The contracting activity of the uterus in pregnant women with a preliminar period

The data available in the literature on the contractile activity of the uterus in the preliminar period are few and contradictory. This, probably, explains the data of the clinic. F. Arias (1989) gives E. Friedman's materials and identifies the latent phase of birth with the preparatory period according to Friedman. The average duration of the latent phase (the preparatory period for Friedman) in the first-pregnant women is 8.6 hours, in the re-parenting - 5.3 hours. About the protracted latent phase, we can speak in those cases when it is equal to 20 hours in primiparas and 14 hours in repetitive women. The most frequent problems associated with the diagnosis of a protracted latent phase are difficulties in determining the timing of onset of labor and the onset of the active phase. In many cases, it is difficult to distinguish between false births and their latent phase. The problem of differential diagnosis between the latent phase of labor and false births does not play a decisive role as long as the obstetrician avoids such active interventions as amniotomy or stimulation of labor. In fact, both false births and a prolonged latent phase are non-hazardous conditions, and expectant tactics do not harm either the baby or the mother. In contrast, intervention can lead to a number of complications and, consequently, to perinatal and maternal morbidity.

The best criterion for recognizing false births and avoiding a prolonged latent phase is a retrospective evaluation of these states. If in a pregnant woman with regular contractions without changes in the uterus the labor activity ceases after the appointment of 0.015 morphine or 0.2 g of secobarbital, we can speak of false labor. Unfortunately, the retrospective diagnosis can not be applied in practice. The best way to exclude such errors is to accurately determine the time of onset of labor. False births are observed in about 10% of primiparous women with the initial diagnosis of a protracted latency phase, in polyhedra with the same diagnosis they are noted in more than 50% of cases. The difference in the incidence of false births indicates how difficult it is to establish the onset of labor in reproductive women.

Comparative analysis of contractile activity of the uterus in the normal and pathological course of the preliminaries allowed to reveal the following characteristic features:

• increase in 2 times the number of fights in the area of the lower segment of the uterus in both primiparous and repetitious;
• an increase in the amplitude of uterine contractions by a factor of 2 in all parts of the uterus, which is especially pronounced in the primiparous and tends to increase in the re-birth; the form of reduction does not exceed 0.5 (the coefficient according to GG Khechinashvili and TA Gusarova);
• an increase in 1.5 times the duration of uterine contraction in the region of the lower segment of the uterus and a decrease in the area of the bottom and body of the uterus; respectively, pauses between uterine contractions are greater in the region of the bottom and body of the uterus and 2 times less in the region of its lower segment.

Preliminary period occurs due to the development of discoordinated contractions of the uterus, while a signal about their occurrence must be considered cramping or aching pain in the abdomen. However, the intensity and nature of the pain, their duration, depend on the stage of discoordination and the rate of their development. So, in the initial stages, the contractions of the longitudinal muscles over the circulatory muscles predominate, and therefore the pains are of a moderate, tolerable character. If the contractile function is not normalized at the initial stages, stage II progressively develops, in which the tone of the circulatory muscles already predominates and painful sensations increase, causing anxiety, poor sleep, increased blood pressure, and other phenomena.

In order to prevent discordant uterine contractions, it is recommended to identify high-risk women during pregnancy and before childbirth, to study the nature of the contractile function of the uterus, to conduct psychophysical, pharmacological and other types of training, and to send pregnant women to the hospital in time. In the preliminar period, hysterography reveals a violation of the so-called "triple descending gradient" of uterine contractions and anomalies of the placenta attachment. It was also established that the pathological course of the preliminar period is most often manifested at night and its correction is necessary taking into account the maturity of the cervix, in particular, glucose-calcium-estrogen-vitamin background and electroanalgesia is recommended.

A prognostic risk map for the development of weakness in labor and the methods of its prevention in the preparatory period for childbirth have been developed. The greatest value, according to the author, is age (30 years and older), obesity II-III degree, genital infantilism, pregnancy retardation, pathological period during the preliminaries and especially a combination of these factors.

In order to predict the risk of developing a breach of contractile activity of the uterus during labor in women with rheumatic heart disease, diagnostic algorithms and differential diagnostic tables have been developed, taking into account the coefficient of information content of various characteristics. For the prevention of breaches of contractile activity of the uterus, it is recommended to apply the medication "Antigipoksin", "Unitiol", "Antioxidant", etizol during the antenatal period.

It is necessary to distinguish the parameters of contractile activity of the uterus in the normal and pathological preliminaries, for this determines the tactics of administering the pregnant women with the justification for the appointment of appropriate therapy.

For a normal preliminar period, a clear decrease in the number of fights and their duration from the bottom to the body and the lower segment is observed in both the first and the re-birth (an average of 8 to 5 fights per hour in primiparas and 7 to 3 in miscarriages with swings ± 1 uterine contraction).

In the pathological preliminar period, a distinctive feature is the increase in the number of fights in 2 times only in the region of the lower segment of the uterus in the primiparous and 3 times in the reproductive.