How many types of forceps are there?
If you challenged an obstetrician to name at least half the "types" of forceps used in the obstetric world, the chances are he or she will fail. There are so many. However, there are only two main groups of forceps. One is the type used for traction only (this is the most common) and the other group is the type used for rotation and traction. The latter are very infrequently used, mainly because situations requiring their use are uncommon and secondly because they are not very popular with obstetricians and probably only a proportion of obstetricians are adequately trained in their use.
What are the potential complications of using forceps for delivery?
Most of these are soft tissue injuries to the mother.
There may be bruising or even lacerations to the perineum and vagina.
Occasionally, injury to the vaginal wall escapes detection and presents a few hours later as a painful and progressive haematoma (blood-clot) under the vaginal skin.
Injuries may be sustained to the bladder and/or urethra. This may show in the form of urine retention.
What is a ventouse?
With the ventouse, a metal or silastic (soft) cup is applied to the scalp. Vacuum is created in the cup, exerting a grip on the scalp skin. If it is a metal cup, the scalp skin is sucked into the cup, while with the soft rubber (silastic) type, the cup moulds itself on the fetal head to fit like a cap. Controlled traction is then applied but this has to be synchronized with uterine contractions and maternal effort. This is an important safety feature of the ventouse.
Are there any important differences between a metal cup and a silastic(soft) ventouse cup?
Not really. They are both equally efficient and just as safe as each other. The metal cup has been around for much longer and the silastic cup only since the early 1970s. However, many obstetricians probably prefer the soft silastic cup, because it is more user-friendly and, in theory at least, has less potential to cause harm to the mother or baby.
As for fetal complications, scalp haematoma (blood clot) is probably more common with ventouse than with forceps.
A complication that is unique to the ventouse but which is exceptionally rare is loss of hair in infancy for the baby.
The most common feature, which parents notice immediately, is the swelling on the baby's head where the ventouse cup has been applied. Metal cups produce a bigger swelling. It takes up to 72 hours for this swelling to disappear. It does not appear to trouble the newborn unduly, because the feeding and sleeping pattern is never disturbed. It is called a chignon. (see picture, right)