Childbirth and Emergency Delivery
NORMAL DELIVERY
When an obstetrician is unavailable or when delivery is precipitous, the emergency physician may be required to perform a routine vaginal delivery. When delivery is not imminent, all attempts should be made to obtain obstetric assistance. All expecting mothers presenting to the ED in possible labor should have an IV established, and uterine contraction and fetal monitoring initiated.
Examination
Maternal blood pressure, heart rate, respiratory rate, and temperature are noted.
Elevated maternal blood pressure may indicate preeclampsia.
Elevated maternal temperature may indicate chorioamnionitis.
Fetal heart rate and maternal uterine contractions are evaluated.
The normal, baseline (measured between uterine contractions) fetal heart rate, which is most easily assessed by Doppler analysis or palpation of the umbilical cord if prolapsed, varies from 120 to 160 beats/min.
Tachycardia (rates more than 160) may be associated with early fetal hypoxia, maternal fever, hyperthyroidism, and the administration of atropine or sympathomimetic agents to the mother.
Baseline rates 100 to 120 beats/min represent mild bradycardia; rates less than 100 beats/min are referred to as marked bradycardia.
Bradycardia is noted in patients with fetal hypoxia and when placental transfer of β-blocking or local anesthetic agents occurs.
Changes in fetal heart rate in relation to uterine contractions may provide additional and important information regarding fetal oxygenation.
Early decelerations are defined when slowing of the fetal heart rate and uterine contractions begin together and are thereafter similar in extent; early decelerations are thought to be caused by transient increases in intracranial pressure from head compression, although early fetal hypoxia may be manifest in this manner as well.
Late decelerations in fetal heart rate occur well after a uterine contraction is established and persist after the contraction is over; this pattern represents fetal hypoxia from any cause.
Variable decelerations occur randomly without relation to uterine contractions and commonly represent fetal hypoxia caused by umbilical cord compression.
When fetal hypoxia is diagnosed or suspected, immediate measures to improve oxygenation (administering O2 to the mother, changing her position, and administering a fluid bolus) are indicated, along with emergent obstetric evaluation for cesarean section.
An ultrasound, if available, can aid in the determination of a breech presentation and identify the presence of twins.
A sterile speculum should next be employed to assess for rupture of membranes (suggested by pooling of fluid in the vagina that is nitrazine-positive (turns blue) and exhibits a ferning pattern when dried (for 10 minutes) and examined by microscope.
The presence of meconium-stained amniotic fluid should be noted and preparations made for the potential need to intubate the child for the purposes of deep suctioning if he or she exhibits respiratory distress after delivery.
The presence and amount of vaginal bleeding should be noted.
If significant maternal bleeding has occurred, a manual exam is deferred until placenta previa has been ruled out by US.
Cervical dilation should be assessed with a sterile-gloved hand and ranges from 0 to 10 cm.
Next cervical effacement is assessed and ranges from 0% effacement (cervix is 3-4 cm in length) to 100% effacement (the cervix is completely thinned).
Finally, fetal station is assessed at 1-cm intervals relative to the ischial spines. When the child’s head is 5 cm above the ischial spine, it is a -5 station. When the child’s head is at the ischial spine, it is at 0 station. When the child’s head is at the perineum (crowning), it is a +5 station.
Preparation
Under all circumstances, oral intake should be prohibited, and if time permits, intravenous access should be established and blood obtained for a complete blood count and routine typing.
A “delivery kit” is available in most emergency rooms and will be helpful.
The vulva and perineum should be prepared and draped in the usual fashion.
Sterile gloves should be worn by the physician.
