Maternal serum vascular endothelial growth factor levels in early ectopic and intrauterine pregnancies after in vitro fertilization treatment.

Fasouliotis SJ, Spandorfer SD, Witkin SS, Liu HC, Roberts JE, Rosenwaks Z.

Fertil Steril. 2004 Aug;82(2):309-13.
https://www.ncbi.nlm.nih.gov/pubmed/15302276