). The 59 women included in the study had at least two symptoms and complaints and all had Motakeff Class 3 labia minora on examination. All cases in both the CT and FT groups consisted of individuals who had only normal delivery, had an episiotomy at delivery, were non-smokers/alcohol users, were married and had active sexual intercourse, had a BMI $>$15 and 25, and had no comorbidities or drug use. All 59 women were high school graduates. The two groups were demographically and educationally similar and the mean ages of the patients were 32.55 $\pm$ 5.44 years and 33.47 $\pm$ 4.51 years, respectively. The general patient characteristics, intraoperative and postoperative findings and complications are summarized in Table 1.

While 29 (100%) of the cases approached with FT were operated in less than 90 minutes, only 10 cases (33.3%) were operated in less than 90 minutes with the CT and Visual Analogue Scale (VAS) scores after CT were significantly higher than in the FT group. Regarding postoperative complications, wound dehiscence was observed in two cases (6.9%) in the FT group compared to six cases (20.0%) in the CT group. Only one patient (3.4%) underwent revision labiaplasty in the FT group compared to five patients (16.7%) in the CT group. No postoperative bleeding complications were observed in any of the women in the FT group. Postoperative bleeding complications were observed in two patients (6.7%) in the CT group. Though not significant, there was a trend towards a higher complication rate in the CT group. The primary outcome measures were FSFI and FGSIS. The comparison of preoperative and postoperative FSFI and FGSIS scores in the women who underwent Freya and Classical Techniques is given in Table 2.

In both groups, postoperative FGSIS scores increased significantly compared to preoperative FGSIS scores (p 0.001), and postoperative FGSIS Appearance, Work, Partner, Healthcare and Embracement scores and total FGSIS score increased statistically significantly compared to the preoperative scores (p 0.001 for all). There was no significant difference between the preoperative and postoperative FGSIS Smell scores. When the postoperative FGSIS feel scores were analyzed, there was a significant increase in the FT group compared to the preoperative period, while there was an increase in the CT group; however, this increase was not statistically significant (p 0.001, p: 0.074, respectively). The percentages of change in the preoperative and postoperative FSFI and FGSIS scores in the FT and CT groups are shown in Table 3, Figs. 6,7.

The percent change (mean percent increase scores) of the preoperative and postoperative FSFI scores was 82.05 $\pm$ 29.93% in patients undergoing the FT and 111.14 $\pm$ 55.33% in patients undergoing the CT. The percentage increase was significantly higher in the CT group. The percentage change in the preoperative and postoperative FGSIS scores was higher in the FT group than in the CT group (89.25 $\pm$ 19.72% and 37.39 $\pm$ 17.42% respectively). Since all other demographic data were similar, only the correlation between age and number of children and postop FSFI and FGSIS scores were analyzed (Table 4).

There was a negative correlation between age and postoperative FSFI scores in the FT group (r = –0.389, p 0.05) (with postoperative FSFI scores decreasing with increasing age in the FT group). In the CT group, there was a positive correlation between the number of children and the postoperative FSFI and postoperative FGSIS scores, and as the number of children increased in the CT group, these two scores increased.

FT is an innovative surgical approach described for the first time in the literature, which can be easily applied independent of anatomical variations, provides genital harmony and has fewer complications and much sexual satisfaction and genital self-image scores in the postoperative period.

Negative effects of genital appearance on patients’ sexuality and self-esteem as well as functional discomfort [15] are the motivations of women who request labiaplasty. Unlike some of the previous reports that aesthetics were major concerns, all of our patients reported functional problems and/or sexual problems as their major motivations for surgery. No significant patient report-based differences were observed in functional hygiene problems or discomfort in either group.

The definition of labial hypertrophy has been variably made [23, 24]. In our practice, we considered surgical intervention if a patient has at least two complaints or symptoms and whether we measure the labia minora as Motakef Class 3 [24]. Various techniques to reduce the labia minora have been published with there being no evidence of one surgical technique being better than the other [6, 15]. The most popular algorithms used to define beauty have been the golden proportion, a mathematical ratio of 1:1.618 obtained by dividing the longer part by the shorter part and being equal to the division product of the whole length divided by the longer part [30]. In the CT technique, the labia minora were subjectively shortened. With the FT approach described in this report, inspired by the Fibonacci sequence, we endeavored to capture the golden ratio during labiaplasty and narrow down the vaginal opening. In our opinion, with this approach, we obtained functional labia minora more suitable for genital harmony (Supplementary Figs. 1,2,3,4,5).

Women should be informed about the potential complications of these surgical procedures. Wound dehiscence (9.5%) [31], hematoma (40%) [32], postoperative bleeding [33], pain [5], edema [34], over-resection, fenestration, and shortened vaginal introitus [6] were most common complications. Total complication rates ranged from 4% [28] to 23.8% [31] in wedge resection, 20% [35] in W-shaped resection, and 2% [12] in custom flask labiaplasty. However, our complications were not serious. The overall complication rate was 17.24% for the FT and 43.33% for the CT group with wound dehiscence, edema, and postoperative bleeding. We identified that there was a tendency for the CT to be more likely to develop wound dehiscence than the FT. In addition, our study provides additional information for postoperative VAS scores, where we found that postoperative VAS scores were significantly lower, especially when using this new approach. Another advantage of the new approach was that the operation time was less than 90 minutes. However, more than half of the cases in the CT group took longer than 90 minutes.

Revision labiaplasty rates are in the order of 2.9–19% [6, 28, 34] depending on the techniques. We have shown similar revision labiaplasty rates (FT: 3.4%, CT: 16.7%) in the present study.

Women wanting labiaplasty desire the procedure so as to improve the appearance of the external genitals and enhance their attractiveness, sexual desire, and self-confidence [36]. Little is known about the benefit of sexual function enhancement and partner satisfaction of these surgeries [15, 37]. Surgical techniques have favorable outcomes in terms of patient satisfaction, and satisfaction rates have always exceeded 90% [6]. The results of these studies suggest that genital cosmetic surgery treats both cosmetic and functional issues and enhances sexual satisfaction [15, 38, 39]. In our series, 100% of the patients were satisfied with the aesthetic, functional, sexual, and overall outcomes of their labiaplasties.

Outcomes evidence for labiaplasty is currently insufficient; however, a number of studies have provided an evaluation of patient satisfaction by means of questionnaires completed by the patients [34]. Having quantitative, specifically designed, validated and reliable PROMs would be useful to improve evidence-based practice, potentially assist with improvements in surgical techniques, and facilitate the decision-making process of patients and surgeons [15, 37]. In a systematic review, 96% of women had clinically significant improvements in questionnaires [3]. In a retrospective study, participating women reported statistically significant increases in their genital appearance satisfaction, sexual satisfaction and psychological well-being [39]. We used FSFI and FGSIS questionnaires to assess changes in sexual function and genital self-image. Our results from the FSFI and FGSIS scores were consistent with promising findings. In a prospective cohort study using the FSFI questionnaire, no significant effect of surgery was noted on desire, lubrication, orgasm, pain, or total score at either time point, but scores on arousal and satisfaction increased immediately after surgery, then fell back to baseline levels on follow-up [40]. In another prospective study, total study group scores on the FGSIS (24.91) were significantly better than entry, 15.58 (p 0.0001), and exceeded the control group’s scores [41]. We evaluated our patients with these questionnaires in the preoperative period and at two months postoperatively. At the second month evaluation, we identified that FSFI score rose from 16.10 to 28.69 (an 82.05% increase) (p 0.001) in the FT group, and 111.14% in the CT group. At second month evaluation, the total FGSIS score was 21.01 (11.24 at entry) for the FT group, and 17.70 (13.00 at entry) for the CT group. In our study, improvements were observed in the women’s sexual satisfaction and psychological well-being, compared to their recalled levels prior to surgery.

The strengths of this study are that it is a new approach, there is a control group, all operations are performed by a single surgeon, the type of operation is based on the patient’s preference, and validated outcome measures are used. The limitations of the current research are its retrospective study design, relatively small sample size on satisfaction, complications, and outcomes (which may not have been representative of the wider population of women seeking labiaplasty), lack of long-term data (only complications one month after surgery and survey evaluations two months after surgery) (meaning that making reliable conclusions regarding postoperative outcomes for patients is currently not possible). Good PROMs need to be developed, as does a reliable method of gathering quantitative measures on sensation before and after labiaplasty.

Many factors should be considered before determining the type of labiaplasty. These include the experience of the surgeon, the extent of the pathology, and the specific characteristics of the patient. This novel labiaplasty approach is simple and safe, and it could be very useful to reduce operative time and postoperative pain by avoiding excessive resection. Moreover, it improves genital appearance and sexual satisfaction. Future research should involve genital surgery focused PROM to assess the outcomes, benefits, and appropriate indications of these different surgical techniques more accurately. We propose the utilization of the golden ratio as the most appealing symmetrical form, which characterizes attractive labias. FT can be explored for achieving a more aesthetically pleasing appearance in labia minora reconstruction during genital gender affirmation surgery for transgender women.

The data obtained from the study can be freely accessed upon contacting the author without neglecting participant information.

EO and NP designed the research study; EO, HK, NY and SK wrote the study; EO performed the surgery; EO, SK, HK, NY analyzed the data and statistics; EO and NY performed literature search; EO and SK critically reviewed the study; NP supervised the final version. All authors contributed to editorial changes in the manuscript. All authors have participated sufficiently in the work to take public responsibility for appropriate portions of the content and agreed to be accountable for all aspects of the work in ensuring that questions related to its accuracy or integrity. All authors read and approved the final manuscript.

This study was approved by the Batman training and research hospital ethics committee (Decision No: 787, date 24/10/2020) and conducted in accordance with the principles of the Declaration of Helsinki. Informed consent forms were obtained from every patient who agreed to participate in the study.

We would like to thank Hamit Can, the art teacher who made the pencil drawings and allowed us to use them in the study.

This research received no external funding.

The authors declare no conflict of interest. Nurullah Peker is serving as one of the Guest editors of this journal. We declare that Nurullah Peker had no involvement in the peer review of this article and has no access to information regarding its peer review. Full responsibility for the editorial process for this article was delegated to Michael H. Dahan.