Normal Pregnancy

What is the purpose of imaging procedures during a normal pregnancy?

• It is unclear whether all women should undergo ultrasound screening during a normal pregnancy. 
• Noted advantages of routine screening ultrasounds include, more accurate pregnancy dating, less frequent labor induction for post term pregnancy, detection of multiple gestation and fetal growth restriction, and identification of fetal malformations. 
• Many studies have conflicting conclusions regarding the utility and the detection rates for all of the aforementioned uses of routine ultrasound, which renders the issue still up for debate. 
• Currently, the American College of Obstetricians and Gynecologists does not recommend routine ultrasound in low-risk pregnancies.   

What is the imaging modality of choice during pregnancy and why?

• Ultrasound is the clinical modality of choice during pregnancy. 
• There is widespread use of sonography in obstetrics and notably it has great potential for identifying fetal abnormalities and for providing reassurance of fetal well-being. 
• Also, there have been no confirmed bad biological effects in mammalian tissue in the frequency range of ultrasound medicine. 
• In the low-intensity range, there have been no fetal risks shown in over 30 years of use.  

What are the findings of normal pregnancy?

• In the first trimester, a basic ultrasound examination includes, gestational sac location, embryo identification, crown-rump length, fetal heart motion, fetal number, uterus and adnexal evaluation. 
• In the second and third trimester, the ultrasound examination includes, fetal number, presentation, fetal heart motion, placental location, amniotic fluid volume, gestational age, survey of fetal anatomy, and evaluation for maternal pelvic masses.