Evaluation of laparo-endoscopic single-site surgery for adnexal mass in pregnant women.

The study was conducted in the International Peace Maternity and Child Health Hospital (IPMCH) affiliated with Shanghai Jiao Tong University in Shanghai, China. We retrospectively included 20 pregnant women who underwent LESS between November 2019 and January 2022 for the treatment of adnexal mass in the IPMCH. Indications for surgery included: (1) ectopic pregnancy rupture in heterotopic pregnancy; (2) ovarian cyst torsion; (3) ovarian tumor with a solid nodule; and/or (4) persistence of adnexal mass or enlargement (diameter > 6 cm) during second trimester (see Table  1 ). The study was approved by the Ethics Committee of IPMCH (approval No. GKLW 2017–77). Written informed consent was obtained from each participant. Table 1 Baseline characteristics of included patients Case Age(yr) BMI (Kg/m 2 ) Gravidity and Parity Number of abdominal surgeries GA (wk) Symptoms Imaging examination The side of adnexal mass Maximum diameter of adnexal mass (mm) Pre-operative diagnosis 1 34 18.2 G1P0 0 15 Backache, bloating US Bilateral 174/104 Ovarian cyst torsion 2 30 18.8 G1P0 0 25 +4 Backache US Right 57 Ovarian cyst torsion 3 22 19.5 G1P0 0 12 Abdominal pain US Right 140 Ovarian cyst torsion 4 37 21.8 G2P0 0 5 +1 Abdominal pain US Left 90 Ectopic pregnancy rupture 5 27 29.5 G1P0 0 13 +6 Urinary frequency US Right 108 Benign ovarian cyst 6 29 24 G1P0 1 16 +5 / MRI Right 165 Benign ovarian cyst 7 39 33.1 G4P1 1 14 +1 / US Left 165 Benign ovarian cyst 8 32 21.8 G1P0 0 18 +2 / MR Left 150 Benign ovarian cyst 9 34 24.1 G3P0 0 15 / MRI Right 99 Benign ovarian cyst 10 31 18.5 G2P0 0 16 +2 / MRI left 70 Ovarian mass with a solid nodule 11 23 28 G1P0 1 14 +4 / MRI Left 92 MCT 12 36 20.1 G1P0 0 12 / US Left 71 MCT 13 36 20.5 G1P0 0 11 abdominal distension US Left 120 MCT 14 26 18.4 G1P0 0 13 +2 / US Bilateral 70/ 43 MCT 15 28 21.5 G1P0 0 17 Abdominal pain with vomiting MRI Left 89 MCT 16 34 21.5 G2P0 0 14 / US Left 92 MCT 17 27 26.17 G1P0 0 13 +2 / US Right 100 MCT 18 33 23.4 G2P1 0 19 +6 / MRI Bilateral 100/80 Benign ovarian cyst 19 33 22 G3P0 1 18 / US Right 80 Benign ovarian cyst 20 34 24.7 G3P0 0 14 MRI Right 100 Benign ovarian cyst BMI body mass index, GA gestational age, US ultrasound, MRI magnetic resonance imaging, MCT mature cystic teratoma Baseline characteristics of included patients BMI body mass index, GA gestational age, US ultrasound, MRI magnetic resonance imaging, MCT mature cystic teratoma Medical records and videos of each surgery were collected from an internal hospital database. Baseline characteristics of each patient, including age, body mass index (BMI), gravidity, parity, gestational age (GA) at surgery, history of abdominal surgeries, clinical diagnosis, and size and location of the mass measured by ultrasonography or MRI were noted (Fig.  1 ). In addition, symptoms, operative-related variables including emergency/non-emergency surgery, surgical approach (including cystectomy, cyst biopsy and fixation, salpingo-oophorectomy, salpingectomy), operative time (from skin incision to the end of suturing), intraoperative bleeding, pre/post operative fetal heart rate (FHR), surgical complications (including bleeding, organ damage, additional port or conversion to laparotomy, infection, poor wound healing, and/or miscarriage), degree of postoperative pain at 24 h assessed by visual analog scale (VAS) system, using a 10 cm line where 0 represents “no pain” and 10 “maximum pain” [ 20 ]. Postoperative medical intervention (magnesium sulfate, progesterone), pathologic findings, and the degree of satisfaction for the treatment (very satisfied, satisfied, uncertain, dissatisfied, or very dissatisfied) [ 21 ] were collected and analyzed. Fig. 1 Magnetic resonance imaging (MRI) characteristics of ovarian masses in 3 pregnant women on T2- weighted (T2W) acquisitions. A , B Ovarian torsion in a pregnancy woman at 25 +4  weeks of gestation. The right ovary was enlarged into size of 50 × 89 × 113 mm, presenting with a 42 × 70 × 48 mm cyst with high signal intensity surrounded by hemorrhagic cystic wall with low signal intensity on coronal and transverse section. C , D Ovarian cystadenoma in a pregnant woman at 16 +2  weeks of gestation. A round-like mass with size of 108 × 130 × 165 mm was found on the upper right region of the uterus, presenting with homogenous high signal intensity on coronal and sagittal T2W section. E , F Ovarian mature cystic teratoma in a pregnant woman at 17 weeks of gestation. A mixed cystic and solid mass with size of 89 × 45 × 60 mm was found on the upper left region of the uterus, presenting with heterogeneous signal intensity on coronal and sagittal section Magnetic resonance imaging (MRI) characteristics of ovarian masses in 3 pregnant women on T2- weighted (T2W) acquisitions. A , B Ovarian torsion in a pregnancy woman at 25 +4  weeks of gestation. The right ovary was enlarged into size of 50 × 89 × 113 mm, presenting with a 42 × 70 × 48 mm cyst with high signal intensity surrounded by hemorrhagic cystic wall with low signal intensity on coronal and transverse section. C , D Ovarian cystadenoma in a pregnant woman at 16 +2  weeks of gestation. A round-like mass with size of 108 × 130 × 165 mm was found on the upper right region of the uterus, presenting with homogenous high signal intensity on coronal and sagittal T2W section. E , F Ovarian mature cystic teratoma in a pregnant woman at 17 weeks of gestation. A mixed cystic and solid mass with size of 89 × 45 × 60 mm was found on the upper left region of the uterus, presenting with heterogeneous signal intensity on coronal and sagittal section Pregnancy complications and obstetric outcomes, including GA of delivery, pregnancy outcome, birth weight and Apgar score at 5 min, were obtained from medical records of those patients who had antenatal examination and delivery at our hospital. Otherwise, this abovementioned information was collected through telephone follow-up. All women completed relevant pre-operative checks. The surgical procedure was performed by the same two gynecologists who were trained and each with a minimum 3 years experience performing LESS. After applying general anesthesia, women were placed in a lithotomy position during surgery. Surgeons then introduced a 20-mm vertical umbilical incision in the abdomen to establish a single-channel single-port opening, then inserted a HangT Port double-ring wound retractor (HangTian KaDi Technology R&D Institute, Beijing, China); CO 2 insufflation was used to create a pneumoperitoneum, which was maintained at around 10-12 mmHg. Visualization of the surgical site was performed using a 10-mm 30° laparoscope and surgeons used conventional laparoscopic instruments for the operation. The ovarian tissue was closed with 2–0 polydioxanone violet monofilament synthetic absorbable BS (Stratafix; Johnson & Johnson) in 1 or 2 layers. Bipolar electrocoagulation and Ligasure were applied for Hemostasis and adnexectomy respectively. Endo Catch bags were used to exteriorize specimens through the umbilical incision, and samples were collected for pathological examination. Umbilical incision was intermittently closed by 2–0 absorbable sutures (Vicryl; Ethicon, Somerville, NJ), including peritoneum, fascia, and subcutaneous tissue, followed by an intradermic running closure with 4–0 absorbable sutures (Vicryl; Ethicon, Somerville, NJ). FHR was monitored before and after surgery. In cases with large adnexal cyst (especially diameter ≥ 10 cm), the cyst was pulled close to the umbilical incision and the ovarian cortex was fixed in place with a 4–0 purse-string suture. The surgeon then cut a small incision to aspirate cystic fluid with a 50 ml syringe or suction device, and the shrivelled cyst was subsequently pulled to the abdominal cavity exterior to complete the cystectomy (Fig.  2 ). Fig. 2 LESS right ovarian cystectomy through umbilical incision. A Enlarged gestational uterus. B Cysts located at the upper right of the uterus. C Cystic fluid was aspirated by inserting a 50 ml syringe to prevent spillage. D , E Cystectomy was performed extraperitoneally. F Cystectomy was finished and checked by the LESS. G ,  H Incision after LESS during pregnancy LESS right ovarian cystectomy through umbilical incision. A Enlarged gestational uterus. B Cysts located at the upper right of the uterus. C Cystic fluid was aspirated by inserting a 50 ml syringe to prevent spillage. D , E Cystectomy was performed extraperitoneally. F Cystectomy was finished and checked by the LESS. G ,  H Incision after LESS during pregnancy Ovarian cystectomy was performed in cases 5–20 (Fig.  3 ). Repositioning, cyst biopsy and fixation for torsion of ovarian cyst was performed in case 1. Cases 2 and 3 underwent salpingo-oophorectomy due to torsion of adnexal mass. salpingectomy for ectopic pregnancy in case 4. Fig. 3 LESS right ovarian cystectomy. A Enlarged gestational uterus. B Cysts located in the posterior of the uterus. C The ovarian cyst was dragged out and exposed. D Cystectomy. E Suture of ovarian tissue. F Survey after sutured LESS right ovarian cystectomy. A Enlarged gestational uterus. B Cysts located in the posterior of the uterus. C The ovarian cyst was dragged out and exposed. D Cystectomy. E Suture of ovarian tissue. F Survey after sutured

The baseline characteristics, including age, body mass index (BMI), GA, location and maximum diameter of the adnexal mass, and the pre-operative diagnosis of all women included in this study are shown in Table  1 . A total of 16 women underwent LESS for more than 60 mm ovarian cyst in the second trimester. Among them, 2 had bilateral cysts. In addition, 1 woman received LESS for ovarian mass with solid nodule in ultrasonography evidence, 2 women for ovarian cyst torsion, and 1 for ectopic pregnancy rupture in heterotopic pregnancy. The average age of patients was 31.25 years (range, 22–39 years) and the average BMI was 21.78 kg/m 2 (range, 18.2–33.1 kg/m 2 ). The average operative GA was 15 +2  weeks (range, 5 +1 –25 +4  weeks), including 2 women in the first trimester and 18 women in the second trimester. The maximum diameter of mass was 102.57 mm (range, 43–174 mm). 7 women experienced symptoms such as abdominal pain, bloating, and/or backache. Case 5 had a history of laparoscopic excision of left ovarian teratoma and case 12 had a history of laparoscopic appendectomy. The perioperative conditions are listed in Table  2 . Three of the women underwent emergency surgery and 17 were treated by non-emergency operation. The mean operative time was 80.80 min (range, 40–185 min) and the average amount of operative bleeding was 28.0 ml (range, 10-50 ml). Postoperative pain assessment indicated that average VAS at 24 h was 1 (range, 0–2), and average hospital stay was 5.15 days (range, 3–7 days). After the surgery, patients were given dydrogesterone (oral administration of 40 mg dydrogesterone for the first time and then 20 mg once a day for 6 days) or/and magnesium sulfate (intravenous administration of loading dose of 6 g magnesium sulfate, followed by continuous infusion at 2 g/h for 12 h), were administered in 4 patients (case No.2,8,13,18). To prevent deep venous thrombosis, after the surgery, all patients were encouraged to move their legs as soon as possible and intermittent pneumatic compression devices were applied. Patients were not given any anticoagulants in the present study. No intraoperative or postoperative complications were reported in any of the surgeries. According to pathological findings of specimens, 8 women were diagnosed with mature cystic terotoma (cases 11–18), while other diagnoses included mucinous cyst adenoma (cases 3 and 5–8), theca luteinized cyst (cases 1, 10, and 20), ovarian fibrothecoma (case 9), benign adnexal cyst and hemorrhagic infarct (case 2), serous cyst adenoma (case 19), and tubal ampullary pregnancy rupture (case 4). All 20 women responded that they were very satisfied with their treatment. Table 2 Perioperative characteristics of included patients Case Emergency surgery (Y/N) Surgical approach Operative time (min) Operative bleeding (ml) Pre/post-Operative FHR (beats per minute) Surgical Complications (Y/N) Postoperative pain (VAS) 24 h Medical intervention Length of stay(days) Histologic diagnosis 1 Y Ovarian cyst biopsy, ovarian repositioning and fixation 65 50 143/135 N 0 N 6 Theca luteinized cyst 2 Y adnexectomy 50 20 132/153 N 1 Magnesium sulfate + dydrogesterone 7 Benign adnexal cyst, hemorrhagic infarct 3 Y adnexectomy 60 50 133/145 N 1 N 2 Mucinous cyst adenoma 4 Y Salpingectomy 115 30 154/151 N 0 N 5 Tubal ampullary pregnancy rupture 5 N ROC 60 20 143/137 N 2 N 6 Mucinous cyst adenoma 6 N ROC 75 40 120/137 N 2 N 6 Mucinous cyst adenoma 7 N LOC 180 50 130/125 N 2 N 7 Mucinous cyst adenoma 8 N LOC 60 20 145/140 N 1 dydrogesterone 5 Mucinous cyst adenoma 9 N ROC 55 35 142/138 N 2 N 7 Theca luteinized cyst 10 N LOC 130 30 148/139 N 2 N 6 Ovarian fibrothecoma 11 N LOC 85 30 143/156 N 2 N 6 MCT 12 N LOC 40 20 125/137 N 0 N 3 MCT 13 N LOC 50 30 148/150 N 0 dydrogesterone 5 MCT 14 N BOC 70 25 122/126 N 0 N 5 MCT 15 N LOC 56 30 147/134 N 0 N 4 MCT 16 N LOC 65 20 156/146 N 2 N 4 MCT 17 N ROC 75 10 155/158 N 2 N 5 MCT 18 N BOC 185 20 145/148 N 1 dydrogesterone 5 MCT 19 N ROC 85 10 154/140 N 0 N 4 Serous cyst adenoma 20 N ROC 55 20 137/150 N 0 N 5 luteinized cyst Y/N Yes / No, LOC left ovarian cystectomy, ROC right ovarian cystectomy, BOC bilateral ovarian cystectomy, FHR fetal heat rate, VAS visual analog scale, MCT mature cystic teratoma Perioperative characteristics of included patients Y/N Yes / No, LOC left ovarian cystectomy, ROC right ovarian cystectomy, BOC bilateral ovarian cystectomy, FHR fetal heat rate, VAS visual analog scale, MCT mature cystic teratoma Obstetric outcomes of all women are shown in Table  3 . 17 women underwent obstetric examination and delivery at our hospital, 2 women underwent prenatal care at another hospital, and 1 woman underwent induced abortion at 16 +5 gestational weeks for her own reasons. Of the 19 women who continued their pregnancy until term birth, 14 delivered through vaginal delivery and 6 underwent cesarean section. The indications for cesarean section included intrauterine distress (cases 1 and 13), breech presentation (case 2), hypertension disorders complicating pregnancy (case 8), gestational diabetes mellitus (case 10), or preterm premature rupture of membranes (case 19). The average GA at delivery was 39 +1  weeks (range, 37- 40 +1  weeks); average birth weight was 3228.95 g (range, 2740-3930 g), and average Apgar score at 5 min was 9.95 (range, 9–10). Table 3 Complications and obstetric outcome of included patients Case Complications during pregnancy GA (weeks) Pregnancy outcome Birth weight (g) Apgar score (5 min) 1 / 38 +5 Cesarean section 3200 10 2 / 39 Cesarean section 2880 10 3 / 39 +4 Vaginal delivery 3930 10 4 HDCP 38 +4 Vaginal delivery 3155 10 5 HDCP, GDM obesity 39 Vaginal delivery 3680 10 6 / 38 +5 Vaginal delivery 3210 10 7 / 39 Vaginal delivery 3015 10 8 HDCP 37 +5 Cesarean section 3395 10 9 / 38 +4 Vaginal delivery 3210 10 10 GDM 39 +6 Cesarean section 2740 10 11 GDM, obesity 40 +1 Vaginal delivery 3650 10 12 / / Induced abortion / / 13 / 39 +2 Cesarean section 3910 9 14 / 38 +6 Vaginal delivery 3120 10 15 HDCP 38 +2 Vaginal delivery 3225 10 16 HDCP 38 +4 Vaginal delivery 3370 10 17 / 38 Vaginal delivery 3000 10 18 GDM 37 +1 Vaginal delivery 2870 10 19 PPROM 36 +3 Cesarean section 2890 10 20 / 38 +1 Vaginal delivery 2900 10 HDCP hypertensive disorder complicating pregnancy, GDM gestational diabetes, PPROM preterm premature rupture of the membranes, GA gestational age Complications and obstetric outcome of included patients HDCP hypertensive disorder complicating pregnancy, GDM gestational diabetes, PPROM preterm premature rupture of the membranes, GA gestational age In one 30-year-old patient with G1P0, which is a spontaneous pregnancy, a right ovarian cyst (54 × 57 × 48 mm) was detected at 7 weeks GA and followed up regularly through ultrasonography. The woman presented to the surgery department with right lower abdominal pain, vomiting and had a fever at 25 weeks GA. Gastrointestinal spasm was diagnosed and conservative treatment was given for four days. After determining treatments were ineffective, she was referred to our hospital. In MRI evidence, the right ovary was enlarged to 50 × 89 × 113 mm, presenting with a 42 × 70 × 48 mm cyst with high signal intensity surrounded by hemorrhagic cystic wall with low signal intensity. After obtaining a diagnosis of ovarian cyst torsion, we immediately performed LESS. During operation, the surgeon found a 360° torsion of the right adnexa, necrosis of the right ovary and fallopian tube, purple-black color, blood clots filling the ovary, and no restoration of blood flow after repositioning the adnexa. Based on these observations, the surgeon then performed a salpingo-oophorectomy (Fig.  4 ). The operation lasted 40 min. Postoperative treatment was carried out with progesterone and magnesium sulfate. Pathological examination suggested benign adnexal cyst with hemorrhagic infarct. Routine obstetric examinations were continued after operation. The woman had a cesarean section at 39 weeks GA because of breech presentation and the newborn weighed 2880 g with an Apgar score of 10 at 5 min. Fig. 4 LESS salpingo-oophorectomy for torsion of right adnexal mass. A Twisted adnexal adhesions with colon and pregnant uterus. B Blunt dissection of adhesions. C Exposure of torsional adnexal mass. D Salpingo-oophorectomy was perfomed by ligasure. E Inspection of the incision. F Removed adnexal mass LESS salpingo-oophorectomy for torsion of right adnexal mass. A Twisted adnexal adhesions with colon and pregnant uterus. B Blunt dissection of adhesions. C Exposure of torsional adnexal mass. D Salpingo-oophorectomy was perfomed by ligasure. E Inspection of the incision. F Removed adnexal mass In a 37-year-old patient with G2P0 (history of spontaneous miscarriage), in-vitro fertilization (IVF) treatment was used to establish successful pregnancy. The woman presented with sudden lower abdominal pain, anal swelling, and dizziness at 5 +1 weeks GA, with a heart rate of 120-125 beats per minute, blood pressure of 85-90/55-63mmHg and blood human chorionic gonadotropin (HCG) level of 19462 IU/L. Ultrasound showed that an echogenic uterine cavity of approximately 12×13×9 mm, mixed echogenic mass of 80×89×57mm in the right fallopian tube, and 79mm of free anechoic in pelvis. The pre-operative diagnosis was heterotopic pregnancy with ectopic pregnancy rupture, intra-abdominal bleeding, and hemorrhagic shock. In emergency LESS, the surgeon clarified rupture of the ectopic pregnancy, then performed right salpingectomy through LESS. Pelvic blood removal was 750 ml. The operation lasted approximately 50 minutes. Progesterone was administered after operation. On the first day post-operation, the peritoneal blood HCG was 31607 IU/L and hemoglobin (Hb) was 67g/L. On day 3 post-operation, ultrasonography showed an embryonic sac, 11×12×17 mm in the uterine cavity that displayed a yolk sac. Final pathology finding was Tubal ampullary pregnancy rupture. Regular obstetric examinations were conducted after surgery. The woman had spontaneous vaginal delivery of a 3155g baby at 38 +4 weeks GA with an Apgar score of 10 at 5 min.

Adnexal mass is a common gynecological condition, but relatively rare to find with surgical indication during pregnancy, with an overall incidence of ovarian mass in pregnancy of 1–6% [ 1 – 4 ]. More often, adnexal mass is detected prenatally by ultrasound during routine testing [ 5 , 6 ]. To date, no internationally accepted clinical guidelines have yet been established for the treatment of adnexal cyst in pregnancy. In general, the management of an adnexal mass found in pregnancy is usually conservative because 90% of the functional cysts will disappear by the second trimester [ 7 ], whereas surgical intervention during pregnancy increases risk of several complications, including abortion, preterm labor, and fetal death [ 8 , 9 ]. However, some types of adnexal masses, such as large, particularly symptomatic, or persistent masses, may require intervention due to major complications, for example, malignancy, torsion, rupture, or compression symptoms arising from cyst. Furthermore, heterotopic pregnancy typically requires surgical removal of the ectopic pregnancy to avoid abdominal hemorrhage and ensure both fetal and maternal safety [ 8 ]. By convention, laparotomy is considered the most appropriate strategy during pregnancy, but with the rapid development of minimally invasive techniques, increasing reports suggest that laparoscopic surgery can provide some notable advantages over laparotomy [ 10 , 11 ]. For instance, laparoscopic surgery facilitates better exposure and less contact with the uterus during operation. In addition, it is less invasive, resulting in decreased pain, reduced pelvic adhesion, as well as shorter hospital stays and recovery time to normal activities compared with laparotomy, without any significant difference in obstetric outcomes between the two approaches [ 12 – 14 ]. Laparo-endoscopic single-site surgery (LESS) is conducted by creating an umbilical incision into a circular platform with multiple operating orifices, through a special single-port or conventional laparoscopic instrument, conferring benefits such as reduced likelihood of wound complications and improved cosmetic results, etc. In recent years, LESS has been widely used for the treatment of benign and malignant gynecological diseases among non-pregnant women [ 15 – 17 ], However, it is not widely performed in pregnant women because the safety and efficacy of LESS application has not been established in these cases and its use may require higher operative proficiency for the surgeon. To address the relative dearth of reports on this advanced technique [ 18 , 19 ], in this current study, we retrospectively examine data from 20 women who underwent LESS for adnexal mass during pregnancy and report in detail on particular cases, providing data to support the use of LESS during pregnancy.

Our findings support the use of LESS treatment for adnexal mass during pregnancy as a safe, feasible option for a wide range of applications. However, due to the small sample size, single-center and single-arm nature of this study, further confirmation of our results is needed through a multicenter, large sample study.

In this study, we retrospectively included 20 pregnant women who underwent LESS for adnexal masses between November 2019 and January 2022. Among these women, GA ranged from 5 +1  weeks to 25 +4  weeks. All women underwent successful LESS with surgical outcomes reported as very satisfactory, and good obstetric outcomes, except for one woman who induced abortion for personal reasons unrelated to LESS. This study also considers single-port laparoscopic surgery during pregnancy to be safe and effective. LESS is currently performed in many gynecological fields, although it requires a longer and more challenging learning curve, which has led to improved cosmetic outcomes through hiding the incision scar in the umbilicus, as well as easier removal of the specimen through a relatively larger umbilical incision compared to traditional laparoscopic surgery. LESS also can reduce morbidities arising from visceral or vascular injuries during trocar insertion, lower risks of postoperative wound infection and hernia formation. Furthermore, Postoperative pain relief in patients facilitates rapid recovery after surgery. optimizes human resource allocation and reduces labor costs. LESS offers more prominent benefits for pregnant patients compared to traditional laparoscopy. Jiang, et al. [ 22 ] compared LESS and conventional laparoscopy in 54 pregnant women and found that the single-port route was associated with less postoperative pain, shorter hospital stays, and lower anxiety. Otherwise, due to uterine enlargement during pregnancy, the adnexal mass is typically closer to the umbilical incision, allowing easier extraction of the cyst from the abdominal cavity, especially for large adnexal cysts (cyst diameter ≥ 10 cm), consequently reducing both strain on the uterus as well as likelihood of abdominal cavity contamination with fluid from ruptured cysts during cystectomy. In addition to facilitate the surgical procedures, LESS can reduce the duration of CO 2 pneumoperitoneum maintenance, thus decreasing the risk of fetal acidosis poisoning [ 23 ]. In terms of obstetric outcomes, one previous study found no significant differences in pregnancy outcomes between LESS and multiport laparoscopic surgery [ 24 ]. Lee, et al. [ 25 ] analyzed the outcomes of singe-port laparoscopy in 14 pregnant women treated for ovarian cysts with diameter > 6 cm and found that two women had miscarriages and one woman had preterm delivery post-operatively, while the rest had full-term pregnancy and delivered without complications. In our current study, no patients experienced spontaneous abortion or preterm delivery related LESS, which was aligns well with results described in other LESS studies [ 26 , 27 ]. However, LESS also has limitations that should be considered in determining surgical approach. In particular, LESS is unsuitable for advanced malignant tumors and severe pelvic adhesions. In addition, LESS may be inadvisable for surgeons lacking advanced technical experience due to limitations of triangulation that can potentially result in frequent conflicts between instruments and lack of help from assistants. Based on these limitations, the following points should be noted in pre-operative decision-making to use LESS in pregnancy. First, patients need thorough assessment of the factors causing pelvic adhesions, such as history of previous pelvic or abdominal surgery or endometriosis. Second, the nature and location of the mass should be rigorously determined by ultrasonography or MRI, and a decision to use LESS should be made with extreme caution in cases with high suspicion of malignancy, especially in advanced or highly malignant tumors [ 27 ]. At the same time, clarifying the relationship between the mass and the uterus can help surgeons design an effective surgical strategy to manage the mass while minimizing contact that can reduced stimulation of the uterus during operation. Third, except in cases requiring emergency surgery, LESS should be administered in the second trimester before the uterus is enlarged and consequently obscures the surgical view, thus improving probability of treatment effectiveness and reducing risk of miscarriage or preterm delivery postoperatively [ 28 ]. Finally, effective communication with women and families before surgery is essential for reducing potential anxiety or fear that can impact patient compliance and adversely affect post-operative satisfaction. It should be noted that all surgical procedures in this study were performed under general anesthesia, and no abnormalities were observed in post-operation examinations or obstetric outcomes. We believe that general anesthesia is relatively safe during pregnancy, which was also reported by Fisher and colleagues [ 29 ]. In these 20 cases, umbilical incision was made by open puncture (Hasson method) to avoid damage to the enlarged uterus or other organs associated with puncture needle. In general, a lithotomy position with a leftward tilt (after 16 weeks of gestation) is recommended to improve venous return and cardiac output. However, the patient’s surgical position can be temporarily adjusted to accommodate the position of the mass. For example, if the mass is located in the left posterior of the uterus, the woman can be tilted to the right side to facilitate dragging out the mass. Meanwhile, surgeons should communicate with the anesthesiologist in real-time [ 30 ]. In our experience, touch or stimulation of the uterus should be minimized, because enlarged uterus brings the adnexal mass closer to the umbilicus or the adnexal mass is large enough (especially diameter ≥ 10cm), cystectomy can be performed extra-abdominally after aspiration of fluid, and specimens can be exteriorized through the umbilicus with Endo Catch bags to avoid leakage of cystic fluid. Before the end of surgery, intra-abdominal CO 2 should be slowly aspirated to avoid rapid, dramatic fluctuations in intra-abdominal pressure and minimize the impacts of changes in abdominal pressure on the fetus. If LESS is difficult, the operation should be immediately converted to multi-port or open surgery to ensure the safety of mother and fetus, and the surgery should be performed by a surgeon very experienced in LESS. At post-operation, tocolytics were administered to women with GA < 12 weeks, who underwent adnexal resection, or who experienced contractions. Pneumatic compression devices and early postoperative ambulation were recommended prophylaxis for deep venous thrombosis. In addition, we do not believe that conventional use of postoperative antibiotics. Finally, careful attention should be paid to fetal heart monitoring after surgery, and ultrasound is recommended to determine the of intrauterine condition of the fetus, if necessary.