Pressure on branches of the lumbosacral nerve plexus during labor may manifest as complaints of intense neuralgia or cramplike pains extending down one or both legs as soon as the head descends into the pelvis. If the nerve is injured, pain may continue after delivery, and variable degrees of sensory loss or muscle paralysis can result. In some cases, there is footdrop, which can be secondary to injury at the level of the lumbosacral plexus, sciatic nerve, or common fibular (peroneal) nerve (Bunch, 2014). Components of the lumbosacral plexus cross the pelvic brim and can be compressed by the fetal head or by forceps. The common ibular nerves may be externally compressed when the legs are positioned in stirrups, especially during prolonged second-stage labor.
Obstetrical neuropathy is relatively infrequent. Wong and associates (2003) evaluated more than 6000 puerperas and found that approximately 1 percent had a conirmed nerve injury. Lateral femoral cutaneous neuropathies were the most
The Puerperium 661 common (24 percent), followed by femoral neuropathies (14 percent). A motor deicit accompanied a third of injuries. Nul liparity, prolonged second-stage labor, and pushing for a long duration in the semi-Fowler position were risk factors. The median duration of symptoms was 2 months, and the range was 2 weeks to 18 months.
Nerve injuries with cesarean delivery include the iliohypo gastric and ilioinguinal nerves (Rahn, 2010). These are dis cussed further in Chapter 2 (p. 15).
Pain in the pelvic girdle, hips, or lower extremities may follow stretching or tearing injuries sustained at normal or diicult delivery. Magnetic resonance (MR) imaging is often informative (Miller, 2015). One example is the piriformis muscle hematoma shown in Figure 36-6. Most injuries resolve with antiinlammatory agents and physical therapy. Rarely, there may be septic pyomyositis such as with iliopsoas muscle abscess (Nelson, 2010; Young, 2010).
Separation of the symphysis pubis or one of the sacroiliac synchondroses during labor leads to pain and marked interference with locomotion (Fig. 36-7). Estimates of the frequency of this event vary widely from 1 in 600 to 1 in 30,000 deliveries (Reis, 1932; Taylor, 1986). In our experiences, symptomatic separations are uncommon. heir onset of pain is often acute during delivery, but symptoms may manifest either antepartum or up to 48 hours postpartum (Snow, 1997). In suspected cases, radiography is typically selected. The normal distance of the symphyseal joint is 0.4 to 0.5 cm, and symphyseal separation > 1 cm is diagnostic for diastasis. Treatment is generally conservative, with rest in a lateral decubitus position and an appropriately itted pelvic binder (Lasbleiz, 2017). Surgery is occasionally necessary in some symphyseal separations of more than 4 cm (Kharrazi, 1997). The recurrence risk is high in subsequent pregnancy, and Culligan and coworkers (2002) recommend consideration for cesarean delivery.
FIGURE 36-6 Inhomogeneous mass of the right piriformis muscle consistent with a hematoma (yellow cursor measurements) is compared with the normal-appearing left piriformis muscle (yellow arrow), postpartum day following vaginal delivery of a 2840-g newborn. The patient had pain over the pubic bone and pain with ambulation. A shuffling gait was noted, and she had difficulty with leg elevation when supine. The patient was treated with physical therapy and analgesics. A pelvic binder was applied, and a rolling walker was provided. She improved quickly and was discharged home on postoperative day S.