Emergency physicians and prehospital care providers must be familiar with the procedure for delivering a newborn, because transfer to a labor suite before delivery is not always possible. Even physicians who work solely in a pediatric emergency department (ED) and have ready access to inpatient obstetric services need a working knowledge of the steps involved. This chapter focuses on normal spontaneous vaginal delivery and the needs of the adolescent mother. A more extensive discussion of newborn delivery can be found in other textbooks (1,2).

The majority of women delivering babies today do so under the guidance of a health care professional who has special training in obstetrics. Women are encouraged to seek prenatal care and to contact their health care provider at the first signs of labor. Occasionally, however, young women unexpectedly present to the ED or clinic in active labor. It is the physician’s job to decide if the pregnant adolescent can be transferred to a labor and delivery suite or if preparation on site for an imminent delivery is necessary.

The birth rate for teenage mothers has been dropping in the United States over the past decade (3). However, pregnant adolescents are still less likely to seek prenatal care and may be at greater risk for delivering in the ED because of their complex social situations. In fact, the pregnant adolescent may deny being pregnant even as the baby is about to be born. Therefore, providers of emergency care must assess the pregnant adolescent carefully, because her first medical contact for pregnancy may be at the time of delivery.

An adolescent patient presenting in labor is likely to be extremely anxious and complaining of severe abdominal pain. The patient may be screaming hysterically and may be unable to answer medical questions. The physician may have to rely solely on physical examination findings, such as the size of the uterus and observed uterine contractions, to determine that the patient is pregnant and about to deliver.

Labor is defined as progressive dilatation of the uterine cervix in association with repetitive uterine contractions. Normal labor is a continuous process that leads to delivery of the products of conception, including the baby and the placenta. The progress and outcome of labor are influenced by four factors: the bony and soft tissues of the maternal pelvis, the contractions of the uterus, the fetus, and the placenta (4). Just before the beginning of labor, a small amount of blood-tinged mucus is discharged from the vagina. This “bloody show” is a plug of cervical mucus mixed with blood and is evidence of cervical dilatation. Rupture of the fetal membranes occurs before onset of labor in approximately 10% of women. The majority of women whose membranes rupture first go into labor within 24 hours. If labor does not begin within 24 hours, the pregnancy is considered to be complicated by prolonged rupture of the membranes, a risk factor for neonatal sepsis. The diagnosis of true labor can be made when the following features exist: (a) contractions occur at regular intervals, (b) the intervals between contractions gradually shorten, (c) the intensity of contractions gradually increases, (d) discomfort localizes in the back and abdomen, (e) the cervix dilates, and (f) discomfort does not stop with sedation.

Labor is usually divided into three stages. The first stage begins with the onset of labor and ends when dilatation of the cervix is complete. The average duration of the first stage of labor is 8 to 12 hours in the primiparous patient and 6 to 8 hours in the multiparous patient. The progress of the first
stage of labor can be monitored by assessing the cervix for effacement and dilatation and determining the fetal station. Effacement of the cervix is a process in which thinning of the cervix occurs. Effacement is expressed in terms of the length of the cervical canal compared with an uneffaced cervix. For example, 0% indicates no effacement whereas 100% indicates that the cervix is very thin (less than 0.25 cm thick).

Dilatation of the cervical os is expressed by estimating the diameter of the cervical opening by direct palpation with the sterile gloved fingers. Complete dilatation occurs at 10 cm.

Fetal station is determined by the position of the presenting part in relation to the level of the ischial spines. If the presenting part is at the spines, it is at “zero station.” If the presenting part is above the spines, the distance is reported in minus figures (e.g., -1 to -3 cm, or “floating”); if below the spines, the distance is reported in plus figures (e.g., +1 to +3 cm, or “on the perineum”).

The second stage of labor extends from full dilatation of the cervix to complete birth of the infant. This stage varies from a few minutes to 1 to 2 hours. Many adolescents presenting in labor will be primiparous and therefore should be expected to labor for 8 to 12 hours before delivering the infant. The second stage of labor also may be longer in the primiparous patient. The third stage of labor is the period from the birth of the infant until completion of the delivery of the placenta. Separation and delivery of the placenta usually occurs within 10 minutes of the end of the second stage of labor.

The vertex (head) is the presenting part in 95% of deliveries. As shown in Figure 100.1, the sequence of events in vertex presentations is as follows:

Vertex vaginal delivery usually occurs spontaneously. The primary role of the clinician is to help control the process to avoid sudden expulsion of the fetus, which could lead to injuries to the mother and infant.

When a patient presents in labor, the clinician must assess the fetus and mother rapidly. If delivery is imminent, the infant should be delivered before transfer; if not, the mother should be transferred to a delivery suite, where personnel are more accustomed to obstetrical procedures.

If complete cervical effacement and dilatation are evident, immediate delivery may be necessary. Delivery is imminent when the contractions last 1 to 2 minutes and occur at intervals of 2 to 3 minutes, and the infant’s head is at the perineum. An obstetrician should be contacted immediately while the physician prepares for the delivery. A box with equipment for emergency delivery should always be ready in the ED.

Every effort should be made for complicated deliveries to occur in a delivery suite. Heavy maternal bleeding and fetal distress are obstetrical emergencies requiring immediate involvement of an obstetrician and should not be managed by ED or clinic staff alone. Breech presentations also are more difficult to manage and have a higher risk of morbidity and mortality for the mother and fetus.

At least two clinicians should be present at the delivery. One person should attend to the mother while the other attends to the newborn. A support person for the mother, either a family member or another health care provider, also should be present. A social worker may be included as part of the team if the mother is particularly upset and difficult to manage.