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Obstatric

Ultrasound in first trimester Goals :

1. Visualization of G.S.:

A- seen :(age):-single or multiple (number of membranes and placentas)-alive: * normal .

*abnormal (anomaly)-dead or blighted ovum

B- Not seen:- decid.reaction- normal endometrial thickness.

2. Localization of G.S :A- Intrauterine ( normal place or aborted).B- Ectopic .

8/3/2019 Ultrasound in 1st, 2nd & 3rd trimester .

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8/3/2019 Ultrasound in 1st, 2nd & 3rd trimester .

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8/3/2019 Ultrasound in 1st, 2nd & 3rd trimester .

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5th

week : G.S. seen6 th week: fetus seen7 th week: heart beats seen.

7-12 th weeks calculated by C.R.LMultiple G.S diagnose multiplepregnancies.

G.Sac:

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Ultrasound in 2 nd and 3 rd trimesters

B.P.D (best at 18-20 w., not after 24-26 w.where FL or HC are better)

- measure the ventricles to excludehydrocephalus .and exclude other fetal anomalies.- sex also seen.- placenta ( 11 th week):

* placenta previa (0.5%)N.B. 1/3-1/2 of placentas in lower segment

.then mostof placentas migrate up.(sure diagnosis at

36 th w)

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8/3/2019 Ultrasound in 1st, 2nd & 3rd trimester .

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* Large for dates uterus 1. mistake in calculation ( usually).2. multiparity.( early more than G.S. and later

more than fetal bodies)3.Vesicular mole and choriocarcinoma.( no D.D.)4. ovarian or uterine tumours5.polyhydramnios :

- maternal D.M .- neural tube defect.- duodenal and esophageal atresia .

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8/3/2019 Ultrasound in 1st, 2nd & 3rd trimester .

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Small for dates uterus :1. mistake in calculation.

2. intrauterine growth retard.3. perinatal death.4.oligohydramnios

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Fetal anomalies

neural tube defects(the commonest)particularly spina bifida and unencephaly( elevate alpha feto prot.)

HEAD- hydrocephalus(16 th w), and

unencephaly(12 th w).SPINE

- spina bifida.+/- meningiocele

- tumours (sacral teratoma)CHEST-congenital diaphragmatic hernia- some cong. Heart diseases- A-V canal defec , and fallot tertralogy .

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8/3/2019 Ultrasound in 1st, 2nd & 3rd trimester .

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G.I.T- duodenal atresia, omphalocele and

gastroschisis.- esophageal atresia indirectly diagnosed

by polyhydramnios.URINARY TRACT ( usually with

oligohydamnios)- hydronephrosis and multicystic kidney

usually unilateral .- post.urethral valve.SKELETON

- short limbs

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