Active Labor and Out-of-Hospital Delivery



Active Labor and Out-of-Hospital Delivery


Kenneth J. Knowles II



OUT-OF-HOSPITAL ACTIVE LABOR


Overview

An increase in out-of-hospital births has occurred in the United States since 2004, from a rate of 0.87% of all births to 1.61% in 2017.1,2 With this increase, the United States has the most out-of-hospital births of any developed country.3 A majority of the out-of-hospital births are planned home births or births at a stand-alone birthing center; however, there is still a proportion of out-of-hospital births that are unplanned. There is a statistically significant increase in early and overall neonatal mortality for births that occur at home.4,5 Whether planned or unplanned, prehospital providers should be aware of the increasing frequency and have the equipment, training, and skills necessary to manage an out-of-hospital delivery. The recognition and appropriate management of a patient in active labor can have a significant impact on the morbidity and mortality of both mother and newborn; therefore, all prehospital providers should have the necessary training and mastery of these skills.


Obstetric History

When evaluating a patient in active labor, key history should be obtained to guide the provider in the field as well as the receiving emergency department or obstetrics unit in directing appropriate care. Providers must assess how far along the pregnancy is by determining the gestational age. Many patients know the gestational age but, if unsure, the provider can determine the gestational age based on the estimated due date (EDD) or the date of the last menstrual period (LMP). Nagel’s rule calculates the EDD using the date of LMP plus 9 months and 7 days.6

Nagel’s rule: EDD = LMP + 9 months and 7 days

If a patient is unsure of her LMP, EDD, or the gestational age, the provider must then rely on their physical examination as a rough estimate. If the fundus is at or above the level of the umbilicus, it can be estimated that the gestational age is at least 20 weeks.7

The prehospital provider should determine the number of previous pregnancies (gravidity) and previous deliveries (parity), as this may impact the decision to transport or stay on scene. A patient with previous deliveries is more likely to rapidly progress through the stages of labor, increasing the chance of an out-of-hospital delivery. In patients with a previous delivery, ask if it was vaginal or via cesarean section. In patients with a previous cesarean section, the major
complication of vaginal birth after cesarean (VBAC) is an increased risk of uterine rupture.8 This risk may increase the need for emergent cesarean section. The prehospital provider should clarify if there were any complications in previous pregnancies. Finally, determine the extent of the patient’s prenatal care.

Information regarding the patient’s current symptoms should be obtained such as the onset of contractions as well as the frequency and duration of each contraction. The provider should note the patient’s membrane status and, if rupture of membranes has occurred, note the color of the amniotic fluid. The normal color of amniotic fluid is clear or blood-tinged. Meconium in the amniotic fluid is suspected if the fluid is described as thick and a greenish-brown color.6 Presence of vaginal bleeding and whether or not the patient is feeling fetal movement should also be noted.


Hypertension in Pregnancy

A full set of vital signs is mandatory in the evaluation of a pregnant patient, with special attention given to the blood pressure. The definition of gestational hypertension is a systolic blood pressure 140 mm Hg or or greater or a diastolic blood pressure 90 mm Hg or or greater, which occurs at 20 weeks’ gestation or later.9 Preeclampsia occurs when the patient develops proteinuria or signs of end-organ dysfunction.9 It may be difficult for a prehospital provider to distinguish gestational hypertension from preeclampsia, but it is important to realize that these patients are at higher risk for developing eclampsia. Eclampsia is the development of seizures in the setting of preeclampsia.10 Recognition is essential as this condition remains one of the most common causes of maternal morbidity and mortality.10 Eclampsia can develop from 20 weeks’ gestation up to 4 weeks’ postpartum.11

The initial care of eclampsia is similar to normal seizure management including prevention of maternal hypoxia and trauma.10 Benzodiazepines may be administered if magnesium is not available. The goal of treatment is to prevent future seizures, more so than treating the current seizure, using magnesium sulfate with an initial loading dose of 4 to 6 g IV over 20 to 30 minutes followed by an infusion of 2 g/h for a minimum of 24 hours.10,11 Most emergency medical services (EMS) do not carry doses this high but it is appropriate to initiate magnesium therapy to the best of the service’s ability, either by a standing treatment protocol or via medical control direction. Treatment with magnesium is only a temporizing measure, with the ultimate treatment of eclampsia being delivery.


Terminology

There are certain terms that are important to know in order to create a standard and unified language.


Trimester

The duration of a pregnancy is divided into trimesters. Weeks 1 through 13 comprise the first trimester. The second trimester is weeks 14 through 27, and the third trimester is weeks 28 through 42.


Rupture of Membranes

The spontaneous rupture of membranes is usually associated with a gush of clear or blood-tinged fluid.6


Prelabor Rupture of Membranes

Membrane rupture that occurs before the onset of contractions is referred to as prelabor rupture of membranes (PROM). The previous term for this was premature rupture of membranes.12


Preterm Prelabor Rupture of Membranes

Preterm prelabor rupture of membranes (PPROM) is defined as PROM that occurs before 37 weeks’ gestation.12


Prolonged Rupture of Membranes

Prolonged rupture of membranes is considered when delivery does not occur within 18 hours of membrane rupture.6


Preterm Birth

A preterm birth is a delivery that occurs before 37 weeks of gestation.11



True Labor Versus False Labor

Providers should distinguish between true and false labor, also known as Braxton Hicks contractions. False labor is defined as contractions that do not result in cervical change and are often irregular, brief, and only present in the lower abdomen.6,13 In contrast to false labor, contractions of true labor do result in cervical change and gradually increase in frequency, intensity, and duration.6


Signs and Symptoms of Labor

Many early findings of labor can be nonspecific such as menstrual-like cramping, low back ache, pressure sensation in the vagina or pelvis, vaginal discharge of mucus, and mild, irregular contractions.13 Although mild and irregular contractions can be a normal finding at any stage of pregnancy, true labor is more likely when the contractions become more regular and increase in frequency, intensity, and duration.13 A bloody show, due to the expulsion of the cervical mucus plug, is a fairly dependable indicator of true labor.14 The bleeding from a bloody show is usually light in volume, dark red in color due to the venous origin, and mixed with the mucous components of the cervical plug.14


Stages of Labor

There are three stages of labor. The first stage begins with regular contractions and ends with full cervical dilation.6 The first stage of labor is divided into a latent phase and an active phase. The latent phase is a slow dilation of the cervix, and the active phase is rapid dilation beginning when the cervix is 3 cm dilated.14 On average, the duration of the first stage of labor ranges from 8 hours for a nulliparous woman to 5 hours in multiparous women.14 The second stage of labor is from full cervical dilation until delivery. The third stage of labor is from the delivery of the infant until the delivery of the placenta.6

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Dec 30, 2020 | Posted by in EMERGENCY MEDICINE | Comments Off on Active Labor and Out-of-Hospital Delivery
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