obstetric ultrasound scan (copy)

The ideal time for the first booking visit is between

11 and 14 weeks gestation

Standard booking tests include

1.Complete Blood Count(CBC)

2. Blood Grouping and Rh typing

3.Rubella titer (IgG and IgM)

4.Hepatitis

5. Hiv

6.TSH

7.Random Blood Sugar

8.Urinalysis.

Excluded Routine Booking Tests

1. LFT

2. GTT

3. Direct Coombs test

Routine screening is offered for

1. Down syndrome

2. Hepatitis C

3. Rubella

4. HIV

The expected date of delivery (EDD) is based on an average pregnancy length of:

280 days

Last Menstrual Period (LMP) is only reliable in calculating EDD if

cycles were regular for at least three cycles prior to conception

more accurate than LMP for dating

Ultrasound

Symphysis–Fundal Height (SFH): Measured from

24 weeks of gestation

The mean height Of symphysis fundal height (SFH) is

20 cm by 20 weeks

large SFH may indicate

Polyhydramnios or twins

Small SFH may indicate

Growth restriction IUGR

First Trimester Ultrasound (Up to 13+6 Weeks) Indications:

1. Suspected miscarriage

2. Vaginal bleeding

3. Uncertain gestational age

4. Multiple gestations

5. Hydatiform mole

6. IUD placement

An intrauterine gestational sac is visible via…….

when -hCG levels are…….

transvaginal ultrasound (TVS)

>1000–1500 IU/L.

The fetal heartbeat can be detected by TVS as early as

6 weeks

Dating Methods

1. Mean Sac Diameter (MSD): Used when no fetal pole is visible.

2. Crown-Rump Length (CRL)

The measurement of choice at 9 weeks and up to 14 weeks

Crown Rump Lenght

Chromosomal Screening (11–13+6 Weeks) Markers

1. Nuchal translucency

2. Serum level PAPPA and free hCG

3. Maternal age

4. Smoking status

5. Weight

Chromosomal Screening (11–13+6 Weeks) Biochemical Trends: In Trisomy 21:

free hCG is high

Chromosomal Screening (11–13+6 Weeks) Biochemical Trends: Smoking and diabetes:

decrease -hCG and PAPP-A levels, which can increase screen-positive results.

Chromosomal Screening (11–13+6 Weeks) Aneuploidy Markers

1. Increased NT (>3mm)

2. absent nasal bone

3. Tricuspid regurgitation

4. reverse flow in the ductus venosus

Chromosomal Screening (11–13+6 Weeks) Triple Screening Is for

Down syndrome

Edward syndrome

Second Trimester (18–23 Week Anomaly Scan purpose:

best window for anatomical evaluation because organ systems are mature enough to visualize, yet early enough for intervention if anomalies are found.

Second Trimester Scan assessment

1. Fetal number

2. Anatomy

3. Cardiac activity

4. Placental position

5. Amniotic fluid

(2nd trim scan) Head Biometry are:

1. The Biparietal Diameter (BPD)

2. Head Circumference(HC)

(They are used for dating from 14 weeks)

(In 2nd trimester scan) Correct BPD Plane

Must show the falx cerebri, cavum septum pellucidum, and thalamus; it must not show the cerebellum or orbits.

(in 2nd trimester scan) Cervical Length: a closed cervical length should be

>2.5 cm

Third Trimester scan indications

1. IUGR

2. macrosomia

3. Fluid abnormalities (oligo/poly)

4. Decreased fetal movement

5. PIH pregancy induced HTN

3rd trim assessment

1. Fetal presentation

2. Size (BPD, HC, AC, FL)

3. placental localisation

4. Well being

Amniotic Fluid Volume measurement

1. Single deepest pool: Normal is 2–8 cm; <2 cm is oligohydramnios, >8 cm is

   polyhydramnios

2. Amniotic Fluid Index (AFI): Normal range is 5–25 cm.

Doppler Studies Assesses fetal blood flow in sites like; (3rd trim)

1. umbilical artery

2. Middle cerebral artery

3. Ductus venosus (antegrade is normal, reversed is hypoxemia)

Most Common Invasive diagnostic Test

Amniocentesis

Amniocentesis timing

14–16 weeks.

most accurate test for Down syndrome early in pregnancy in advanced maternal age

Chorionic Villus Sampling (CVS)

Amniocentesis can diagnose

1. chromosomal issues (Turner, Edward syndrome)

2. infections like toxoplasmosis

Rubella Infection in the first trimester increases the risk of:

1. Microcephaly

2. Congenital cataract

3. Heart disease

4. Deafness

   (Not typically intracranial calcification)

station of the presenting part requires

Vaginal examination

Abdominal Palpation Used to assess

fetal number, size, presentation, and engagement, but not the station

Adnexal Mass Malignancy: Ultrasound scores depend on:

1. Multilocular cysts

2. Solid areas

3. Bilateral lesions

4. Ascites

   (NOT endometrial thickness)

Pelvic Exam: A bimanual exam can evaluate:

Uterine size, direction, masses (cannot reliably evaluate the size of normal adnexae)