Early serum interleukin-8 evaluation may prove useful in localizing abnormally implanted human gestations after in vitro fertilization.

To determine whether early measurement of the serum cytokines interleukin-2 receptor (IL-2R), IL-6, and IL-8 along with human chorionic gonadotropin (hCG) and progesterone (P(4)) can differentiate an ectopic from an intrauterine gestation. Retrospective analysis. University-based fertility center. 75 women who underwent treatment with in vitro fertilization (IVF) and subsequently had an ectopic gestation (n = 15), spontaneous abortion (SAB) (n = 30), or term delivery (TD) (n = 30). Serum samples were obtained 14 (day 28) and 21 (day 35) days after oocyte retrieval. Serum concentrations of IL-2R, IL-6, IL-8, P(4), and hCG. Median hCG readings on day 28 and day 35 were statistically significantly lower in the ectopic gestation group than in those with spontaneous abortion or term delivery. On day 28, median IL-8 levels were lower in the ectopic gestation group when compared with all intrauterine gestations combined. No statistically significant differences in IL-2R or IL-6 levels were noted between groups. Despite P(4) supplementation, median day-35 P(4) levels were lower in ectopic gestation than in the spontaneous abortion and term delivery cycles. In the setting of a rise or plateau in hCG levels, low day-28 IL-8 and day-35 P(4) levels suggested an extrauterine implantation. This assay combination may facilitate earlier diagnosis of an ectopic gestation when pregnancy location is unclear.