Know the ultrasound indication according to each trimester and recognize the standardized steps to perform a basic obstetric ultrasound and a specialized routine.
Describe the role of ultrasound to diagnosis of miscarriage,
fetal death and the warning signs of fetal distress.
Identify common difficulties to perform an obstetric ultrasound and how to overcome them.
The obstetric ultrasound is a method that complements the clinical evaluation during the prenatal,
being used to monitor fetal vitality and growth,
as well as its development; it also helps evaluates placental and amniotic fluid.
Among the sonographic modes,
the obstetric ultrasound is performed with the aid of the M-B mode and the Doppler .
To perform the obstetric US the assessment can be transabdominal or transvaginal and the transducer frequency are 3,5 MHz (transabdominal) or 5,0 MHz (transvaginal) at least.
This pictorial essay aims...
Findings and procedure details
The first trimester evaluation
The first trimester of gestation corresponds to the period between the confirmation of a viable gestation up to 13 weeks and 6 days.
Ultrasonographic follow-up of this period has a predictable,
accurate and reproducible pattern,
with a variation of approximately half a week of expected (figure 1).
The first trimester evaluation consists on the ultrasound until 10 weeks and 6 days and morphologic ultrasound from 11 weeks to 13 weeks and 6 days .
- First trimester ultrasound (until 10 weeks...
Obstetric ultrasound is a complementary exam that has gained value in the prenatal follow-up,
mainly because of its ability to accurately follow the fetal development and to be able to predict some intrauterine complications.
The systematization of the examination is fundamental so that all the maternal and fetal structures are evaluated in each gestational period,
we propose in this work to compile succinctly and didactically a practical approach of obstetric ultrasound evaluation (figure 42).
Department of Radiology,
São Paulo - Brazil.
Normal and Abnormal US Findings in Early First-Trimester Pregnancy: Review of the Society of Radiologists in Ultrasound 2012 Consensus Panel Recommendations.
Graham III GM.
Ultrasound Evaluation of Pregnancy in the First Trimester.
Donald Sch J Ultrasound Obstet Gynecol.
ISUOG practice guidelines: Performance of first-trimester fetal ultrasound scan.
Ultrasound Obstet Gynecol.