RU2605809C1 - Method of prediction of perinatal foetal death - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to obstetrics and gynecology, and can be used for prediction of perinatal foetal death. At registration of pregnancy in women prognostic criteria are determined: education, age of sexual debut in years, presence of hypertensive and/or arterial hypertension in past medical history, registered marriage, presence of obesity according to body weight index more than 25.0, menarche age in years, smoking, presence of official place of work, presence of genital pathology infectious miscarriage in past medical history, impending parturition by count. Prognostic features are measured in points. LDF1 and LDF2 coefficients are calculated by formulas. If LDF1 > LDF2, high risk of perinatal foetal death is prognosed. If LDF2 > LDF1 low risk of perinatal foetal death is prognosed.

EFFECT: method enables accurate prediction of perinatal foetal death by integrated assessment of most optimal parameters.

1 cl, 4 tbl, 2 ex

Description

The invention relates to medicine, in particular to the field of obstetrics and gynecology, and can be used to predict perinatal fetal death.

Over the past 20 years, the Russian Federation exists in conditions of depopulation and a constant increase in the incidence rate among all age groups of the population. In this situation, preserving the health of newborns is not only a medical problem and a priority task of social policy, but is also considered as a factor of national security (Arkhangelsky V.N. et al., 2004; Velichkovsky B.T., 2001; Rimashevskaya N.M., 2002; Baranov A.A. et al., 2005; Sukhanova L.P., 2006; Sharapova O.V., Tsybulskaya I.S., 2000). Thus, protecting the health of mothers and children is the most important task of the state, since it determines the future of the nation, which was confirmed in the Concept of the Demographic Policy of the Russian Federation until 2025, the National Priority Project “Health” (Volodin NN, 2009; Starodubov V.I., 2009; Sukhanova L.P., 2010; Frolova O.G., 2010; Shirokova V.I., 2011). Speaking about the health of the child, it is necessary to remember that it is determined by the course of the perinatal period, which determines the potential of his health for the rest of his life (Tsybulskaya IS, 1999). It is perinatal pathology that causes most childhood diseases and almost all childhood disabilities (Frolova O.G., Chumakova O.V., Baybarina E.N., 2008; Lisitsyn Yu.P., 2009; Shabalov N.P., 2009; Baranov A.A., Albitsky V.Yu., 2010; Sukhanova L.P., 2006). Accordingly, the most urgent task of the obstetrician-gynecologist today is to provide optimal conditions for pregnancy and delivery for the formation of a healthy generation (Kulakov V.I., 2007; Lineva O.I., 2007; Serov V.N., 2008; Sidorova I. .S., 2009; Savelyeva G.M., 2010; Strizhakov A.N., 2010; Sukhikh G.T., 2010; Czeizel A.E., 2005). In the literature, the issue of the causes, structure, and methods for predicting perinatal death of a fetus has been raised many times, however, there are practically no systematized data, especially recently. The perinatal period (as defined by WHO) begins at 22 weeks of gestation (with a fetal weight of 500 g and a length of 25 cm) and ends at the end of 7 days of fetal life (168 hours). Two fundamentally different approaches to this problem are found in the literature: some authors consider perinatal losses, emphasizing the unity of the etiology and pathogenesis of death of the fetus and newborn regardless of the time of his death, while other authors divide perinatal losses into antenatal, intranatal and postnatal, taking into account different etiologies and pathogenesis of these processes.

Perinatal mortality is one of the most important objective criteria for the work of the obstetric service at all stages of care, and in conditions of antenatal care, and at the stage of antenatal care, and in the obstetric hospital, including emergency care. The indicator also characterizes the work of the entire health care system, taking into account the large number of extragenital pathologies in pregnant women, as well as the social situation in society. The indicator of perinatal fetal death also characterizes the pediatric service, including the possibility of nursing deeply premature babies. Accordingly, for many years there has been a study and comparison of statistical indicators of perinatal death, as well as the constant identification of its causes. When analyzing the literature, one also has to take into account the fact that in most studies the number of observations is small from 30 to 50, respectively, it is difficult to talk about any serious statistical conclusions (Gusak Yu.K., Chikin V.G., 2005; Kurtser M .A., 2010; Sorokina Z.Kh., 2006).

That is why the first task posed in the analysis of the literature was precisely the assessment of the statistical laws of the dynamics of perinatal losses, their causes and associated conditions. In the 90s in Russia, the intensity of childbearing sharply decreased, while reproductive losses increased during all periods of pregnancy and in the first year of life of newborns (Sukhanova L.P., Kuznetsova T.V., 2010). Moreover, when comparing the birth rate with the level of perinatal and infant mortality (as well as with the level of maternal mortality), a negative correlation was revealed, that is, the lower the birth rate, the higher the level of perinatal, infant and maternal mortality.

However, in 2010-2020. another fertility decline is planned in connection with the entry into the reproductive age of the “generation of the 90s” - girls born after 1991, just in the period of declining birth rates. The demographic crisis, however, may not come, as in recent years the contribution to the procreation of women of the older age group has been increasing. Unfortunately, in this case, it is possible to predict a slight increase in perinatal losses due to the increased frequency of somatic, gynecological and obstetric pathologies in these women (Rusanova N.E., 2007).

From tables 1 and 2 it can be seen that the perinatal mortality rate over the past 10 years is constantly decreasing, while the decrease is mainly due to early neonatal mortality (it decreased by almost 3 times during this time), while the decrease in antenatal death is much less significant - less than 30%. Such dynamics characterizes, mainly, the improvement of the quality of inpatient obstetric and pediatric care - the improvement of the quality of delivery, the provision of resuscitation benefits to newborns, including premature babies with low and extremely low body weight. The fact is that since the creation of domestic perinatology, its main goal was to reduce reproductive losses, and the tasks were to organize pediatric resuscitation services, round-the-clock vigil of neonatologists in all maternity hospitals, the presence of pediatricians at all births, the creation of a staged system for nursing premature infants, including with extremely low body weight, etc. (Sotnikova K.A. et al., 1971; Barashnev Yu.I., 1989; Savelyeva G.M., 1989; Baranov A.A., 1990). Numerous studies, publications, and scientific conferences have been devoted to these problems (Ignatieva R.K., 1973; Muchiev G.S., Frolova O.G., 1979; Antonov A.G. et al., 1983; Behrman RE, 1987; Fanaroff A.A., Graven SN, 1987). A similar approach yielded results, and, accordingly, early neonatal mortality decreased significantly. A number of authors associate such dynamics with an increase in the number of delivery by cesarean section (Sukhanova L.P., Kuznetsova T.V., 2010). However, other authors (WHO Recommendations, 1985, Deneux-Tharaux C, 2006, NIH Conference, 2006, MacDorman MF, 2008), believe that an increase in the rate of operative delivery of more than 10% is impractical and worsens.

Different authors give slightly different percentage data on the proportion of antenatal death (from 48.3 to 77.9%) in the structure of perinatal mortality, depending on the region and the level of medical care in hospitals of various levels (Gusak Yu.K., Chikin V .G., Novikova A.V., 2001; Sukhanova L.P., Kuznetsova T.V., 2010; Sorokina Z.Kh., 2006: Nadzharyan I.G., 2004). The relative increase in antenatal fetal death is also associated with untimely diagnosis of fetal hypoxia, especially in obstetric hospitals, where fetal death most often occurs (Sukhanova L.P., Sklyar M.S. 2007). There is also an opinion (Zhdanova V.Yu., Trubnikova L.I., 2009; Kravtsova L.A., 2010), mainly antenatal fetal death occurs in socially disadvantaged pregnant women. One of the mechanisms for the development of antenatal fetal death, especially occurring suddenly, is called the development of life-threatening arrhythmias (Kravtsova L.A., 2010), although arrhythmia is most likely just a symptom of heart damage, in particular the rhythmogenic zone, with viral myocarditis. This symptom can appear in the terminal stage, and its identification does not help prevent the antenatal death of the fetus. In the report on the main indicators of the obstetric and gynecological services (Frolova Z.Z., Tokova Z.Z., 2005), released in 2005, all the main causes of death of fetuses and newborns were highlighted. In the future, almost all authors compare their results with these data, using the separation given in the report. The main causes of perinatal death according to different authors are shown in table 3.

In the same report, it was decided to determine the relationship of perinatal death of the fetus / newborn with the condition of the mother. A system of terms was developed: “non-pregnancy conditions” (these included cardiovascular diseases, metabolic diseases, etc.), “pregnancy complications” (gestosis; hematological conflict), “complications of the placenta, umbilical cord and fetal membranes "," complications of childbirth and delivery "; "harmful effects transmitted through the placenta or breast milk." It was noted that in about a quarter of cases, the reasons on the part of the mother could not be established.

The main causes of perinatal death by the mother according to different authors are shown in table 4.

All authors come to a common opinion (Talalaev A.G., Samsygina G.A., 1992; Sukhanova L.P., Kuznetsova T.V., 2010) that such a high rate of undetermined maternal causes can speak of two possible problems: firstly, the lack of an objective analysis of each specific case; secondly, about the extremely low level of obstetric care when a child dies for an apparently healthy woman in childbirth for no apparent reason (Talalaev A.G., Samsygina G.A., 1992).

In his report Frolova O.G. and Tokova Z.Z. (2005) also proposed to classify all perinatal losses according to preventability into 4 groups:

1) unavoidable - caused by factors whose action cannot be eliminated (incompatible with life-threatening diseases and genetic diseases, fulminant infections, etc.);

2) conditionally preventable - due to reasons whose consequences are difficult to eliminate, but possible;

3) preventable - caused by factors whose action could and should have been eliminated (all cases of medical errors and negligence);

4) losses with an unexplained cause - if the cause of death is not clear and it is impossible to determine the degree of preventability.

That is, most perinatal losses are preventable, unavoidable losses should be predictable and the outcome of pregnancy should not be a surprise either for a woman or for doctors.

When analyzing antenatal fetal death, researchers set themselves various goals. The main goal is to analyze the causes of this complication in women with prenatal fetal death.

These studies can identify gaps in a particular institution, district, city, etc. and give general recommendations (Suvorova G.S., 2007, Baimuradova S.M., 2007; Zinchenko I.V., 2007). Other authors raise the possibility of timely diagnosis of critical conditions of the fetus with emergency surgical delivery (Arzhanova, O.N. et al., 2006; Piazze J. et al., 2005), or the use of surgical delivery to all patients with diagnosed hypotrophy to reduce perinatal mortality (Vania et al., 2005). These authors regard delivery in the presence of a critical condition of the fetus as a method of reducing the level of antenatal death of the fetus, develop methods for diagnosing these conditions, criteria for "failure of treatment", indications for emergency cesarean section (Evseeva Z.P., 2009). However, conducting an operative delivery according to indications from the fetus, especially in a critical condition, is often a contentious issue. Firstly, it is possible to reduce the frequency of antenatal fetal death by increasing early neonatal mortality - the baby will die anyway, but already in utero. Secondly, conducting surgical delivery, we create a risk of complications associated with cesarean section and worsen the state of health of a woman before subsequent delivery. Thirdly, by developing any criteria and making any tactical decisions, it is almost impossible to talk about their real role in improving statistical indicators, since in this case it is impossible to conduct control studies - we all act as part of job descriptions. That is, it is easy to postulate a specific tactic leading to excellent results, but it is impossible to prove that it is precisely this that allows the fetal death of the fetus to be reduced to zero, or at least seriously reduced.

A factor contributing to the development of complications is the age of the pregnant woman, and especially the primiparous woman. It is generally accepted that the most favorable age for childbearing is 20-24 years. Data from recent years disprove this postulate: the least number of complications, including the lowest percentage of perinatal losses, occur at the age of 25-29 years (0.1%), then the age groups 20-24 (1.25%) and 30- 34 years (1.29%), 35-39 years (2%), and the greatest losses in patients of the older age group 40 years and older (3%) (Sukhanova L.P., 2006).

The risk of perinatal losses is increased in women with occupational hazards, in particular working with harmful and toxic substances (44.6%), this group is more likely to have early neonatal death and a low Apgar score of 0–2 for newborns (Najaryan I. .G., 2004). A number of researchers note that perinatal losses are provoked by an unfavorable situation in the family: the absence of a registered marriage, divorce, and loneliness of the expectant mother. Data are provided that only 50% of women with perinatal loss of a child are registered in a registered marriage, another 21.1% have an unfavorable psychological microclimate in the family (Kostyuchek D.F., 2003). Also, adverse living conditions (among 14.4%) are attributed to risk factors for perinatal losses (Nadzharyan I.G., 2004), although this indicator is assessed both by objective estimates and by the subjective feeling of a woman, therefore it is often difficult to determine true state of things.

It has been established that bad habits (smoking, alcoholism, drug use) are registered in more than half of women with perinatal losses (Nadzharyan I.G., 2004). The majority of pregnant women (56.7%) who subsequently lost their children in the perinatal period did not register well in the antenatal clinic and / or visited the obstetrician-gynecologist irregularly (Kostyuchek D.F., 2003).

Of the diseases of the mother that are not associated with pregnancy, the largest role in the development of various complications, including antenatal death of the fetus, is assigned to diseases of the cardiovascular system (Dobrovolskaya IV, 2011). This is due, on the one hand, to the high prevalence of this pathology among women of childbearing age on average in the population (40.4%) (Shalnova S.A., 2006). The prevalence of hypertension (GB) in the population of pregnant women is also high and reaches 4-9% (Shekhtman M.M., 2005; Bartosh L.F., 2007; Strizhakov A.N., 2009). On the other hand, it is against the background of diseases of the cardiovascular system that the frequency of such pregnancy complications as gestosis sharply increases (from 36% to 86%) (Demchenko E.Yu., 1996; Timokhina TF, 2003; Shekhtman M.M. ., 2005; Makatsaria A.D., 2010; Dobrovolskaya I.V., 2011). Such a significant spread in the frequency of gestosis is explained by different interpretations of the hypertensive conditions in a pregnant woman in various studies, the difficulty of differential diagnosis and the overdiagnosis of combined gestosis (Bartosh L.F., 2007). Also, diseases of CVS, in particular AH, in 45% -85% lead to the development of PN (Strizhakov A.N. et al., 2009; Dobrovolskaya I.V., 2011).

Another factor provoking a large number of pregnancy complications and, as a consequence, placental insufficiency, is anemia. The frequency of anemia in the pregnant population reaches 41.7% and is, among other things, a socially significant pathology. The cause of anemia is not only a lack of iron associated with its increased consumption by the fetus, but also a background (before pregnancy) inadequate nutrition of the mother, which is typical for women from low-income groups. That is why the WHO takes into account precisely the anemia of pregnant women as a criterion for the social well-being of society and a marker of the quality of life of the population (Sukhanova L.P., 2006). During pregnancy, anemia causes a complex of hypoxic disorders in the body of the mother and fetus, provokes the development of placental insufficiency with all its complications. In addition, the constant existence of the fetus under conditions of anemia during the entire prenatal period leads to the formation of severe lesions of all the organs of the child, including the central nervous system, which is further manifested by hypoxic genesis encephalopathy and severe anemia in children of the first year of life due to inhibited erythropoiesis (Yu. I. Barashnev, 2001; Shcheplyagina L.A., 2002; Shankaran S., Bauer CP., Bain R et al., 1996; Baranov A.A., Shcheplyagina L.A., 2000).

Other extragenital diseases also increase the risk of perinatal fetal death. So, in this group of patients revealed diseases of the endocrine system (10.3%), respiratory diseases (70.3%), digestive diseases (26.6%), including chronic gastritis (6.1%), chronic cholecystitis (5.3%), diseases of the urinary system (22.2%), including chronic pyelonephritis (18.4%), cystitis (2.5%), ICD (1.3%). Of the infectious diseases, a special role is given to a history of childhood infections (chickenpox - 78.7%, measles - 11.4%, mumps - 14.5%), as well as syphilis (8.6%) and candidiasis (4% ), speaking of their pronounced effect on perinatal mortality (Nadzharyan I.G., 2004). Indeed, when comparing literature data with data on the incidence rate of the adult population of the Russian Federation in 2010 (Incidence rate of the Russian population in 2010, Statistical Materials, 2011), all these diseases are much more common among the aforementioned women than among the Russian population.

The authors also note in women with perinatal losses, increased gynecological morbidity, namely: chronic inflammatory diseases (15.6%), uterine malformations (1.3%), infertility (31.2%); as well as features of sexual behavior, such as the early onset of sexual activity (in 47%), premarital sexual activity (62%). The most common infections of the genital tract were candidiasis (26.2%), mycoplasmosis (21.3%), chlamydia (21.3%), syphilis (19.3%), trichomoniasis (9.7%) (Kostyuchek D. F., 2004).

However, in most sources, a comparison of the incidence of mothers with perinatal losses was carried out with the incidence of the adult population according to the Ministry of Health and Social Development of the Russian Federation. This is not a completely correct comparison, since the incidence of pregnant women is very often indicated on the exchange card from the patient’s words, it is not always confirmed by the conclusion of a specialist doctor, past history of the disease is indicated as existing, etc. Accordingly, it is more correct to compare the incidence for all of the above pathologies with a group of women in the same region who gave birth to live children.

When analyzing the reproductive history of this group, it was noted that the greatest risk of perinatal losses is observed in the first and fourth and subsequent births. Of the complications of pregnancy, vulvovaginitis (65.1%), chronic fetoplacental insufficiency (58.9%), bacteriuria (32.5%), preeclampsia (31.1%), acute placental insufficiency (22.6%) were most common. multiple pregnancy (3.1%) (Nadzharyan I.G., 2004). When analyzing these data, it is necessary to take into account that, for example, acute placental insufficiency (premature detachment of a normally located placenta) is not a factor contributing to perinatal fetal death, but its immediate cause, that is, the prognostic role of this pathology is obvious. On the other hand, the diagnosis of chronic placental insufficiency is often made in the obstetric institution, where the pregnant woman comes with antenatal fetal death, regardless of whether this diagnosis was made before or not. The diagnosis of chronic placental insufficiency is convenient because it does not require histological verification before the pregnant woman is discharged from the hospital, it allows the woman to explain the cause of her baby’s death, and to reduce the number of complaints from the patient and her relatives. A similar situation can be with pre-eclampsia. In the Statistical Materials of the Russian Health Service (Incidence of the Russian population in 2010, Statistical Materials, 2011), all conditions associated with gestosis are divided into two categories: arterial hypertension, edema, proteinuria and preeclampsia, eclampsia. In patients with perinatal losses in the obstetric institution, most often there is an overdiagnosis of all conditions associated with pregnancy, respectively, any pathological condition, such as edema or hypertension, is immediately regarded as preeclampsia. The frequency of hypertension, edema and proteinuria during pregnancy, childbirth and the postpartum period in St. Petersburg is 54.7%, preeclampsia and eclampsia 12.5%.

Thus, all of the above etiological and provoking factors lead to the same pathogenetic mechanisms: the formation of pathology from the mother, placenta or fetus, the development of complications, up to antenatal death. Moreover, different authors indicate different etiological and provoking factors, which gives the impression that any pathology is the cause of perinatal losses (Serov V.N., 2002; Afanasyeva N.V., Strizhakov A.N., 2004; Ailamazyan, 2002 ; Semennikov M.V., 2007).

The purpose of the invention: the development of a more accurate model for predicting perinatal fetal death during a complete examination of pregnant women based on the minimum, but a sufficient number of the simplest and most always investigated symptoms and clinical and laboratory indicators that do not require highly qualified medical personnel and high-tech instrumental research methods.

The solution to this problem is ensured by the fact that prediction of perinatal fetal death becomes possible when registering for pregnancy. The method is based on determining a woman's prognostic signs: education (X1), age of sexual debut in years (X2), history of hypertension and / or arterial hypertension (X3), officially registered marriage (X4), obesity according to body mass index (BMI) more than 25.0 (X5), menarche age in years (X6), smoking (X7), the presence of an official place of work (X8), the presence of a genital pathology of any localization of the infectious origin in the anamnesis (X9), upcoming births in a row ( X10); assess prognostic signs in points: X1 as “1 point” in primary education, “2” - average, “3” - higher, X3-X5, X7-X9 as “1 point” in the presence, “0” - in the absence , then calculate the coefficients of LDF1 and LDF2 by the formulas:

LDF1 = 8.579 * X1 + 4.347 * X2 + 2.67 * X3 + 3.875 * X4 + 2.282 * X5 + 7.409 * X6 + 5.858 * X7 + 0.134 * X8 + 0.93 * X9 + 1.688 * X10-101.56,

LDF2 = 11.716 * X1 + 4.666 * X2 + 1.024 * X3 + 4.621 * X4 + 1.625 * X5 + 7.166 * X6 + 4.909 * X7-0.772 * X8 + 1.473 * X9 + 1.359 * X10-110.807,

and with LDF1> LDF2, a high risk of perinatal fetal death is predicted; with LDF2> LDF1, a low risk of perinatal fetal death is predicted.

The formulas were obtained as a result of studying exchange cards, childbirth histories and newborn histories of 634 patients. Various predictive factors were evaluated in order to identify the most significant of them for subsequent inclusion in the model for predicting perinatal fetal death. And also based on this, develop a model of this function.

The listed criteria are part of the mathematical-statistical method of discriminant analysis in medical practice (Discriminant Analysis) of the Statistica - 7 application package.

We have developed a model for predicting perinatal fetal death during maternity check-ups in antenatal clinics (usually in the first trimester of pregnancy). A discriminant analysis was chosen as the mathematical modeling apparatus, the main purpose of which is to identify predictors that significantly affect the classification of a particular pregnant woman as one of the groups: perinatal fetal death or a favorable perinatal outcome, as well as the calculation of the coefficient of linear discriminant function for these signs with the aim of subsequent differential diagnosis for a specific patient.

To solve the problem of model development, the method of step-by-step selection of the most prognostically significant signs with a reliability level of at least 95% (p <0.05) was chosen.

Statistically significant (p <0.001) models for predicting perinatal fetal death were performed at two levels: predicted perinatal fetal death (LDF1) and predicted favorable outcome of labor (LDF 2) when registering for pregnancy.

To solve the problem of differential diagnosis and prognosis of perinatal death, the values of signs included in the model obtained during the examination of a specific pregnant woman were substituted into the LDF formulas and the equations were solved.

The method is implemented as follows. When registering for pregnancy on the basis of education, the age of sexual debut, the presence of arterial hypertension, registered marriage, the age of menarche, the presence of obesity, smoking, an official job, the genital pathology of infectious genesis and parity of labor, these signs make it possible to determine a linearly discriminant function (LDF) according to the formulas:

LDF1 = 8.579 * X1 + 4.347 * X2 + 2.67 * X3 + 3.875 * X4 + 2.282 * X5 + 7.409 * X6 + 5.858 * X7 + 0.134 * X8 + 0.93 * X9 + 1.688 * X10-101.56,

LDF2 = 11.716 * X1 + 4.666 * X2 + 1.024 * X3 + 4.621 * X4 + 1.625 * X5 + 7.166 * X6 + 4.909 * X7-0.772 * X8 + 1.473 * X9 + 1.359 * X10-110.807,

Where

X1 Education X2 Sexual debut age X3 Arterial hypertension X4 Registered Marriage X5 Obesity X6 Age of menarche X7 Smoking X8 Official place of work X9 Genital pathology of infectious genesis X10 Delivery Parity

and with LDF ₁ > LDF ₂ in pregnant women, a high risk of perinatal fetal death is considered;

with LDF ₂ > LDF ₁ , a pregnant woman believes a low risk of perinatal fetal death.

Upon admission to the antenatal clinic, the proposed model ensures that the perinatal death of the fetus coincides with the real result in 80.1% of cases. In the group of pregnant women with favorable outcomes, the coincidence of the predicted diagnosis with real results was 84.78%. In all pregnant women, the predicted diagnosis coincided with real results in 82.4%.

We give examples of practical implementation.

Pregnant A., 25 years old, got registered for pregnancy in the period of 5 weeks in February 2010 in the antenatal clinic of the city of Vyborg. Secondary education, has a permanent job, profession - worker. The marriage is not registered. Past diseases: colds, childhood infections, hepatitis A in childhood. Of the bad habits, smoking is noted. Allergic history is not burdened, there was no blood transfusion, trauma, surgery, blood contact infections, sexually transmitted diseases, tuberculosis, mental illness denies. Heredity is not burdened. The father of the child (according to the pregnant woman) is healthy.

Gynecological history: menstruation from 16 years old, established within 2 years, 6 days, after 24 days, regular, moderate, painless. Sex life from 17 years out of wedlock. Gynecological diseases denied. The first pregnancy.

On examination, the height is 164 cm, weight 57.4 kg, BMI 21.3 (normal). The size of the pelvis is 25-28-34-21 cm (within normal limits). Somatic and gynecological examination of the pathology was not revealed.

When registering, the diagnosis is: Pregnancy 5 weeks. Chronic nicotine intoxication.

This pregnant woman had such important prognostic signs as the late onset of menarche, early sexual debut, secondary education, smoking, and the absence of a registered marriage.

To determine the severity, we solve the problems using the LDF formulas: we substitute the values of the signs included in the model obtained during examination of a particular pregnant woman, and we solve the equations:

LDF1 = 8.579 * 2 + 4.347 * 17 + 2.67 * 0 + 3.875 * 0 + 2.282 * 0 + 7.409 * 16 + 5.858 * 1 + 0.134 * 1 + 0.93 * 0 + 1.688 * 1-101.56 = 200.11,

LDF2 = 11.716 * 2 + 4.676 * 17 + 1.024 * 0 + 4.621 * 0 + 1.625 * 0 + 7.166 * 16 + 4.909 * 1-0.772 * 1 + 1.473 * 0 + 1.359 * 1-110.807 = 199.64.

From the differential problem, we see that LDF1> LDF2, which means that a pregnant woman has a high risk of perinatal fetal death.

Thus, we assign this pregnant woman to a risk group for perinatal fetal death. In this pregnant woman, the predicted outcome coincided with the real one. The patient was discharged after childbirth with a diagnosis of “Delivery 1 urgent. HCV carrier. Chronic nicotine intoxication. Decompensated placental insufficiency. Antenatal fetal death. "

Pregnant B., 28 years old, got registered for pregnancy in the period of 5 weeks in the antenatal clinic of the city of St. Petersburg. Higher education, has a permanent job, no occupational hazards. Marriage registered first. Past diseases: colds, repeated pneumonia, once - urethritis, polyvalent allergy. Denies bad habits. There was no blood transfusion, trauma, surgery, blood contact infections, sexually transmitted diseases, tuberculosis, mental illness denied. Heredity is not burdened. The father of the child (according to the pregnant woman) is healthy.

Gynecological history: menstruation from 12 years old, established within 2 years, 6 days, after 27 days, regular, moderate, painless. Sex life since 18 years in marriage. Gynecological diseases: ectopia of the cervix (not treated), chlamydia and ureaplasmosis (sanitized before pregnancy). The first pregnancy.

On examination, the height of 161 cm, weight 62.8 kg, BMI 29.47 (obesity). The size of the pelvis is 26-29-34-21 cm (within normal limits). On somatic examination, pathology was not detected. A gynecological examination confirmed the diagnosis of cervical ectopy.

When registering, the diagnosis is: Pregnancy 5 weeks. Polyvalent allergy. Ectopia of the cervix.

This pregnant woman had such important prognostic signs as the presence of genital pathology of infectious genesis (ectopy of the cervix) and obesity.

To determine the severity, we solve the problem: according to the LDF formulas, we substitute the values of the signs included in the model obtained during examination of a particular pregnant woman, and we solve the equations:

LDF1 = 8.579 * 3 + 4.347 * 18 + 2.67 * 0 + 3.875 * 1 + 2.282 * 1 + 7.409 * 12 + 5.858 * 0 + 0.134 * 1 + 0.93 * 0 + 1.688 * 1-101.56 = 176.05,

LDF2 = 11.716 * 3 + 4.676 * 18 + 1.024 * 0 + 4.621 * 1 + 1.6251 * 1 + 7.166 * 12 + 4.909 * 0-0.772 * 1 + 1.473 * 1 + 1.359 * 1-110.807 = 178.46.

From the differential problem, we see that LDF2> LDF1, which means that we expect a pregnant woman to have a low risk of perinatal fetal death.

Thus, we assign this pregnant woman to a low risk group for perinatal fetal death. In this pregnant woman, the predicted outcome coincided with the real one. The patient was discharged after childbirth with a diagnosis of “Delivery 1 urgent. Large fruit. "

Thus, the discriminant model for predicting perinatal fetal death is performed when taking maternity clinics. The model is based on a small (no more than 15) number of signs that are easy to obtain when analyzing complaints, medical history, pregnancy and standard diagnostic methods, while it has a fairly high information ability (74.6% -82.8%) and is statistically significant (p <0.001).

The formulas were obtained as a result of a retrospective study of all the documentation relating to the course of pregnancy, childbirth and the postpartum period, as well as the protocols of the study of the placenta and autopsy of the fetus / newborn in 664 pregnant women. Various predictive factors were evaluated in order to identify the most significant of them for subsequent inclusion in the model for predicting perinatal fetal death. And also based on these data, a model of this function has been developed.

The listed criteria are part of the mathematical-statistical method of discriminant analysis in medical practice (Discriminant Analysis) of the Statistica - 7 application package.

The following symptoms were selected as predictive factors: level of education, age of menarche and sexual debut, presence of arterial hypertension, registered marriage, obesity of any degree, official job, genital pathology of infectious genesis, smoking.

The most significant signs were: level of education (p <0,000), age of onset of sexual activity (p <0,000), presence of hypertension and arterial hypertension (p <0,01), permanent work (p <0,01), term for setting dispensary registration for pregnancy (p <0,000), the beginning of dispensary registration for pregnancy up to 12 weeks (p <0,000), negative Rh factor (p <0,01), blood contact infections (p <0,000), impaired carbohydrate metabolism (p < 0,000), inflammatory diseases of the genital tract (p <0,000), trichomoniasis (p <0,000), cytomegalovirus infection (p <0,01), conditionally pathogenic microflora according to the microbiological study of the cervical canal (p <0,000), congenital malformations of the fetus (p <0,000), exacerbation of chronic infections (p <0,000), threatened abortion (p <0,000), gestosis (p <0,000), full-term pregnancy (p <0,000), the minimum level of pregnant hemoglobin (p <0,000), toxic lesions (p <0,01), the level of red blood cells of the newborn (p <0,000), histological structure of the placenta (normal structure, ascending infection, hematogenous viral infection, decompensated chronic placental failure) (p <0.000), breech (p <0.000), newborn glucose level (p <0.000). The method is based on signs, the analysis of which is already possible when taking a pregnant woman to the dispensary.

To solve the problem of model development, the method of step-by-step selection of the most prognostically significant signs with a reliability level of at least 95% (p <0.05) was chosen.

A statistically significant (p <0.001) model for predicting perinatal fetal death at two levels:

- high risk of perinatal fetal death (LDF1):

LDF1 when registering for pregnancy = 8.579 * X1 + 4.347 * X2 + 2.67 * X3 + 3.875 * X4 + 2.282 * X5 + 7.409 * X6 + 5.858 * X7 + 0.134 * X8 + 0.93 * X9 + 1.688 * X10-101.56,

- low risk of perinatal fetal death (LDF2):

LDF2 when registering for pregnancy = 11.716 * X1 + 4.666 * X2 + 1.024 * X3 + 4.621 * X4 + 1.625 * X5 + 7.166 * X6 + 4.909 * X7-0.772 * X8 + 1.473 * X9 + 1.359 * X10-110.807.

To solve the problem of differential diagnostics and prognosis of perinatal fetal death, the values of the signs included in the model obtained during the examination of a particular pregnant woman were substituted into the LDF formulas and the equations were solved. The evaluated patient should be assigned to the group for which the LDF values were the highest. So, if LDF1 turned out to be the greatest, then perinatal fetal death is most likely for this pregnant woman.

When registering for pregnancy in a group with high rice of perinatal fetal death, the proposed model ensures that the predicted severity of the course coincides with the actual result in 80.1% of cases. In the group of pregnant women with a low risk of perinatal fetal death, the coincidence of the predicted diagnosis with real results was 84.8%. In groups of pregnant women with varying degrees of risk of perinatal fetal death, the coincidence of the predicted diagnosis with real results was 82.4%.

Thus, the discriminant model for predicting perinatal fetal death, based on the simplest clinical signs, has a fairly high information ability (84.6-82.8%) and is statistically significant (p <0.001).

The solution of the model can be carried out using an elementary calculator, or a program for a personal computer can be developed in Microsoft Office Excel 2007. You can use the model at the stage of female consultation at the place of dispensary observation of the pregnant and obstetric institution, where the pregnant / woman in labor arrives for delivery. An important point is that the model is developed on the basis of the simplest signs available for identification.

Claims (1)

A method for predicting perinatal fetal death, characterized in that when registering for pregnancy in a woman, prognostic signs are determined: education (X1), age of sexual debut in years (X2), history of hypertension and / or arterial hypertension (X3), officially registered marriage (X4), the presence of obesity according to body mass index (BMI) of more than 25.0 (X5), menarche age in years (X6), smoking (X7), the presence of an official place of work (X8), the presence of genital pathology of infectious genesis a history of vaginitis, endo cervitis, endometritis, salpingoophoritis, bartholinitis, etc. (X9), the upcoming birth of the account (X10); assess prognostic signs in points: X1 as “1 point” in primary education, “2” - average, “3” - higher, X3-X5, X7-X9 as “1 point” in the presence, “0” - in the absence , then calculate the coefficients of LDF1 and LDF2 by the formulas:
LDF1 = 8.579 * X1 + 4.347 * X2 + 2.67 * X3 + 3.875 * X4 + 2.282 * X5 + 7.409 * X6 + 5.858 * X7 + 0.134 * X8 + 0.93 * X9 + 1.688 * X10-101.56,
LDF2 = 11.716 * X1 + 4.666 * X2 + 1.024 * X3 + 4.621 * X4 + 1.625 * X5 + 7.166 * X6 + 4.909 * X7-0.772 * X8 + 1.473 * X9 + 1.359 * X10-110.807,
and with LDF1> LDF2, a high risk of perinatal fetal death is predicted; with LDF2> LDF1, a low risk of perinatal fetal death is predicted.