Sonographic assessment of symphyseal joint distention intra partum

Abstract

Objective. To elucidate whether there is a distention of the symphysis pubis intra partum and whether a history of pelvic pain during pregnancy is associated with increased distention during delivery. Methods. Using ultrasonography, the width of the symphysis pubis was measured on two occasions during delivery; firstly, upon engagement of the fetal head in the pelvic inlet, secondly, when the largest diameter of the fetal head was at the level of the ischiadic spines. The first measurement was conducted in 24 patients, the second measurement was obtained in 16 of these patients. Results. The average width of the symphysis pubis at onset of labor was 5.8 mm. The average distention of the symphysis during labor was 1.1 mm for those without pelvic pain and 0.2 mm for those with a history of pelvic pain during pregnancy (p = 0.02). Parity and ensuing birth weight had no statistically significant influence on degree of distention. Conclusion. The symphyseal distention during labor is minimal regardless of parity and size of the child. No added symphyseal distensibility was found in patients with a history of pelvic pain.

Neandertal birth canal shape and the evolution of human childbirth

“…In addition, the neonate's anteroposterior head dimensions have 132 mm of space in Tabun's outlet (Tabun's transverse outlet dimensions), compared with 122 mm in a human outlet (human female mean anteroposterior outlet dimensions). Hormonal relaxation of ligaments during human childbirth enlarges the anteroposterior outlet dimensions by Ϸ10%-20%, but the transverse dimensions by only Ϸ5%-7% (33,34). Assuming that ligament relaxation was the same in Neandertals as in humans, the neonate's anteroposterior head dimensions during childbirth would have 139-141 mm of space in Tabun, compared with 134-146 mm in humans.…”

MR Obstetric Pelvimetry: Effect of Birthing Position on Pelvic Bony Dimensions

“…We are aware that this limitation prevented us from measuring the influence of pregnancyrelated joint laxity in late gestation, for which there is ample documentation [6,[19][20][21][22][23][24][25]. However, changes in pelvic dimensions observed in nonpregnant women should become even more pronounced during delivery.…”

Peripartum Pubic Symphysis Separation: A Case Report and Review of the Literature

“…However, several authors have advocated ultrasound as an initial imaging study as there is no ionizing radiation exposure, and it can assess the extent of the lateral symphysis separation as well as the superior-inferior displacement of the symphysis. [5][6][7][8] In some cases, computed tomography of the pelvis is necessary to assess for other pelvic trauma or retroperitoneal hemorrhage. 1 There has also been a report of the use of magnetic resonance imaging in the assessment of peripartum pubic symphysis diastasis that demonstrated the subtle soft-tissue injuries that accompanied very minimal symphysis separations in symptomatic patients.…”