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64
are delivered at highly specialized hospitals rather than being transported there after
birth [25, 26]. For this reason, every effort should be made to transfer a pregnant
patient with preeclampsia/eclampsia to a tertiary care facility prior to delivery, espe-
cially if she is far from term.
Emergency Medical Treatment and Active Labor Act (EMTALA) imposes spe-
cic obligations on health care providers to perform a medical screening examina-
tion and to provide stabilizing treatment to any patient with an emergency medical
condition. In pregnant patients, this includes both the mother and fetus. Several
steps must be taken before transfer can take place: (1) Assessment of fetal viability,
gestational age, and well-being. (2) Stabilizing treatment with control of blood pres-
sure and convulsions, and seizure prophylaxis with a loading dose of magnesium
sulfate if appropriate (3) Maternal laboratory assessment (complete blood count and
platelet count, liver enzymes, creatinine, urine protein) 4) Fetal monitoring if avail-
able (5) Consultation of obstetric/perinatal team (6) Transmission of all records for
review [27].
Special Considerations
Postpartum Preeclampsia, Eclampsia, andHELLP
Most hypertensive emergencies associated with pregnancy occur antepartum or
within the rst 48h after delivery. Blood pressure has been shown to rise over the
rst week after delivery and peaks on postpartum days 3–6. This is likely due to a
combination of physiologic uid mobilization, volume expansion, and the use of
medications such as nonsteroidal anti-inammatory pills (for pain) and ergot deriv-
atives such as ergometrine or methylergonovine (for treatment of uterine atony), all
of which can cause hypertension [28].
Why preeclampsia, eclampsia, and HELLP occur after delivery—considered the
denitive treatment—is unknown. There is some evidence that immediate postpar-
tum curettage improves blood pressure and other outcomes for patients with severe
preeclampsia, which suggests that there may be biological activity in the lingering
material present in the uterus after the delivery of the placenta [10].
Preeclampsia and eclampsia may occur up to 6weeks postpartum. The estimated
prevalence of postpartum preeclampsia ranges from 0.3% to 27.5% of all pregnan-
cies in the United States; this wide range likely reects a combination of unrecog-
nized mild disease and patients that present to non-obstetric healthcare settings
[29]. The incidence of postpartum eclampsia appears to be increasing and now rep-
resents about 13–16% of all cases of eclampsia [30–33].
Many women in the postpartum period may present to the ED for evaluation
instead of being seen by their obstetric provider. Early treatment of preeclampsia,
eclampsia, and HELLP syndrome in the postpartum patient hinges on whether the
clinician recognizes late presentations of these disorders. The criteria for diagnos-
ing postpartum preeclampsia, eclampsia, and HELLP syndrome are the same as in
the antepartum period. Women who develop postpartum preeclampsia and
W. Sherman et al.
65
eclampsia may have had no evidence of hypertensive disease during their pregnancy
in up to 63% of cases [28]. In the postpartum period, headache is the most common
presenting symptom of preeclampsia and is present in up to 60–78% of patients [28,
29, 34]. It should be noted that headache could also herald other potentially serious
conditions. An estimated 10–11% of postpartum patients with headache have criti-
cal conditions such as intracranial bleed, stroke, mass, or cerebral venous sinus
thrombosis [35]. Patients with postpartum preeclampsia may also present with
abdominal pain, chest pain, shortness of breath, visual changes, or increased swell-
ing, similar to antepartum patients. Preeclampsia and eclampsia in the postpartum
period should be managed the same as in the antepartum period by controlling
blood pressure and initiating magnesium sulfate for seizure prophylaxis/control.
HELLP syndrome may develop rst in the postpartum period in up to 30% of
cases and should be considered in any patient with abdominal pain, nausea, or vom-
iting [36]. Postpartum presentations of this disorder usually occur within 48h fol-
lowing delivery, and patients may deteriorate suddenly. Studies on the natural
history of this disorder suggest that uncomplicated HELLP patient lab parameters
including platelets and LDH levels should improve by the 4th postpartum day, or
with 72h of platelet nadir [37]. Severe cases of HELLP with evidence of dissemi-
nated DIC, platelet counts <20,000 cells/microL, and ascites may have delayed lab
recovery [38]. In general, however, if lab values continue to worsen after the 4th day
postpartum, diagnoses other than HELLP syndrome should be strongly considered
[4]. As platelets rebound from HELLP syndrome, they may signicantly overshoot
normal values [37].
Management of HELLP diagnosed in the postpartum period is similar to the
antepartum period and includes magnesium sulfate, blood pressure control, and
close monitoring of vital signs and laboratory values. IV uid resuscitation should
be administered conservatively for hemodynamically stable patients. The threshold
for prophylactic platelet transfusion is controversial and depends on patient-specic
factors. Actively bleeding postpartum patients with HELLP with severe thrombocy-
topenia or anemia should be transfused similarly to any bleeding thrombocytopenic
or anemic patient. Steroids have not been shown to improve clinical outcomes con-
sistently and are not currently recommended by ACOG [4, 39]. Therapeutic plasma
exchange does not help with this condition.
Because fetal status is no longer a consideration in the postpartum patient,
women with life-threatening conditions or who are at high risk of developing seri-
ous complications associated with HELLP syndrome, postpartum preeclampsia,
and eclampsia may be better managed in an intensive care unit than on a postpar-
tum unit.
Preeclampsia Less Than 20Weeks ofGestation
As stated, preeclampsia is dened as occurring after 20 weeks of gestation. Very
rarely, preeclampsia can occur before 20 weeks, usually in abnormal pregnancies
complicated by triploidy, trophoblastic disease, or antiphospholipid antibody
5 Hypertensive Disorders ofPregnancy
66
syndrome [40–44]. Case reports have been published describing preeclampsia before
20weeks without these abnormalities, and authors refer to this occurrence as “pure”
preeclampsia [45, 46]. This is an extremely unusual phenomenon and not likely to be
diagnosed in the ED.A much more common scenario—and potential pitfall for emer-
gency clinicians—would be a patient presenting with signs/symptoms of preeclamp-
sia who is farther along in her pregnancy than previously thought (incorrect dates) and
is in fact greater than 20weeks of gestation. Emergency clinicians should conrm the
gestational age of any pregnant patient presenting to the ED with hypertension and
ensure the most accurate pregnancy dating method was used.
Chronic Hypertension withSuperimposed Preeclampsia
Pregnant patients with chronic hypertension presenting to the ED can be especially
challenging for emergency clinicians. These patients are at risk for developing
superimposed preeclampsia, and clinicians should not be reassured that the patient’s
blood pressure is “always high.” Indeed, 13–40% of patients with chronic hyperten-
sion will go on to develop superimposed preeclampsia [47, 48], and these women
have the highest rates of adverse maternal-fetal outcomes of all hypertensive disor-
ders of pregnancy. In 2022, the Chronic Hypertension and Pregnancy (CHAP) study
concluded that more aggressive medical treatment of chronic hypertension may
help to reduce the incidence of superimposed preeclampsia with or without severe
features [49]. Superimposed preeclampsia should be suspected when there is a sud-
den increase in blood pressure that was previously well controlled, new-onset pro-
teinuria or sudden increase in proteinuria, or if any other signs/symptoms of
end-organ damage are present. ED management of chronic hypertensive patients
with superimposed preeclampsia is the same as patients with preeclampsia.
Long-Term Outcomes andPrevention
Women affected by preeclampsia experience an increased risk of developing chronic
hypertension, heart failure, coronary artery disease, and stroke [50]. The adjusted
risk increases twofold, except for heart failure, in which a fourfold increase was
found [51]. Those with a history of preeclampsia were also found to have an
increased risk of death from ischemic heart disease, myocardial infarctions, and
stroke [52]. Preeclamptic women are also at increased risk for long-term arrhyth-
mias with supraventricular tachycardias being the most associated arrhythmia in
preeclamptic women [53].
With the increased long-term risk of multiple cardiovascular diseases after pre-
eclampsia, careful consideration must be taken into place when treating a patient
with a history of preeclampsia. A thorough pregnancy history (with a focus on
hypertensive disorders in pregnancy) should be obtained in a primiparous or mul-
tiparous patient.
Measures can be taken to help prevent or delay the onset of preeclampsia. The
U.S.Preventative Services Task Force and ACOG both recommend a daily 81mg
W. Sherman et al.
67
aspirin for pregnant individuals who are at high risk for preeclampsia [54]. Inhibition
of platelet aggregation, reduced vasoconstriction, and anti-inammatory effects are
the basis by which aspirin may help preeclampsia [53]. New pregnancy diagnoses
are commonplace in the emergency department so clinicians should take this into
consideration for women who are high risk for preeclampsia. It is recommended
that daily aspirin therapy be initiated between 12 weeks and 28 weeks gestation and
ideally before 16 weeks [54].
Summary
Hypertension complicates many pregnancies and is a leading cause of maternal and
fetal morbidity and mortality. It is critical that emergency clinicians assess the blood
pressure of pregnant patients presenting to the ED for any reason and screen for
signs/symptoms of end-organ damage. Early identication and appropriate manage-
ment of the hypertensive disorders of pregnancy can improve outcomes for both
mother and baby. Treatment of preeclampsia and eclampsia can begin in the ED and
includes blood pressure control and seizure prophylaxis with magnesium sulfate.
The denitive treatment of preeclampsia, eclampsia, and HELLP syndrome is deliv-
ery. Depending on maternal condition and gestational age, transfer to a tertiary
facility may be required.
Key Points
• Pregnant patients that are greater than 20weeks of gestational age and up to
6weeks postpartum presenting to the ED for any reason and are noted to be
hypertensive must be evaluated for signs and symptoms of end-organ damage to
rule out preeclampsia.
• Proteinuria is no longer required to make the diagnosis of preeclampsia.
• Labetalol, hydralazine, and nifedipine are all considered rst-line treatments for
severe hypertension in pregnancy.
• Patients with preeclampsia with severe features require magnesium sulfate ther-
apy for prophylaxis against eclampsia.
• Magnesium sulfate is the drug of choice for treatment of eclamptic seizures.
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© The Author(s), under exclusive license to Springer Nature Switzerland AG 2025
J. Borhart (ed.), Emergency Department Management of Obstetric
Complications, https://doi.org/10.1007/978-3-032-10261-4_6
6
Prelabor Rupture ofMembranes
andPreterm Labor
LiliS.Wei, EricK.Wei, andBrianSharp
Introduction
Prelabor rupture of membranes (PROM) and preterm labor are challenging obstetric
complications for any emergency physician. Both require prompt and effective
diagnosis and management to optimize maternal and neonatal outcomes. In the
United States, preterm delivery complicates approximately one in ten births and is
a signicant contributor to perinatal morbidity and mortality. In 2022, preterm birth
and low birth weight was the cause of 14% of all infant deaths [1]. Preterm PROM
complicates approximately 2–3% of all pregnancies in the United States and term
PROM occurs in 8% of pregnancies [2]. When preterm PROM occurs, several com-
plications can result, including infection, premature delivery, placental abruption,
and umbilical cord prolapse.
Complications of late pregnancy including PROM and preterm labor are infre-
quently managed in the emergency department (ED). Many hospitals have protocols
where these patients are triaged directly to a labor and delivery (L&D) unit for fur-
ther management by an obstetrician. However, an obstetrician or L&D unit may not
always be immediately available, and emergency physicians must be comfortable
initially managing these complications. Fetal and maternal morbidity can be reduced
L. S. Wei (*)
Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, Northwell
Health, Northern Westchester Hospital, Mt. Kisko, NY, USA
e-mail: lwei5@northwell.edu
E. K. Wei
Department of Emergency Medicine, NYC Health + Hospitals/Bellevue, Icahn School of
Medicine at Mt. Sinai, New York, NY, USA
e-mail: Eric.wei@nychhc.org
B. Sharp
BerbeeWalsh Department of Emergency Medicine, University of Wisconsin,
Madison, WI, USA
e-mail: bsharp@medicine.wisc.edu
72
with accurate diagnosis of PROM and preterm labor, intervention to delay preterm
delivery, timely administration of corticosteroids, and, in certain cases, magnesium
sulfate and antibiotics.
Prelabor Rupture ofMembranes
Prelabor rupture of membranes (PROM) is rupture of membranes before labor and
can occur at term or preterm. Preterm PROM refers to the rupture of membrane
before labor that occurs prior to 37weeks of gestation. Preterm PROM complicates
approximately 2–3% of all pregnancies in the United States [2]. During pregnancy,
the amniotic membrane protects the fetus from infection while providing an envi-
ronment that allows for both growth and movement. The fetal membranes are com-
posed of several distinct layers. The inner layer closest to the fetus is the amnion and
the outer layer is the chorion. A spongy layer separates the amnion from the chorion
and allows the amnion to slide along the chorion. The chorion rmly adheres to the
uterine decidual tissue [3].
Membrane rupture may occur for several reasons. At term it occurs due to nor-
mal physiologic weakening of membranes, while preterm membrane rupture can
occur for several pathologic conditions [4, 5]. At an earlier gestational age, one of
the most common reasons is intraamniotic infection [6]. A previous history of pre-
term PROM is a risk factor for either preterm PROM or preterm labor in future
pregnancies. Other risk factors include short cervical length, history of vaginal
bleeding during pregnancy, low socioeconomic status, cigarette smoking, and illicit
drug use [7, 8]. Other cases may be without any identiable risk factors.
Labor is the ideal result of ruptured membranes at term; however, when the fetus
is preterm, labor that often follows membrane rupture is problematic given the asso-
ciated fetal complications of prematurity.
Emergency Department Evaluation
Initial evaluation of the patient presenting with PROM includes determination of
duration, amount, and persistence of uid leakage. Classically, patients report a sud-
den gush of uid with continuous leakage. If the clinical history is unclear, patients
should be asked questions about recent vaginal or cervical infections, recent sexual
activity, douching, and previous pelvic surgery.
The next step in diagnosis is determining the gestational age of the pregnancy
based on patient’s reported last menstrual period (LMP) or previous ultrasonogra-
phy scans. If the patient is unable to report either menstrual or prior ultrasound dat-
ing, an ultrasound can be obtained in the ED to determine gestational age.
Ultrasounds become less accurate for obstetric dating with advancing gestational
age. Generally, ultrasound dating has an accuracy of +/− 2weeks in the second tri-
mester and +/− 3weeks in the third trimester [9]. In addition to estimating gesta-
tional age, obstetric ultrasound is indicated to determine the fetal presentation, an
L. S. Wei et al.
73
Table 6.1
Testing for PROM
Method Result
Commercial rupture of [fetal]
Membranes test
Positive/negative
Fetal bronectin (FFN) Positive/negative
Nitrazine Amniotic uid pH7.1–7.3 turns nitrazine paper yellow;
>7.3 is blue
Ferning Amniotic uid crystallizes and appears like a fern,
identied under microscope
Pooling on speculum exam Amniotic uid collects in the posterior vaginal vault
Ultrasonography (not diagnostic) Oligohydramnios (dened as amniotic uid index (AFI)
<5 cm or maximum vertical pocket (MVP) <2 cm)
estimated fetal weight, and amount of amniotic uid. Oligohydramnios, dened as
amniotic uid index (AFI) ≤5cm or maximum vertical pocket (MVP) <2cm by
objective measurement on sonogram, may be present in PROM but is not diagnostic.
Examination of patients with possible PROM should be performed under sterile
conditions with a sterile speculum to minimize the risk of introduction of infection.
Avoid direct digital examination of the cervix in women with PROM because the
risk of subsequent infection has been shown to be proportional to the number of
digital examinations [10]. Table 6.1 lists the components of diagnosing
PROM.During the speculum exam, the clinician should begin by visualizing the
cervix to assess for dilation and effacement and look for any presenting fetal parts
or umbilical cord prolapse. The diagnosis of PROM is conrmed by visualization of
passing of uid from the endocervical canal into the vagina and/or a “pool” of uid
in the posterior vaginal vault. Having the patient cough or applying gentle fundal
pressure may assist in visualizing the passage of uid. If in doubt, the uid can be
tested via nitrazine test for pH.The pH of normal vaginal uid is 3.8–4.5, while
amniotic uid pH is 7.1–7.3 [2]. Blood or semen contamination, alkaline antisep-
tics, and bacterial vaginosis can increase the vaginal pH and lead to a false-positive
nitrazine test. Alternatively, false-negative test results may occur with prolonged
membrane rupture and minimal remaining uid. Vaginal uid may also be applied
to a microscope slide and examined for the presence of ferning or tested for the
presence of fetal bronectin (FFN). FFN is an adhesive glycoprotein found in amni-
otic uid and placental tissue and may be useful as a predictor of preterm birth. It is
a sensitive but nonspecic test for PROM; a negative test result suggests intact
membranes, but a positive test result is not diagnostic.
Several commercial tests are available for diagnosis of PROM and are reported
to have high sensitivity. However, high false positive rates in patients with intact
membranes and symptoms of labor have also been reported [11]. Of note, the manu-
facturer’s instructions are to use the commercial tests in combination with tradi-
tional clinical assessments for the diagnosis of PROM.Recently, the U.S.Food and
Drug Administration released an advisory for clinicians to be cautious with these
tests as there is concern for “misuse, overreliance, and inaccurate interpretation of
lab test results from rupture of membrane tests” when the tests are used in isola-
tion [12].
6 Prelabor Rupture ofMembranes andPreterm Labor