Utility of first trimester obstetric ultrasonography before 13 weeks of gestation: a retrospective study

First trimester pregnancy is defined as twelve weeks after the last menstrual period. Ultrasonography has revolutionized validation and management of first trimester pregnancies. The aim was to analyze ultrasonographic findings of first trimester pregnancies in University of Uyo teaching hospital (UUTH), Uyo, Nigeria.

The departmental ultrasonographic records of pregnant women who were referred to Radiology department of UUTH, Uyo, Nigeria. For ultrasound scans were retrospectively reviewed. The period under consideration was from 8^th January 2013 to 8^th February, 2016. Demographic data and ultrasonographic parameters of first trimester pregnancies like gestational sacs were recorded. Data were statistically analyzed using SPSS Chicago 13. Exclusion criterion included incomplete data and acyesis despite positive βhCG test.

26.4% (n-645) of the 2438 pregnant women who underwent obstetric ultrasonography had first trimester ultrasonography during the studied period. The peak frequency was seen in the 20-29 age range with 52.2% (n-337) and followed by 30-39 age range with 41.7% (n-269). The commonest first trimester ultrasound findings was viable pregnancy with 42.5% (n-274), followed by incomplete miscarriage with 34.3% (n-221). The least finding was trophoblastic pregnancies 0.3% (n-2). The earliest age at which normal viable pregnancy was diagnosed in this study was 5weeks 5days from the last menstrual period. Only 2.19% (n-6) of the normal viable pregnancies were multiple pregnancies and they were all twins. The highest number of referrals to Radiology Department for first trimester ultrasonography was from accident and emergency unit with 34.42% (n-222) while antenatal clinic referral was only 16.12% (n-104).

The commonest first trimester's obstetric ultrasonographic findings in Uyo, Nigeria are viable pregnancies and are predominantly single gestation. The earliest age of ultasonographic pregnancy detection in Uyo is 5week 5days and peak maternal age is second and third decades.