New insights into the mechanisms underlying recurrent pregnancy loss

J Obstet Gynaecol Res. 2019 Feb;45(2):258-265. doi: 10.1111/jog.13837. Epub 2018 Oct 16.


Recurrent pregnancy loss (RPL), defined as multiple consecutive miscarriages, is a devastating disorder for which there are no good treatment options. Two opposing paradigms have emerged to explain RPL. The prevailing clinical viewpoint is that RPL is caused by a spectrum of subclinical disorders, ranging from thrombophilia to anatomical, endocrine and immunological disorders, that somehow converge on a 'fragile' early pregnancy state, leading to miscarriage. A new paradigm, based on emerging concepts around early implantation events, challenges the conventional thinking around RPL. It purports that the high incidence of embryonic aneuploidies and mosaicism coupled with a cycling endometrium necessitates the introduction of multiple 'quality control' checkpoints in the first trimester of pregnancy to limit maternal investment in a failing pregnancy. Here we review the evidence underpinning both paradigms and examine how new thinking around RPL may lead to more effective preventative strategies.

Keywords: decidualization; endometrium; implantation; miscarriage; recurrent pregnancy loss.

Publication types

  • Review

MeSH terms

  • Abortion, Habitual / etiology*
  • Decidua / physiology*
  • Embryo Implantation / physiology*
  • Female
  • Humans
  • Pregnancy
  • Pregnancy Trimester, First / physiology*