Blood loss following noncomplicated transvaginal oocyte retrieval for in vitro fertilization

Transvaginal ultrasonic follicle puncture has now become the method of choice for oocyte retrieval among most in vitro fertilization (IVF) units. The procedure, which involves puncture then aspiration of ovarian follicles, inevitably results in damage to the fine vascular network of blood vessels on the ovarian surface and theca interna layer, and tends to produce varying degrees of blood loss. The transvaginal ultrasonically guided retrieval of oocytes can be considered noncomplicated when the procedure does not result in injury to iliac vessels, trauma to pelvic viscera, or iatrogenic pelvic infections (1, 2), which would necessitate laparoscopy and or laparotomy. The aim of our study was to quantify the amount of blood loss that should be considered “normal” after noncomplicated transvaginal ultrasonically guided retrieval of oocytes, to characterize the factors that are related to the amount of blood loss, and to identify the patients who have the highest risk of hemorrhage. Before beginning our study, we performed a power analysis of potential participants. We established the sample size after evaluating the number of women of fertile age in our area, and we used the previous years’ data to calculate the prevalence of sterility problems and the percentage of women who had undergone in vitro fertilization. Thus, our prospective study was based on a sample of 220 women, 25 to 42 years old, who underwent assisted reproduction from January 1998 to May 1999. We excluded the women who had mild or severe ovarian hyperstimulation syndrome or thrombocytopenia, those who were taking anticoagulant drugs, and those who were overweight (body mass index 25 to 30) or obese (body mass index greater than 30). The study was approved by the local hospital ethics committee and all of the participants gave written informed consent.