Items tagged “obstetrics”

Crown rump length (CRL) is the length of the embryo or fetus from the top of its head to bottom of torso. It is the most accurate estimation of gestational age in early pregnancy, because there is little biological variability at that time. Measurement CRL is measured as the largest dimension ...

Echogenic fetal bowel is an observation in antenatal ultrasound imaging, in which fetal bowel appears to be brighter than it is supposed to be. It is a soft marker for trisomy 21 and has several other associations. When observed, it needs to be interpreted in the context of other associated abno...

The interstitial line sign is an ultrasound finding in interstitial ectopic pregnancy. It is an echogenic line from the mass to the endometrial echo complex. Reportedly it has high sensitivity (80%) and specificity (98%).

Nuchal translucency is the normal fluid-filled subcutaneous space identified at the back of the fetal neck during the late first trimester and early second trimester (11 weeks 3 days to 13 weeks 6 days). It should not be confused with the nuchal fold, which is seen in the second trimester.   P...

Tubal ectopic pregnancy, also known as adnexal ectopic pregnancy, is the most common location of an ectopic pregnancy. Epidemiology It is the most common type of ectopic by far, accounting for 93-97% of cases. Pathology Although the fallopian tube has many anatomical parts, for the purposes ...

The twin peak sign, also known as the lambda (λ) sign, is the triangular appearance of the chorion insinuating between the layers of the intertwin membrane and strongly suggests a dichorionic diamniotic twin pregnancy. It is best seen in the first trimester (between 10-14 weeks) 5. While the pre...

A missed miscarriage, sometimes termed a missed abortion 3, is a situation when there is a non-viable fetus within the uterus, without symptoms of a miscarriage.   Radiographic features Ultrasound Ultrasound diagnosis of miscarriage should only be considered when either a mean gestation sac d...

Retained products of conception (RPOC) refer to the persistence of placental and/or fetal tissue in the uterus following delivery, termination of pregnancy or a miscarriage.  Epidemiology RPOC complicates ~2.5% (range 1-5%) of all routine vaginal deliveries 12. According to one prospective st...

Antenatal soft ultrasound markers are fetal sonographic findings that are generally not abnormalities as such but are indicative of an increased age-adjusted risk of an underlying fetal aneuploidic or certain non-chromosomal abnormalities. Most of the described features do not constitute a stru...

Fetal tachycardia is an abnormal increase in the fetal heart rate. It is variably defined as a heart rate above 160-180 beats per minute (bpm) and typically ranges between 170-220 bpm (higher rates can occur with tachyarrhythmias). Epidemiology The estimated prevalence is ~0.4-1% of pregnancie...

Subchorionic hemorrhage occurs when there is perigestational hemorrhage and blood collects between the uterine wall and the chorionic membrane in pregnancy. It is a frequent cause of first and second trimester bleeding. Epidemiology It typically occurs within the first 20 weeks of gestation. W...

Fetal bradycardia refers to an abnormally low fetal heart rate, a potentially ominous finding. A sustained first trimester heart rate below 100 beats per minute (bpm) is generally considered bradycardic. The average fetal heart rate changes during pregnancy, however, and some consider the lower ...

Placental (venous) lakes refer to a phenomenon of formation of hypoechoic cystic spaces centrally within the placenta. Finding placental lakes during a second trimester ultrasound scan is not associated with any uteroplacental complication or with an adverse pregnancy outcome. They can, however,...

Absent end-diastolic flow (AEDF) in an umbilical artery Doppler assessment is a useful feature that indicates underlying fetal vascular stress if detected in mid or late pregnancy. It is often classified as Class II in severity in abnormal umbilical arterial Dopplers 9. Epidemiology Associatio...

Anhydramnios is a term where there is a complete or near-complete lack of amniotic fluid (sometimes referred to as "liquor volume"). Pathology Anhydramnios can result in a number of situations: fetal renal tract anomalies Potter syndrome (bilateral renal agenesis): most common  large ureter...

The term pregnancy of unknown location (PUL) is assigned when neither an intrauterine pregnancy (IUP) or an ectopic pregnancy is identified on transvaginal ultrasound in the context of a positive pregnancy test. Clinical presentation pelvic pain vaginal bleeding positive pregnancy test Path...

Peripartum/postpartum cardiomyopathy is a dilated cardiomyopathy that may occur in the last trimester of pregnancy through the first several months postpartum. Epidemiology The estimated incidence in the United States ranges from one in 900 to one in 4000 live births, with an increased inciden...