Second-trimester loss and subsequent pregnancy outcomes: What is the real risk?

This study was performed to determine whether second-trimester pregnancy loss was associated with an increased risk for spontaneous preterm birth or recurrent second-trimester loss in a subsequent pregnancy.

A retrospective cohort study was conducted. Patients with a second-trimester pregnancy loss (n = 38), a spontaneous preterm birth (n = 76), and a full term delivery (n = 76) were identified from 2002 to 2005 (index pregnancy). Computerized medical records were used to obtain demographic and obstetrical histories.

Frequencies of subsequent second-trimester loss were 27%, 3%, and 1% in the second-trimester loss, spontaneous preterm birth, and full-term delivery cohorts, respectively. Frequencies of subsequent spontaneous preterm birth were 33%, 39.5%, and 9% in the same 3 cohorts. Patients with a prior second-trimester loss were 10.8 times more likely to have recurrent second-trimester loss or spontaneous preterm birth, compared with those with prior full-term delivery (confidence interval 3.6 to 32.1, P < .0001).

Patients with a prior second-trimester loss are at significantly increased risk for spontaneous preterm birth and recurrent second-trimester loss in their next pregnancy.