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Association of vasa previa at delivery with a history of second-trimester placenta previa.

OBJECTIVE
To evaluate whether vasa previa at delivery is associated with a history of second-trimester placenta previa.


STUDY DESIGN
Retrospective, case-control study of all vasa previa cases at Good Samaritan Regional Medical Center from January 1, 1991, to May 1, 2001. Cases were identified by ICD-9 codes and confirmed by chart review. Each case was matched in a 1:4 ratio with controls based upon normal placentation at delivery, ultrasound documentation of midtrimester placental location, maternal parity and gestational age at delivery.


RESULTS
During the study period, 13 cases of vasa previa were identified. Nine cases (9/13, 69.2%) of vasa previa at delivery had a second-trimester placenta previa as documented by midtrimester ultrasonography, whereas 2 controls (2/52, 3.8%) had a second-trimester placenta previa (P < .000001, OR = 56.3, 95% CI = 8.9-354.1).


CONCLUSION
There is a highly significant association between vasa previa at delivery and a history of second-trimester placenta previa.