Third stage of labor placental complications and placenta-associated syndromes

To evaluate the association between third stage placental complications and placental insufficiency associated disorders, also known as, placenta associated syndromes.

A population-based retrospective cohort study comparing placental-related perinatal outcomes of parturient with (study group) and without third stage placental complications, defined as a composite of retained placenta, adherent placenta, placenta accrete, need for manual removal of the placenta, postpartum curettage and revision of the uterine cavity. A univariate analysis was followed by a multivariable logistic regression model.

During the study period, 263,023 deliveries met inclusion criteria, of which, 10,281 (3.9%) experienced placental complications during the third stage of labor. Parturient in the study group had significantly higher rates of placental insufficiency associated disorders which included among others: hypertensive disorders of pregnancy (6.5 versus 5.6%, p < .001), stillbirth (1.9 versus 0.7%, p < .001) and preterm delivery (9.9 versus 7.7%, p < .001). Using a multivariable regression model, while controlling for confounders such as maternal age and induction of labor, third stage placental complications were independently associated with placental insufficiency associated disorders.

Our findings suggest that placental associated adverse pregnancy outcomes and third stage placental complications may represent different manifestations of a common pathological or inadequate placentation process.