Abstract
In this retrospective cohort study, we investigated the relationship between delayed presentation of first-trimester ultrasonographic landmarks of intrauterine pregnancy and perinatal outcomes. Patients presenting as pregnancies of unknown location who ultimately had intrauterine pregnancies were included and divided into two groups, determined by visualization of intrauterine landmarks at hCG <2000 or ≥ 2000. From 487 total patients, there was no significant difference in incidence of favorable perinatal outcome (73.3% vs 73.7%, RR=1.01, 95% CI 0.98-1.10). Of 439 live births, mean birthweight was statistically significantly lower by 115 g in the latter group. No significant difference was found for other neonatal or maternal outcomes. Our findings suggest no relationship between delayed presentation of intrauterine landmarks and poor perinatal outcomes, but a potential association with lower birthweight, though this may have limited clinical significance.