Many women wonder whether having a retroverted uterus can be a factor in pregnancy loss, but the answer is usually no.
About 20% of women have a uterus that tips toward the back rather than the forward. This is called a retroverted uterus and is also known as a tipped or tilted uterus. Generally, doctors consider this a normal variation and it causes no problems and rarely requires treatment.
No medical studies have ever tied having a retroverted uterus to any risk of miscarriage.
In most cases, a retroverted uterus will assume the normal position at some point during pregnancy. In rare cases, a tilted uterus that does not correct during pregnancy may become trapped in the pelvis leading to a condition called "incarcerated uterus." An incarcerated uterus can cause second-trimester miscarriage or other pregnancy complications, but this condition is extremely uncommon and would not be a factor in unexplained first-trimester miscarriage.
Sources:
Lettieri, L., J.F. Rodis, D.A. McLean, W.A. Campbell, and A.M. Vintzileos, "Incarceration of the gravid uterus. Obstetrics and Gynecology Survey Sept 1994. Accessed 21 Feb 2008.
University of Maryland Medical Center, "Retroversion of the uterus." 8 Nov 2006. Accessed 21 Feb 2008.
