Frontal previa

Frontal presentation - a subspecies of the front of presentation; it is unstable form (Fig. 88). Occurs within descent act, when a head, going forward forehead, has been delayed in this state, as the chin can not go down due to various reasons. The causes of the frontal presentation are the same as prednisolone and facial. Elimination of these causes can lead to changes in the frontal presentation, if the head is still at the entrance to the pelvis and the amniotic fluid is not moved. When the discharge of water and inserted the head by a large segment of the latter is fixed permanently in the frontal previa. Be inserted in the frontal previa can not only large magnitude head. In the literature there are indications that the small value of the fetus can contribute to establishing head in the frontal previa. Small quantities head coming forehead down into the pelvis and does not meet the conditions conducive to its bending, as it is observed at birth twins. Childbirth in the frontal previa are characterized by a prolonged course. The total duration of births on average in nulliparous is 24 h 51 min and multiparous - 13 hours and 17 minutes In physiological delivery in the occipital previa expectancy at periodama 11 h 54 min and in multiparous - 9 hours 34 minutes (in. A. Ermakov, 1954). Only in those cases when the fetus small size or childbirth come prematurely, the duration of births in the frontal previa is close to the norm.
The originality of biomechanism of labor and prolonged their course adversely affect the condition of the mother and the fetus (see Fig. 93 and 98).
Head comes into the pelvis and is lowered into its cavity of a skull seam in the transverse size or when lowering the front seam passes from the lateral dimension in oblique, and "wings of a nose" is sent to the symphysis. As soon as the upper jaw (the point of fixation) touches the bottom edge of the womb, starts flexing heads and the birth of her to the occiput. Thus there is excessive voltage perineal tissue as the head when frontal previa must go through the pelvis circle, the corresponding oral occipital its size (planum maxillo-occipitale) and equals 35 see
Head pulls in the direction of small slanting size. When seem occiput (the second point of fixation), head begins to straighten up) and are exempt upper and lower jaw (Fig. 89). Generic tumor is formed early, usually reaches of large magnitude, occupies the entire forehead and extends in one direction before the eyes and in the other to a large fontanel. During childbirth in front the form of the frontal presentation is even less favorable. This option frontal presentation is very rare; the fixation point is the large fountain and the angle between his chin and neck.

Fig. 88. Frontal presentation. The head goes the pelvis.

Fig. 89. Frontal presentation. The cutting head.

Frequency frontal abnormal presentations small. According to the Semenovsky Wiederseh, frontal previa met in 0,13%, D. S. Chapin - 0.1%, S. S. holmogorova - 0,08%, B. N. Mikhailova - 0,11%, 3. L. Filippov - 0.06%, N. I. O. Yakovleva and Savelevoj - a 0.05%, N. Ivanov - 0.04%in. A. Ermakova - 0,026%.
Frontal presentation occurs mostly in multiparous at the age of 20-30 years. Frequency frontal abnormal presentations increases as the narrowing of the pelvis; according to our clinic, the narrowing of the pelvic was observed in 21.1% of the frontal abnormal presentations.
The forecast. If the face of presentation in most cases do not cause adverse effects for either the mother or the fetus, frontal presentation, on the contrary, threatened both. It depends, as already mentioned, from the adverse inserting head and its passing through the birth canal plane largest size.
Due to unfavorable insertion head and slow promote it through the birth canal possible all sorts of complications, such as rupture of the uterus and perineum, fistulas and other
According to D. S. Chapin, a number of gaps reaches 25%, and according to S. S. holmogorova - 60%.
Morbidity and mortality after birth in the frontal previa quite high (by S. S. Kolmogorov - 2,9%, for centuries Ermakov - 4,9%).
Labor at Calvary previa unfavorable not only for the mother but for the fetus. Frequent and strong contractions cause infringement of placental circulation, which may cause asphyxia and death of the fetus. Mertvorozhdennosti by S. S. Holmogorova is 46.5%, for centuries Ermakov - 20,4%.
The possibility of occurrence of these complications require the doctor vigilance in the conduct of birth and application of appropriate preventive and therapeutic measures.
Recognition of the frontal presentation on the basis of the external examination impossible, as the deviation of the neck to the back is not as pronounced as in personal presentation.
The diagnosis is based solely on data vaginal studies. If probed his forehead with his seam as the lowest scum of the head and clearly felt on one side of the nose and eyebrows, and with another - front corner of the large fontanel, then, undoubtedly, there frontal presentation. Neither mouth nor chin in the study are not achieved.
In doubtful cases the examination is performed under General anesthesia of the entire hand.
Also characteristic of the head of the newborn (Fig. 90).

Fig. 90. Head of the newborn, who was born in the frontal previa.

Labor management. When the frontal previa childbirth end spontaneously only in 53% of cases; 47% have to resort to rapid delivery. The operational methods of delivery is most often used caesarean section or application of obstetrical forceps, rarely turn on the legs then extract of the fruit and it is rarely craniotomy (perforation aksceleracija) and chroniclethe.
According to S. S. holmogorova, the number of obstetric interventions in the frontal previa reaches 78,72%. On materials of B. N. Mikhailova, surgical delivery at Calvary abnormal presentations used in 76-93% of cases. Thus, the active intervention in the frontal previa is necessary to apply much more often, than at the front. Despite the questionable forecast when the conservative wait-and-see tactics of delivery, we consider it expedient, as frontal presentation is unstable - it occurs during childbirth and often spontaneously eliminated. According to centuries Ermakova, in half of the cases of childbirth at Calvary previa there is a shift in his face, and less occipital presentation. In some cases, allowed attempts to fix hand frontal presentation by transferring him in the face, as, for example, advises, A. Soloviev, or in the occipital (C. S. Kolmogorov). However, remember that correcting the frontal presentation is possible only in the beginning of labour and living fetus when forehead had no time firmly fixed at the entrance to the pelvis and there is no pronounced degree of deformation of the head, no stretching the lower segment of the uterus and there is a sufficient degree of disclosure throat. Attempts to fix the frontal presentation at high degrees narrow pelvis should not be made.
Depending on the assigned task is to translate the frontal presentation in front or, on the contrary, in the occipital - made corresponding movement of a finger, put into the mouth of the fetus.
Outer arm contributes to the implementation of this manipulation. Our attitude to this method is very restrained. With wide hips and the average value of the fruit of the frontal presentation are not dangerous for the mother, and only the first two periods of births in these conditions has slowed.
Surgical delivery shows only where natural delivery is impossible; indications for surgical intervention may arise not only from the mother, but also from the fetus. The choice of method of delivery must comply with the particular case (see labor at the front previa), with frontal previa according to the available indications and conditions apply: forceps delivery, turning fruit on foot with its subsequent extraction, cesarean section, and perforation of the head of the fetus with subsequent kranichsee. Thus, the turn of the fetal stem valid in cases where there is no spatial mismatch between the value of head and size of the pelvis, with the full opening of the throat and mobility of the fetus.
The rotation is not possible in cases when on the uterus there is a scar after the former cesarean sections, with large fruit size.