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A Case of Abruptio Placentae with a History of H1N1 Influenza Infection


     Y.S. was a 19 y/o Hispanic female who presented to the labor and delivery ward complaining of abdominal pain and vaginal bleeding. The patient was G1 P0, and at 33+1 weeks. Estimated date of confinement was 8/28/09 by ultrasound, as stated by the patient. She reported that while at work and at around 12:00 p.m. she felt she needed to use the restroom. She states that when she attempted this, there was a ‘gush” of blood into the toilet. Soon after this incident she called her husband, whom suggested that she call an ambulance. The ambulance arrived, and brought her to the nearest hospital. Upon the 12:39 arrival to the emergency department, the patient was rapidly triaged, and immediately sent, while still on stretcher, to the Labor and Delivery ward for further evaluation.

     On arrival to labor and delivery the patient was seemingly stable and in no acute distress. A nurse attempted electronic fetal monitoring, but fetal heart tones were difficult to attain. Initial rudimentary ultrasound indicated baseline heart tones of 120 beats per minute. Concerns related to extensive bleeding and decelerated fetal heart tones warranted a more extensive ultrasound to rule out abruptio placentae. The ultrasound tech and surgeon on call were contacted. The ultrasound demonstrated positive findings for placental abruptio. Additionally, the fetal heart tones began to severely decelerate, with a nadir of 85 beats per minute. The surgeon was at bedside during these findings, and the decision was made to perform an emergent cesarean section. The baby was delivered at 13:10, as was the placenta. Amniotic fluid was bloody, with clots. APGAR scores were 0 at one minute and 0 at 5 minutes. The stillborn male weighed 3lb 10oz. The placenta was completely abrupted with many clots on the maternal side. Pathological examination of the placenta reported a severe placental abruption (100%), with no evidence of inflammation or infarction.

Patient Information:

PMH: Patient reported being hospitalized at 28 week’s gestation for a high fever of three      days duration. The patient reports testing positive for H1N1 strain of influenza,      and received Tamiflu as treatment. No other history was attained.

PSH: Denies any previous surgeries.

OBHx: This was the patient’s first pregnancy. She reported 6 total prenatal visits.

GYNHx: Menarche at 17 y/o q 28 days x 7 days
     Patient denies history of birth control usage.
     Patient denies history of sexually transmitted infection.

Social Hx: Denies tobacco/ETOH/Use of street drugs.
     Employed fulltime at a dental clinic.
     Patient lives with husband. Patient is on Medicaid, has completed one year of      college, and denies domestic abuse.
Medications: Prenatal vitamins, last dose taken the day before.

Allergies: NKDA

Review of Symptoms:

     Patient denied any problems or symptoms, except for mild cramping in the      abdomen, which began 2 hours prior to onset of bleeding.

Physical Exam:

Vitals: BP: 128/92, P: 101, R: 20, T: unavailable
Weight: 128
Height: 5’0
General: Cooperative, frightened female. Large amount of blood grossly seen on clothes and      shoes.
HEENT: EOMI, no lesions appreciated
Neck: No lymphadenopathy, no lesions detected
CVS: Not available.
LU: Not available
ABD: Firm to palpation, non tender.
Uterine contractions: Non detected
GU: Not available
Reflexes: Not available
Extremities: Not available

Note: Due to the urgency of the situation and the rapid onset of action a more comprehensive physical exam and evaluation was not possible.



     Placental abruption is defined as premature separation of the normally implanted placenta. Classification of placental abruption takes into account whether the hemorrhage is acute or chronic, concealed or clinically evident, and mild or severe. There are many different causes of abruption, yet the end result is the same; blood leaks into the decidua basalis, forming a hematoma. The hematoma shears off additional vessels causing more bleeding and increased pressure, thus the separation progresses. Eventually, if severe, the clot becomes so significant that the placenta is unable to exchange adequate nutrients and waste to sustain the fetal demands.

how it is clinically seen?:
Clinically, one sees vaginal bleeding and abdominal pain, with uterine hypertonicity, non-reassuring fetal heart tones, and tachysystole. Abruption poses significant risk to the mother and baby. The incidence of placental abruption is reported to be 1 in 100 births, and in 1 in 830 deliveries the abruption is so severe that it results in stillbirth. [1-11] It is of note, that peak incidence of placental abruption is at 24-26 weeks gestation. [1] The diagnosis for placental abruption is largely clinical, and must be in the differential diagnosis for any pregnant female presenting with vaginal bleeding, abdominal pain, preterm labor and trauma.

Risk Factors:
     Risk actors for placental abruption can be separated into those of acute origin, medical and obstetric risk factors, and behavioral risk factors. Acute events are mostly correlated with trauma, and motor vehicle accidents top this list. Additionally, swift uterine decompression (rupture of membranes in polyhydramnios or delivery of first twin) can prompt placental abruption. Medical and obstetric risk factors include, hypertensive diseases of pregnancy, diabetes, chronic renal insufficiency, high fever, chorioamnionitis, premature rupture of membranes, past or current ischemic disease of the placenta, and inherited thrombophilia.[12-17] Behavioral factors include smoking, and cocaine use.

     Complications of placental abruption are divided into those affecting the mother, and those involving the fetus. Maternal complications include: hypovolemia, disseminated intravascular coagulopathy, renal failure, adult respiratory distress syndrome, multisystem organ failure, and death. Complications to the fetus include: growth restriction, fetal hypoxemia or asphyxia, preterm birth, or perinatal death. [9, 11-14]

How to manage?:

     Initial management of suspected abruption includes continuous fetal monitoring, at least one wide-bore intravenous line, close vitals monitoring, and Foley catheter placement to monitor urine output, which should be maintained at above 30 ml/hr. In addition, a CBC, blood type and rh, and coagulation study should be obtained. If possible, after the preceding actions have been completed a sonographic examination should be performed in hemodynamically stable patients. The presence of sonographic features of abruption has high positive predictive value. [15] If the mother is stable, and the fetal heart tracing is reassuring, vaginal birth is possible. If the fetal heart tracing is non-reassuring, then cesarean delivery is indicated. One study in 2003, suggested that a decision to delivery of less than 20 minutes is associated with better outcomes than decision to delivery of 30 minutes in cases involving fetal bradycardia. [16] A population based cohort study in 2001, found that perinatal mortality in pregnancies affected by abruption was 119 per 1000 births, yet births not complicated by abruption had 8.2 per 1000. [13] Approximately one half of the deaths were due to preterm labor, and most of the rest were due to intrauterine asphyxia, which has been found to happen when at least fifty percent of the placenta has detached. [11] In subsequent pregnancies, women with a prior abruption have several fold increased risk of having another abruption.[3,17-21] The risk of recurrence for a prior abruption patient is 5-15% compared to general population baseline of 0.4-1.3 percent. [3, 22, 23] Following two consecutive abruptions the risk of another rises to 20-25 percent. [21, 24] This risk is also higher following a severe abruption rather than a mild one. [21] Of note, when the abruption leads to fetal demise, there is a 7 percent incidence of the same result in a future pregnancy. [25] All of the preceding data strongly suggest that in a patient with a previous abruption, it is advisable to have a scheduled delivery as soon as the fetal lungs are mature. 

     As was documented in the case above, the patient had been hospitalized at 28 weeks gestation following 3 days of high fever. The patient was diagnosed with the H1N1 strain of influenza, and was given a course of oseltamivir. Very little is currently known about the effects of this flu strain on pregnant women and the fetus. A recently published article from the Lancet evaluated 34 confirmed or probable cases of H1N1 in pregnant women reported to the CDC from April 15 to May 18, 2009. The study was the first major study examining the H1N1 flu and its effects on the pregnant female and the fetus. This particular study found that pregnant women may be at an increased risk for complications from the pandemic H1N1 strain. The study did not encounter any placental abruptions, but as data accumulates it will be important to look at effects on the fetus, and if there is a correlation with H1N1 infection and placental abruption. Indeed, the CDC reports that “an excess of influenza-associated deaths among pregnant women were reported during the pandemics of 1918–1919 and 1957–1958. Adverse pregnancy outcomes have been reported following previous influenza pandemics, with increased rates of spontaneous abortion and preterm birth reported.” Furthermore, the Lancet, and CDC recommended prompt treatment with anti-influenza drugs if flu is suspected, as the benefits of treating, so far, outweigh the risks; current guidelines recommend oseltamivir, or zanamivir. Oseltamivir is orally introduced, and zanamivir is inhaled as a powder. Therefore, oseltamivir has greater systemic absorption. These medications are known to be most effective when used within 48 hours after initial symptom onset, but presently, it is recommended to use these drugs at any time during a influenza infection in a pregnant female, whether within the 48 hour time frame or not. Furthermore, current recommendations from the CDC recommend chemoprophylaxis for pregnant women exposed to probable H1N1 virus, for ten days past the last exposure date. In this case, zanamivir may be the prudent choice as it has less systemic absorption, but providers must be wary of pulmonary contraindications, which then would warrant oseltamivir usage. It is important to note that oseltamivir and zanamivir are class C rated during pregnancy, yet, as stated above, the benefits appear to outweigh the risks at the present time.
     The patient described above had approximately 5 weeks separating her flu hospitalization and the massive abruption. Although this writer was unable to obtain the information from that hospital stay, three days of high fever, as reported by the patient, certainly could have detrimental effects on the placenta. Fever has been found to be a risk factor for abruption. [4] It is possible that the febrile episode initiated an insidious placental abruption, leading ultimately to the complete abruption described above. The current recommendations from the CDC are to treat any hyperthermia during pregnancy with acetaminophen.
     It is well known that the pregnant female is in an immunologically deficient state, thus the American College of Obstetrics and Gynecology, as well as the American Academy of Family Physicians has recommended that all pregnant women, and those who may become pregnant receive a flu vaccination. Of the two available H1N1 flu vaccines available, the Trivalent Influenza Vaccine (TIV), which is injected into the patients arm is the only one recommended for pregnant women. The Live Attenuated Influenza Vaccine (LAIV) which is nasally administered is not recommended for pregnant women, but they need not avoid any persons who have received this vaccination.
     The arriving flu season presents great opportunity. There appear to be adequate stocks of H1N1 vaccine, which would allow health care to be prepared to contend with a flu epidemic. Our level of preparedness is impressive, and professionals in health care must act to encourage those most at risk to take advantage of vaccinations and treatments. Additionally, this season will also provide the research world with ample data regarding pregnancy, H1N1 flu, and our methods of protecting this population against the flu. 


1.Ananth, CV, Getahun, D, Peltier, MR, et al. Placental abruption in term and preterm gestations: evidence for heterogenicity in clinical pathways. Obstet Gynecol 2006; 107:785

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26. Online:

Article By: John Richey MSIII
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