Single serum activin a testing to predict ectopic pregnancy.
BACKGROUND
Ectopic pregnancy (EP) is an important cause of maternal deaths in early pregnancy because most fatal cases result from delayed diagnosis and inappropriate investigation.


OBJECTIVE
We evaluated whether the measurement of activin A may be useful in the diagnosis of EP in women with unknown pregnancy location.


METHODS
The study was designed as an open observational study.


METHODS
The study was set in a tertiary referral center for obstetric care.


METHODS
Patients were women with unknown pregnancy location (n = 536) who had complaints of bleeding, pain, or cramping.


METHODS
Interventions included clinical examination; transvaginal ultrasound scan; human chorionic gonadotropin (hCG), progesterone, and activin A measurements; laparoscopy; uterine curettage; and histological examination.


METHODS
Main outcome measures were pregnancy outcomes and evaluation of sensitivity, specificity, and predictive values of hCG, progesterone, and activin A as diagnostic tests for the detection of EP.


RESULTS
Pregnancy outcomes included 155 (28.9%) viable intrauterine pregnancies (IUP), 305 (56.9%) first-trimester spontaneous abortion (SAB), and 76 (14.2%) EP. SAB had the lowest (P < 0.0001) hCG and progesterone concentrations, significantly lower than EP (P < 0.001) and IUP (P < 0.001). In EP, levels were significantly (P < 0.001) lower than in IUP. On the contrary, activin A levels were lowest (P < 0.0001) in EP, significantly lower than in SAB (P < 0.001) and IUP (P < 0.001). IUP had significantly (P < 0.001) lower activin A levels than SAB. When evaluated by the receiver operating curve analysis, activin A at the cutoff of 0.37 ng/ml combined a sensitivity and a specificity of 100 and 99.6%, respectively, for prediction of EP. When activin A concentrations were below the cutoff, the positive predictive value for EP was 97.43%, and 0% for concentrations higher than 0.37 ng/ml.


CONCLUSIONS
Activin A measurement may identify patients at risk of EP with a high sensibility and specificity.
Florio
Pasquale
P
Chair of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics and Reproductive Medicine, University of Siena, Policlinico Le Scotte, viale Bracci, 53100 Siena, Italy.
Severi
Filiberto Maria
FM
Bocchi
Caterina
C
Luisi
Stefano
S
Mazzini
Massimo
M
Danero
Secondo
S
Torricelli
Michela
M
Petraglia
Felice
F
D028341:Activins / Q000097:blood*; D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011271:Pregnancy, Ectopic / Q000097:blood* / Q000175:diagnosis*; D011374:Progesterone / Q000097:blood; D011446:Prospective Studies; D012372:ROC Curve
D006063:Chorionic Gonadotropin; C422405:activin A; D028341:Activins; D011374:Progesterone