Valerie L. Williams and Amy E. Young
History of present illness
A 24-year-old woman presents to the emergency department complaining of vaginal bleeding. She reports a three-day his- tory of vaginal spotting. She also complains of mild lower abdominal cramping, rated at a level of 4 on a scale of 0–10.
She has been inconsistently taking oral contraceptive pills. She reports her last menstrual period was 10 weeks earlier. Her cycles were previously regular.
She has no prior pregnancies. She is otherwise healthy and has not had prior surgery. She takes no medications other than her birth control pills.
Physical examination
General appearance:Well-nourished, well-hydrated woman in minimal discomfort
Vital signs:
Temperature: 37.0°C Pulse: 105 beats/min
Blood pressure: 95/55 mmHg Respiratory rate: 18 breaths/min Oxygen saturation: 98% on room air HEENT:Unremarkable
Neck:Supple
Cardiovascular:Regular rate and rhythm without rubs, murmurs, or gallops
Lungs:Clear to auscultation bilaterally
Abdomen:Soft, nondistended, with tenderness to palpation in both lower quadrants without associated rebound or guarding. Bowel sounds present
Pelvic:
Speculum examination: Clotted blood in the vaginal vault obscuring the cervix. When blood was removed, the cervix appears closed
Bimanual examination: No cervical motion or adnexal tenderness. Uterus is eight-week size, mobile, and slightly tender to palpation. Cervix is closed on digital exam.
Adnexa are not enlarged
Extremities:No clubbing, cyanosis, or edema Neurologic:Nonfocal
Laboratory studies:
Hb: 9.1 g/dL
Blood type: B positive Urine pregnancy test: Positive
Imaging:A pelvic ultrasound is obtained (Fig. 36.1a,b)
How would you manage this patient?
This patient has a threatened abortion. The ultrasound showed an intrauterine pregnancy with a crown rump length of 20 mm. Normal fetal cardiac activity was present, confirming viability. A quantitative beta-human chorionic gonadotropin (beta-hCG) was unnecessary given these ultrasoundfindings.
Cervical nucleic acid amplification tests (NAATs) for gonor- rhea and chlamydia were negative. The patient was reassured.
A repeat ultrasound is unnecessary unless the patient has increased pain, a dilated cervical os, increased bleeding or passage of tissue, or an inability to obtain fetal heart tones with future assessments. The pregnancy was unplanned but desired. She was reassured that conception while taking oral contraceptive pills has no known adverse affects. Prenatal care was initiated and the patient had an uncomplicated pregnancy and delivery.
Threatened abortion
Threatened abortion refers to a viable intrauterine pregnancy with vaginal bleeding and a closed cervical os. Vaginal bleeding occurs in 15–25% of viable intrauterine pregnancies. The eti- ology is not fully understood, but bleeding may occur at the time of implantation or as the placenta expands (subchorionic hemorrhage) [1]. Bleeding is a presenting symptom of many early pregnancy complications including spontaneous abor- tion, molar pregnancy, and ectopic pregnancy. Spontaneous abortion is the spontaneous termination of a pregnancy prior to 20 weeks’ gestation. It occurs by expulsion of products, failure of the embryo to develop, or death of the fetus in utero.
Clinically, it can be categorized into threatened, missed, inevit- able, incomplete, or complete abortion. Rapid diagnosis is important. Ectopic pregnancy must be ruled out as it can be life threatening. Early pregnancy loss is common and early confirmation allows the patient a broad range of management options under controlled circumstances. In addition to abnor- mal pregnancy, the differential diagnosis includes cervicitis, cervical lesions, polyps at the external cervical os, and a decid- ual reaction in the cervix.
Patients will typically present with vaginal bleeding and mild abdominal or pelvic pain and cramping. Physical examination findings may include an enlarged, minimally tender uterus, blood in the vaginal vault, and a closed cervical
Acute Care and Emergency Gynecology, ed. David Chelmow, Christine R. Isaacs and Ashley Carroll. Published by Cambridge University Press.
© Cambridge University Press 2015.
os. A definite diagnosis cannot be made on clinical assess- ment alone. In a patient like this with bleeding but where her enlarged uterus and otherwise benign examination make ectopic unlikely, determination must be made as to the viability of the pregnancy and the presence of other explan- ations, particularly cervicitis. Evaluation would typically include cervical NAATs for gonorrhea and chlamydia, blood type determination, and an ultrasound. The Rh D antigen is present on fetal erythrocytes as early as 38 days’ gestation.
Rh-negative patients should receive anti-D immune globulin to prevent Rh isoimmunization. A dose of 50μg is effective prior to 12 weeks. Ultrasound is the critical study for establishing the location, gestational age, and viability of a pregnancy.
In this patient, ultrasound clearly shows a normal embryo with normal fetal heart motion, indicative of a viable preg- nancy. Ultrasound can confirm that a pregnancy is viable through observation of fetal heart rate activity, and earlier in pregnancy can confirm early pregnancy loss through failing to observe appropriate milestones. Thefirst definitive sign of an intrauterine gestation is the gestational sac. It appears four to five weeks after the last menstrual period. It is characterized by a sonolucent center surrounded by two symmetrical, thick echogenic rings. This “double decidual sign” (Fig. 36.2) is the ultrasound correlate of a chorionic cavity surrounded by decidualized endometrium. Once a gestational sac is visualized, the mean sac diameter should grow 1 mm per day. A yolk sac appears by the time the mean sac diameter reaches 13 mm. It appears as a 2–6 mm, perfectly round, symmetrical structure
(Fig. 36.3). An embryonic pole appears around week 6 when the gestational sac reaches 20 mm. Fetal cardiac activity should be present at an embryo length of 4 mm. Once fetal cardiac activity is present, as it was in this patient, the risk of pregnancy failure is less than 5% [1,2]. These patients should be managed expectantly. Deviations from these normal mile- stones are indicative of early pregnancy failure. Some can be detected on a single ultrasound examination, others require serial examinations. Ultrasound findings that are diagnostic or highly suggestive of early pregnancy failure are listed in Table 36.1[3].
There are no effective treatments for threatened abortion.
Although often prescribed, there is no evidence to support bed rest to prevent spontaneous abortion in women with first-trimester bleeding [4]. Bed rest has both direct and indir- ect consequences. Immobilization in pregnancy potentially increases the risk for thromboembolism due to the hypercoa- gulable state of pregnancy. Other less direct harms include disruption of social relationships and loss of income.
Progesterone has been prescribed in the past to support a potentially deficient endometrium for implantation. The quality of data to support this practice is poor and progester- one has not been shown to improve outcomes [5]. Reassurance should be given to the patient as bleeding can cause significant maternal anxiety. She should be counseled that bleeding in the first trimester is common and pregnancy loss after the presence of fetal cardiac activity is rare. Physical activity restrictions are unlikely to impact thefinal outcome. Routine prenatal care should be addressed including prenatal vitamins (a)
(b)
Fig. 36.1 Transvaginal ultrasound (a, top;
b, bottom) from a 24-year-old pregnant female with vaginal bleeding.
Table 36.1 Guidelines for transvaginal ultrasonographic diagnosis of pregnancy failure in a woman with an intrauterine pregnancy of uncertain viability*
Findings diagnostic of pregnancy failure Findings suspicious for, but not diagnostic of, pregnancy failure
Crown–rump length of7 mm and no heartbeat Crown-rump length of<7 mm and no heartbeat
Mean sac diameter of25 mm and no embryo Enlarged yolk sac (>7 mm)
Absence of embryo with heartbeat2 weeks after a scan that showed a gestational sac without a yolk sac
Absence of embryo with heartbeat11 days after a scan that showed a gestational sac with a yolk sac
* Adapted from Doubilet et al. [3].
Fig. 36.3 Transvaginal ultrasound demonstrating an intrauterine gestational sac with a yolk sac.
Fig. 36.2 Transvaginal ultrasound demonstrating an intrauterine gestational sac with a double decidual sign.
Case 36: A woman withfirst-trimester vaginal bleeding
and avoidance of tobacco and alcohol. This patient should be encouraged to establish prenatal care.
First-trimester bleeding is associated with an increased risk of spontaneous abortion. This risk is low if fetal cardiac activity is present on ultrasound. Risk factors associated with pregnancy loss include extremes of age (<20 or>35 years) and moderate to severe bleeding. First-trimester bleeding has also been associated with other adverse pregnancy outcomes. In a systematic review of viable pregnancies that hadfirst-trimester bleeding, threatened abortion was associated with a signifi- cantly higher incidence of antepartum hemorrhage, preterm premature rupture of membranes, preterm delivery, intrauter- ine growth restriction, low birth weight, perinatal mortality, 5 minute Apgar score less than 7, and congenital anomalies [6]. These risks are low, however, and there is no data to suggest specific interventions to prevent these adverse events.
First-trimester bleeding alone is not currently an indication for increased fetal or maternal surveillance.
Conception while taking oral contraceptive pills, as occurred in this patient, is not rare. There is no evidence that exposure in early pregnancy to combined hormonal contra- ception is associated with any adverse outcome [7] and bears no relationship to this patient’s bleeding. The patient can be
counseled that conceiving while taking combined hormonal contraceptives poses no risk to the fetus.
Key teaching points
Vaginal bleeding is common in thefirst trimester. Every reproductive-age woman presenting with vaginal bleeding should be evaluated with a urine pregnancy test.
In pregnant females with vaginal bleeding, a pelvic ultrasound is indicated to determine pregnancy location, gestational age, and viability. If fetal cardiac activity is present, the risk of pregnancy loss is low.
Common ultrasound criteria to diagnose early pregnancy failure include a mean sac diameter (MSD) greater than 20 mm without a fetal pole or an embryo length greater than 4 mm without fetal cardiac activity.
Once viability is documented, standard prenatal care should be initiated.
Patients who have threatened abortions may have a slightly increased risk of other adverse pregnancy outcomes including antepartum hemorrhage, preterm premature rupture of membranes, preterm delivery, intrauterine growth restriction, and low birth weight.
References
1. Paul M, Lichtenberg S, Borgatta L, eds.Management of Unintended and Abnormal pregnancy. Chichester, Blackwell Publishing Ltd, 2009.
2. Perriera L, Reeves MF. Ultrasound criteria for diagnosis of early pregnancy failure and ectopic pregnancy.Semin Reprod Med2008;26:373–82.
3. Doubilet PM, Benson CB, Bourne T, Blaivas M. Diagnostic criteria for
nonviable pregnancy early in thefirst trimester.N Engl J Med2013;369:
1443–51.
4. Aleman A, Althabe F, Belizan J, Bergel E. Bed rest during pregnancy for preventing miscarriage.Cochrane Database Syst Rev2005;2:CD003576.
5. Wahabi HA, Fayed AA, Esmaeil SA, Al Zeidan RA. Progestogen for treating threatened miscarriage.Cochrane Database Syst Rev2011;12:CD005943.
6. Saraswat L, Bhattacharya S, Maheshwari A, Bhattacharya S.
Maternal and perinatal outcome in women with threatened miscarriage in thefirst trimester: a systematic review.
Br J Obstet Gynecol2010;117:245–57.
7. World Health Organization.Medical Eligibility Criteria for Contraceptive Use, 4th edn, 2009. Available athttp://
whqlibdoc.who.int/publications/2010/
9789241563888_eng.pdf?ua=1.