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First Trimester Ultrasound (and other varied topics assigned to me): Nuts and Bolts. Honor M. Wolfe. Objectives. Review ed scan process Perform and/or interpret the results of selected tests used in the diagnosis and management of early pregnancy loss: (PC)
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First Trimester Ultrasound (and other varied topics assigned to me): Nuts and Bolts Honor M. Wolfe
Objectives • Review ed scan process • Perform and/or interpret the results of selected tests used in the diagnosis and management of early pregnancy loss: (PC) a. Quantitative serum hCG titer b. Ultrasonography (abdominal and endovaginal) c. Serum progesterone d. Complete blood count
Objectives List ultrasonography findings that are often associated with genetic disorders for: (PC) a. Duodenal atresia b. Omphalocele c. Nuchal translucency/nuchal skin fold d. Echogenic bowel e. Heart Defects f. Diaphragmatic hernia g. Ventriculomegaly Counsel patients about the risks and benefits of various methods of invasive fetal testing, such as: (PC, ICS) a. Chorionic villus sampling b. Amniocentesis c. Cordocentesis d. Pre-implantation genetic testing
The Process • Radiology and Ob both do 1st trimester ultrasound • It was a long, long process • The result is • Better patient care • Better efficiency • Happier ob gyn residents • But …….its working • Continue to respect the sonographers
The Process • Radiology will not do a pelvic ultrasound for a pregnant patient who is > 12 week EGA • We cannot use their machines • Not for ovarian torsion, not for PID, not for pelvic mass • NEVER…. • So what are the options • Clinical assessment • Midlevel machine from labor and delivery
OB ULTRASOUND REPORTS • An ultrasound is NOT a consult • Reports • Generic note in WEB CIS • Results of ultrasound • May include recs – or NOT • Route to me to sign, images will be reviewed • If the reading provider disagrees with your read, gyn consult resident will be paged
First trimester Ultrasound • Where is the pregnancy? • Is it viable? • Prognosis • How many are there • And what type
Where is the pregnancy: Ectopic Pregnancy • 2% of pregnancies/6% of maternal mortality • 18% 1st trimester pregnancies presenting ED bleeding/pain • 33% pregnancies following tubal sterilization • 10% ectopic pregnancies • 33% pregnancies following an ectopic = ectopic • What if you see an IUP • 1% rate of heterotopic pregnancy • Especially if ART
Diagnosis • History and physical • Risk factors • Progesterone • Independent of hcg • < 5: 100% specificity for “abnormal” pregnancy • > 20: usually associated with normal IUP • 5 – 20:equivocal • Most ectopics: 10 - 20
Diagnosis • Discriminatory Zone • The value above which it is abnormal not to see an IUP • HCG • Transvaginal ultrasound: 1500-2000 (for CREOG) • Transabdominal ultrasound: ?????
UNC Discriminatory Zones • “ideal” scanning conditions • David Ryan • Positive and negative predictive value
Ectopic Pregnancy: Bhcg • 71% outside range • 21%: increase as nml IUP • 8%: decrease as SAb
Ectopic pregnancy: Ultrasound findings • Sensitivity • 73 – 91% • Initial ultrasound • Up to 1/3: nothing in uterus or tubes • “Pregnancy of unknown location” • Pregnancy of unknown location • 7 – 20% ectopic pregnancy
Where is the pregnancy? • If you see it in the cervix – think of cervical ectopic • Look at the shape • Regular, irregular • Look at the vascularity • If SAb, - there shouldn’t be much • Look for a heart beat • If Sab – there won’t be one
Ultrasound reports • Unless I see a yolk sac or the “sac” is > 10 mm you will see…. • Cannot rule out ectopic pregnancy • If I think there is an ectopic you will see • ECTOPIC! • Because • Bowel is not friendly to sound waves • And • I have not seen the patient (radiology)
Viability • Quants not rising? • ACOG < 53% rise in 48 hours • Patients want another ultrasound • 5/10/20 rule • FHR • Empty amnion
5/10/20 (err on the side of the pregnancy) • Non viable if (under ideal scanning conditions) • CRL 5 mm and No fetal heart tones OR • MSD 10 mm and no yolk sac OR • MSD 20 mm and no fetal pole • What makes conditions non ideal? • Transducer: setting and mHz • Uterus: position, fibroids • Maternal: obesity, full bladder • Bowel gas • Sonographer experience
Early IUP • Sac or pseudosac? • Sac
Fetal Heart Rate • Grey scale • Should be very obvious if there • M Mode • Tough to interpret with small CRL • Color/power doppler • Clearest option when not scanning yourself • ?? Damaging • If there is a question of viability • MUST HAVE COLOR/POWER
Subchorionic Bleed • Pretty common – especially in 1st trimester bleeding
1st trimester subchorionic hemorrhage • Sab – 7 – 57% but… • Ultrasound is better now – and we see smaller bleeds • Likely on the lower end – but look at the size and the GA
Retained POC • 13 mm “best” clinical use • But – look at the endometrium • Is the stripe uniform in thickness • “bulges” • Is the stripe heterogeneous • And – color flow doppler