Aneuploidy refers to an abnormal number of chromosomes that is not an exact multiple of the haploid number of chromosomes for the species (23 in humans). Humans normally have a diploid karyotype, with two complete chromosome sets, for a total…
Ultrasound plays an important role in the assessment of women carrying multiple gestations. Sonography is used to evaluate the number of gestations; characterize the type of twinning; assess fetal anatomy, growth, and complications; and guide diagnostic and therapeutic interventions. As…
Placenta Evaluation of the placenta, umbilical cord, and cervix is an important component of the second and third trimester obstetrical ultrasound examination. Ultrasound facilitates assessment of placental location and appearance, relationship of the placenta to the cervix, umbilical cord insertion,…
The standard obstetrical ultrasound examination delineated in the ACR-ACOG-AIUM-SRU Practice Parameter for the Performance of Obstetrical Ultrasound incorporates imaging of the fetal musculoskeletal system, including the femur length (FL); the calvarium during measurement of the biparietal diameter and head circumference;…
The standard second and third trimester fetal ultrasound examination includes evaluation of the kidneys, urinary bladder, and amniotic fluid volume. A significant abnormality of both kidneys or of the urinary bladder can result in oligohydramnios. Cyclical changes in the size…
The standard obstetrical ultrasound examination delineated in the ACR-ACOG-AIUM-SRU Practice Parameter for the Performance of Obstetrical Ultrasound incorporates imaging of the fetal gastrointestinal system, including the stomach (presence, size, and situs) and umbilical cord insertion site into the fetal abdomen.…
The practice guideline for the standard obstetrical ultrasound examination identifies the four-chamber, left ventricular outflow tract (LVOT), and right ventricular outflow tract (RVOT) views as the minimum components in evaluation of the heart. Additional views are incorporated during dedicated fetal…
Central nervous system (CNS) abnormalities are among the most common congenital anomalies. A systematic evaluation of the head and spine should be performed to include, at a minimum, the following structures listed in the practice guideline for the standard obstetrical…
Ultrasound is the most widely used imaging test in early pregnancy. Confirmation of a live intrauterine pregnancy requires sonographic identification of an intrauterine gestational sac with an embryo exhibiting cardiac activity. Other disorders such as failed intrauterine pregnancy, ectopic pregnancy,…
The sonographic evaluation of the fetus includes assessments that extend beyond simple evaluation of fetal anatomy. Fetal well-being can be evaluated using surveillance methods such as fetal size and growth, Doppler waveform analysis, and the biophysical profile (BPP). In combination…