What treatments prevent miscarriage after recurrent pregnancy loss?
A subsequent RCT comparing PLI with placebo among 79 women with primary RSA of unknown cause again found no significant difference in live birth rates (89% vs 71%, respectively).4 However, an additional RCT evaluating PLI (32 patients) vs placebo (19 patients) among women with unexplained primary RSA did find significantly higher birth rates with PLI (84% vs 25%; P=.001). This small study used different techniques than previous PLI studies.5
A later meta-analysis of 5 RCTs including a total of 246 patients also found that IVIG did not improve the subsequent live birth rate for women with a history of primary or secondary RSA (OR=0.98; 95% CI, 0.45–2.13).6
Aspirin. An RCT involving 54 pregnant women (mean age 32.7 years) with a history of primary RSA of unknown cause (negative standard workup) evaluated 50 mg of aspirin daily (n=27) vs placebo (n=27).7 The method of blinding was not reported.
The live birth rate was identical for the 2 groups (88%). A second (unblinded) trial randomized 805 women from a large referral center (mean age 34 years) with a history of first-trimester RSA (not differentiated between primary and secondary RSA) of unknown cause to either 75 mg of aspirin daily or no treatment.8 There was no significant difference in the live birth rate between those who took aspirin (251/367; 68.4%) and those who did not (278/438; 63.5%; OR=1.24; 95% CI, 0.93–1.67).
Recommendations from others
The American College of Obstetricians and Gynecologists (ACOG) states that “it has not been shown conclusively that progesterone treatment or corpus luteum support (HCG) influences pregnancy outcome for women with recurrent spontaneous abortion.”9 ACOG does not recommend immunotherapy, citing a lack of demonstrated efficacy (IVIG and PLI), a lack of standards for cell storage and administration, and a risk profile similar to that of blood transfusion (PLI). They recommend “couples with otherwise unexplained recurrent pregnancy loss should be counseled regarding the potential for successful pregnancy without treatment.”
