Advantages of fetal vacuum extraction

For a number of years, there has been a debate about the advantages of the operation of applying obstetric forceps or vacuum extraction of the fetus. Plauche concluded that with technically correct and indicated in each individual case use of a vacuum extractor, it is effective and less traumatic compared to other instrumental methods of delivering a child. When analyzing modern data on the operation of applying obstetric forceps and vacuum extraction, it can be said that vacuum extraction is less traumatic and is especially necessary when the internal rotation of the head has not occurred, and the sagittal suture is in the transverse diameter of the pelvis. Moreover, when comparing the effect of vacuum extraction and cesarean section, some authors come to the conclusion that vacuum extraction is a less traumatic operation for both the mother and the fetus. It should be noted that at the same time, a number of authors are improving both the device and the operation of vacuum extraction of the fetus itself.

Currently, a large number of studies have been published on the operation of vacuum extraction of the fetus. At the same time, according to the majority of domestic and foreign clinicians, the latter is most preferable in cases of persistent weakness of labor, a protracted second stage of labor, and endometritis. It should be noted that intrauterine asphyxia of the fetus often occurs in these situations. Thus, according to research data, in 55% of cases, the main reasons forcing obstetricians to perform vacuum extraction of the fetus with complete and incomplete opening of the cervix were a violation of the condition of the intrauterine fetus against the background of persistent weakness of labor that does not respond to medication.

It is important to note that for successful vacuum extraction of the fetus, it is necessary to perform the operation accurately with knowledge of the biomechanics of labor. It is necessary to prepare the device accordingly, checking its tightness, prepare the woman in labor for the operation as with other vaginal birth operations, and provide adequate pain relief taking into account the condition of the woman in labor and the fetus. The selection of the vacuum extractor cup is extremely important. It is recommended to use the largest size of the vacuum extractor cup (No. 6 or No. 7), of course, if the degree of dilation of the uterine os allows it.

At the same time, most obstetricians do not resort to vacuum extraction of the fetus until the cervix is fully dilated. However, there are reports of the use of vacuum extraction of the fetus with incomplete dilation of the cervix. In domestic literature, the use of a vacuum extractor for delivery with incomplete dilation of the cervix is called vacuum stimulation of labor, with complete vacuum extraction of the fetus. As is known, with forceps, traction depends on the strength of the operator. Mathematical calculations have shown that during the operation of applying obstetric forceps, the force is 20 times greater than during vacuum extraction of the fetus. Moreover, it has been shown that vacuum extraction requires only less than 40% of the traction force used when applying obstetric forceps. It has also been shown that vacuum extraction is safer compared to the operation of applying obstetric forceps, especially exit forceps. However, when time is needed to rotate the head or when lowering a high head, the overall compression and traction levels are equal to or even greater than those when applying obstetric forceps. It is especially important to perform traction synchronously with a contraction or pushing; they must stop simultaneously with the contraction. Tractions must be perpendicular to the plane of the cup, since the so-called "oblique" tractions lead to a redistribution of pressure forces at different poles of the cup and it will press inward on the skin surface of the fetal head. In this case, if there is no progress in advancing the presenting part, it is necessary to choose another method of delivery after 3 or 4 tractions, since if the vacuum cup breaks off, the fetus may be injured. If abrasions or damage to the skin surface of the fetal head are detected, re-application of the vacuum extractor cup is dangerous. In the absence of damage, the vacuum extractor cup can be re-applied. Thus, the general rule is as follows: if the cup separates from the fetal head 3 or more times, or the total duration of vacuum extraction exceeds 30 minutes, the vacuum extraction operation should be stopped.

A significant advantage of vacuum extraction is the absence of the need for additional increase in the volume of the presenting part, as is observed during the operation of applying obstetric forceps. In case of fetal asphyxia, vacuum extraction is used in 2.5-44.5% of cases. It is believed that with full opening of the cervix and the head located in the cavity of the small pelvis or on the pelvic floor, acute asphyxia of the intrauterine fetus is an indication for the application of obstetric forceps. However, according to the authors, in 24.4%, vacuum extraction was performed only in connection with the onset of intrauterine asphyxia of the fetus: in the initial stages of asphyxia, high position of the head or, conversely, with an intruding head and insufficiently active pushing, anatomically narrowed pelvis, etc. It should be noted that in case of fetal asphyxia, it is recommended to use an outlet vacuum extractor. For this purpose, doctors suggest using a large cup (60 mm in diameter) with an instantaneous increase in vacuum to 0.8 kg/cm2 ^. This is often sufficient to perform immediate extraction of the fetus without the formation of a so-called "artificial birth tumor" inside the cup due to the tissues of the fetal head. Complications for the mother and fetus are usually minimal. The use of a modified vacuum extractor cup and electric pumps to create a vacuum has dramatically changed the technical problems, thereby significantly improving the immediate and remote results of this operation.

One of the most comprehensive studies is the research of modern authors Vacca et al, which compared obstetric forceps and vacuum extraction of the fetus under identical conditions. It was shown that maternal trauma, blood loss during childbirth, and the use of analgesics were significantly lower in the group using a vacuum extractor. However, the latter, according to the authors, may predispose to an increase in the amount of moderate jaundice in newborns. At the same time, vacuum extraction reduced maternal trauma by 2 times - from 25% to 12.5%. In children born with the use of obstetric forceps, the condition was more severe than with the use of vacuum extraction of the fetus. It is important to note that the average time of the interval between the application of a vacuum cup or forceps and the subsequent delivery was the same for both groups - 26 minutes, with an average duration of the second stage of 92 minutes. In children, subcutaneous hematomas were more frequent in the operation of applying obstetric forceps, but in most cases they were small - less than 2.5 cm in diameter. At the same time, cephalohematoma was more frequent in the operation of vacuum extraction of the fetus, but the difference was large only in the presence of small cephalohematomas with a diameter of less than 2.5 cm. Extensive cephalohematomas were one in each of the two groups. These data show that after an unsuccessful application of obstetric forceps, they usually proceed to abdominal delivery. At the same time, after an unsuccessful vacuum extraction of the fetus, they usually try (sometimes unsuccessfully) to apply obstetric forceps before resorting to cesarean section. Differences in professional skill lead to a tendency to apply a vacuum extractor by most young obstetricians, as indicated by a number of authors. Most operators with experience using forceps use them, so they were more often used by obstetricians with more experience.

Thus, vacuum extraction of the fetus expands the possibilities of operative delivery through the natural birth canal. At the same time, a number of modern obstetricians believe that obstetric forceps and vacuum extraction of the fetus can be used for the same indications. Other authors believe that vacuum extraction of the fetus is indicated mainly in conditions when extraction of the fetus by obstetric forceps is impossible. Modern methods of operative delivery through the natural birth canal, despite great achievements in practical obstetrics, still remain quite imperfect. Their use should be carried out according to strict indications and by highly qualified doctors, but an attempt to replace them with the cesarean section method in the interests of the fetus cannot be accepted by domestic obstetricians.

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