Pregnancy and Delivery Outcomes in Women With Persistent Versus Resolved Low‐Lying Placenta in the Late Third Trimester

Abstract

Objectives The safest mode of delivery in low‐lying placenta is debatable. Little is known about outcomes in low‐lying placenta resolved during the late third trimester. We compare outcomes of women with persistent versus resolved low‐lying placenta. Methods A retrospective analysis on a prospective cohort of women with low‐lying placenta confirmed at 28–30 weeks sonography (01/2009 to 03/2018). Women were followed up serially every 2 to 3 weeks until delivery to assess the placental edge‐to‐internal os distance (IOD), and included if scan was performed within 28 days before delivery. Results There were 86 women: in 21 the low‐lying placenta resolved, whereas in 65 persisted (n = 15 IOD 1–10 mm, n = 50 IOD 11–20 mm). Antepartum bleeding associated with higher rates of urgent cesarean delivery in 1–10 mm (P = .041) but not in 11–20 mm (P = 1.000) and >20 mm (P = .333). Among women with IOD >10 mm allowed to labor, vaginal delivery occurred in 76.7% (11–20 mm) and 94.1% (>20 mm) (P = .155), with no difference according to parity (70% and 80% in multiparas, P = .696; 60% and 72.7% in nulliparas, P = .698). Severe PPH (P = .922) and hemoglobin drop (P = .109) were similar among groups. Women with IOD 11–20 mm and >20 mm and vaginal delivery bled less than women with similarly located placenta and cesarean delivery (P = .009 and P = .048). Conclusions Women with IOD >10 mm have high chances of deliver vaginally with no further increase of their hemorrhagic risk. Success of vaginal delivery is independent of parity and antepartum bleeding. Labor should be managed in an adequate hospital setting.

Mode of birth in women with low-lying placenta: protocol for a prospective multicentre 1:3 matched case–control study in Italy (the MODEL-PLACENTA study)

“…In a recent publication, we reported that 77% of women with an IOD between 11 and 20 mm give birth vaginally when allowed to labour. 18 A similar rate (85%) was reported by a Jansen et al in their systematic review and meta-analysis. 19 …”

“…The evaluation of 9 years of practice (2009–2018) after the introduction of this new protocol confirmed our previous results, showing a 77% rate of vaginal birth in women with an IOD between 11 and 20 mm admitted to TOL. 18 The rate of emergency CS due to haemorrhage was 16.3%. These findings are consistent with data from a recent systematic review by Jansen et al , 19 reporting a vaginal birth rate and an emergency CS rate of 85% and 14%, respectively, in women with an IOD between 11 and 20 mm.…”

“…In particular, evidence suggests that these women might still present an increased risk of postpartum haemorrhage compared with women with a normally located placenta since the second trimester scan. 18–20 …”

Trial of Labor Compared With Elective Cesarean Delivery for Low-Lying Placenta

“…13,18 Furthermore, among the studies included in this meta-analysis reporting blood loss by internal os distance or actual rather than planned mode of delivery, only one provided information about how blood loss was assessed (with a collector bag), 18 three studies defined PPH using different cutoffs for vaginal and cesarean deliveries, 16,19,21 and one did not define PPH at all. 20 All of these points limit the robustness of the results reported by Jansen et al 35 Our data, analyzed using propensity score methodology to limit indication bias, support a policy of trial of labor for women diagnosed with low-lying placenta presenting around term with an internal os distance of 11-20 mm. Attempting labor is also a possible option for women when this distance is 1-10 mm as the incidence of blood-loss related maternal outcomes, including severe PPH, did not differ between the trial-of-labor and elective cesarean delivery groups.…”

Economic analysis of mode of birth in women with low-lying placenta

“…The clinical data inputs used for this retrospective economic analysis belongs to a paper previously published by our group (15), aiming to compare outcomes of women with persistent versus resolved lowlying placenta in the late third trimester. The study was approved on April 13, 2006 by the Institutional Review Board (protocol No.…”