RU2846795C1 - Method for determining foetal hypotrophy during pregnancy - Google Patents

Abstract

FIELD: medical science.

SUBSTANCE: invention refers to medicine, namely to obstetrics, and can be used for foetal status assessment. Foetal weight and length are determined by ultrasonic fetometry. A foetal hip length is measured; the foetal length is determined by dividing the foetal hip length by empirical coefficient 0.14. Foetal ponderosa index (FPI) is calculated as ratio of foetal weight to its length in corresponding week of pregnancy. Foetal malnutrition is determined if the calculated FPI is less than the FPI of a healthy foetus on the respective week of pregnancy in accordance with Table 1 set out in the description.

EFFECT: technique is easy to use, provides the reliable diagnosis of foetal hypotrophy during pregnancy simplified by measuring the foetal length along the femoral length taking into account the more stable position of the foetal legs in the uterus.

1 cl, 1 dwg, 5 tbl, 1 ex

Description

Field of technology

The invention relates to medicine, namely to obstetrics, and can be used to determine the condition of the fetus.

State of the art

Diagnosis of hypotrophy The fetal weight is of utmost importance. In Russia, the tables, equations, and programs developed by V.N. Demidov et al. are most widely used for ultrasound determination of fetal weight.

A method for determining the condition of the fetus in the prenatal period is known (see patent for invention RU2066975, IPC A61B 8/00, published on September 27, 1996), which includes the use of ultrasound biometry to determine the weight of the fetus. In this case, the weight of the fetus for 30-42 weeks of pregnancy is determined by the formula MP 70 x BPD + 30 x DZ + 25D 6500, where MP is the weight of the fetus, g; BPD is the biparietal diameter of the head, mm; DZ is the abdominal diameter, mm; 25 is the average daily weight gain of the fetus, g; D is the number of days in complete weeks of pregnancy. Then, the normal weight of the fetus for a given gestational age is determined taking into account the growth gradations of pregnant women and grade I hypotrophy and paratrophy is established when the actual weight deviates from the normal by 1 to 15% hypotrophy, grade II paratrophy when the actual weight deviates from the normal by 15 to 20% and grade III hypotrophy and paratrophy when the deviation is 20% or more.

This method is inconvenient for use in practical obstetrics, as it includes numerous ultrasound fetometric indicators and requires complex calculations.

A method for determining fetal malnutrition during pregnancy is known, which includes knowledge of the exact gestational age, fetal weight, and fetal length. It is proposed that fetal length be determined by the humeral length using the formula P = 10.0 * P - 12.0, where P is the humeral length. After entering the specified data into a computer, a special program determines the degree of fetal malnutrition during pregnancy (Savel'eva GM, Sukhikh GT, Serov VN, Radzinsky VE, Manukhin IB. Obstetrics. National Guide. - M .: Geotar-Media. - 2015. P. 127) .

The disadvantage of this method is the poor testing of the program and the inaccuracy of the method, associated with a large spread of the measured value due to the constant movement of the fetus's arms.

The closest in technical essence is the method for determining the relative deficiency of fetal weight (hypotrophy) established using the ponderal index (Index pondero-longitudinalis (Ipl) = fetal weight in g/fetal length in cm. (Govorka E. The human placenta / [Translated from Polish by Cand. Sci. (Med.) V.F. Levanyuk]. - Warsaw: Polish State Medical Publishing House, 1970. - 471 p. ill.; 25, p. 353):

in premature fetuses with hypotrophy (33-37 weeks), the Ipl indicator is ≤45,

in full-term fetuses with hypotrophy (38-42 weeks), the Ipl indicator is ≤57,

in post-term fetuses with hypotrophy (>42 weeks), the Ipl indicator is ≤45.

But, to determine the ponderal index, in addition to the weight, it is necessary to know the length of the fetus.

However, there is a problem with measuring fetal length, the determination of which is not discussed in this source. Furthermore, the proposed method does not account for the detection of fetal malnutrition at all weeks of pregnancy.

Disclosure of the essence of the invention

The technical problem of the present invention is to develop a method for determining fetal hypotrophy during pregnancy using the results of observation of a large group of subjects and determining patterns in measurements of the fetal ponderal index during and after pregnancy.

The technical result consists in carrying out a reliable diagnosis of fetal hypotrophy during pregnancy, simplified by determining the length of the fetus based on the length of the femur, taking into account the more stable position of the fetal legs in the uterus.

In order to achieve the specified technical result in the method for determining fetal malnutrition during pregnancy, including determining the weight and length of the fetus, calculating the fetal ponderal index (FPI) as the ratio of the weight of the fetus to its length in the corresponding week of pregnancy, according to the solution , the length of the fetal femur is measured by ultrasound fetometry, the length of the fetus is determined by dividing the length of the fetal femur by the empirical coefficient of 0.14, fetal malnutrition is determined when the value of the calculated FPI is less than the FPI value of a healthy fetus in the corresponding week of pregnancy in accordance with Table 1.

Brief description of the drawings

The invention is illustrated by a drawing which shows a diagram of the minimum fetal ponderal index of the fetus during pregnancy depending on the gestational age in weeks .

Implementation of the invention

The method is carried out as follows.

During a routine examination, the gestational age is determined, an ultrasound examination of the fetus's condition is performed, including determination of fetal weight using one of the standard methods, measurement of fetal femur length, and determination of fetal length by dividing the fetal femur length by an empirical coefficient of 0.14. The fetal ponderall index is calculated as the ratio of fetal weight to length. This value is compared with the minimum fetal ponderall index, shown on the empirical chart (see diagram). If the index value is lower than the height of the chart bar, the fetus is diagnosed with hypotrophy.

Theoretical justification

Fetal growth restriction (FGR) is not an independent disease entity, but rather a consequence of various pathological processes occurring in the maternal-placental-fetal system. Therefore, the ICD-10 includes several categories that allow for the classification of FGR and its causes. Of particular interest when diagnosing FGR is the ICD-10 section "Fetal growth restriction and malnutrition" (code P05), which pertains to Chapter XVI "Certain conditions originating in the perinatal period" (codes P00-P96) and describes all conditions associated with impaired fetal weight and growth:

P05.0 "Small for gestational age fetus (a condition where the fetus's body weight is below and its body length is above the 10th percentile for gestational age; the fetus's length may be normal; synonyms are "small" for the calculated term, hypotrophic type, or asymmetrical form;

P05.1 Small for gestational age (a condition where the fetus is both weight and length below the 10th percentile for gestational age); synonyms include small for gestational age, 5yA (Small for gestational age), hypoplastic type, or symmetrical form.

To achieve this objective, ultrasound measurements of femur length were performed in 452 normal-weight fetuses with absolute and relative birth weight deficit at gestational ages ranging from 32 to 42 weeks, and subsequent height measurements were performed in the corresponding newborns immediately after birth.

Based on the obtained parameters, the ratio of fetal growth to femur length was estimated. This value is 1/0.14.

Thus, by determining the fetal femur length (F) by ultrasound, it is possible to estimate fetal height (FH) using the following formula: FH = FH/0.14. Knowing the fetal weight in grams and the fetal height in cm, the ponderall index is determined as the ratio of fetal weight to length. If this index is below the norm, a relative fetal underweight (hypotrophy) is diagnosed. The following pattern has been established, shown in Table 1.

Table 1. Values of the minimum fetal ponderal index of the fetus at different stages of pregnancy.

Pregnancy period, weeks Minimum ponderal index of a healthy fetus Diagnosis if the fetal index is less than the minimum 35 fetal hypotrophy 37.5 fetal hypotrophy 40 fetal hypotrophy 42.5 fetal hypotrophy 45 fetal hypotrophy 47.5 fetal hypotrophy 50 fetal hypotrophy 52.5 fetal hypotrophy 55 fetal hypotrophy 57.5 fetal hypotrophy 60 fetal hypotrophy 60 fetal hypotrophy 60 fetal hypotrophy 60 fetal hypotrophy 60 fetal hypotrophy

The figure shows a diagram of the minimum fetal ponderal index during pregnancy. If the index is lower than the height of the column, the fetus is diagnosed with hypotrophy.

The experimental data presented below confirm that the determination of the fetal ponderal index during pregnancy using the proposed method clearly indicates the development of fetal hypotrophy or the absence of hypotrophy, which is important for determining tactics for clinical monitoring of the course of pregnancy.

Below are examples of practical use.

Group I – urgent delivery of infants with normotrophy.

Full name. Fetal femur length at end of pregnancy (cm) Baby weight (g) Baby's height (cm) Thigh length/
growth ponderal index at birth infant hypotrophy fetal weight (g) at 30 weeks of pregnancy Fetal femur length (cm) at 30 weeks of pregnancy Fetal growth (cm) ponderal index at 30 weeks of pregnancy fetal hypotrophy G.K.S. 7.4 3510 51 0.145 68.8 No 1850 6 42.8 43.2 No K.E.A. 6.8 3020 49 0.139 61.6 No 1650 5.7 40.7 40.5 No G.G. 6.2 3100 51 0.122 60.8 No 1826 6.1 43.6 41.9 No U.N.S. 7.25 3460 52 0.139 66.5 No 1551 5.2 37.1 41.8 No S.Z.N. 7.25 3680 51 0.142 72.2 No 1693 5.8 41.4 40.9 No

Group I. All infants in this group show normotrophic fetal ponderal indices at birth and at 30 weeks of gestation.

Group II – urgent delivery of infants with varying degrees of fetal malnutrition

Full name. Fetal femur length at end of pregnancy (cm) Baby weight (g) Baby's height (cm) Thigh length/
growth ponderal index at birth infant hypotrophy fetal weight (g) at 30 weeks of pregnancy Fetal femur length (cm) at 30 weeks of pregnancy Fetal growth (cm) ponderal index at 30 weeks of pregnancy fetal hypotrophy P.O.A. 6.2 2900 50 0.124 58.0 Yes 1728 6.2 44.3 39.0 Yes M.E.M. 7 2940 50 0.14 58.8 Yes 1757 6.3 45.0 39.1 Yes K.N.O. 6.7 2760 49 0.137 56.3 Yes 1565 5.7 40.7 38.5 Yes B.M.V. 7 2780 47 0.149 59.1 Yes 1483 5.6 40.0 37.1 Yes P.O.A. 6.2 2900 50 0.124 58.0 Yes 1728 6.1 43.6 39.7 Yes

Group II. All infants in this group show fetal ponderal index (FPI) indicators of malnutrition at birth and at 30 weeks of gestation.

Group III – premature birth of infants with normotrophy

Full name Fetal femur length at end of pregnancy (cm) Baby weight (g) Baby's height (cm) Thigh length/
growth ponderal index at birth infant hypotrophy fetal weight (g) at 30 weeks of pregnancy Fetal femur length (cm) at 30 weeks of pregnancy Fetal growth (cm) ponderal index at 30 weeks of pregnancy fetal hypotrophy M.N.B. 6.8 2710 48 0.142 56.5 No 1591 5.5 39.3 40.5 No K.N.S. 7 2860 49 0.142 58.4 No 1875 6.2 44.3 42.4 No F.A.A. 6.4 2200 46 0.139 47.8 No 1620 5.5 39.3 41.3 No H.D.S. 6.1 2950 50 0.122 59.0 No 1920 6.4 45.7 42.0 No Sh.Z.A. 7 2490 50 0.14 49.8 No 1800 5.6 40.0 45.0 No

Group III. All infants in this group show normotrophic fetal ponderal indices at birth and at 30 weeks of gestation.

Group IV – premature birth of infants with varying degrees of hypotrophy (n=24).

Full name Fetal femur length at end of pregnancy (cm) Baby weight (g) Baby's height (cm) Thigh length/
growth ponderal index at birth infant hypotrophy fetal weight (g) at 30 weeks of pregnancy Fetal femur length (cm) at 30 weeks of pregnancy Fetal growth (cm) ponderal index at 30 weeks of pregnancy fetal hypotrophy K.A.A. 5.4 1320 38 0.143 34.7 Yes 1180 5.2 37.1 31.8 Yes I.O.I. 5.5 1460 40 0.137 36.5 Yes 1253 4.5 32.1 39.0 Yes O.A.V. 5.2 1200 37 0.14 32.4 Yes 1310 4.9 35.0 37.4 Yes Z.M.V. 6.2 1730 46 0.134 37.6 Yes 1490 4.6 32.8 45.4 Yes

Group IV. All infants in this group show fetal ponderal index (FPI) evidence of malnutrition at birth and at 30 weeks of gestation.

Claims (1)

A method for determining fetal malnutrition during pregnancy, including determining the weight and length of the fetus, calculating the fetal ponderal index (FPI) as the ratio of the weight of the fetus to its length in the corresponding week of pregnancy, characterized in that the length of the fetal femur is measured by ultrasound fetometry, the length of the fetus is determined by dividing the length of the fetal femur by an empirical coefficient of 0.14, and fetal malnutrition is determined if the value of the calculated FPI is less than the FPI value of a healthy fetus in the corresponding week of pregnancy in accordance with Table 1 set out in the description.