IUP t Prenatal care FIGURE 19-3 One suggested algorithm for evaluation of a woman with a suspected ectopic pregnancy. aExpectant management, D&C, or medical regimens are suitable options. bMay consider repeat 3-hCG level if normal IUP suspected. 3-hCG = beta human chorionic gonadotropin; D&C = dilatation and curettage; IUP = intrauterine pregnancy; VS
Nondiagnostic t D&Cb Chorionic villi Absent t Treat ectopic pregnancy Present = transvaginal sonography.
With early normal progressing IUPs, Barnhart and coworkers (2004b) reported a 53-percent 48-hour minimum rise with a 24-hour minimum rise of 24 percent. Seeber and associates (2006) found an even more conservative minimal 35-percent 48-hour rise in normal IUPs. With multifetal gestation, this same anticipated rate of rise is expected (Chung, 2006). Despite these guidelines, Silva and colleagues (2006) caution that a third of women with an ectopic pregnancy will have a 53-percent rise at 48 hours. They further reported that no single pattern characterizes ectopic pregnancy and that approximately half of ectopic pregnancies will show decreasing �-hCG levels, whereas the other half will have increasing levels. Also, despite a declining �-hCG level, a resolving ectopic pregnancy may rupture.
With a failing IUP, patterned rates of �-hCG level decline can also be anticipated. Following spontaneous abortion, rates decline by 21 to 35 percent at 48 hours and 68 to 84 percent at 7 days. Of note, these ranges relect that �-hCG percentages drop faster if the initial �-hCG level is higher (Barnhart, 2004a). With resolving PULs, Butts and coworkers (2013) found greater rates of decline that ranged from 35 to 50 percent at 48 hours and 66 to 87 percent at 7 days for starting hCG values between 250 and 5000 mIU/mL.
In pregnancies without these expected rises or falls in �-hCG levels, distinction between a nonliving IUP and an ectopic pregnancy may be aided by additional �-hCG levels (Zee, 2014). Again delay is balanced against the risk from rupture. D&C is an option and provides a quicker diagnosis balanced against normal pregnancy interruption. Before curettage, a second TVS examination may be indicated and may display new informative indings.
A single serum progesterone measurement may clariy the diagnosis in a few cases (Stovall, 1989, 1992). A value exceeding 25 ng/mL excludes ectopic pregnany with 92-percent sensitivity (Lipscomb, 1999a; Pisarska, 1998). Conversely, values <5 ng/mL are found in only 0.3 percent of normal progressing IUPs (Mol, 1998; Verhaegen, 2012). hus, values <5 ng/mL suggest either a nonliving IUP or an ectopic pregnancy. Because in most ectopic pregnancies, progesterone levels range between 10 and 25 ng/mL, the clinical utility of this practice is limited. One caveat is that pregnancy achieved with assisted reproductive technology may be associated with higher than usual progesterone levels (Perkins, 2000).