# Placental Location Site and Associated Intrapartum, Postpartum, and Neonatal Complications: A Comprehensive Review and Meta-Analysis

## TL;DR

This study finds that where the placenta implants in the uterus is linked to various pregnancy and birth complications, such as cesarean delivery and infant growth issues.

## Contribution

The study provides a meta-analysis confirming specific placental location associations with intrapartum, postpartum, and neonatal outcomes.

## Key findings

- Midline placenta increases odds of macrosomia/LGA and decreases non-cephalic presentation and retained placenta.
- Low-lying placenta increases non-elective cesarean section and postpartum hemorrhage.
- No significant link found between placental location and certain neonatal outcomes like Apgar score or neonatal death.

## Abstract

Background/Objectives: Adverse intrapartum, postpartum, and neonatal complications have been linked to placenta implantations sites. However, different reviews have led to contrasting conclusions about placental locations and pregnancy outcomes. We aim to determine if there is a relationship between the placental implantation site and intrapartum, postpartum, and neonatal outcomes. Methods: The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed during this review. The literature search used PubMed, CINAHL, and Embase. Years searched was not a study limitation. Only articles in English were included. Two authors reviewed the abstracts. Results: Of 40 articles identified as specific to intrapartum, postpartum, and/or neonatal complications (with some articles overlapping categories), 19 included intrapartum complications, 19 included postpartum complications, and 22 included neonatal complications. Pregnancies with a midline placenta (compared to a lateral placenta) had a greater likelihood of macrosomia/LGA infant (odds ratio (OR), 1.52 (95% CI: 1.22–1.90)) and lesser likelihood to have non-cephalic presentation (OR, 0.17 (95% CI: 0.06–0.51)), FGR/SGA infant (OR, 0.68 (CI: 0.55–0.85)), and retained placenta (OR, 0.33 (95% CI: 0.22–0.50)). Pregnancies with a low-lying placenta (compared to within uterine corpus) were more likely to have non-elective cesarean section (OR, 1.94 (95% CI: 1.06–3.55)) and postpartum hemorrhage (OR 1.49 (95% CI: 1.12–1.97)). Conclusions: Significant associations between placental location site and intrapartum complications (non-cephalic presentation, non-elective cesarean section), postpartum complications (postpartum hemorrhage, retained placenta), and neonatal complications (FGR/SGA, Macrosomia/LGA) were identified. There were no significant associations identified between the placental location site and several neonatal complications, including Apgar < 7 at 5 min, NICU admission, IUFD, and neonatal death.