Ob1 Lec - Ultrasound

OB Lecture 2 - SONOGRAPHIC PRENATAL DETECTION OF FETAL ANATOMIC CONGENITAL ANOMALIES USTMED ’07 Sec C - AsM Congenital Anomaly consists of a departure from the normal anatomic architecture of an organ or system individual alterations of form or structure can be classified as malformations, deformations, and disruptions Malformation is a morphologic defect of an organ, part of an organ, or a larger area of the body resulting from an intrinsically abnormal developmental process. Deformation refers to an abnormal form, shape, or position of a part of the body caused by non-disruptive mechanical forces.

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A.I.U.M. Guidelines: 2nd and 3rd Trimester assessment of gestational age should be accomplished by using BPD, FL;Fetal growth assessment requires the addition of FAC evaluation of the uterus and adnexae study should include cerebral ventricles, spine, stomach, urinary bladder, umbilical cord insertion site and renal region Fetal lie, number and presentation should be documented An estimate of the amount of amniotic fluid (increased, decreased, normal) reported The placental location should be recorded and its relationship to the internal os determined

Disruption is a morphologic defect of an organ, part of an organ, a larger region of the body resulting from a breakdown, or interference with an originally normal developmental process. Incidence of Congenital Anomalies: Accurate documentation depends on many factors including: the type of examination (body surface examination, extensive examination including evaluation of internal organs); and ethnic, geographic, and social variations in the incidence of individuals malformations. The incidence of major anomalies was 2.04% while that of minor anomalies was 14.7%. • •

Are there structural/functional anomalies present

Criterion Gestational sac CRL BPD & FL FAC

Date 5-10 wks 8-12 wks 12-28 wks 26 wks onwards

Error < 7 days <10 days < 14 days

Amniotic Fluid Volume 1. Single vertical depth (Manning) > 2 cm 2. AFI (Phelan) 9 cm up to 22 cm

The cardinal principle behind the diagnosis of congenital anomalies with ultrasound is recognition of a departure from normal fetal anatomy. The sonographic recognition of congenital anomalies depends on knowledge of normal fetal anatomy, ultrasound resolution, and the natural history of the disorder.

Anomalies Identified by Ultrasound

(A/N: I didn’t include all the pictures because they weren’t clear. Try to crossreference with other books)

- Early Hydrocephalus Cysts

- Dandy-Walker umbilical artery waveforms in a normal and growth-restricted fetus at approximately the same gestational age.

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- Longitudinal Fetal Spine

- Spina Bifida

Ultrasound Historical Background Shift of major proportions brought in by the late professor Ian Donald in his pioneering work in obstetrics ultrasound, early 60s. A.I.U.M. Guidelines: First Trimester

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location of the gestational sac should be documented; the embryo should be identified and the crown-rump length recorded presence or absence of fetal life should be reported fetal number should be documented evaluation of the uterus (including cervix) and adnexal structures should be performed

Fundamental and Basic Questions of Fetal Assessment what is the fetal age? How many fetuses are there?