Newborns death risk factors after surgical interventions in the early neonatal period

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BACKGROUND

Modern surgery in the early neonatal period has undergone significant changes in recent years. Thanks to the development of antenatal diagnostics, most congenital malformations (CMs) can now be detected even before birth. The preferred technique is currently a radical one-stage correction of developmental anomalies; however, there is also no unequivocal rejection of the staged correction of congenital defects, such as congenital heart defects [19]. The preferred approach includes minimally invasive and endosurgical interventions. Endosurgical interventions allow for the correction of CMs with minimal risk to the patient’s health. However, this type of surgery is far from being possible in any hospital because the surgeon must know the anatomical and physiological characteristics of newborns, have experience in the treatment of newborns including premature ones, and master endosurgical techniques [9, 18].

Congenital heart disease is one of the most significant causes of neonatal mortality. This is partly associated with the need for surgical treatment in the first days of life, which became possible with the improvement of cardiac surgery. In recent years, noteworthy results have been achieved in the field of surgical technique, perfusion, anesthesia, and nursing of infants, especially due to the individualization approach in each case. The authors noted that the risk of cardiac surgery in the neonatal period sharply increased in the presence of other factors, such as low gestational age and low body weight [23]; however, other risk factors are currently under-investigated.

CMs and central nervous system tumors are reasons for surgical interventions in the early neonatal period. In the case of CMs of the central nervous system, mortality in the neonatal period is low; however, it reached 20% after the removal of intracranial tumors, which is most often associated with severe malignancy [14].

Many studies have focused on the issues of reducing postoperative mortality in the neonatal period; however, most of them focused on discussing the correctness and timeliness of diagnostics and formulating indications for surgical treatment [4, 6, 8, 9, 16, 22], surgical treatment methods [1, 9, 10, 20], surgery timing [19, 24], and postoperative management methods [17].

Recently, the number of children requiring surgical treatment of necrotizing enterocolitis, the so-called disease of preterm survivors, has been increasing [21, 29]. The main risk factor for the development of this condition is a low birthweight (up to 1000 g). Since 2012, after the transition to the new live birth criteria ¹, along with a gradual decrease in mortality from respiratory distress syndrome, the number of children with necrotizing enterocolitis is growing simultaneously [21, 34, 45]. According to some authors, the mortality rate from this disease ranges from 50% to 100% [2, 18, 32]. Such a high mortality rate is due to the severity and extent of the pathological process and postoperative complications [13, 16, 18]. In addition, complications and causes of postoperative death of children such as acute renal failure, which is caused by dehydration, asphyxia, sepsis, and disseminated intravascular coagulation syndrome, are described [13, 19, 49].

Thus, the analysis of literature data on postoperative neonatal deaths showed that recent research focuses on the search for modern methods and approaches to surgical treatment and improvement of diagnostic methods; however, other prognostic markers (anamnestic, clinical, and instrumental) are studied enough.

This study aimed to determine the risk factors for infant death in the neonatal period after surgical interventions performed in the early neonatal period.

MATERIALS AND METHODS

This retrospective study analyzed data from the medical records of children treated at the Perinatal Center of the St. Petersburg State Pediatric Medical University (a third-level obstetric institution) between 2013 and 2020. The “deceased” group included 77 newborns that underwent surgery in the early neonatal period (first 168 h of extrauterine life) and died within the first 28 days of life. The “survived” group included 287 children who underwent surgery in the perinatal period and survived 28 days. The study groups were comparable in terms of the indications for surgical treatment, which were conditionally divided into three groups (Table 1):

 

Table 1. The structure of indications for surgical intervention in the study groups

Таблица 1. Структура показаний к хирургическому вмешательству в исследуемых группах

Indicator / Показатель	Deceased / Погибшие (n = 77)	Survived / Выжившие (n = 287)	Statistical significance / Статистическая значимость
Congenital malformations / Врожденные пороки развития	61 (79.2%)	238 (82.9%)	χ2 = 0.67, р = 0.416
of which were diagnosed prenatally / из них диагностированы пренатально	40 (65.6%)	215 (90.3%)	χ2 = 24.75, р = 0.000
Conditions arising in the neonatal period / Состояния, возникшие в период новорожденности	13 (17.1%)	48 (16.7%)	χ2 = 0.05, р = 0.823
Metabolic disorders / Нарушения обмена веществ	3 (3.7%)	1 (0.4%)	χ2 = 1.67, р = 0.190

 

CMs: This included disorders occurring during the neonatal period (hemodynamically significant persistence of fetal communications, pneumothorax, and need for surgical treatment of necrotizing enterocolitis) [27].

Congenital and acquired metabolic disorders: The main indications for surgical treatment in both groups were CMs (Table 2). The percentage of CMs detected prenatally was statistically significantly lower in the main group than in the control group, which became one of the risk factors for infant death in the first month of life, despite surgical interventions. This can be associated with the transfer of newborns to a specialized hospital, need for treatment, etc.

 

Table 2. The share of congenital malformations of various organs and systems diagnosed in children of the studied groups

Таблица 2. Удельный вес врожденных пороков развития различных органов и систем, диагностированных у детей исследуемых групп

Indicator / Показатель	Deceased / Погибшие (n = 77)	Survived / Выжившие (n = 287)	Statistical significance / Статистическая значимость
Сongenital malformations сardio-vascular system / Пороки развития сердечно-сосудистой системы	36 (59.0%)	40 (16.8%)	χ2 = 46.22, р = 0.000
Сongenital malformations сentral nervous system /Пороки развития центральной нервной системы	–	57 (24.0%)	–
Сongenital malformations пastrointestinal tract / Пороки развития желудочно-кишечного тракта	1 (1.6%)	51 (21.4%)	χ2 = 22.24, р = 0.000
Diaphragmatic hernia / Диафрагмальная грыжа	2 (3.3%)	25 (10.5%)	χ2 = 3.03, р = 0.08
Neoplasms / Новообразования	1 (1.64%)	22 (9.2%)	χ2 = 5.22, р = 0.022
Multiple malformations / Множественные пороки развития	20 (32.8%)	6 (2.5%)	χ2 = 56.53, р = 0.000
Number of operations (max–min) / Количество операций (max–min)	2.065 ± 1.681 (1–11)	1.692 ± 1.144 (1–7)	p = 0.024

 

Among the CMs of the gastrointestinal tract, duodenal atresia was registered in the main group, and atresia of the esophagus, duodenum, large and small intestines, and anus was diagnosed in the control group. Cardiovascular defects were represented by congenital heart defects, coarctation of the aorta, and aneurysm of the vein of Galen in both study groups. The neoplasm group included pathological formations of various localizations (abdominal cavity, chest cavity, small pelvis, cranial cavity, external localization, and including teratoma). In the main group, surgical treatment of hemangioma was performed, and in the control group, surgical treatment of sacrococcygeal teratomas, ovary formations, femoral and parietal regions, face, abdominal cavity, cranial cavity, and the retroperitoneal space. No surgical interventions for CMs of the central nervous system were performed in the main group. In the control group, hydrocephalus, rachischisis (myelocele, meningomyelocele, and meningomyeloradiculocele), cranioschisis (occipital meningocele, encephalocele, encephalomeningocele, and craniovertebral meningocele), Arnold–Chiari syndrome, and subependymal cyst of the cerebral ventricle were registered. The number of surgeries during the first 7 days of life was statistically significantly higher in the main group than in the control group.

Thus, multiple CMs and CMs of the cardiovascular system were diagnosed statistically significantly more often in the main group, while all other groups of CMs were diagnosed more often in the control group.

STUDY RESULTS

The sex ratios in the main and control groups (boys/girls) were 57/43% and 60/40%, respectively, and the difference was statistically insignificant (p = 0.604). No statistically significant differences were noted in the age and social status of mothers in the main and control groups, that is, they were comparable according to these indicators (Table 3).

 

Table 3. Social status of mothers of newborns of the studied groups

Таблица 3. Социальный статус матерей новорожденных исследуемых групп

Indicator / Показатель	Deceased / Погибшие (n = 77)	Survived / Выжившие (n = 287)	Statistical significance / Статистическая значимость
Registered marriage / Зарегистрированный брак	62 (80.5%)	247 (86.1%)	χ2 = 0.14, р = 0.86
Оfficial place of work/ Официальное место работы	51 (66.2%)	179 (62.4%)	χ2 = 0.54, р = 0.46
The level of education / Уровень образования
·             initial / начальное ·             average / среднее ·             high / высшее	6 (7.8%) 31 (40.3%) 40 (51.9%)	8 (2.8%) 183 (63.8%) 96 (33.4%)	χ2 = 4.75, р = 0.09
Pregnancy record / Учет по беременности	76 (98.7%)	283 (98.6%)	χ2 = 0.07, р = 0.92
Mother’s age, years (max–min) / Возраст матери, лет (max–min)	30.76 ± 5.866 (17–41)	29.85 ± 5.769 (16–53)	р = 0.255

 

The distribution of mothers by blood groups I, II, III, and IV was not statistically significantly different, with 34.2%, 39.5%, 18.6%, and 7.6% and 37.5%, 34.4%, 25%, and 3.1%% in the main and control groups, respectively. The ratio of mothers with a negative Rh factor in both groups was almost equal to 14 (18.2%) and 54 (18.8%), which was statistically not significant.

Chronic nicotine intoxication, hypertension, arterial hypertension, and chronic serum hepatitis B and C were noted statistically significantly more often in mothers of deceased newborns (Table 4). Urinary system pathologies in the main and control groups included CMs (polycystic kidney disease and kidney duplication), urolithiasis and cystitis and were statistically significantly more often detected in the deceased group, whereas no statistically significant differences were found in the frequency of chronic pyelonephritis in the study groups. In both groups, liver and gastrointestinal tract diseases included liver steatosis, cholelithiasis, calculous cholecystitis, chronic gastritis, and duodenal ulcer, and no statistically significant differences were noted. In the study groups, thrombocytopenia and thrombocytopathy, vision pathologies (mild to severe myopia and retinal angiopathy), varicose veins, chronic tonsillitis, respiratory system pathologies (chronic pharyngitis and bronchitis, bronchial asthma, and injuries in history), anemia, grade 1 and 2 obesity, injuries (fractures of the pelvis, coccyx, and long tubular bones, knee ligament rupture, closed craniocerebral injury, and cerebral concussion), skin diseases (vitiligo, psoriasis, atypical dermatitis, and neurodermatitis), hypercoagulability, hereditary thrombophilia, antiphospholipid syndrome, and diabetes mellitus were registered with equal frequency, and no statistically significant differences were noted.

 

Table 4. Somatic morbidity of mothers of newborns of the studied groups

Таблица 4. Соматическая заболеваемость матерей новорожденных исследуемых групп

Indicator / Показатель	Deceased / Погибшие (n = 77)	Survived / Выжившие (n = 287)	Statistical significance / Статистическая значимость
Chronic nicotine intoxication / Хроническая никотиновая интоксикация	9 (11.7%)	7 (2.4%)	χ2 = 6.25, р = 0.016
Essential hypertension and arterial hypertension / Гипертоническая болезнь и артериальная гипертензия	13 (16.9%)	19 (6.6%)	χ2 = 4.52, р = 0.033
Chronic serum hepatitis B and C / Хронические сывороточные гепатиты В и С	7 (9.1%)	7 (0.7%)	χ2 = 7.04, р = 0.010
Chronic pyelonephritis/ Хронический пиелонефрит	10 (13.0%)	21 (6.5%)	χ2 = 1.56, р = 0.211
Pathology of the urinary system / Патология мочевыводящей системы	14 (18.2%)	2 (0.7%)	χ2 = 5.85, р = 0.016
Pathology of the gastrointestinal tract and liver / Патология желудочно-кишечного тракта и печени	18 (23.4%)	42 (13.0%)	χ2 = 2.83, р = 0.092
Chronic tonsillitis / Хронический тонзиллит	5 (6.5%)	16 (5.6%)	χ2 = 0.05, р = 0.816
Pathology of the respiratory system / Патология дыхательной системы	3 (3.9%)	7 (2.4%)	χ2 = 0.11, р = 0.745
Injuries / Перенесенные травмы	5 (6.5%)	4 (1.4%)	χ2 = 2.91, р = 0.088
Varicose disease / Варикозная болезнь	5 (6.5%)	33 (11.5%)	χ2 = 1.08, р = 0.284
Vision pathology / Патология зрения	14 (18.2%)	33 (11.5%)	χ2 = 1.48, р = 0.223
Anemia / Анемия	1 (1.3%)	2 (0.70%)	χ2 = 0.25, р = 0.621
Obesity / Ожирение
·             first degree / первой степени	4 (5.2%)	7 (2.4%)	χ2 = 0.92, р = 0.646
·             second degree / второй степени	3 (3.9%)	7 (2.4%)
Pathology of the thyroid gland / Патология щитовидной железы	16 (20.8%)	21 (7.7%)	χ2 = 7.59, р = 0.007
Diabetes mellitus / Сахарный диабет	–	1 (0.4%)	–
Hypercoagulation, APS, hereditary thrombophilia / Гиперкоагуляция, антифосфолипидный синдром, наследственная тромбофилия	3 (3.9%)	7 (2.4%)	χ2 = 0.11, р = 0.745
Тhrombocytopenia, thrombocytopenia / Тромбоцитопения, тромбоцитопатия	3 (3.9%)	7 (2.4%)	χ2 = 0.75, р = 0.387
Skin diseases / Заболевания кожи	3 (3.9%)	4 (1.4%)	χ2 = 0.52, р = 0.482

 

Thus, the mothers of deceased newborns statistically significantly more often had chronic nicotine intoxication, urinary system and thyroid gland pathologies, and chronic serum hepatitis B and C.

Uterine fibroids, infertility (primary and secondary), congenital malformations of the genitals, endometriosis, ovarian tumors, chronic inflammation of pelvic organs (salpingoophoritis and endometritis), chronic urogenital infection (ureaplasmosis and chlamydia), menstrual disorders, and surgical treatment of gynecological diseases were detected in the study groups with equal frequency. Cervical ectropion and chronic inflammation of lower genital tract organs (vaginitis and bacterial vaginosis) were statistically significantly more common in mothers of deceased newborns (Table 5).

 

Table 5. Gynecological morbidity of mothers of newborns of the studied groups

Таблица 5. Гинекологическая заболеваемость матерей новорожденных исследуемых групп

Indicator / Показатель	Deceased / Погибшие (n = 77)	Survived / Выжившие (n = 287)	Statistical significance / Статистическая значимость
Uterine fibroids / Миома матки	3 (3.9%)	7 (2.4%)	χ2 = 0.09, р = 0.771
Primary infertility / Бесплодие первичное	3 (3.9%)	21 (7.7%)	χ2 = 1.72, р = 0.199
Secondary infertility / Бесплодие вторичное	4 (5.2%)	13 (4.5%)	χ2 = 0.01, р = 0.973
Congenital malformations of the genitals / Врожденные пороки развития полового аппарата	1 (1.3%)	–	–
Menstrual irregularities / Нарушения менструального цикла	3 (3.9%)	–	–
Еndometriosis / Эндометриоз	1 (1.3%)	–	–
Оvaran tumors / Опухоли яичника	1 (1.3%)	–	–
Chronic inflammatory of the pelvic organs / Хронический воспалительный процесс органов малого таза	5 (6.5%)	4 (1.4%)	χ2 = 2.81, р = 0.094
Chronic inflammation of the organs of the lower floor of the genital tract / Хроническое воспаление органов нижнего этажа полового тракта	8 (10.4%)	4 (1.4%)	χ2 = 8.22, р = 0.005
Ectopia of the cervix / Эктопия шейки матки	8 (10.4%)	2 (0.7%)	χ2 = 10.48, р = 0.001
Ureaplasmosis / Уреаплазмоз	5 (6.5%)	–	–
Chlamydial infection / Хламидиоз	3 (3.9%)	–	–
Transferred operations / Операции в анамнезе	3 (3.9%)	–	–

 

The number of pregnancies and childbirths, history of miscarriages, missed miscarriages, and ectopic pregnancies, abortions in primiparas, preterm births, and perinatal losses in the study groups were registered equally frequently. Two or more abortions in multiparous women, history of placental insufficiency in a previous pregnancy, and previous delivery by cesarean section were statistically significantly more common in mothers of deceased newborns (Table 6).

 

Table 6. Features of the obstetric anamnesis of mothers of newborns of the studied groups

Таблица 6. Особенности акушерского анамнеза матерей новорожденных исследуемых групп

Indicator / Показатель	Deceased / Погибшие (n = 77)	Survived / Выжившие (n = 287)	Statistical significance / Статистическая значимость
Pregnancy by account (max–min) / Беременность по счету	2.747 ± 2.075 (1–11)	2.389 ± 1.56 (1–9)	р = 0.109
Childbirth by account (max–min) / Роды по счету	1.845 ± 1.023 (1–6)	1.789 ± 0.946 (1–5)	р = 0.662
Miscarriagess / Выкидыши, замершие беременности	7 (9.1 %)	30 (10.5 %)	χ2 = 9.67, р = 0.085
Miscarriages (number) / Выкидыши, замершие беременности (количество)	0.239 ± 0.917	0.122 ± 0.388	р = 0.101
A history of abortion in a nulliparous / Аборт в анамнезе у первородящей	3 (3.9%)	12 (4.2%)	χ2 = 0.00, р = 0.978
Two or more abortions in a multiparous / Два и более абортов у повторнородящей	14 (18.2%)	18 (6.3%)	χ2 = 8.37, р = 0.004
Placental insufficiency / Плацентарная недостаточность	2 (2.6%)	–	–
Ectopic pregnancy / Эктопическая беременность	1 (1.3%)	8 (2.5%)	χ2 = 0.34, р = 0.558
Caesarean section / Кесарево сечение	6 (7.8%)	5 (1.7%)	χ2 = 5.62, р = 0.017
Рreterm birth / Преждевременные роды	2 (2.6%)	9 (3.1%)	χ2 = 0.03, р = 0.860
Рerinatal losses / Перинатальные потери	1 (1.3%)	–	–

 

Pregnancy as a result of assisted reproductive technologies, namely, in vitro fertilization and intracytoplasmic sperm injection, infectious lesions of the genital tract caused by Trichomonas vaginalis and Chlamydia trachomatis, mycoplasma and ureaplasma infections, presence of opportunistic microflora in the cervical canal, gestational diabetes mellitus, moderate and severe preeclampsia, cholestatic hepatosis, thrombocytopenia, isthmic–cervical insufficiency (including its correction with the installation of an obstetric unloading pessary), placenta previa, premature detachment of a normally located placenta were noted with an equal frequency in the study groups. Threatened abortion (both single, double, and multiple), acute respiratory viral infections during pregnancy, exacerbations of chronic infectious diseases, inflammatory diseases of the lower genital tract, early toxicosis, carriage of Cytomegalovirus and Herpes simplex types 1 and 2, asymptomatic bacteriuria, and anemia of pregnancy were registered statistically significantly more often in mothers of deceased newborns (Table 7).

 

Table 7. Features of the course of pregnancy in the study groups

Таблица 7. Особенности течения беременности в исследуемых группах

Indicator / Показатель	Deceased / Погибшие (n = 77)	Survived / Выжившие (n = 287)	Statistical significance / Статистическая значимость
Pregnancy as a result of ART / Беременность в результате вспомогательных репродуктивных технологий
·             IVF / экстракорпоральное оплодотворение	10 (13.0%)	38 (13.2%)	χ2 = 0.01, р = 0.914
·             ICSI / интрацитоплазматическая инъекция сперматозоида	–	4 (1.4 %)	–
Early toxicosis / Ранний токсикоз	4 (5.2%)	–	–
Inflammatory diseases of the lower genital tract / Воспалительные заболевания нижнего отдела полового тракта	16 (20.8%)	5 (1.8%)	χ2 = 18.51, р = 0.000
Trichomoniasis / Трихомониаз	1 (1.3%)	–	–
Chlamydia trachomatis	1 (1.3%)	–	–
Cytomegalovirus	7 (9.1%)	–	–
Herpes simplex 1, 2	3 (3.9%)	–	–
Mycoplasma / Ureaplasma	3 (3.9%)	–	–
Genital opportunistic microflora / Условно-патогенная микрофлора	3 (3.9%)	–	–
Threat of abortion / Угроза прерывания беременности
·             single / однократная	12 (15.6%)	4 (1.4%)	χ2 = 45.87, р = 0.000
·             double / двукратная	6 (7.8%)	2 (0.7%)	χ2 = 20.50, р = 0.000
·             multiple / многократная	8 (10.4%)	–	–
Gestational diabetes mellitus / Гестационный сахарный диабет	10 (13.0%)	15 (5.2%)	χ2 = 3.46, р = 0.068
Истмико-цервикальная недостаточность / Isthmic-cervical insufficiency	2 (2.6%)	12 (4.2%)	χ2 = 0.26, р = 0.611
Obstetric unloading pessary / Акушерский разгружающий пессарий	1 (1.3%)	2 (0.7%)	χ2 = 0.13, р = 0.72
Moderate preeclampsia / Умеренная преэклампсия	3 (3.9%)	28 (9.8%)	χ2 = 2.71, р = 0.174
Severe preeclampsia / Тяжелая преэклампсия	7 (9.1%)	10 (3.5%)	χ2 = 2.23, р = 0.142
Сholestatic hepatosis / Холестатический гепатоз	4 (5.2%)	2 (0.7%)	χ2 = 3.95, р = 0.05
Thrombocytopenia / Тромбоцитопения	1 (1.3%)	–	–
SARS during pregnancy / Острая респираторная вирусная инфекция во время беременности	16 (20.8%)	3 (1.1%)	χ2 = 25.39, р = 0.000
Exacerbations of chronic infections / Обострения хронических инфекций	7 (9.1%)	2 (0.7%)	χ2 = 7.19, р = 0.007
Asymptomatic bacteriuria / Бессимптомная бактериурия	4 (5.2%)	–	–
Рlacenta previa / Предлежание плаценты	7 (9.1%)	15 (5.2%)	χ2 = 0.83, р = 0.370
Рremature detachment of a normally located placenta /Преждевременная отслойка нормально расположенной плаценты	9 (11.7%)	24 (8.4%)	χ2 = 0.42, р = 0.522
Anemia in pregnancy / Анемия беременных
·             mild degree / легкой степени	17 (22.1%)	11 (3.8%)	χ2 = 28.42, р = 0.000
·             medium degree / средней степени	1 (1.3%)	–	–

 

Ultrasound data during pregnancy were analyzed. Diagnosed pathological conditions and structural aspects of the placenta are presented in Table 8.

 

Table 8. Ultrasound data in the study groups

Таблица 8. Данные ультразвукового исследования в группах

Indicator / Показатель	Deceased / Погибшие (n = 77)	Survived / Выжившие (n = 287)	Statistical significance / Статистическая значимость
Increased NT / Увеличение толщины воротникового пространства	1 (1.3%)	–	–
Chronic placental insufficiency / Хроническая плацентарная недостаточность	11 (14.3%)	–	–
Circulatory failure / Недостаточность кровообращения	7 (9.1%)	2 (0.7%)	χ2 = 18.06, р = 0.002
Fetal hypotrophy / Гипотрофия плода	9 (11.7%)	2 (0.7%)	χ2 = 20.86, р = 0.000
Polyhydramnios / Многоводие	11 (14.3%)	17 (5.9%)	χ2 = 4.55, р = 0.033
Оligohydramnios / Маловодие	5 (6.5%)	4 (1.4%)	χ2 = 4.29, р = 0.038
The only artery of the umbilical cord / Единственная артерия пуповины	1 (1.3%)	2 (0.7%)	χ2 = 0.25, р = 0.628
Immune and non-immune fetal edema / Иммунный и неиммунный отек плода	–	2 (0.7%)	–

 

The rates of increased thickness of the collar space, a single umbilical artery, and prenatally diagnosed fetal edema were not statistically significantly different. In the deceased group, the pathological conditions of the placental complex, namely, chronic placental insufficiency, circulatory failure (stages IA and B, II, and III), fetal hypotrophy, oligohydramnios, and polyhydramnios, were diagnosed statistically significantly more often.

As regards the characteristics of delivery (Table 9), the duration of stages 1, 2, and 3 of labor, frequency of amniotomy, and perineotomy were not statistically significant different in the groups. In the group of deceased newborns, vaginal delivery was statistically significantly more common. Operative vaginal delivery was not used in the study groups.

 

Table 9. Features of delivery in the studied groups

Таблица 9. Особенности родоразрешения в исследуемых группах

Indicator / Показатель	Deceased / Погибшие (n = 77)	Survived / Выжившие (n = 287)	Statistical significance / Статистическая значимость
Duration of the first stage of labor, minutes / Длительность первого периода родов, мин	295.250 ± 178.103	333.000 ± 137.264	р = 0.308
Duration of the second stage of labor, minutes / Длительность второго периода родов, мин	14.611 ± 13.342	12.986 ± 8.227	р = 0.514
Duration of the third stage of labor, minutes / Длительность третьего периода родов, мин	9.375 ± 3.096	10.274 ± 3.216	р = 0.311
Caesarean section, including / Кесарево сечение, в том числе	39 (50.7%)	211 (73.5%)	χ2 = 14.76, р = 0.000
·             emergency / экстренное	29 (74.4%)	140 (66.4%)	χ2 = 2.03, р = 0.152
·             planned / плановое	10 (25.6%)	71 (33.6%)	χ2 = 4.26, р = 0.119
Perineotomy / Перинеотомия	4 (5.2%)	14 (4.9%)	χ2 = 0.01, р = 0.909
Amniotomy / Амниотомия	2 (2.6%)	2 (0.7%)	χ2 = 1.64, р = 0.200
Manual examination of the uterine cavity / Ручное обследование полости матки	–	9 (3.1%)	–
The duration of the waterless period / Длительность безводного промежутка	292.650 ± 277.343	1409.638 ± 5616950	р = 0.377
Delivery with whole amniotic sac / Родоразрешение с целым плодным пузырем	30 (39.0%)	127 (44.3%)	χ2 = 0.84, р = 0.658
Amniotic fluid is light / Околоплодные воды светлые	56 (72.7%)	272 (94.8%)	χ2 = 23.57, р = 0.000
Meconium staining of amniotic fluid / Мекониальная окраска околоплодных вод	6 (7.8%)	11 (3.8%)	χ2 = 6.19, р = 0.013
Intrauterine fetal hypoxia / Внутриутробная гипоксия плода	6 (7.8%)	30 (10.5%)	χ2 = 0.49, р = 0.487
Breech presentation / Тазовое предлежание	5 (6.5%)	3 (1.1%)	χ2 = 6.56, р = 0.010
Transverse position of the fetus / Поперечное положение плода	1 (1.3%)	–	χ2 = 3.12, р = 0.078

 

Amniotic fluid discharges were analyzed. The duration from rupture to delivery and childbirth with a whole fetal bladder was not statistically significantly different. In the survived group, the normal color of the amniotic fluid was statistically significantly more common, whereas meconium-stained and blood-tinged amniotic fluid were statistically significantly more common in the main group. Moreover, the diagnosis of intrauterine fetal hypoxia during childbirth was established in the study groups with approximately equal frequency, and no statistically significant differences were detected. In the deceased group, deliveries were statistically significantly more frequent with breech presentation.

No statistically significant differences in the gestational age, weight and height of newborns, and weight and height of full-term newborns were noted. The 1-min and 5-min Apgar scores were statistically significantly lower in the deceased group (Table 10).

 

Table 10. Massometric indicators and Apgar score in children of the studied groups at birth

Таблица 10. Массометрические показатели и оценка по шкале Апгар у детей исследуемых групп при рождении

Indicator / Показатель	Deceased / Погибшие (n = 77)	Survived / Выжившие (n = 287)	Statistical significance / Статистическая значимость
Pregnancy duration, weeks (max–min) / Срок беременности, недель (max–min)	35.442 ± 5.310 (23–40)	36.582 ± 5.194 (22–40)	р = 0.436
Weight of newborns, g (max–min) / Масса новорожденных, г (max–min)	2516.04 ± 1019.99 (400–4460)	2684.82 ± 1015.99 (400–5740)	р = 0.200
Weight of full-term newborns, g (max–min)/ Масса доношенных новорожденных, г (max–min)	3085.57 ± 599.20 (1870–4460)	3221.36 ± 548.62 (1880–5740)	р = 0.147
Height of newborns, cm (max–min) / Рост новорожденных, см (max–min)	45.686 ± 7.482 (23–56)	46.739 ± 7.267 (24–57)	р = 0.200
Growth of full-term newborns, cm (max–min) / Рост доношенных новорожденных, см (max–min)	49.897 ± 3.235 (43–56)	50.616 ± 2.575 (42–57)	р = 0.132
Apgar score at 1st minute (max–min) / Оценка по шкале Апгар на 1-й минуте (max–min)	5.471 ± 2.452 (1–8)	6.515 ± 2.092 (2–9)	р = 0.000
Apgar score at 5th minutes (max–min) / Оценка по шкале Апгар на 5-й минуте (max–min)	6.618 ± 2.130 (1–8)	7.695 ± 1.848 (2–9)	р = 0.000

 

In the analysis of the histological structure of the placenta, stage 3 ascending infection and chlamydial choriodeciduitis were statistically significantly more common in the deceased group. Meanwhile, hematogenous infection (mycoplasma, herpetic, and RNA-viral) and placental insufficiency, both chronic and acute, were not statistically significant different between the groups (Table 11).

 

Table 11. Features of the structure of the placenta of newborns of the studied groups

Таблица 11. Особенности строения последа новорожденных исследуемых групп

Indicator / Показатель	Deceased / Погибшие (n = 77)	Survived / Выжившие (n = 287)	Statistical significance / Статистическая значимость
Ascending infection / Восходящее инфицирование
·             the first stage / первой стадии	11 (14.3%)	82 (28.6%)	χ2 = 5.51, р = 0.018
·             the second stage / второй стадии	11 (14.3%)	21 (7.3%)	χ2 = 2.85, р = 0.267
·             the third stage / третьей стадии	12 (15.6%)	16 (5.7%)	χ2 = 6.71, р = 0.010
Chlamydial choriodeciduitis/ Хламидийный хориодецидуит	12 (15.6%)	11 (3.8%)	χ2 = 11.47, р=0.001
Mycoplasma choriodeciduitis / Микоплазменный хориодецидуит	21 (27.3%)	108 (37.6%)	χ2 = 2.01, р = 0.156
RNA viral choriodeciditis / РНК-вирусный хориодецидуит	17 (22.1%)	90 (31.4%)	χ2 = 2.09, р = 0.149
Herpetic choriodeciditis / Герпетический хориодецидуит	42 (54.5%)	165 (57.5%)	χ2 = 0.12, р = 0.723
Hematogenous infection, unspecified / Гематогенное инфицирование	1 (1.3%)	5 (1.7%)	χ2 = 0.01, р = 0.914
TORCH infection / TORCH-инфекция	1 (1.3%)	2 (0.7%)	χ2 = 0.62, р = 0.429
Total hematogenous infection / Всего гематогенное инфицирование	52 (67.5%)	216 (75.3%)	χ2 = 1.91, р = 0.591
Chronic placental insufficiency / Хроническая плацентарная недостаточность
·             compensated / компенсированная	25 (32.5%)	161 (56.1%)	χ2 = 4.15, р = 0.041
·             subcompensated / субкомпенсированная	32 (41.6%)	75 (26.1%)	χ2 = 4.54, р = 0.033
·             decompensated / декомпенсированная	1 (1.3%)	1 (0.4%)	χ2 = 1.35, р = 0.246
Acute placental insufficiency / Острая плацентарная недостаточность	2 (2.6%)	12 (4.3%)	χ2 = 0.68, р = 0.410

 

Thus, the unfavorable prognostic risk factors for neonatal death after surgery performed in the early neonatal period are as follows:

• Multiple CMs and congenital heart diseases in the child
• Lack of prenatal diagnosis of the malformation
• Chronic nicotine intoxication, hypertension and arterial hypertension, chronic serum hepatitis B and C, urinary system and thyroid gland pathologies, cervical ectropion, chronic inflammation of the lower genital tract organs (vaginitis and bacterial vaginosis), two or more abortions in multiparous women, history of placental insufficiency in a previous pregnancy, previous delivery by cesarean section
• Threatened abortion (both single, double, and multiple), acute respiratory viral infections during pregnancy, exacerbations of chronic infectious diseases, inflammatory diseases of the lower genital tract, early toxicosis, carriage of Cytomegalovirus and Herpes simplex types 1 and 2, asymptomatic bacteriuria, and anemia in the current pregnancy
• Circulatory inefficiency, small-for-gestational-age fetus, abnormal amniotic fluid volume diagnosed by ultrasound in the third trimester of pregnancy
• Breech presentation of the fetus and meconium staining of amniotic fluid
• Stage 3 ascending infection of the placenta and chlamydial choriodeciduitis

DISCUSSION OF RESULTS

Modern surgery in the early neonatal period has undergone significant changes in recent years. Thanks to the development of prenatal diagnostics, most CMs can now be detected even before birth. According to Appendix No. 1 of the Order of the Ministry of Health of the Russian Federation No. 1130n ², “If, according to the conclusion of a case conference, surgical correction of fetal malformations in the neonatal period is possible, pregnant women are referred for delivery to obstetric hospitals that have departments (wards) of resuscitation and intensive care for newborns and the possibility of providing medical care in Pediatric Surgery.” A similar procedure for providing medical care in prenatal diagnostics of CMs allows for performing timely surgical treatment to reduce postoperative losses.

A few studies are investigating risk factors for neonatal death after surgeries performed in the first days after birth. In the literature, congenital heart defects are one of the main causes of death of children after surgeries performed in the early neonatal period [2, 3, 5, 39, 40], which is consistent with the data obtained in this study. According to the literature, the main fields of the search for measures to reduce postoperative mortality can be the development of methods of surgical interventions [2, 3, 35, 39, 42, 44], improvement of anesthesia [12], clarification of indications, contraindications, and schemes for the use of pharmacological drugs [33, 43], and development of care methods for newborns [25, 26, 31, 37, 47] in the postoperative period [17].

It was not possible to find studies investigating studying microbial damage to the organs and systems of the newborn, condition of the placenta, and postoperative outcomes; however, an association between postoperative complications and levels of markers of the systemic inflammatory response (thrombocytopenia, C-reactive protein, and procalcitonin) was reported [23, 28, 30]. The factors that increase the risk of postoperative complications in the neonatal period include gestational anemia [26, 33], arterial hypertension [46], chronic placental insufficiency, circulatory failure according to dopplerometry [28], and low Apgar scores at birth [25], which is consistent with the data obtained in the study.

Many authors have indicated factors in increasing postoperative mortality such as low gestational age and low birthweight [23, 30, 36, 41, 48]; however, the data obtained in our work are consistent with the opposite opinion, where no statistically significant differences in gestational age and birthweight were registered [7].

Studies have noted the need for improving the complicated course of the neonatal period, which may require surgical interventions (necrotizing ulcerative colitis and spontaneous intestinal perforation) [11, 38, 41, 48]. Moreover, one of the risk factors is chorioamnionitis during childbirth [36]. Some authors have indicated the presence of certain pathogenic microflora in children who underwent surgical interventions in the neonatal period, without specifying their role in the development of complications or lethal outcomes [15].

CONCLUSIONS AND PRACTICAL RECOMMENDATIONS

The results of this study on risk factors for postoperative mortality of newborns, who underwent surgical treatment within the first 7 days of extrauterine life, such as chronic inflammation of lower genital tract organs (vaginitis and bacterial vaginosis), exacerbations of chronic infectious diseases, asymptomatic bacteriuria, and stage 3 ascending infection of the placenta, indicate a significant role of bacterial infection. In pregnant women with prenatally diagnosed fetal CMs, bacteriological studies and an emergency histological examination of the placenta must be performed to identify possible microbial lesions, as well as timely examination and treatment of newborns with an upcoming surgery or after it.

ADDITIONAL INFORMATION

Author contribution. Thereby, all authors made a substantial contribution to the conception of the study, acquisition, analysis, interpretation of data for the work, drafting and revising the article, final approval of the version to be published and agree to be accountable for all aspects of the study.

Competing interests. The authors declare that they have no competing interests.

Funding source. This study was not supported by any external sources of funding.

About the authors

Vitaly F. Bezhenar

Academician I.P. Pavlov First St. Petersburg State Medical University

Email: lida.ivanova@gmail.com

MD, PhD, Dr. Sci. (Med.), Professor, Director of the Department of Obstetrics, Gynecology and Reproductology

Russian Federation, Saint Petersburg

Lidiia A. Ivanova

Kirov Military Medical Academy

Author for correspondence.
Email: lida.ivanova@gmail.com

MD, PhD, Associate Professor, Department of Obstetrics and Gynecology

Russian Federation, Saint Petersburg

Dmitry O. Ivanov

Saint Petersburg State Pediatric Medical University, Perinatal Сenter

Email: doivanov@yandex.ru

MD, PhD, Dr. Sci. (Med.), Professor, Chief Freelance Neonatologist of the Ministry of Health of Russia, Rector, Head of the Department of Neonatology with courses of Neurology and Obstetrics and Gynecology

Russian Federation, Saint Petersburg

Olga L. Krasnogorskaya

Saint Petersburg State Pediatric Medical University, Perinatal Сenter

Email: krasnogorskaya@yandex.ru

MD, PhD, Associate Professor, Head of the Department of Pathological Anatomy at the rate of Forensic Medicine

Russian Federation, Saint Petersburg

References

Supplementary files