Types of Obstetrical Forceps

Forceps are medical devices used to assist childbirth when the head of the infant is stuck in the birth canal. More than 600 types of forceps have been designed; however, fewer than 10 are currently used by medical professionals. The general design of a forceps consists of two blades that fit to the infant's head, shanks that connect the blades to the handle or handles, a locking mechanism that controls how tightly the blades conform to the head, and a handle or handles. Forceps can be divided into three categories: classical, modified classical and specialized.

Classical Forceps

• Classical forceps are used when the infant's head is visible at the opening of the birth canal and does not need to be rotated, or when the infant's head is no more than 1.2 inches from the opening of the birth canal, whether requiring rotation or not. Classical forceps have short shanks, as they are not intended to reach far into the birth canal. Examples include Eliot, Simpson and Wrigley's forceps.

  Eliot forceps have roundly curved blades, which make them more suitable for second and subsequent births, as the roomier birth canal does not mold the infant's head as much as in a first birth. Simpson forceps are similar to Eliot, but the curve of the blades is more elongated, so as to fit properly to the head of an infant that has been molded by passage through the birth canal. Both Eliot and Simpson forceps have a pelvic curve, designed to accommodate the angle of the birth canal, which can be used to apply traction to the infant's head.

  Wrigley's forceps are used when the infant's head is right at the entrance of the birth canal; therefore, they have no pelvic curve and little ability to apply traction.

Modified Classical

• Modified classical forceps designs are classical designs that have been slightly modified to deal with different birthing situations. They generally have longer shanks, and so are used when the infant's head is stuck in the birth canal between 1.2 inches and 2 inches from the birth canal opening. Examples include Tucker-McLane forceps and Luikart Modification forceps.

  Tucker-McLane forceps have rounded blade curvature like Eliot forceps, for fitting a round and unmolded infant head (one that has not changed shape from being squeezed through the birth canal).

  Luikart Modification forceps are "fenstrated"; that is, the blades contain openings to lessen pressure applied to the infant's head. Other than being fenstrated, Luikart Modification forceps are identical to Simpson forceps.

Specialized Forceps

• Specialized forceps are designed for very specific birthing situations and are not used otherwise. Examples include Kielland, Barton and Piper forceps.

  Kielland forceps are used when the infant is between 1.2 and 2 inches from the birth canal opening and needs to be rotated before being assisted out. Kielland forceps have a rounded blade curvature and a very small pelvic curve, to allow rotation without damage to the birth canal.

  Barton forceps have one fixed curved blade and one hinged blade to assist when an infant's head is stuck sideways in the birth canal, facing one of the mother's hips rather than her spine.

  Piper forceps have a deep pelvic curve that is specially designed to assist when an infant's head becomes stuck during a breech birth, which occurs when the legs exit the birth canal before the head.