Pregnancy Outcomes After Second Trimester Pregnancy Loss and Termination for Medical Reasons Before 24 Weeks: A Historical Cohort Study [PASTeL-2].

Abstract

To investigate if second trimester pregnancy loss (second trimester miscarriage [STM] or termination for medical reasons [TFMR]) was associated with subsequent adverse pregnancy outcomes. Retrospective cohort study. Conducted using the Aberdeen Maternity and Neonatal Databank [AMND] in Aberdeen, United Kingdom. Women with and without a history of STM or TFMR (between 13 + 0 and 23 + 6 weeks' gestation). Logistic and linear regression were used to determine associations between exposed (prior STM or TFMR) and unexposed women (women with prior livebirth). The primary outcome was subsequent spontaneous preterm birth, defined as spontaneous onset of labour and birth between 24 + 0 and 36 + 6 weeks' gestation. The study included 65 592 women with first and second pregnancies recorded from 1950 to 2017. Women who had a STM in their first pregnancy (n = 935) were at significantly greater risk of spontaneous preterm birth in the next pregnancy (4.3% vs. 1.5%; adjusted Odds Ratio [aOR] 2.55 (95% CI 1.81 to 3.50); p < 0.01). Women with STM in their first pregnancy were two-fold more likely to have a repeat second trimester miscarriage (3.7% vs. 1.1%; aOR 2.25 (95% CI 1.53 to 3.19); p < 0.01). Women who had a first TFMR (n = 177) were significantly more likely to have a repeat TFMR (adjusted OR [aOR] 6.59 (3.4% vs. 0.3%, 95% CI 2.54 to 13.99); p < 0.01). There was no observed increased risk of spontaneous preterm birth after TFMR detected in this sample (aOR 1.06 (95% CI 0.39 to 2.87); p = 0.91) though the sample size was too small to be conclusive. Women with a history of second trimester pregnancy loss have an increased risk of adverse pregnancy outcomes in a subsequent pregnancy. Consequently, antenatal care surveillance and counselling may need to be increased for women with a prior STM, who are at risk of spontaneous preterm birth and other adverse obstetric outcomes including pre-eclampsia. Women after TFMR can be reassured by our findings; however, larger cohorts are needed to confirm these results.