Emergency OB USDr. Wananee Meennuch

6-July-2016

Objectives

• Refresh your (& my) knowledge• Experience share• Inspiration in one of your learning paths

Outlines

• Normal anatomy and US findings• Common 1st trimester emergency conditions: Vaginal bleeding & pelvic pain

• Common 2nd-3rd trimester emergency conditions: Vaginal bleeding +/- contraction

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http://www.ehd.org/

Yolk sac

Yolk sac

The yolk sac

• No YS in GS >8 mm Æ abnormal • No embryo in a GS >16 mm Æ abnormal • No embryo in GS of 25 mm Æ Dx failed pregnancy • No yolk sac or embryo on 2 scans / 7-10 days apart = definitive evidence of a failed intrauterine pregnancy

Intrauterine Fluid Collection

• MSD of 2-3 mm (GA =4.5-5 weeks)

• E-hCG = 1,000-2,000 mIU/mL Æ gestational sac seen on TVS

• “double decidual sign”

Gestational sac : GS

Ultrasound in Obstetrics and Gynecology, Vol 1Eberhard Merz

First-trimester bleeding

• 27% of pregnancies• overall risk of miscarriage about 12%

serum HCG levels clinical presentation DDx

First-trimester bleeding

threatened abortion

Failed intrauterine pregnancy

Gestational trophoblastic

disease

Ectopic pregnancy

F 34 YO, GA 8 weeksVaginal bleeding

The interval for F/U

LMP/ date of assisted reproduction

Patient symptoms

Growth rate of the GS + rise in the levels of E-hCG

Blighted ovum

FHR

Absence of cardiac activity in embryo

Normal range of FHR • 6.2-7 wk = 100-120 BPM • after 7 wk = 137-144 BPM

Scan mode• pulsed Doppler beam temperature in tissues•only M-mode US should be used

Video clips

US findings in first-trimester bleeding with a poor outcome

• Bradycardia (FHR < 100)• slow growth rate of the embryo

• abnormally small or large GS /embryo

• enlarged amniotic cavity • empty amniotic cavity

• No cardiac activity with visualization of the amnion

• abnormal size or shape of the yolk sac

• low position / irregular shape of GS

• GS volume after 7 weeks

Subchorionic hemorrhage

common finding during the 1st trimester

Moderate - large subchorinic bleeding compared to GS size Æ poor outcome

http://emedicine.medscape.com/article/404971-overview#a4

F 32 YO GA = 8 weeks, vaginal bleeding

RPOC =Retained product of conceptus

F 33 YO GA = 6 weekVaginal spotting

Gestational Trophoblastic Disease -GTD

• First trimester : variable appearance- a small, echogenic endometrial mass without cystic spaces- mixed echogenic and cystic material - DDx hydropic degeneration and retained products of

conception.

• Second trimester : distended endometrial cavity filled with innumerable small cystic spaces

Summary 1st trimester bleeding

• TVS is the study of choice for early pregnancies. • TAS : useful to assess the amount of free fluid and for

abnormalities beyond the FOV of TVS• correlate with the quantitative E-hCG level & with the

clinical presentation• The lack of an intrauterine GS does not necessarily

indicate ectopic pregnancy

Summary 1st trimester bleeding

• A failed pregnancy : - GS >25 mm & no yolk sac/ embryo- an embryo measuring ≥7 mm & no cardiac activity.• Use M-mode to document embryonic viability and measure

heart rate

• Doppler US should not be used to evaluate a normal early embryo.

Ectopic Pregnancy

• Extrauterine GS with a live embryo = 100% specific

• Extrauterine tubal ring with central fluid or + a yolk sac and/or a nonviable embryo

• a complex, extraovarian, extrauterinemass

• Color Doppler : variableColor and pulsed Doppler imaging is not

necessarily useful

• MRI : unusual ectopic pregnancies, GTD, or vascular abnormalities, but should not delay urgent or emergent care in an unstable patient.

• CT may be useful in trauma or acute non-gynecologic pain, for staging of malignancy, or if MRI is not possible.

Ectopic Pregnancy

• 80% : ipsilateral to corpus luteum…must be distinguished from it!!!

rathachai@gmail.com

Ectopic pregnancy

• 4% unusual location• Intrauterine ectopic locations Æ interstitial, cervical,

and within a Cesarean section scar

• Heterotopic pregnancies = intrauterine + extrauterinepreg. (extremely rare, but much higher incidence from assisted reproduction

A 34 YO femaleS/P IVFVaginal bleeding for 1 day

ACUTE PELVIC PAIN IN THE REPRODUCTIVE AGE GROUP

Gynecologic - obstetrical Nongynecologic

hemorrhagic ovarian cysts appendicitis

pelvic inflammatory disease inflammatory bowel disease

ovarian torsion infectious enteritis

ectopic pregnancy diverticulitis

spontaneous abortion/ labor urinary tract calculi

placental abruption pyelonephritis

pelvic thrombophlebitis

ACUTE PELVIC PAIN IN THE REPRODUCTIVE AGE GROUP

• EE >21 mm virtually excludes the possibility of ectopic pregnancy• Absence of an intrauterine pregnancy when the β-hCG level > 3510

mIU/mL : strongly suggestive of ectopic pregnancy• TVS should be used whenever possible• TAS is recommended for larger FOV. • Doppler imaging should be avoided in the setting of developing

intrauterine pregnancy• •Low-dose NCE- CT for acute pelvic pain in pregnancy for non-

Gyne condition, 2nd/3rd trimester

SECOND & THIRD TRIMESTER BLEEDING

• placenta previa (most common) • placenta accreta (highest risk of life threatening)• placental abruption• vasa previa

SECOND & THIRD TRIMESTER BLEEDING

• bloody vaginal discharge (“bloody show”) • cervical infection or neoplasm• uterine rupture : severe pain in late pregnancy (had prior C/S and uterine Sx)

http://www.stanfordchildrens.org/

F. 36 YO vaginal bleeding Æ Placenta previa?

18 weeks10 weeks

Placenta previa

• painless bleeding• near the end of 2nd- 3rd trimester• 2.8/1,000 in singleton pregnancies• 3.9/1,000 in twin pregnancies• risk factors: age over 30, multiparity, prior C/S, and

prior abortions

Placenta previa

4 types:

(1) complete previa—covers the internal os (central or asymmetric)(2) partial previa—partially covering(3) marginal—placental edge going to the internal os(4) low-lying—to within 2 cm of the internal os

• placental edge <2 cm from internal os

measure placental edge - internal os distance

• placental edge >2 cm from internal os exclude placenta previa

• Safety? TVS: safe for previa, including pt. with vag.

bleeding

• Contraindication to TVS: incompetent Cx with a bulging amniotic sac/ suspected preterm PROM

Æ TransperinealUS

Placenta Accreta

• abnormally adherent to the uterus• increased C/S• incidence = 1 in 533 deliveries

RadioGraphics, http://pubs.rsna.org/doi/abs/10.1148/rg.287085060

Placenta Accreta

Risks: • placenta previa & multiple C/S • Advanced maternal age• Multiparity• Asherman’s syndrome (Uterine synechiae)• Fibroids

• Placenta increta : chorionic villi invading the myometrium• Placenta percreta : penetration of chorionic villi through the uterus

Placenta Accreta: US findings

• loss of the normal retroplacental hypoechoic zone• localized thinning of the myometrium• increased vascularity at placental-myometrial interface

on CDUS

Placenta Accreta: US findings

• “Numerous coherent vessels” at the placental base: • inseparable cotyledon (fetal villous) and intervillous

(maternal) circulations with extreme hypervascularity

Placental Abruption

Vaginal bleeding

Uterine tenderness Contraction

Risk factors

• HT• pre-eclampsia• PROM• cigarette smoking• cocaine abuse• thrombophilias• abdominal trauma.

www.cardiosmart.org

Placental Abruption

• Marginal• Retroplacental• Preplacental

Nonconcealed VS. Concealed

Placental Abruption: US findings

• Thickened, with rounded bulging

• heterogeneous echotexture• loss of normal basal plate interface

• Hematoma: variable

RadioGraphics, http://pubs.rsna.org/doi/abs/10.1148/rg.295085242

Vasa Previa

• umbilical vessels traverse the fetal membranes in the lower uterine segment in front of the presenting part and cross over the internal cervical os unprotected by the placental or umbilical cord

• http://vasaprevia.com/

Vasa Previa

• high risk of fetal death• Neurologic deficit due to fetal exsanguination• Incidence is 1/2,500 deliveries

Type 1 velamentous insertion of the cord

Type 2 succenturiate lobe, with interconnecting vessels between it & the main placenta traversing the internal os

Figure 13 Vasa previa. Transvaginal power Doppler US image obtained at 18 weeks gestation shows an anterior placenta (P). There is vascular flow in a vessel (V) that is closely applied to the internal cervical os (O). Follow-up US at 32 weeks gestation showed resolution of the vasa previa, thus allowing subsequent uneventful vaginal delivery.RadioGraphics, http://pubs.rsna.org/doi/abs/10.1148/rg.295085242

Published in: Khaled M. Elsayes; Andrew T. Trout; Aaron M. Friedkin; Peter S. Liu; Ronald O. Bude; Joel F. Platt; Christine O. Menias; RadioGraphics 2009, 29, 1371-1391.DOI: 10.1148/rg.295085242© RSNA, 2009

One PowerPoint slide of each figure may be downloaded and used for educational, non-promotional purposes by an author for slide presentations only. The RSNA citation line must appear in at least 10-point type on all figures in all presentations. Pharmaceutical and Medical Education companies must request permission to download and use slides, and authors and/or publishing companies using the slides for new article creations for books or journals must apply for permission. For permission requests, please contact the publisher at permissions@rsna.org

Summary

xVaginal bleeding in the 2nd or 3rd trimester ass. with increased risks Mother & Fetus.

xTAS = primary imagingxTVS needed for visualization of Cx & internal os(+/- transperineal US)

Summary : Placenta previa

xDecribe distance of the placental edge to the internal os

x Reevaluated during pregnancy for a potential resolution depending on the degree of attachment to the opposing wall.

Summary :Placental abruption

• clinical diagnosis• emergency US : placental thickening, heterogeneity, and

a periplacental hematoma

Summary: Placental accreta

• Prior C/S Æ increase the risk of placental accreta• US findings: intraplacental lacunes, increased vascularity,

myometrial thinning, and focal placental bulge • MRI improves Dx confidence

Summary: Vasa previa

• Serious risk that needs to be recognized and requires a planned C/S.

• Velamentous cord insertion VS. interconnecting vessels of accessory placental lobe (succenturiate lobe), over internal Cx os