Vacuum extraction

If you are not an experienced obstetrician, you will find a vacuum extractor invaluable (M 22.3), so if you are not already using one, you must! It has many advantages in the confined space of the reduced pelves so common in many communities. Unlike forceps, the vacuum cup takes up no space in a mother's birth canal, and it is difficult to injure her accidentally. Her baby's head can rotate spontaneously at the optimum level, and if it is deflexed, vacuum extraction will often flex it. Most importantly, a vacuum extractor is less likely to damage his brain than forceps. The indications for its use in a hospital are somewhat broader than those in a health centre (M 22.3).

VACUUM EXTRACTION INDICATIONS. These indications only apply if the absolute requirements below are met. (1) Delay in the second stage[md]more than an hour in a primigravida, and 30 minutes in a multigravida, especially delay caused by malrotation of the occiput. (2) To reduce maternal effort if a mother has cardiac failure or gestational hypertension. (3) To minimize the strain on a scarred uterus. (4) Relative CPD due to deflexion and malrotation of the head. If there is absolute CPD don't use a vacuum extractor, it will be ineffective and potentially dangerous.

Her cervix should be fully dilated. Some obstetricians apply it at 8 cm, but this can cause tears, and should never be tried if there is any CPD. The rule of ''Three pulls' (M 22.3) still applies, but two ''extra pulls' are allowed to reach full dilatation; then you must deliver her in three pulls. (5) Vacuum extraction is occasionally indicated before full dilatation of the cervix when there is fetal distress in multips without any CPD. (6) Fetal distress in a second twin with a cephalic presentation when the cervix has closed down. The height of the head does not matter in this situation, provided you can get the cup on the occiput. (7) Prolapse of the cord in multips.

CONTRAINDICATIONS. (1) Prematurity, because of the risk of intracerebral haemorrhage. (2) A malpresentation. (3) CPD and a dead baby[md]outlet forceps or a destructive operation would be safer. (7) An exceptionally uncooperative mother.

CAUTION ! The application of a vacuum extractor before full dilatation is rarely indicated, and is usually dangerous: the only exceptions are (5), (6), and (7) above. Don't apply one for delay late in the first stage. If this does not respond to oxytocin, it is likely to be due to CPD. If (a) she was [mt]3 hrs dilating from 7 to 10 cm on the partogram, or (b) her fundal height is [mt]40 cm (suggesting a large baby), expect difficulty. Do the vacuum extraction in the theatre, and prepare for section.

ABSOLUTE REQUIREMENTS. (1) A proper indication. (2) Good uterine contractions, which means 3 to 4 every 10 minutes lasting over 40 seconds. (3) A cephalic presentation. (4) The baby's head must be 1/5 or less above his mother's pelvic brim. Always determine its station in relation to her pelvic brim, and not to her ischial spines; if her pelvis is shallow and there is much caput, you may be able to feel it below her spines before it is engaged. (5) The head must descend with contractions and bearing- down efforts. (6) You should know where the occiput is, because traction will be more effective if you can put the cup there. Co-operation by a mother who is fully conscious is desirable, but not essential.