Subsequent pregnancy outcomes following second trimester miscarriage-A prospective cohort study

Pregnancy after second-trimester miscarriage represents as clinical challenge. This study sought to determine the rates of recurrence, preterm birth and live births in a cohort of 185 women with previous second-trimester miscarriage. We hypothesized that there would be a higher rate of second-trimester miscarriage and preterm birth in subsequent pregnancy after second trimester miscarriage. The primary objectives of this study were to establish rates of second-trimester miscarriage, preterm birth and live births in this cohort. Secondary objectives were to examine medical and surgical interventions, in addition to other pregnancy outcomes and complications.

This was a prospective cohort study carried out in a tertiary referral center in southern Ireland with over 8000 deliveries per year. 175 women were followed up. Inclusion criteria were an ultrasound confirmed second-trimester miscarriage between June 2009 and June 2013 and subsequently having a pregnancy between July 2009 and January 2016. Fifty-five women did not become pregnant during the study period and were excluded. Ten women were excluded for missing data.

Between July 2009 and January 2016, 110 women became pregnant following a previous second-trimester miscarriage. In total, 81 babies were born to 77 mothers. The recurrence rate of second-trimester miscarriage was 6.3% (7/110) and the preterm birth rate was also 6.3% (7/110). The cesarean section rate was 45%. Including those who experienced first or second trimester miscarriage, 47% (78/155) of those who were followed up did not go on to have a live infant.

Women experiencing second-trimester miscarriage are at increased risk in subsequent pregnancies of recurrence. Second-trimester miscarriage needs to be highlighted as a risk factor for adverse pregnancy outcomes. Greater research into its pathophysiology is required to advance preventative measures.