[Effect of serum prolactin on cycle stimulation and fertilization of human oocytes]

During cycle stimulation for in-vitro fertilisation (IVF) some patients develop hyperprolactinaemia. Since prolactin (PRL), being an aromatase inhibitor, can interfere with follicular fluid steroid metabolism, we examined the influence of high serum PRL levels on the endocrine response and fertilisation rate of oocytes. 33 consecutive patients stimulated by hMG/hCG for IVF were included in this study. Two groups of patients were established: Group 1 consisting of 18 patients with serum PRL levels less than or equal to 25 ng/ml, and group 2 containing 15 patients, who developed PRL levels greater than 25 ng/ml during cycle stimulation. The serum oestradiol (E2), progesterone (P) and PRL levels 3, 2 and 1 day before and at the day of follicle puncture were evaluated. The decrease of E2 levels at the day of oocyte retrieval was significantly steeper in group 1. The P levels 2 days before oocyte retrieval were significantly higher in group 1 indicating the onset of preovulatory luteinization. Luteinization after the hCG injection was more effective in group 1 resulting in significantly higher P levels. Fertilisation and cleavage rates were significantly higher in patients with normal PRL levels. High serum PRL levels therefore might indicate an interference in follicular and oocyte development leading to oocytes of inferior quality.