Pelvimetry is the measurement of the female

pelvis The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

. It can theoretically identify cephalo-pelvic disproportion, which is when the capacity of the pelvis is inadequate to allow the fetus to negotiate the birth canal. However, clinical evidence indicate that all pregnant women should be allowed a trial of labor regardless of pelvimetry results.

Indication

Theoretically, pelvimetry may identify cephalo-pelvic disproportion, which is when the capacity of the pelvis is inadequate to allow the fetus to negotiate the birth canal. However, a woman's pelvis loosens up before birth (with the help of hormones). A

Cochrane review Cochrane (previously known as the Cochrane Collaboration) is a British international charitable organisation formed to organise medical research findings to facilitate evidence-based choices about health interventions involving health professi ...

in 2017 found that there was too little evidence to show whether pelvimetry is beneficial and safe when the baby is in

cephalic presentation A cephalic presentation or head presentation or head-first presentation is a situation at childbirth where the fetus is in a longitudinal lie and the head enters the pelvis first; the most common form of cephalic presentation is the vertex p ...

. A review in 2003 came to the conclusion that pelvimetry does not change the management of pregnant women, and recommended that all women should be allowed a trial of labor regardless of pelvimetry results. It considered routine performance of pelvimetry to be a waste of time, a potential liability, and an unnecessary discomfort.

Components

The terms used in pelvimetry are commonly used in obstetrics. Clinical pelvimetry attempts to assess the pelvis by clinical examination. Pelvimetry can also be done by

radiography Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeut ...

and

MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...

. Low-dose 3D-rendered CT scans can be used for estimating the main pelvimetry parameters:

History

Traditional obstetrical services relied heavily on pelvimetry in the conduct of delivery in order to decide if natural or operative

vaginal delivery A vaginal delivery is the birth of offspring in mammals (baby, babies in humans) through the vagina (also called the "birth canal"). It is the most common method of childbirth worldwide. It is considered the preferred method of delivery, with l ...

was possible or if and when to use a

cesarean section Caesarean section, also known as C-section or caesarean delivery, is the surgical procedure by which one or more babies are delivered through an incision in the mother's abdomen, often performed because vaginal delivery would put the baby or ...

. Women whose pelvises were deemed too small received caesarean sections instead of birthing naturally. Traditional obstetrics have characterized four types of pelvises: * Gynecoid: Ideal shape, with round to slightly oval (obstetrical inlet slightly less transverse) inlet. * Android: triangular inlet, and prominent ischial spines, more angulated pubic arch. * Anthropoid: the widest transverse diameter is less than the anteroposterior (obstetrical) diameter. * Platypelloid: Flat inlet with shortened obstetrical diameter.

References

{{Pregnancy Obstetrical procedures Pelvis

Indication

Components

History

See also

References