PIP studies background and study purpose

The PIP studies

The PIP studies are three separate trials of endometrial pipelle sampling in different groups of participants:

  • PIP-IVF (in women undergoing IVF/embryo transfer)
  • PIP-UE (in couples with unexplained infertility)
  • PIP-PCOS (in couples with subfertility related to polycystic ovarian syndrome)

The PIP studies began recruitment in June 2014, and we plan to recruit approximately 1500 women across the three studies. The PIP studies are being led from Auckland, New Zealand, and recruitment is expected to start at a number of overseas sites over time.

The PIP-IVF study has closed to recruitment.

Why are the PIP studies being conducted?

Women who have previously failed to get pregnant after multiple embryo transfers are often defined as having “recurrent implantation failure”.  In this group of women, researchers have found that performing an endometrial pipelle sample increases the chances of pregnancy in the next IVF cycle.

However, it is not known whether endometrial sampling is also helpful for women on their first or second IVF cycle, or women who are having a frozen-thawed embryo transfer. It is also not known whether endometrial pipelle sampling could be beneficial in couples with unexplained infertility, or subfertility related to PCOS, who are trying to conceive with sexual intercourse.

Endometrial pipelle sampling may increase the chance of pregnancy in these women too.

The three PIP studies aim to assess whether pipelle sampling improves pregnancy and live birth rates in three different groups of participants.

How does endometrial sampling increase pregnancy rates?

It is believed that endometrial sampling may increase the chance of pregnancy by causing a minor injury in the lining of the womb. This injury produces an inflammatory response as part of the wound healing process. Biological molecules which are released as part of this inflammatory response are thought to also assist in implantation of the embryo into the lining of the womb. As embryo implantation is the first crucial step in the establishment of a pregnancy, the wound response created by pipelle sampling is thought to lead to a higher rate of successful implantations and therefore pregnancies.