RU2447837C2 - Method for determining cranially presented foetus weight category in practically healthy pregnant women - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to obstetrics. To determine a cranially presented foetus weight category in practically healthy women, a fundal height is measured. Additionally, a pregnant woman is examined for a pregnancy weight gain, a pregnancy length, a prothrombin index, a fibrinogen concentration, a hemoglobin concentration. A canonic value is calculated by formula: K=-15.9285+0.2496*A-0.0660*B+1.0571*C+0.0548*D-0.0481*E-0.1165*F, wherein: A is the fundal height (cm), B is the prothrombin index (%), C is the fibrinogen concentration (g/l), D is the pregnancy length (days), E is the hemoglobin concentration (g/l), F is the weight gain (g). If the K values is less then -0.41, the newborn weight category is predicted to be less than 4000 grams, and the K value exceeding -0.41 - more than 4000 grams.

EFFECT: method provides more accurate prediction of the foetus weight category in women with no systemic pathologies ensured by the discriminant analysis of the most informative tests.

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Description

The invention relates to medicine, the section "obstetrics", and is intended to determine the category of mass of the fetus in the head presentation for choosing the tactics of childbirth in pregnant women without systemic pathology and with physiological pregnancy.

It is known that, along with the condition of a pregnant woman, the fetal mass plays an important role in choosing the optimal obstetric delivery tactics [1, 3]. Existing methods for determining the estimated mass of the fetus can be divided into two groups:

1. Methods based on formulas and equations using physiological and clinical indicators, such as the height of the uterine fundus (VDM), abdominal circumference (coolant), height, weight, etc .; (Formulas of Jordania, Johnson, Lankovets, Yakubova, Lazareva, etc.) [3, 4].

2. Instrumental research methods (ultrasound, x-ray, etc.).

The prototype of our proposed method is developed by Lazareva I.V., Minaev Yu.L. (2009) [4] a method for determining the weight of the fetus for all women by determining the circumference of the abdomen, the height of the uterine fundus, the external size of the pelvis of the patient and subsequent calculation using the regression equation.

The well-known formulas are developed as universal for all groups of weight and conditions of a pregnant woman, which a priori increases their error in determining the weight, can often lead to an erroneous justification in choosing a delivery method, especially in cases of fetal macrosomia and in the presence of systemic pathology in the mother (obesity, diseases cardiovascular system, etc.), and, as a result, increases the frequency of complications during childbirth.

It is important to note that it is not the mass itself that plays a key role in the choice of delivery tactics, but the weight group of the fetuses - lightweight, with normal weight, large weight and very large weight (macrosomia) [1].

As a rule, the weight category (two groups of fruits with a large and very large weight) serves as a prerequisite for caesarean section [1, 2, 3].

In this regard, along with the clinical and obstetric indications of pregnancy development, the correct determination of the fetal weight category plays a significant role in the optimal choice of obstetric delivery tactics and, as a result, leads to a significant reduction in the frequency of birth complications.

The task of determining the category of fetal mass in women without obesity, cardiovascular disease and physiological pregnancy is solved by obtaining the following physiological and clinical indicators: height of the uterine fundus, duration of pregnancy, weight gain and hemodilution indicators (prothrombin index, fibrinogen concentration, hemoglobin concentration ) with the subsequent calculation of the canonical value according to our formula and assigning the fetal mass to one of two categories: up to 4000 grams and more 4000 grams.

The proposed method differs from the prototype:

- instead of regression, discriminant analysis is used with the construction of a canonical quantity;

- the equation contains the most informative physiological and clinical indicators found in a pregnant woman: height of the uterine fundus, weight gain during pregnancy, duration of pregnancy, prothrombin index, fibrinogen concentration, hemoglobin concentration.

The method is as follows. A pregnant woman in the third trimester determines the height of the uterine fundus, weight gain during pregnancy, duration of pregnancy, prothrombin index, fibrinogen concentration and hemoglobin concentration. The obtained values are substituted into the equation:

K = -15.9285 + 0.2496 · A-0.0660 · B + 1.0571 · C + 0.0548 · D-0.0481 · E-0.1165 · F,

where K is the canonical quantity, A is the height of the uterine fundus (cm), B is the prothrombin index (%), C is the concentration of fibrinogen (g / l), D is the duration of pregnancy (days), E is the concentration of hemoglobin (g / l) , F - weight gain (kg).

The resulting K value is compared with a value of "-0.41". When the K value is less than "-0.41", it is concluded that the mass of the newborn is less than 4000 grams. The value of K more than "-0.41" - the body weight of the newborn is more than 4000 grams. With K equal to "-0.41" - equally likely we can expect the mass of the newborn as less than 4000 grams, and more than 3999 grams.

The clinical effectiveness of the resulting equation is 82.75%, specificity 75%, sensitivity 85.71%.

Example 1. A primiparous woman without obesity and without CVD diseases, a history of 2 abortions without complications, with the following parameters: A - uterine fundus height (cm) = 39, B - prothrombin index (%) = 100, C-concentration of fibrinogen (g / l) = 4,2, D - duration of pregnancy (days) = 294, E - concentration of hemoglobin (g / l) = 110, F - weight gain (kg) = 6. Value K = 1,767. Expected to weigh more than 4000 gr. The true weight of the newborn is 4540 grams.

Example 2. A primiparous woman without obesity and without CVD diseases, there is no history of abortion, 23 years old, height - 174 cm, weight before pregnancy 60 kg, with the following parameters: A - uterine fundus height (cm) = 36, B - prothrombin index (%) = 93, C - fibrinogen concentration (g / l) = 3.7, D - pregnancy duration (days) = 288, E - hemoglobin concentration (g / l) = 124, F - weight gain (kg) = 20. The calculated value of K = -1.68. Predicted weight less than 4000 gr. The true weight of the newborn is 3680 grams.

Thus, the claimed method allows women without systemic pathology to predict the category of fetal mass by the minimum number of the most informative tests, which reduces the cost of diagnostic tests, shortens their time, improves accuracy, allows you to choose the optimal delivery tactics and reduce the risk of perinatal pathology in mother and newborn .

Literature

1. Classification of large fruits / V.I. Grishchenko [et al.] // Vopr. protection of motherhood and childhood. - M., 1990. - P. 41-44.

2. Cherepnina A.L. Large fetus: modern tactics of pregnancy and childbirth. Perinatal outcomes: abstract. dis. ... cand. honey. sciences. - M., 2006 .-- 21 p.

3. Chernukha EA The birth block. - M .: Triad-X, 2005 .-- 710 p.

4. Lazareva N.V., Minaev Yu.L. The method of determining the mass of the fetus. - Application for invention No. 2007127157/14 G01N 33/74 dated 2009.01.27

Claims (1)

A method for determining the category of fetal mass in the head presentation in practically healthy pregnant women, including measuring the height of the uterine fundus, characterized in that the woman additionally determines weight gain during pregnancy, pregnancy duration, prothrombin index, fibrinogen concentration, hemoglobin concentration, the canonical value is calculated from the formula:
K = -15.9285 + 0.2496 · A-0.0660 · B + 1.0571 · C + 0.0548 · D-0.0481 · E-0.1165 · F,
where A is the height of the uterine fundus (cm), B is the prothrombin index (%), C is the concentration of fibrinogen (g / l), D is the duration of pregnancy (days), E is the concentration of hemoglobin (g / l), F is the weight gain (g), and with a value of K less than "-0.41", the category of mass of the newborn is predicted to be less than 4000 g, with a value of K greater than "-0.41" - more than 4000 g.