REVISITING THE PECULIARITIES OF PREGNANCY AND CHILDBIRTH IN WOMEN WITH UTERINE SCARRING SYNDROME

In recent years, there has been an increase in the number of operations on the uterus in women of reproductive age with the formation of “uterine scarring syndrome” (USS), which can lead to complicated pregnancy and childbirth. To assess of anatomical and functional features of uterine scar, pregnancy and perinatal outcomes in USS women. A prospective analysis of clinical anamnestic data, pregnancy and childbirth in 398 USS women was conducted; ultrasound and Doppler assessment of morpho­functional status of the uterus using the Accuvix V20 Prestige (Samsung Medison, Republic of Korea) was made. Statistical analysis was performed using Statistica 13.0 (Dell Inc., USA) software. In 74.62 % of 398 women, the scar on the uterus is due to a previous caesa rean section (CS), in 24.11 % due to conservative myomectomy (CME), in 1.25 % – because of endo­ scopic interventions for incomplete uterine septum, in 25.87 % of women it was the result of “small” gynecological surgery. In 97 % of women with a scar on the uterus after the previous CS, there was no “passport of surgery”: ultrasound revealed the localization of the scar in the lower uterine segment in 96.48 % of 398, corporate scar – in the remain­ ing 3.51 % of women; ultrasound signs of relative “anatomic” scar failure were noted in 10.80 % of pregnant women. In 48.73 % of women pregnancy was complicated by the threat of abortion or premature birth, in 30.40 % anemia was diagnosed, in 24.87 % of the women under observation placental dysfunction took place. 78.1 % of women had delivery at term, 13.2 % had premature birth, 97.3 % had births CS, and 2.7 % of wom­ en had labours through canalis obstetricus. In 1.3 % of women labor was complicated by uterine hypotension, and uterine devascularization procedures was performed. The most common reasons for the formation of USS are cesarean section, conservative myomec­ tomy and various “small” intrauterine operations. Pregnancy with this syndrome is most often complicated by the threat of its termination and childbirth before term, anemia, placental dysfunction and Intrauterine growth retardation . The choice of delivery tactics is conditioned by the totality of hystory, the status of the scar on the uterus, obstetric status and the wishes of the woman herself. It is advisable to look for methods to assess the morpho­functional status of the operated uterus and predict the perinatal consequen­ ces of pregnancy in these women at the stage of preconception preparation.


Urgency.
In recent years the number of surgical procedures on the uterus in reproductive age women has been increased worldwide. This leads to the subsequent formation of "uterine scarring syndrome" (USS), which can be a cause of compli cated pregnancy and childbirth. The most common causes of USS are caesarean section (CS), conservative myomectomy (CME), and uterine plastic surgery account of abnormalities of uterine development or placenta accreta spectrum disorders [1,[3][4][5]. A considerable number of these women have reproductive intentions [1,2,9], and therefore the issue of prevention of complications during pregnancy and child birth in this cohort [1, 2-3, 5, 6] is of particular relevance. The most threatening complications of pregnancy include localization of the placenta directly in the uter ine scar; placental implantation; scar diastasis or rupture [6]. Diagnosis and monitoring of the ability of the uterine scar is carried out using modern imaging methods, which include ultrasound, hysteroscopy, MRT and CT, but the ultrasonographic method, with a verified safety during pregnancy, is considered the "gold standard" [4,10]. Ultrasound allows to determine the scar's thickness, the presence of re cesses (niches) and other features that allow to predict its elasticity and the ability to with stand significant burdens during pregnancy and childbirth [11].
In USS presence, pregnancy is accompanied by a high frequency of various perinatal complications, repeated occurrences in the abdominal cavity are signifi cantly increased, and maternal morbidity becomes 3-4 times higher than with child birth through natural birth canal [1,2]. Despite the considerable and continuing interest of researchers, the optimization of pregnancy and childbirth in USS women, the diagnostic criteria of the anatomical and functional capacity of the operated uterus remains an important area of modern obstetrics.
Objective. To assess anatomical and functional features of uterine scar, preg nancy and perinatal outcomes in USS women.
Material and methods. On the basis of the perinatal center of the third level Communal health Protection Institution "Odessa Regional Clinical Hospital" during the 2016-2018, 13729 births were performed. 4729 or 34.4 % of women had cae sarean section births.
A prospective analysis of the course of pregnancy and childbirth was performed in 398 USS women, in 107 of them (26.8 %) the presence of two or more scars after CS was established.
The criteria for the patients selection was the history of surgical intervention on the uterus (cesarean section, conservative myomectomy or plasticity due to developmental abnormalities), time after the previous operation more than 2 years (taking into account the time of repair and restoration of morpho-functional status of myo metrium), lack of extragenital pathology, pregnancy with one fetus.
Transabdominal (according to clinical protocols) ultrasound with the help of Accuvix V20 Prestige (Samsung Medison, Republic of South Korea) scanner was performed to all the patients at 11-13, 19-22 weeks of gestation. Transvaginal ul trasound was performed to further visualize the scar after the previous CS. In dy namics, the transabdominal ultrasound of the scar area after CS was performed within 32 and 36-38 weeks.
Additionally, Doppler examination of the blood flow was performed in the uterine arteries, in the area of the scar on the uterus. All studies were performed after obtaining PICs.
Primary statistical analysis of the data was performed with descriptive statistics using Statistica 13.0 software (Dell Inc., USA); linear discriminant analysis was used to predict the ability of the uterine scar after a previous CS.
Results and discussion. The vast majority of the patients under examination were country women -230 or 57.7 %; 168 (42.2 %) of them were towns women. By social status, 115 or 28.8 % of women were housewives, 107 (26.8 %) were manual workers, 95 (23.8 %) were employees, 81 women (20.3 %) were students. The average age of the patients was (33.2 ± 1.1) years.
In 297 women or 74.6 %, the uterine scar was due to a previous CS, in 96 or 24.1 % it was conditioned by conservative myomectomy (presence of fibroids and, including, concomitant endometriosis), 5 women or 1.3 % underwent endoscopic surgery on the account of incomplete uterine septum.
In all women, the intergenetic interval from the time of the previous surgery was more than 2 years.
In addition to these "large" gynecological surgeries, 103 women (25.9 % of 398) had a history of "small" surgery (scraping, hysteroscopy, etc.), which also alter uterus's morpho-functional status and are included in the concept of "operated uterus".
Among women operated on for uterine fibroids, 46 out of 96 (47.9 %) were expecting first births.
According to the anamnesis of the women with scars after CS, it was found that in the previous pregnancy, the main indications for surgical delivery were pelvic presentation of the fetus in 49 (16.5 %) of 297, fetal distress -in 54 (18.2 %), obstructive births (anomalies of delivery, clinically narrow pelvis, etc.) in 111 (37.4 %), progressive preeclampsia -in 12 (4.1 %), premature placental abruptionin 18 (6.1 %) of 297 women. 141 patients or 47.5 % had timely delivery and 156 or 52.5 % of women had time urgent ones. It should be noted that almost 97 % (386 out of 398) of uterus scar women after CS did not have a so-called "CS passport" with a clear description of the indications for surgery, type of uterus's incision, techniques for suturing the incision on the ute rus, course postoperative period. It was necessary to orient by the term of pregnancy when the operation was performed and other indirect indications of the possible type of surgery and technique used. Ultrasound had a decisive role here and the localization of the scar in the lower segment was established in 384 (96.5 %) of 398 pregnant women, corporate scar was diagnosed in the rest 14 of 398 women or 3.5 %. CME scar or metroplasty women did not report any complications after surgery. CME was performed by laparoscopic approach in 84 of 96 women or 91.3 %, while the remaining 12 (12.5 %) had a laparotomy. The average time after CME and metro plasty was (2.7 ± 0.2) years.
In patients with a scar on the uterus after CME, its localization corresponded to the primary localization of the removed myomatous node. The most frequently so-called "fundal" scars located in the uterine fundus (39 or 40.6 % of 96 women) and corporate (37 or 38.5 %) scars were onserved. In 10 (1.1 %) women the scar area was not identify. 10 women (1.1 % out of 96) has history of multiple nodes removed, but the scar area was not clearly established. In this cohort of patients, the "passport" of the previous operation was in 72 of 96 (75 %), but in 21 of them (29.2 %) information about the localization and suturing of the "bed" of the remote myomatous node was absent. Another drawback of these records was the lack of information about penetration into the uterine cavity during myomectomy.
In the analysis of pregnancy in USS women the following features were revealed (Table). No statistically significant difference in pregnancy in patients with 1 or 2 scars on the uterus after CS was found. In every second woman, pregnancy was complicated by the threat of interruption or the threat of preterm birth (48.7 %), in every third woman (30.4 %) anemia was diagnosed. On the basis of ultrasound and Doppler data of hemodynamic abnor malities of uterine-placental-fetal circulation, every fourth pregnant woman in the 3rd trimester had "placental dysfunction", realized in intrauterine growth retardation in 11.3 % of the patients under observation.

Pregnancy complications in women with operated uterine syndrome
According to ultrasound and Doppler examinations of the scar area after CS, ultrasound signs of relative "anatomical" scar failure were noted in 43 (10.8 %) of 398 women at 32 weeks gestation. Thus, the in homogeneity and irregularity of the scar along thickness of the myometrium was found in 38 (9.5 %) of 398 pregnant women, atypical location of the scar (above the area of the lower segment or its low location) -in 24 (6.1 %) of 398 women. From these patients history it was estab lished that the previous CS was produced urgently in the process of childbirth. In addition, thinning of the myometrium in the area of the scar (up to 2 mm) was detected in 29 women (7.3 % of 398). A significant reduction in vascularization in the scar area was found in 29 of 398 pregnant women (7.3 %), which is characteristic of myometrium connective tissue degeneration.
The absence of complaints and any clinical manifestations of anatomic and functional inability of the scar on the uterus in this group of women allowed to prolong the pregnancy. An individual plan of pregnancy's management was developed, including supervision in the hospital, with dynamic cardiotocographic control of the state of the fetus, uterine tone and the general condition of the pregnant woman, providing psychological support, with the prevention of respiratory disorders syndrome in the fetus in the case of urgent delivery.
Despite the possibilities of modern diagnostic methods for assessing the condi tion of the scar on the uterus, there are no precise "mathematical" criteria for its anatomical and functional failure and the final choice about the method of delivery remains with the patient. In most cases, women in this group insist on termination of pregnancy by caesarean section.
Pregnancy ended in 38-40 weeks in 343 (86.2 % of 398) women, 55 (13.2 %) women had premature labours at the term 33 -36 weeks. In all cases of preterm birth, caesarean section was produced.
Taking into account the wishes of women and their rejection of childbirth per vias naturalis, 311 USS pregnant women (78.1 % of 398) were delivered surgi cally abdominally in the planned order in the period of 39-40 weeks (Fig. 2). It should be noted that 10 women in this group had an attempt of per vias naturalis births, but in the process obstructive of childbirth was developed (4 cases), fetal distress in 4 cases, in 2 cases women changed their decision and insisted on completion childbirth by caesarean section. Through natural birth routes 11 (2.7 % of 398) USS women delivered. 3 of them after CME (27.3 % of 11), 8 (72.7 %)after CS. In all cases of childbirth through the natural maternity ways regional methods of anesthesia of childbirth were applied.
The average blood loss during caesarean section was (650 ± 230) ml; in 5 (1.3 % of 387 caesarean sections) births were complicated by uterine hypotension, on this occasion an uterine devascularization procedures was performed. There were no cases of massive obstetric haemorage.
Thus, the analysis of the course of pregnancy and childbirth in women with uterine scarring syndrome allows to draw a number of conclusions.
Conclusions. The most common reasons for the formation of uterine scarring syndrome are cesarean section (74.62 %), conservative myomectomy (24.11 %), various "small" intrauterine operations (scraping, hysteroscopy, etc.) (25.87 %). The complicated course of pregnancy in the presence of uterine scarring syndrome is caused by the high frequency of threatened miscarriage and premature delivery (29,64 %), anemia (52,76 %), placental dysfunction (24,87 %), intrauterine growth retardation (11.3 %). The choice of delivery tactics in the presence of uterine scarring syndrome is conditioned by the totality of the history data, examination and evaluation of the condition of the scar on the uterus with the use of visualization techniques and wi shes of the woman herself. It seems appropriate to look for methods of assessing the morpho-functional status of the operated uterus and predicting the perinatal conse quences of pregnancy in these women at the stage of pre-gravidar preparation.