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Delivery by Kielland's forceps has largely been abandoned by the current generation of obstetricians. The suggestion to consign the instrument to the obstetric museum was first made in the 1980s1–4, and the final death knell was sounded by the studies comparing it unfavourably with the ventouse5–9. In many hospitals in the UK, Kielland's forceps are no longer available, and a whole generation of practising obstetricians are incapable of using them safely. Surveys in the UK and the USA suggest that vacuum extraction is more popular10–13. It is, therefore, almost inevitable that the use of Kielland's forceps will decline, unless the experience of senior obstetricians is imparted to those in training. Within decades a superbly designed instrument, ideal for treating malposition of the fetal head, will be lost to our profession.

In 1915, Christian Kielland (1871–1941) first described his forceps to achieve delivery from the mid-pelvis in cases of malrotation (occipito-posterior and occipito-transverse positions of the fetal head)14,15. Kielland (sometimes spelt Kjelland) originally recommended his forceps to be applied to the fetal head arrested in a high transerve or occipito-posterior position. He suggested that the anterior blade was first inserted by passing it in front of the baby's head with the concavity of its cephalic curve facing the pubic bone. In this position the blade was then passed high into the uterus until the tip was seen to ‘tent up’ the anterior abdominal wall. The blade was then rotated through 180° and then drawn downwards until it fitted against the side of the fetal head. The posterior blade was then inserted directly into the hollow of the sacrum. The two blades were then locked, traction being made in a posterior direction, with a rotational force being added between contractions to bring the occiput to an anterior position. The original Kielland manoeuvre was associated with trauma, including uterine rupture, and therefore fell into disrepute.

When caesarean section came to be regarded as a safe procedure the use of forceps for the delivery of the unengaged head was no longer justified. However, Kielland's forceps were widely used in cases of malrotation with the fetal head in the midcavity of the pelvis. The mode of application of the forceps was more conventional by today's standards. Where possible, the forceps were applied directly. Therefore in a direct occipito-posterior position each forceps blade would be passed directly into the sacral hollow in turn, and slid into position alongside the fetal head. In the case of an occipito-transverse position, the anterior blade would be slid over the fetal head first, followed by the posterior blade into the hollow of the sacrum. Occasionally, the ‘wandering’ application would be used, where the anterior blade was inserted posteriorly into the hollow of the sacrum, and then rotated to the correct position over the anterior side of the fetal head. The posterior blade was applied directly. Rotation was then effected, followed by delivery with traction. In any instrumental delivery adequate analgesia is essential, and in more recent years this has meant regional analgesia.

Kielland's forceps are superbly designed for delivery in the case of malposition. The forceps are light, and easy to manoeuvre. Various modifications of Kielland's forceps (e.g. Moolgaoker's forceps) are cumbersome, heavy and complicated. The absence of a pelvic curve makes the instrument ideally suited for rotation, and sliding lock allows asynclitism to be corrected easily. Correction of the position of the fetal head is achieved by a rotational force on the forceps. The sensation when the head reaches the occipito-anterior position is characteristic. Delivery is effected by traction on the forceps. The forceps are ideally suited for rotation, more than any other instrument.

The ventouse has largely superseded rotational forceps. Although ease of use (that is, less skill is required) of the ventouse may partly explain this trend, the general conclusions of systematic reviews suggest an advantage for the ventouse, a reduction in maternal trauma and anal sphincter injuries16–19. The differences are not great, and are not significant at long term follow up6. What is apparent from the systematic reviews is that forceps are more effective in achieving vaginal delivery. In experienced hands, it is a safe and effective instrument.

The studies undertaken comparing the ventouse and ‘forceps’ are confusing and inconsistent with regard to the use of Kielland's forceps. The randomised trials comparing the ventouse with forceps tend to group ‘rotational’ and ‘nonrotational’ deliveries together, and therefore it is impossible to draw any conclusions about the safety and complications of Kielland's forceps. Because of the decline in Kielland's forceps, randomised trials comparing the two methods of delivery in cases of malposition would be difficult to conduct, and in view of the rarity of important outcomes such as maternal and fetal trauma, would require large numbers of participants. The comparison would therefore need to be conducted at a national level, either by a multicentre study, or by the use of a national database. Such national databases are already highly developed in Scandinavia.

One major disadvantage of the ventouse is its higher rate of failure to achieve a vaginal delivery when compared with forceps16. In a randomised trial the ‘Silc-cup’ vacuum extractor had a success rate of 73% compared with 90% with forceps20. The failures occurred in three groups: women with large babies, prolonged second stage of labour and occipito-posterior position21. These are cases for which the Kielland's forceps are recommended. It has been shown that metal vacuum cups could exert 30% more traction than soft cups22, and thus to avoid the high failure rates with the ventouse it is clearly necessary to use soft cups in a discriminatory fashion. One of the largest randomised trials in the UK8 comparing ventouse and forceps used a detailed protocol for the use of the ventouse, the metal or silastic cup being used depending on the position of the fetus. The favourable results for the ventouse were due in part to the soft cup being used only for straightforward ‘lift-out’ deliveries. Where the baby was large, there was excess caput or the head was deflexed the anterior Bird cup was used, and the posterior Bird cup for occipito-posterior positions where the head was deflexed23. In many hospitals in the UK the silastic cup only is used, the metal cups being unavailable. A high failure rate might be expected, particularly where the fetus is in an occipito-posterior or occipito-transverse position.

Clearly there is a dichotomy with regard to instrumental vaginal delivery. Either the infant is in an occipito-anterior position, in which case the silastic vacuum cup is recommended; or there is a malposition, in which case the metal cup or the Kielland's forceps should be used. Where no metal cup is available, Kielland's forceps is preferred.

It has been shown that the risk of damage increases significantly in babies who are exposed to attempts at both vacuum and forceps delivery24. ‘Failed ventouse’ is thought by some obstetricians to be an absolute contraindication to forceps delivery. However, where there are no signs of fetal hypoxia a trial of forceps may be justified. If the first attempt at delivery is with the silicone cup a trial of Kielland's forceps or of vacuum extraction with a metal cup should be considered. This situation can be avoided, however, by using the most appropriate instrument for the initial attempt at delivery.

Instrumental vaginal delivery remains as an area of obstetrics where dexterity, experience and sound judgment are required. A trained obstetrician should be able to assess each operative delivery on its merits, and use the most suitable instrument, the silastic cup, the metal cup or rotational forceps. Obstetricians who possess the skill of Kielland's forceps delivery should impart this skill to the next generation before it is lost. Obstetricians should be versatile in the use of both Kielland's forceps and vacuum extraction.

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