A case-control pilot study of low-intensity IVF in good-prognosis patients

Low-intensity IVF (LI-IVF) is rapidly gaining in popularity. Yet studies comparing LI-IVF to standard IVF are lacking. This is a case-control pilot study, reporting on 14 first LI-IVF and 14 standard IVF cycles in women with normal age-specific ovarian reserve under age 38, matched for age, laboratory environment, staff and time of cycle. LI-IVF cycles underwent mild ovarian stimulation, utilizing clomiphene citrate, augmented by low-dose gonadotrophin stimulation. Control patients underwent routine ovarian stimulation. LI-IVF and regular IVF patients were similar in age, body mass index, FSH and anti-Müllerian hormone. Standard IVF utilized more gonadotrophins (P<0.001), yielded more oocytes (P<0.001) and cryopreserved more embryos (P<0.001). With similar embryo numbers transferred, after ethnicity adjustments, standard IVF demonstrated better odds for pregnancy (OR 7.07; P=0.046) and higher cumulative pregnancy rates (63.3% versus 21.4%; OR 6.6; P=0.02). Adjustments for age, ethnicity and diagnosis maintained significance but oocyte adjustment did not. Cost assessments failed to reveal differences between LI-IVF and standard IVF. In this small study, LI-IVF reduced pregnancy chances without demonstrating cost advantages, raising questions about its utility. In the absence of established clinical and/or economic foundations, LI-IVF should be considered an experimental procedure. Low-intensity IVF (LI-IVF) is increasingly propagated as an alternative to standard IVF. LI-IVF has, however, never been properly assessed in comparison to standard IVF. Such a comparison is presented in the format of a small pilot study, matching LI-IVF cycles with regular IVF cycles and comparing outcomes as well as costs. The study suggests that LI-IVF, at least in this setting, is clinically inferior and economically at best similar to standard IVF. LI-IVF should, therefore, as of this point not be offered as routine IVF treatment but only as an experimental procedure.