Am J Perinatol 2020; 37(01): 104-111
DOI: 10.1055/s-0039-3400309
SMFM 2019
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Antenatal Detection of Abnormal Placental Cord Insertion across Different Trimesters: A Prospective Cohort Study

1  Department of Obstetrics and Gynecology, Graduate Entry Medical School, University of Limerick, Limerick, Ireland
,
Ailish Hannigan
2  Department of Biostatistics, Graduate Entry Medical School, University of Limerick, Limerick, Ireland
,
Peter Kelehan
3  Department of Pathology, National Maternity Hospital, Dublin, Ireland
,
Keelin O'Donoghue
4  Department of Obstetrics and Gynaecology, University College Cork, Cork, Ireland
,
Amanda Cotter
1  Department of Obstetrics and Gynecology, Graduate Entry Medical School, University of Limerick, Limerick, Ireland
› Author Affiliations
Further Information

Publication History

06 June 2019

30 September 2019

Publication Date:
22 November 2019 (online)

Abstract

Objectives This article prospectively examines the use of ultrasound for antenatal detection of abnormal placental cord insertion (PCI) and compares the antenatal classification with delivered placental classification.

Study Design This prospective cohort study examined 277 singleton pregnancies in a tertiary center. Scans were performed between 10 and 14, 18 and 22, and 32 and 34 weeks where PCI site was identified and its shortest distance to margin measured. Standardized images of delivered placentas were taken and digitally measured. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of antenatal classification compared with delivered placental classification were calculated.

Results Abnormal PCI (distance < 2 cm from margin) was confirmed in 30/277 (11%) placentas at delivery. Note that 102/277 (37%) of PCI sites were classified as abnormal in the first trimester (T1), 43/277 (16%) in the second trimester (T2), and 28/277 (10%) in the third trimester (T3). Sensitivity (73%) and specificity (91%) were highest at T2. The PPVs were low (22% in T1, 51% in T2, and 64% in T3) and the NPVs were high (96% in T1 and 97% in both T2 and T3) for all scans.

Conclusion Abnormal PCI can be detected antenatally with optimal agreement with postnatal classification in T2. However, the incidence is overestimated at early scans with low PPVs.

Note

This study was presented at the 39th Annual Meeting of the Society for Maternal-Fetal Medicine, Las Vegas, Nevada, February 11–16, 2019.