Fetopelvic disproportion (FPD) refers to the inability of the fetal head to pass through the maternal pelvis; it occurs in 1% to 3% of all primigravidas. This can be related to pelvic capacity or fetal factors. In absolute FPD, the fetal head is too large for the maternal pelvis, so that vaginal birth cannot be safely achieved and cesarean delivery is required. Normally, the fetus delivers in the occiput-anterior position, assuming a flexed attitude, and with a suboccipitobregmatic diameter of 9.5 cm. If the fetal head takes other positions (occiput-posterior, brow), the delivering diameter of the head is larger, 11.5 cm and 13.5 cm, respectively. Most fetuses presenting with this larger diameter will not fit through the maternal pelvis.
Any contraction of the pelvis will impede the passage of the fetus through the birth canal. The maternal pelvis can be contracted at the inlet (defined as a diagonal conjugate of 11.5 cm); at midpelvis (defined as 15.5 cm—the sum of the interishial spinous and posterior sagittal diameters of the midpelvis); or at the pelvic outlet (defined as an interischial tuberous diameter of 8 cm or less). In relative FPD, the fetus may be delivered vaginally if a favorable combination of other factors can be achieved: efficient uterine contractions; favorable fetal attitude, presentation, and position; maximization of maternal pelvic diameters; adequate molding of the fetal head; adequate expulsive efforts by the mother; and adequate stretching of maternal soft tissues.
FPD can lead to prolonged labor, with delayed engagement of the fetal head in the pelvis and increased risk of umbilical cord prolapse. Prolonged labor can place the mother at risk for dysfunctional uterine contractions, fluid and electrolyte imbalance, exhaustion, hypoglycemia, uterine rupture, need for operative delivery, and postpartum hemorrhage. Risks to the fetus include hypoxia, hypoglycemia, acidemia, and infection. Vaginal delivery may be difficult in these patients, with increased risk of maternal vaginal, cervical, and perineal lacerations; fractured sacrum or coccyx; fetal birth asphyxia; shoulder dystocia (difficult delivery because of fetal shoulder position); and traumatic birth injuries, especially cervical spine, nerve, clavicle, and cranial injuries. Some women who experience FPD that resulted in a cesarean delivery with one infant are able to deliver a subsequent infant vaginally.
The cause of FPD can be attributed to maternal and fetal factors. Maternal factors include inability of the pelvic soft tissues to stretch adequately and inadequate diameters of the maternal bony pelvis. Contractures of the maternal pelvis may occur in one or more diameters of the pelvic inlet, midpelvis, or pelvic outlet. Fetal macrosomia (fetal weight 4000 g), incomplete flexion of the fetal head onto the chest, occiput posterior or transverse fetal position, and inability of the fetal head to mold to the maternal pelvis all contribute to the syndrome.
Nursing care plan assessment and physical examination
Patients may have a family history of fetal macrosomia or pelvic contractures. Any personal history of rickets, scoliosis, or pelvic fracture should also be noted. Gestational diabetes, which may contribute to fetal macrosomia, may be present. Ask the patient about her prior deliveries to ascertain whether she has delivered an infant vaginally before.
Determine the pelvic type of the woman. Android and platypelloid pelvic classifications are not favorable for a vaginal birth; the gynecoid and anthropoid pelvis classifications are present in 75% of all women and are favorable for a vaginal birth. Perform an internal exam; the following findings indicate a contracted pelvis and a potential for FPD to occur if the woman becomes pregnant: ability to touch the sacral promontory with the index finger; significant convergence of the side walls; forward inclination of a straight sacrum; sharp ischial spines with a narrow interspinous diameter; and a narrow suprapubic arch.
If FPD is suspected during labor, physical assessment should include pelvic size and shape; fetal presentation, position, attitude, and presence of molding or caput succedaneum of the fetal head (swelling on the presenting part of the fetal head during labor); fetal activity level; maternal bladder distension and presence of stool in rectum; duration, frequency, and strength of contractions; effacement and dilation of the cervix; and descent of the fetal head in relation to the
mother’s ischial spines. Common assessment findings with FPD during labor include delayed engagement of the fetal head, a lack of progress in cervical effacement, and dilation in the presence of adequate uterine contractions. If fetal hypoxia or hypoglycemia occurs, loss of fetal heart rate variability, late decelerations, or fetal bradycardia may be seen on the electronic fetal monitor. Fetal scalp stimulation may fail to elicit heart rate acceleration, and fetal capillary blood pH obtained by scalp sampling may indicate acidosis.
Assess the patient and partner (or other labor support people present) for ability to cope with the difficult labor and ability to maintain a positive self-concept and role performance. Assess the presence of anxiety or fear related to the mother’s or baby’s well-being or to medical interventions such as forceps or vacuum extractor use or cesarean delivery. Feelings of exhaustion, disappointment, or failure are common.
Nursing care plan primary nursing diagnosis: Risk for injury of mother or fetus related to traumatic delivery.
Nursing care plan intervention and treatment plan
Medical management of FPD can include the use of pitocin to induce or augment labor contractions, manual or forceps rotation of the fetus into an occiput anterior position, and vaginal delivery assisted by outlet forceps or vacuum extractor. The cutting of a midline or mediolateral episiotomy is often necessary. If shoulder dystocia occurs, the McRoberts maneuver (extreme flexion of the mother’s legs at the hips) and firm suprapubic pressure may accomplish delivery. In some cases, intentional fracture of the infant’s clavicle is used to accomplish delivery in the presence of severe shoulder dystocia. When vaginal delivery appears to be impossible or likely to be very traumatic, cesarean delivery is indicated.
Labor patients using analgesia or anesthesia require careful monitoring. For patients using narcotic analgesics, monitor the maternal pulse, blood pressure, and respirations. Watch for signs of respiratory depression. Since intravenous (IV) narcotics readily cross the placenta, observe the fetal heart rate; often, a temporary loss of variability is seen. For patients using regional anesthesia, monitor maternal pulse, blood pressure, and respirations. Check the mother’s blood pressure every 1 to 5 minutes for 15 minutes after the epidural or spinal bolus dosage and then every 30 minutes. Watch for lowered blood pressure.
Have the laboring woman change positions frequently (approximately every half hour) to encourage movement of the fetal head into a favorable position for delivery. Sitting, squatting, positioning on hands and knees, or side lying (alternating sides) may be used. Avoid supine positioning. To encourage rotation of a fetus from a posterior position, suggest lying on the same side as the fetal limbs, or position the mother on her hands and knees. Pelvic rocking exercises may be helpful. Encourage periods of ambulation, as long as the membranes are not ruptured or the fetal head is well applied to the cervix.
Keeping the bladder and rectum empty allows maximum pelvic space for the descent of the fetal head. Fluid and caloric intake should be attended to during labor. In some delivery settings, however, patients may receive IV solutions for electrolyte, fluid, and/or glucose intake. In other settings, ice chips, clear liquids, or a light diet may be encouraged.
In the second stage of labor, instruct the laboring woman to use her diaphragm and abdominal muscles to bear down during contractions. Help her find a comfortable and effective position for pushing, such as supported squatting, semi-sitting, side lying, or sitting upright in bed or on a chair, birthing stool, or commode. Perineal massage during pushing will help decrease the likelihood of an episiotomy or decrease the degree of episiotomy needed.
Provide encouragement of the patient’s coping strategies and assistance with pain management. Nonpharmacologic aids that can be offered include breathing techniques, massage, sacral counterpressure, rocking chair, application of heat or cold, visualization or relaxation techniques, therapeutic touch, music, showering or bathing, companionship, and encouragement. Provide emotional support; families are often unprepared to deal with an unplanned, unwanted cesarean birth.
Nursing care plan discharge and home health care guidelines
Be sure the patient understands the nature of and care of any birth injuries sustained by the infant. Ensure that plans for follow-up care can be carried out by the family. Review use of any pain medication prescribed, as well as nonpharmacologic comfort measures for episiotomy, lacerations, and hemorrhoid care. Instruct the patient to report any increase in perineal or uterine pain, foul odor, fever or flulike symptoms, or vaginal bleeding that is heavier than a menstrual period. Sadness or mood swings that persist beyond 4 weeks should be reported to the physician.