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UDC 618.333-091
INTRANATAL FETAL DEATH IN TERM DELIVERY: CLINICAL AND PATHOMORPHOLOGICAL CORRELATIONS
Altai State Medical University, Barnaul
Altai regional children's clinical hospital, Barnaul
Altai regional clinical perinatal center "DAR", Barnaul
O.V. Remneva, A.Ye. Chernova, Yu.N. Nesterov, T.V. Burakova
Cases of death of a full-term fetus in term deliveries require in-depth analysis, since they are most often associated with an underestimation of the degree of obstetric risk of the mother and the choice of irrational tactics for labor management. Risk factors for intranatal death of a full-term fetus in term deliveries in Altai Krai were identified in this study: the patients were multipara women of different professions, with epilepsy and syphilis prevailing in the structure of the somatic pathology. Pregnancy of women who had full-term intranatal losses is complicated by the threat of interruption at a later date, preeclampsia, anemia, gestational pyelonephritis, delayed fetal growth, which indicates the presence of chronic secondary placental insufficiency, often an infectious genesis, confirmed by histological investigation of the placenta. The course of urgent labor in women with intranatal losses is complicated by the weakness of labor, progressive intranatal distress of the fetus, which determines the fatal outcome for the newborn. The intranatal death of a full-term fetus is due to preventable causes - asphyxia in childbirth and / or its combination with intrauterine infection. Key words: causes of intranatal mortality, full fetus, risk factors.
According to the Russian Federal State Statistics Service, since 2006, there has been marked positive dynamics of basic demographic parameters in the Russian Federation. However, Altai Krai refers to the number of regions with negative natural increase [1]. Due to the reduction of the region's reproductive potential connected with the demographic crisis of 1990s, the problem of perinatal losses remains topical [2]. In spite of the transition to new criteria of life birth, during the recent 10 years the rate of perinatal death in the region is considered stable (2006 - 9,5 promille, 2016 -9,6 promille) due to the obstetrics and neonatal services [3]. Nevertheless, in Altai Krai since 2009 there has been registered the increase of the perinatal death rate over the average Russian value. The overwhelming majority of perinatal death cases in the region traditionally accounts for early neonatal and antenatal losses. The rate of intranatal losses in the structure of perinatal death is always minimal (2016 - 7,9%, absolute index - 22 cases).
However, cases of death of a full-term fetus in term deliveries require in-depth analysis, since they are most often associated with an underestimation of the degree of obstetric risk of the mother and the choice of irrational tactics for labor management [4]. Supposedly, an obvious solvation of problem of death of a full-term fetus in term deliveries is the elimination of its preventable causes by means of compulsory monitoring of the fetal state, but two review of Cochrane Collaboration in 2013 and 2015 proved that the routine use of fetal cardiotocography (CTG) in antenatal and intranatal periods does not improve the perinatal outcome, but only contributes to the growth of number of caesarean sections and instrumental
deliveries [5, 6]. All existing methods of antenatal observation (CTG, sonography) does not possess prognostic potential in terms of various gestational complications, as they are quite informative but not specific, and allow to register only hypox-ia and academia of the fetus preventing the fetal outcome conditioned by only these reasons [7, 8]. For this very reason, in the conditions of limited possibilities of means of diagnosis of fetal state, it is necessary to reveal the basic causes of full-term fetus death, to form the risk groups among women bearing intranatal losses specific for the given region aimed at a thorough fetal monitoring in these groups, to eliminate the controlled reasons of full-term fetus death and conduct a differentiated preconception preparation.
Research objective: to reveal the risk factors and basic causes of full-term fetus death.
Tasks: to study clinical anamnestic features of women having perinatal losses; to analyze the informational value of paraclinic methods of diagnosis of the fetal state shortly before and in the process of term labor; pathomorphological evaluation of fetuses and afterbirths.
Subject of research: cases of intranatal death of full-term fetus in districts of Altai Krai.
Materials and methods
There was performed a clinic-statistical analysis of medical documentation on 252 cases "mother - full-term newborn" for the period of 2006-2015 in cities and districts of Altai Krai which were divided into two groups. The main group included 52 women at the age from 17 to 40 years whose term delivery resulted in the death of full-term fetus. The control group was formed by the lottery meth-
od and included 200 women at the age from 17 to 40 who had given birth to alive full-term newborns. In the compared groups there was performed a clinic-statistical analysis of age, social status, somatic, obstetrics and gynecological anamnesis, peculiarities of pregnancy course, delivery, functional characteristic of the fetoplacental complex by the third ultrasound screening, data of cardiotocography during labor, pathomorphological characteristics of the fetus and afterbirth. The statistical significance was confirmed by the analysis of fourfold tables using Pearson's chi-square test %2.
The study took into consideration: labor and delivery medical record (form №096/u), individual medical history (form №111/u), exchange notifying record (form №113/u), protocols of afterbirth histological characteristics and post-mortem examination of the fetus (form №013-1/u).
Results and discussion
The average age of women in the main group constituted 26,7±5,7 years, in the control group -25,2±4,8 years (p>0,05). The analysis pf social status showed that patients of the main group had working occupations (34,6%) and significantly rarer were clerks (19,2%) in relation to women of the control group (12,5% and 55,0% respectively; p<0,05). The somatic anamnesis is significantly more aggravated in women of the main group in terms of frequency of organic brain disease - epilepsy (8,0%) and chronic specific infections including syphilis (21,0%) than in patients of the control group (0,5% an 1,5% of cases respectively; p<0,05). The frequency of detection of cardio-vascular pathology (45,0%) and urinary system diseases (19,0%) in both groups did not differ significantly (p>0,05). The majority of women of the main group were multiparous with aggravated obstetric anamnesis (AOA) (50,0%), while the control group was
significantly prevailed by primigravida women (38,5%) and multiparous patients with AOA were registered in 31,0% of cases (p<0,05).
There were revealed no differences of the features of obstetric anamnesis in the compared groups (p>0,05). It should be noted, that patients with intranatal losses (61,5%) turned out to be gynecological healthy more often that patients of the control group (44,4%, p<0,05). The evaluation of pregnancy course revealed that in women of the main group pregnancy was rarer complicated by threatened miscarriage at early stages (25,0%) and more often - during the whole 2nd-3rd trimester (50,0%) in relation to the control group (62,5% and 15.0% respectively; p<0,05). Preeclampsia developed only in women who had suffered intranatal losses (1,9%). Moreover, anemia of pregnancy, being one of the leading factors aggravating the severity of placental insufficiency, was observed in every second woman with fetal death in term delivery, while in the control group, it was diagnosed in every fifth case (21,0%) [9].
During pregnancy, patients of the main group had a significantly higher total infectious index than the women who had given birth to alive full-term newborns. Thus, infectious complications of pregnancy in the main group were registered in 59,6% cases against 35,0% in the control group (p<0,05). The leading infectious disease manifesting itself during pregnancy having ended in the death of the fetus in delivery was gestational pyelonephritis (17,3%). In the control group the manifestation of pyelonephritis accounted for only 4,0% of pregnancies (p<0,05). The echoscopic characteristic of the fetoplacental complex in the 3rd trimester showed that the significant marker of placental insufficiency - intrauterine growth restriction (IGR) - was revealed only in women who had lost the fetus in term delivery (7,7%) (Figure 1) [10].
Figure 1.
Echoscopic characteristic of the fetoplacental complex in patients with intranatal losses by the 3rd ultrasound screening (%)
Horizontal axis: CD 1A, 1B, 2 - circulatory deficiency 1A, 1B, 2 degree; IGR - intrauterine growth restriction; no marker of FPI - no
markers of fetoplacental insufficiency.
Vertical axis: percentage (%).
Columns: blue - main group; red - control group.
*p<0,05 - confidence interval of error probability.
There were revealed no significant differences in the frequency of circulatory deficiency (CD) of the fetoplacental complex among the pa-
tients of compared groups: CD 1A were revealed in the main and control groups in 19% of cases, CD 1B - 5,8% in the main and 2,5% in the control
group, CD 2 - only in the control group in 1,5% of cases (0,05). In women of the main group hy-dramnios was observed significantly rarer than in the control group (13,5% and 31,0% respectively; p<0,05). Generally, echoscopic markers of placen-tal insufficiency lacked in patients having intranatal losses (11,5%) significantly higher in relation to women who had given birth to alive full-term children (29,5%; p<0,05). All women of the main group had obstructed labour. Poor uterine contraction strength was registered significantly more often in women of the main group (62,9%) compared to women of the control group (14,5%; p<0,05).
Only in women having intranatal losses there was registered umbilical cord prolapse (11,5%; p<0,05). Only by intranatal losses in every fifth case (21,1%) there was diagnosed expressed disorder
accompanied by meconium coloring of amniotic fluid in every third woman in labor (30,8%) which in 7,7% of cases lead to the necessity of assisted vaginal delivery - vacuum extraction of the fetus. Me-conium coloring of amniotic fluid in women who had given birth to alive full-term newborns was observed significantly rarer - in every tenth case (12,0%; p<0,05). By the analysis of intranatal CTG decompensated (21,1%) and compensated disorders (44,2%) of cardio-vascular activity of the fetus were registered significantly more often in fetuses of the main group in relation to fetuses of the control group where disorders of cardio-vascular activity of the fetus had only compensated character (7,5% of cases; p<0,05) (Figure 2).
Results of the pathomorphological fetal autopsy are shown in Figure 3.
of the heart rhythm of the fetus according to CTG
100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%
7.5*
21,1*
44,2*
92,5*
34,6*
<6
points
■ 6-7
points
■ 8-10
points
*p<0,05
Main group
ConLrol group
Figure 2.
Frequency of disorders of the intrauterine state of the fetus according to intranatal cardiotachography in points
according to Fisher's scale (%)
Columns: №1 - main group; №2 - control group. Vertical axis - percentage (%).
Green - <6 points according to Fisher's scale; red - 6-7 points according to Fisher's scale; blue - 8-10 points according to Fisher's scale.
*p<0,05 - confidence interval of error probability.
Figure 3.
Basic reasons of the intranatal fetal death according to the pathomorphological study (%)
Blue - asphyxia; red - asphyxia + intrauterine infection; green - intrauterine infection + intrauterine development
disorder; purple - intrauterine infection.
The figure demonstrates that in the overwhelming majority of cases intranatal losses were determined by fetal asphyxia in labor (69,2%), including cases in combination with intrauterine infection (IUI) (19,2%). In every tenth case, pathologists considered IUI as the main cause of death and in 2% of cases - combination of IUI with fetal congeni-
for asphyxia in more than 70% of cases was pla-cental insufficiency (PI), both isolated acute (7,0%) and its combination with chronic (40,0%) and inflammatory afterbirth changes (34,0%). The results of the histological examination of afterbirths showed histological markers of placental insufficiency in all afterbirths of the main group (Figures
tal anomalies (FCA). The morphological ground
4, 5).
11,5* 3,8* ^^ 19,2* ■ CPI3 ■ CPI2
M 34,6 21,1 CPI 2 + API ■ CPU
7,7* y 13,4 13,4* CPI 1 + API *p<0,05
Figure 4.
Histological examination of afterbirths in women of the main group (%) CPI 1,2,3 - chronic placental insufficiency compensated, subcompensated, decompensated. CPI 2 + API - acute placental insufficiency in combination with chronic subcompensated placental insufficiency. CPI 1 + API - acute placental insufficiency in combination with chronic compensated placental insufficiency. *p<0,05 - confidence interval of error probability.
Figure 5.
Histological examination of afterbirths in women of the control group (%) CPI 1,2,3 - chronic placental insufficiency compensated, subcompensated, decompensated. CPI 2 + API - acute placental insufficiency in combination with chronic subcompensated placental insufficiency.
Chronic decompensated placental insufficiency (CPI 3) was revealed only in patients of the main group in 3,8% of cases, subcompensated (CPI 2) -in 19,2% of cases in the main group and in 5,0% in the control group (p<0,05). Acute placental insufficiency (API) (7,0%), its combination with chronic compensated (CPI 1) (13,4%) and subcompensat-ed forms (21,1%) was observed only in women of the main group. Cases of thrombosis of umbilical vessels were registered only by intranatal loses (11,5%, p<0,05).
Conclusion
The preformed clinic-statistical study in Altai Krai revealed that intranatal death of a full-term fetus is more often observed in multiparous women of working occupations whose structure of somatic pathology is significantly dominated by epilepsy and chronic specific infections, particularly, syphilis. The pregnancy of women with full-term intranatal losses is aggravated by threatened miscarriage at late stages, preeclampsia, anemia, gesta-tional pyelonephritis, delayed fetal growth, which indicates the presence of chronic secondary placen-tal insufficiency, often an infectious genesis, confirmed by histological investigation of the placenta.
The course of urgent labor in women with intranatal losses is complicated by the weakness of labor, progressive intranatal distress of the fetus, which determines the fatal outcome for the newborn. The intranatal death of a full-term fetus is due to preventable causes - asphyxia in childbirth and / or its combination with intrauterine infection.
Thus, in 2/3 of cases, the intranatal fetal death in term delivery (of asphyxia) is considered preventable from obstetric point by the choice of sustainable tactics of labor management on the background of hardware monitoring of the fetal state. The majority of risk factors connected with unfavorable perinatal outcome are also modified (somatic pathology, occupational hazards). The issues of prevention of perinatal losses due to intrauter-ine infection non-verified by the etiological factor are still unsolved, which presents further scientific concern.
References
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Contacts:
Corresponding author - Remneva Olga Vasilyev-na, Doctor of Medical Sciences, Professor, Head of the Department of obstetrics and gynecology with the course of further vocational education of Altai State Medical University, Barnaul. 656019, Barnaul, Popova Ulitsa, 29. Tel.: (3852) 542360. Email: [email protected]
