Ultrasonography and β-hCG Ectopic pregnancy

a pregnancy not in uterus



algorithm of management of pregnancy of unknown location, is, positive pregnancy test no pregnancy found on transvaginal ultrasonography. if serum hcg @ 0 hours more 1000 iu/l , there no history suggestive of complete miscarriage, ultrasonography should repeated possible.

where no intrauterine pregnancy seen on ultrasound, measuring β-human chorionic gonadotropin (β-hcg) levels may aid in diagnosis. rationale low β-hcg level may indicate pregnancy intrauterine yet small visible on ultrasonography. while physicians consider threshold intrauterine pregnancy should visible on transvaginal ultrasound around 1500 iu/ml of β-hcg, review in jama rational clinical examination series showed there no single threshold β-human chorionic gonadotropin confirms ectopic pregnancy. instead, best test in pregnant woman high resolution transvaginal ultrasound. presence of adnexal mass in absence of intrauterine pregnancy on transvaginal sonography increases likelihood of ectopic pregnancy 100-fold (lr+ 111). when there no adnexal abnormalities on transvaginal sonography, likelihood of ectopic pregnancy decreases (lr- 0.12). empty uterus levels higher 1500 iu/ml may evidence of ectopic pregnancy, may consistent intrauterine pregnancy small seen on ultrasound. if diagnosis uncertain, may necessary wait few days , repeat blood work. can done measuring β-hcg level approximately 48 hours later , repeating ultrasound. serum hcg ratios , logistic regression models appear better absolute single serum hcg level. if β-hcg falls on repeat examination, suggests spontaneous abortion or rupture. fall in serum hcg on 48 hours may measured hcg ratio, calculated as:



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{\displaystyle hcg~ratio={\frac {hcg~at~48h}{hcg~at~0h}}}

an hcg ratio of 0.87, is, decrease in hcg of 13% on 48 hours, has sensitivity of 93% , specificity of 97% predicting failing pul. majority of cases of ectopic pregnancy have serial serum hcg levels increase more expected iup (that is, suboptimal rise), or decrease more expected failing pul. however, 20% of cases of ectopic pregnancy have serum hcg doubling times similar of iup, , around 10% of ep cases have hcg patterns similar failing pul.