1Asst professor,
2Professor and Head,
Low lying placeta is the common observation when obstetrician seats on sonography machine. But as we know as the pregnancy advances most of them migrate. This study is to assesse the rate of migration of a low-lying placenta during the third trimester by transvaginal sonography and the eventual route of delivery.
This is the longitudinal type of study which includes the patients with a placenta lying within 3 cm of the internal cervical os between 20 -22weeks. The exact distance between the center of the internal cervical os and the leading edge of the placenta was measured by transvaginal sonography, repeated at approximately 4-weeks intervals until delivery.
Total 600 antenatal patients were undergone TVS at 20–22 weeks. Prevalence of low lying placenta in mid trimester was 9.1%.Follow up trans vaginal sonography showed that in 41 cases placenta has migrated beyond 3cm from the internal os. In late 3rd trimester or at term, age and parity did not influence the migration. Highest migration rate (94.28%) was found where distance between placental edge and internal os was >2cm. Anterior low lying placenta showed lesser migration (70%).
Low lying placenta is more concerned to obstetrician. Placental migration may occur progressively throughout the third trimester. The initial position of the placental edge and the subsequent rate of migration can be used to predict the eventual route of delivery.
