Preparation for Precipitous Delivery

Alison Schroth Hayward

Tess Wiskel

OVERVIEW

Emergency medicine providers must be prepared to manage obstetric deliveries at all times. Patients may present to any medical facility with precipitous labor and an emergency clinician may be the only one on-site with no time to call in consultants to assist. The Emergency Medical Treatment & Labor Act (EMTALA) specifically highlights active labor as a medical emergency that must be treated and stabilized to the extent possible prior to transfer, or until the emergent condition has resolved. Precipitous delivery is defined as extremely rapid labor with expulsion of the fetus in less than 3 hours. This occurs in 3% of deliveries in the United States annually.¹ By definition, any birth in the emergency department is precipitous.²

RISK FACTORS

In nulliparous women, precipitous delivery is associated with preterm delivery and teenage mothers, whereas in multiparous women precipitous delivery is associated with hypertensive disorders. There is also a link between cocaine abuse and precipitous delivery.¹^,³

CLINICAL FEATURES

History

Evaluation of a pregnant patient who may be in labor includes a focused history and review of prenatal records if possible. The history consists of three main parts: (1) evaluation for true labor, (2) general obstetric history, and (3) pertinent general medical and surgical history.

To evaluate if the patient is in labor, ask about the onset, frequency, and intensity of contractions; if fluid was expelled to suggest rupture of membranes; and evidence of mucus plug, bloody show, or vaginal bleeding. A description of fetal movements should be obtained as well as signs and symptoms of infection, including fever, chills, or vaginal discharge or lesions.
Obstetric history includes the patient’s parity, prior deliveries including timing, types, and any complications, as well as estimated due date or gestational age, extent of prenatal care, and any complications.
The patient should be asked about medical conditions, surgical history, allergies, current medications, and illicit substance use.⁴

Physical Examination

Vital signs are required in the initial evaluation of any pregnant patient including documenting the fetal heart rate. The fetal heart rate should be monitored before, during, and after contractions and can be done by auscultation, ultrasound, or electronic fetal monitoring. Over 20 weeks of pregnancy, a normal fetal heart rate is between 120 and 160 beats/min.⁴ An abdominal examination should be performed for fundal height, uterine tenderness, and intensity as well as frequency of contractions. Fetal lie or position can also be determined: transverse, longitudinal, or oblique to help aid in delivery decisions. The abdominal examination can help determine fetal presentation and position with Leopold maneuvers. These maneuvers are done on the supine woman, assessing the fundus, either side of abdomen, above the pubic symphysis and along the pelvic inlet. If a smooth, rounded, and hard fetal part is felt at the uterine fundus, this suggests breech presentation. Although useful for experienced obstetricians, the utility of Leopold maneuvers for the emergency provider with an imminent delivery is likely limited.⁵ Ultrasound imaging should ideally be used for this assessment.

Speculum Examination

A sterile speculum examination should then be performed. Initially evaluate externally for lesions that may indicate a herpes infection and then insert the speculum to evaluate for pooling of amniotic fluid, cervical dilation, and effacement. Avoid lubricant to allow performance of a nitrazine test for rupture of membranes. To determine if there are ruptured membranes, evaluate for pooling of fluid in the posterior fornix or use nitrazine strips to detect the basic pH of amniotic fluid (>7.0) compared to the acidic pH of vaginal secretions (4.5-5.0). Amniotic fluid also crystallizes in a pattern called ferning. Fluid can be placed on a glass slide, allowed to dry, and viewed under a microscope where a ferning pattern is identified (see Figure 15.1). If there is vaginal bleeding, both speculum and digital examinations are contraindicated until transvaginal ultrasonography has ruled out placenta previa. If placenta previa is suspected, speculum and digital examinations should be avoided. A pelvic examination can also help identify the presenting part, the part of the fetus closest to the cervical canal. The presenting part can be the fetal head (cephalic), fetal lower body, (breech) or shoulder (if in transverse lie).⁴^,⁵^,⁶

Digital Examination

If there are no contraindications, such as placenta previa or preterm prelabor rupture of membranes, a sterile digital examination should be performed to determine cervical dilation and effacement. The index and middle fingers of a sterile gloved hand can determine dilation as the distance
between cervical edges, 0 to 10 cm, with 10 representing full dilation. Effacement refers to thinning of the cervix, with the length of the cervix decreasing, ranging from 0% to 100%. The digital examination can also characterize cervical consistency, in a range from soft to firm. The position of the fetus relative to the ischial spine known as fetal station should also be determined. This classification ranges from -5 to 5, which refers to centimeters above or below the ischial spines, with 0 indicating the fetal head between the ischial spines and 5 just before crowning.⁵^,⁷

Figure 15.1: Amniotic fluid ferning pattern. (Reproduced with permission from Evans RJ, Evans MK, Brown YMR, Orshan SA, eds. Canadian Maternity, Newborn, and Women’s Health Nursing: Comprehensive Care Across the Lifespan. Philadelphia, PA: Wolters Kluwer; 2015; 317-352.)

DIAGNOSTIC TESTING

Women presenting in labor should have a complete blood count, blood type and screen, and coagulation studies ordered. Additionally, for women without prenatal care, syphilis, hepatitis B, and HIV testing should be considered.⁵

Determining Active Labor

Labor is defined by uterine contractions resulting in cervical effacement and dilation, with active labor referring to cervical dilation greater than or equal to 3 cm accompanied by uterine contractions. Effacement of the cervix occurs with shortening to a circular, thin wall.

Labor consists of three stages: (1) first stage of labor with increasing uterine contractions resulting in effacement and dilation of the cervix to 10 cm; (2) second stage of labor from dilation of the cervix to 10 cm until delivery of fetus; (3) third stage of labor from delivery of the fetus to delivery of the placenta.⁷

The first stage of labor has both a latent phase which is a relatively slow phase up to 3 to 5 cm of cervical dilation and an active phase with relatively rapid cervical dilation to 10 cm. Contractions increase in frequency from approximately every 10 minutes to every minute in the second stage of labor. The second stage of labor lasts from 50 minutes for nulliparas to 20 minutes for multiparas; however, it is highly variable.⁵

Ultrasound

A transabdominal bedside ultrasound can confirm fetal presentation in conjunction with physical examination and Leopold maneuvers. Fetal heart rate can also be determined using ultrasound, with M-mode preferred over pulsed Doppler for potential risks to the fetus given higher thermal index with pulsed Doppler. These theoretical risks are higher during first-trimester organogenesis. Ultrasound should be used with the lowest possible exposures to gain the necessary information; however, there are no documented adverse effects to pregnancies using diagnostic ultrasound.⁸

Triage of Women in Labor

In 1986, Congress enacted the EMTALA to give public access to emergency medical services regardless of ability to pay.⁹ As in all patients presenting to the emergency department, EMTALA requires a medical screening examination of the pregnant woman and fetus without consideration of insurance status or ability to pay.

EMTALA defines labor as the process of childbirth beginning at the latent stage of labor and continuing through the delivery of the fetus and placenta, with stabilization occurring after delivery of the placenta. This defines any stage of true labor as being an emergency medical condition and thus unstable for transfer. If a qualified medical professional, however, is able to determine a patient is in “false labor” after a period of observation, the pregnant woman is considered stable and safe for transfer from the pregnancy standpoint. However, if the patient is in true labor and therefore deemed unstable, transfer is acceptable if the benefits of transfer outweigh the risks. Transfer is deemed unsafe when there is “inadequate time to effect a safe transfer to another hospital before delivery” or the “transfer may pose a threat to the health or safety of the woman or unborn child.”¹⁰

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