Second and third trimester emergencies

Second and third trimester emergencies

Dr. Kosar Kamal Ahmed H.D diagnostic radiology

Lecture 3

Lecture over view Essential elements of an emergency scan

Determining the presenting part of the fetus

Fetal lie

Measurements of GA (BPD & FL )

Location of placenta

Amniotic fluid assessment

Problems or emergencies during this time

Preterm labor , location of placenta , haemorrhage , oligo / poly

hydramnios

Early second trimester ( < 16 weeks )

cervical incompitence and habitual abortion

Essential elements of an emergency scanpresenting part of the fetus

Cephalic presentation


Breech presentation


Back and abdomen presentation

Essential elements of an emergency scanEstimation of gestational age

BPD The BPD is the maximum diameter of a transverse

section of the fetal skull at the level of the

.parietal eminences

Essential elements of an emergency scanEstimation of gestational age

BPD • A single optimal measurement of the BPD will predict the

• gestational age to within ± 5 days.

• It is more accurate at predicting the date of delivery than an

optimal menstrual history.

• It is more accurate than CRL ( Why ?)

• Recent data report that HC is more accurate than BPD

Estimation of gestational age BPD

• Lateral ventricles view:• rugby-football-shaped skull• a long midline equidistant from the proximaland distal skull echoes• the cavum septum pellucidum bissecting the

midline one-third of the distance from thesynciput to the occiput

• the two anterior horns of the lateralventricles, symmetrically placed about theMidline

• all or part of the posterior horns of the lateralventricles symmetrically placed about themidline .

Measurement of the BPD can be done in two ways or two schools :

Estimation of gestational age BPD

Thalami view : ●a rugby-football-shaped skull

●a short midline equidistant from the proximal

and distal skull echoes

●the cavum septum pellucidum bisecting the

midline one-third of the distance from the

synciput to the occiput

●the thalami

Measurement of the BPD can be done in two ways or two schools :

Estimation of gestational age BPD Measurement of the BPD can be done in two ways or two schools :

However thalami view Is the view of choice in American literature and

Many departments in UK

Estimation of gestational age FL

-This measurment is as accurate as BPD

in the prediction of GS -The upper femur should be selected for

measurement -To ensure that the section obtained is

not oblique ( soft tissue should be

visible beyond both ends of the

femur and the bone should not

appear to merge with the skin of the

thigh at any point

Essential elements of an emergency scanIdentification of location of placenta

• The placenta is best identified by scanning the uterus

longitudinally and is easily recognized by its more echogenic

pattern compared with that of the underlying myometrium

• Placenta can be in :

– Proper position

– Low lying

– Marginal previa

– Previa

Essential elements of an emergency scan

Identification of location of placenta

Fundal , anterior or posterior Normal

>2 cm away from internal Os

Essential elements of an emergency scan

Identification of location of placenta

Placenta is partially covering the internal Os

Essential elements of an emergency scanIdentification of location of placenta

Covering the internal Os

Essential elements of an emergency scanAmniotic fluid assesment

Three methods 1. Subjective assessment :

With experience, it is possible to classify amniotic fluid volume into the broad categories

absent, low, normal, increased and excessive.

2. Single deepest pool :

The size of the deepest cord-free pool of amniotic fluid is assessed with the ultrasound

probe perpendicular to the maternal abdomen; The vertical depth of the largest pool is

measured A depth of 2–3 cm is normal

3. Amniotic fluid index :

This is a semiquantitativetechnique for assessing amniotic fluid volume,Using the maternal

umbilicus as a reference point, the abdomen is divided into four quarters.

With the ultrasound probe held in the longitudinal axis of the mother and perpendicular to

the floor the largest vertical pool depth in each quadrant is recorded.


Three methods

Subjective method


Three methods Deepest vertical pocket

Essential elements of an emergency scanAmniotic fluid assesment Three methods

Amniotic fluid index (AFI )

End of part one Thank you

Health & Medicine

Second and third trimester emergencies