Case study from Hospital Antonio Lorena, within the obstetrical service.

HPI:  37 yo pregnant female of 32 weeks and 4 days gestation presents to the emergency room because of significant vaginal bleeding over the past hour.  The patient also reports some contractions, but denies any continuing abdominal pain.  She denies any recent trauma.

Past Obsetrical History:
-G3 P2002 (3 gestations, 2 full term, 0 pre-term, 0 miscarriages, 2 currently living)
-2 previous SVD’s (spontaneous vaginal delivery)
-Last birth was 9 years ago by SVD, weighed 3800 grams
-No previous obstetrical complications or morbidity

Past Medical History:  None
Past Surgical History:  None
Family History:  Unremarkable, no history of twins or multiple gestations
Social History:  Patient lives with her husband in the Santiago district of Cuzco.  Denies any smoking, alcohol or other drug use during her pregnancy.  Denies any spousal abuse.  Completed elementary school, currently works as a housewife.  Low economic status.

Current Gestational History:
-G3 P2002
-Date of Last Menstration:  4/11/11
-Estimated Date of Delivery:  1/22/12
-Estimated Gestational Age (based on dates):  32 4/7 weeks
-No prior antenatal care

Physical Exam:
Vital Signs:  Stable (BP – 110/70, P – 72)
General Appearance:  No apparent distress, appeared clinically stable
Skin:  Elastic, capillary reflex < 2 seconds

Uterine Height:  30 cm
Fetal Lie: Longitudinal
Contractions:  Present
Fetal Heart Tones:  144 x minute

Cervical Exam:  Deferred

Brief Differential Diagnosis:
– Placenta Previa
– Placental Abruption
– Displacement of Cervical Mucous Plug
– Premature Rupture of Membranes
– Cervicitis
– Vaginitis/Vulvovaginitis

Diagnostic Tests: Transabdominal Ultrasound (see below)
Number of Gestations:  1
Lie:  Longitudinal
Presentation:  Cephalic
Position:  Right
Fetal Heart Tones:  144 x minute
Fetal Movements:  Present
Placenta:  Total occlusion of internal cervical os

Discussion:  Based on this patient’s clinical presentation, placenta previa was suspected and further confirmed by transvaginal ultrasound.  Placenta previa is defined as the presence of placental tissue over or adjacent to the cervical os, and can be described within a variety of possibilities:

• Total placenta previa—the internal os is covered completely by placenta
• Partial placenta previa—the internal os is partially covered by placenta
• Marginal placenta previa—the edge of the placenta is at the margin of the internal os
• Low-lying placenta—the placenta is implanted in the lower uterine segment such that the placental edge does not reach the internal os, but is in close proximity to it
• Vasa previa—the fetal vessels course through membranes and present at the cervical os

Diagram showing different categorizations of placenta previa.

Classically, the clinical presentation of placenta previa is painless vaginal bleeding in the second or third trimester.  In contrast, placental abruption, classically presents with painful vaginal bleeding.

Risk Factors:
Below is a list of several risk factors that are associated with placenta previa.  Our patient had several, including increased parity, increased maternal age, and residence in higher altitude.

List of associated risk factors for placenta previa. From "Bates Obstetrics."

Diagnostics:
Transabdominal (96-98% sensitivity) or transvaginal (almost 100% sensitivity) ultrasounds are the diagnostic methods of choice for confirming placenta previa.  Ultrasound can not only diagnose placenta previa, but further define it as complete, partial, or marginal, which can have implication in how to manage the patient. Placenta previa that is diagnosed before 24 weeks of gestation should be managed conservatively, and a repeat sonogrophy should be done between 28 and 32 weeks’ gestation.  Many cases of placenta previa that are diagnosed in the second trimester will resolve by the third trimester.

Patient's ultrasound image consistent with complete placenta previa (total occlusion). Compare with the 2 textbook images shown below.

Textbook image of placenta previa from "William's Obstetrics." Transabdominal sonogram of the placenta (white arrowheads) behind the bladder covering the cervix (black arrowheads).

Textbook image of placenta previa from "William's Obstetrics." Transvaginal sonographic image of the placenta (arrows) completely covering the cervix adjacent to the fetal head.

Cervical Examination:
A cervical examination was deferred in our patient, as appropriate management.  Because of the risk of provoking life-threatening hemorrhage, a digital examination is absolutely contraindicated until placenta previa is excluded.  Such digital cervical examination is never permissible unless the woman is in an operating room with all the preparations for immediate cesarean delivery—even the gentlest digital examination can cause torrential hemorrhage.

Management:
Women with a previa may be considered in one of the following categories:

• The fetus is preterm and there are no other indications for delivery
• The fetus is reasonably mature
• Labor has ensued
• Hemorrhage is so severe as to mandate delivery despite gestational age.

Furthermore, as part of management, large-bore intravenous access and baseline laboratory studies (hemoglobin, hematocrit, platelet count, blood type and screen, and coagulation studies) should be obtained. If the patient is less than 34 weeks’ gestation, administration of antenatal corticosteroids should be undertaken (as was done in our patient) as well as an assessment of the facility’s emergency resources for both the mother and the neonate.

Some pictures below show the cesarean operation of our patient, and the delivery of a healthy baby:

Prepping the patient before surgery.

First incision.

Extracting the baby...

The baby is then transferred to the pediatrics team where they begin any necessary resuscitation.

Closing up the fascia and fatty tissues.

Sewing up the initial incision within the skin.

Final product after suturing is complete.

References:
1.  Williams Obstetrics.  23rd ed.  New York: McGraw-Hill Medical, c2010.  
2.  Gabbe: Obstetrics: Normal and Problem Pregnancies, 5th ed. Churchill Livingstone, c2007.
3.  Emedicine