Test not useful in case of tubal pregnancy is: (AIIMS Nov. 2012)
1. Some physical findings that have been found to be predictive (although not diagnostic) for ectopic pregnancy include the following:
a. Presence of peritoneal signs
b. Cervical motion tenderness
c. Unilateral or bilateral abdominal or pelvic tenderness - Usually much worse on the affected side
a. On pelvic examination, the uterus may be slightly enlarged and soft, and uterine or cervical motion tenderness may suggest peritoneal inflammation.
b. An adnexal mass may be palpated but is usually difficult to differentiate from the ipsilateral ovary.
a. Serum β-HCG levels correlate with the size and gestational age in normal embryonic growth.
b. In a normal pregnancy, the β-HCG level doubles every 48-72 hours until it reaches 10,000-20,000mIU/mL.
c. In ectopic pregnancies, β-HCG levels usually increase less.
d. In early, healthy intrauterine pregnancies, serum levels of β-HCG double approximately every 2 days, an increase in β-HCG of less than 66% would be associated with an abnormal intrauterine pregnancy or an extrauterine pregnancy.
a. Ultrasonography is probably the most important tool for diagnosing an extrauterine pregnancy, although it is more frequently used to confirm an intrauterine pregnancy.
b. Visualization of an intrauterine sac, with or without fetal cardiac activity, is often adequate to exclude ectopic pregnancy.
c. The exception to this is in cases of heterotropic pregnancies, which occur in between 1 in 4000 and 1 in 30,000 spontaneous pregnancies.
5. Definite ectopic pregnancy
a. In the presence of a definite ectopic pregnancy, a thick, brightly echogenic, ringlike structure is located outside the uterus, with a gestational sac containing an obvious fetal pole, a yolk sac, or both.
b. The endometrium could be thick or show pseudo saC.
6. Extrauterine mass
a. The presence of a tender adnexal mass on ultrasonographic images suggests an ectopic pregnancy.
b. HSG is a test for tubal patency.
(Ref: Williams 22nd ed pg 258-262)