Clinical Trial: Pregnancies of Uncertain Location or Viability Research

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Pregnancies of Uncertain Location or Viability Research

Brief Summary: Study to determine the diagnostic accuracy of the double decidual sac sign to predict an intrauterine pregnancy prior to ultrasonographic visualisation of embryonic contents using modern ultrasound technology.

Detailed Summary:

This diagnostic accuracy study will be conducted following the standards for reporting of diagnostic accuracy study (STARD) guidelines. Participants will be recruited from Nurture Fertility, Nottingham, United Kingdom at the time of embryo transfer. If the subsequent pregnancy test is positive, participants will be invited to attend for an additional transvaginal ultrasound scan at 33-34 days gestation. This scan will be considered to be the 'index test'.

The index test will be performed by a single investigator with experience in early pregnancy ultrasound following standard operating procedures using a Voluson E8 machine with a high frequency (5-9MHz and 9-12MHz) transvaginal probe. During the early scan the presence or absence of the following structures will be recorded: an intrauterine fluid collection (defined as a uniformly round, hypoechoic structure with an echogenic rim); the double decidual sac sign (DDSS) (defined as two concentric echogenic rings of tissue that surround the intraendometrial fluid collection that impress upon the endometrial stripe); yolk sac (defined as a spherical, hyperechoic ring situated eccentrically within the gestation sac); and fetal pole (defined as a small linear echogenic structure adjacent to the yolk sac, on the side closest to the gestational sac). If more than one intrauterine fluid collection is visualized then each will be considered as a separate entity. The findings from the early scan will be interpreted immediately and recorded separate to the main clinical notes. Participants will be excluded further from the study if at this point no intrauterine fluid collection is detected or if an intrauterine fluid collection containing a yolk sac or fetal pole is identified. Referral pathways to local Early Pregnancy Assessment Units (EPAU) will be in place for any woman in whom this early scan is strongly suggestive of an ectopic
Sponsor: University of Nottingham

Current Primary Outcome: Intrauterine Pregnancy [ Time Frame: Repeat transvaginal ultrasound performed 8-16 days after the index test ]

A viable intrauterine pregnancy is defined by ultrasonographic identification of an intrauterine gestation sac with a fetal pole of any length with demonstrable fetal heart pulsations. A non-viable intrauterine pregnancy is defined as either an empty intrauterine gestation sac with mean sac diameter greater than 25mm or an intrauterine gestation sac containing a fetal pole with crown rump length greater than 7mm with no demonstrable fetal heart pulsations or in the absence of a viable embryo, no significant increase in the growth of the gestation sac or length of the fetal pole on two ultrasound scans performed more than 7 days apart. Where women underwent surgical or medical management of miscarriage, histological confirmation of the products of conception will be obtained when possible.


Original Primary Outcome: Same as current

Current Secondary Outcome: Ectopic Pregnancy [ Time Frame: Repeat transvaginal ultrasound performed 8-16 days after the index test ]

Ectopic pregnancies will be confirmed either by direct visualisation of an ectopic pregnancy during surgery with histological confirmation, or, in those managed medically with methotrexate or conservatively, unequivocal identification of an ectopic pregnancy on ultrasound scan. Ultrasonographic appearances indicative of an ectopic pregnancy include: an empty endometrial cavity with either an inhomogenous adnexal mass or an empty extra-uterine sac or a yolk sac or fetal pole with or without cardiac activity in an extra-uterine sac


Original Secondary Outcome: Same as current

Information By: University of Nottingham

Dates:
Date Received: March 1, 2016
Date Started: January 2015
Date Completion:
Last Updated: March 1, 2016
Last Verified: March 2016