Hysteromyoma is one of the most common gynecopathies; its incidence in women of childbearing age reaches 40% [1—4]. In recent years, hysteromyoma has been observed in younger women more often. Research by Professor N. A. Schukina of Moscow Regional Research Institute of Obstetrics and Gynecology (GBUZ MO MONIIAG) showed that in 2008—2015, the percentage of young patients with hysteromyoma was 6% in average and tended to double from 4.1% in 2009 to 8.4% in 2015 [5]. Hysteromyoma is a hormone-dependent lesion featuring steroid hormones and their receptors as key factors of smooth muscle tissue growth and differentiation [6]. There is more and more evidence that the growth of fibroids is driven by progesterone [7—11], which makes fibroids increase in their sizes rapidly during pregnancy in 10-30% of cases [12]. Large and giant tumours can lead to fatal complications in mothers and feti [13—16] which requires a prompt decision on their removal during gestation. The world literature emphasises that abdominal myomectomy in pregnant women is an extremely rare practice featuring very few positive results [17]. The GBUZ MO MONIIAG Department of Gynecology headed by Professor S.N. Buyanova has 20 years of experience in safe lower midline laparotomy and myomectomy of symptomatic large and giant fibroids during pregnancy [18, 19]. In some cases, birth per vias naturales took place in the obstetric hospital of GBUZ MO MONIIAG, which is certainly preferable given the increasing number of caesarean sections [20—22].

We present a unique case study: laparotomy removal of giant myoma nodules during pregnancy in a 17-years-old patient Z. at 8 weeks’ gestation, who was admitted to the Department of Gynecology of GBUZ MO MONIIAG in January 2019. This case deserves special attention for several parameters that involve maximum exposure to perinatal complications: adolescent pregnancy and childbirth; a giant fibroid with impaired circulation; myomectomy during pregnancy. The World Health Organisation defines adolescents as those people between 10 and 19 years of age featuring insufficient reproductive and social maturity. The pregnancy was unintended, and the girl did not even know that she had uterine fibroids. Three weeks before the hospital admission, she started to experience growing lower abdominal pain; her abdomen quickly gained the size which did not correspond to the gestation stage. On the day of admission, the patient had a thorough clinical and laboratory examination, including pelvic ultrasound, in the women clinic of GBUZ MO MONIIAG. Progressive 8 weeks' uterogestation and a conglomerate mass of myoma nodules measuring 20×18×20 cm and showing signs of impaired circulation, which occupied the entire left side of the lesser and greater pelves, were detected. As soon as the patient signed a voluntary informed consent to operative treatment and was prepared for surgery, a lower midline laparotomy and myomectomy were performed (Fig 1.); the uterine cavity was not opened and the pregnancy was preserved. During the surgery, it was found that the entire small and large pelves were occupied by a conglomerate mass of myoma nodules measuring 20x18x20 cm, of soft consistency and whitish colour and with a liquid component coming from the uterine anterior wall, isthmus and left margin of the uterus extending to the left parametrium and under the bladder. The body of uterus had the size corresponding to the gestation stage and was of bluish discoloration and soft consistency; it was shifted distinctly to the right and retroposed by the aforementioned conglomerate mass of myoma nodules. The ovaries and fallopian tubes were normal. The uterus was delivered to the incisional wound carefully. Two semilunar incisions were performed over the most prominent part of the conglomerate mass of myoma nodules along the anterior wall of the uterus. The conglomerate mass of nodules was removed mostly through sharp dissection without opening the uterine cavity though it was deformed by the lower pole of the mass (Fig. 2). A favourable circumstance was that the chorion was located on the left lateral wall of the uterus. Thus, the pregnancy was preserved. After removal of the conglomerate mass of myomas nodules, the integrity of the uterus was restored with three rows of separate vicryl sutures: the 1^st and 2^nd rows were musculomuscular, the 3^rd one—serous-muscular (Fig. 3, 4). Intraoperative blood loss was 400 ml; it was replaced with infusion of crystalloid and colloidal solutions and 600 ml of fresh frozen plasma. No perioperative complications occurred. Morphologic analysis of the extracted conglomerate mass of nodules showed that there was a leiomyoma with marked edema. In the hospital, the patient was given progestational therapy for 7 days. Before leaving the hospital, the patient underwent pelvic ultrasound; progressive 9 weeks' uterogestation without hemodynamic abnormalities was detected. The sutures on the uterus after myomectomy showed no problems; no hematomas were present. For the entire gestation stage, the patient was carefully monitored by doctors and taken to hospital twice for prevention of threatening miscarriage. In September 2019, the pregnant woman of the age of 18 was admitted to the Department of Obstetrics for childbirth. Diagnosis: 37—38 weeks pregnancy. Cephalic presentation. Scar on the uterus after lower midline laparotomy and myomectomy at 8 weeks' gestation. Edema caused by pregnancy. Mild anaemia (hemoglobin100 g/l). The 10-days preparation for childbirth included anti-anaemic, sedating, and spasmolytic medications and symptom management. U/S results: estimated fetal weight of 2,800—2,900 g; the 45—62 mm thick placenta located along the anterior wall of the uterus; the placenta is of the 2—3 degree of maturity in the 2^nd degree of calcification; single nuchal encirclement was present. The myometrium was observed in all visible areas; myometrial thickness of the anterior wall varied from 6 mm in the upper part to 3 mm in the lower one. Medical conclusion: 37—38 weeks pregnancy. Cephalic presentation. No hemodynamic abnormalities were present. Diffuse thickening of the placenta. Given the pregnant woman insisting on birth per vias naturales, biological maturity of parturient canals, no signs of an incompetent uterine scar after myomectomy, and small estimated fetal weight, the doctors opted for programmed vaginal delivery with close ultrasound monitoring of the uterine scar condition. Prolonged peridural analgesia was used for relieving the pains of childbirth. 8 hours after the beginning of regular labour featuring occipitopubic position of the vertex, a live full-term girl of 3,200 g, 50 cm tall, with no visible congenital abnormalities and with a loose nuchal cord was born; the Apgar score 8 and 9 points. 5 minutes later, the placenta separated without assistance, and the afterbirth with all the lobes and membranes came out; the placenta size: 18×19×2.5 cm, weight: 560 g, the cord is 70 cm long, with velamentous insertion. Pelvic ultrasound was performed: the body, neck and appendages of the uterus are unremarkable; the uterine scar area has no niches and deformities; the myometrial thickness in this area is 1.7 cm. 4 days after the childbirth, the mother and her child were discharged from the hospital.

Fig. 1. Progressive uterine pregnancy 8 weeks of gestation (pregnant woman on the operating table).

Fig. 2. Removal of a giant conglomerate of myomatous nodes.

Fig. 3. Uterus with pregnancy after myomectomy.

Fig. 4. Extracted node conglomerate.

Conclusion

In recent years, the number of pregnant women of early and late childbearing age with hysteromyoma has been steadily increasing, and these are no longer isolated cases. Medical guidelines that include an improved pregnancy and childbirth algorithms for patients with large and giant uterine fibroids, as well as the list of clear indications and contraindications for myomectomy at gestation and an algorithm of reasonable selection of the childbirth method (vaginal delivery or cesarean section) should be developed to reduce the incidence of perinatal complications in such patients thus improving mothers and their unborn children's health.

Participation of authors:

Concept of the study — S.N. Buyanova, L.S. Logutova, N.A. Shchukina

Collecting and processing of data — E.L. Babunashvili, N.A. Shchukina, M.A. Chechneva, I.O. Shuginin, K.D. Shengeliya

Text writing — E.L. Babunashvili, T.S. Kovalenko, N.V. Yudina, M.G. Shcherbatykh

Editing — S.N. Buyanova, L.S. Logutova, E.L. Babunashvili

Authors declare lack of the conflicts of interests.