Pregnant women who were not married or living with a partner were more likely to have a first-trimester miscarriage than those who were married or living with a partner.

Source: "Risk Factors for First Trimester Miscarriage--Results from a UK-Population-Based Case-Control Study" Maconochie, N. Doyle, P., Prior, S., and Simmons, R.

London School of Hygiene and Tropical Medicine Vol. OnlineEarly, Number . December, 2006. Page(s) 1-17.