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Home , Decidua, Gestational sac, Yolk sac

1/10/2020

Early Ultrasound: From PUL to IUP (And Everything In Between)

Todd R. Jenkins, MD, MSHA

Early Pregnancy Ultrasound

• Learning Objectives – Describe the ultrasound findings associated with normal early pregnancy – Apply the knowledge of normal early pregnancy to diagnose early pregnancy loss/abnormalities – Recognize abnormal early pregnancy conditions based on ultrasound findings

Early Pregnancy Ultrasound

• Disclosures

– None

1 1/10/2020

Early Pregnancy Ultrasound

• 25 YOF LMP 5 weeks ago presents to the Emergency Department reporting a 6-hour history of vaginal bleeding with associated lower abdominal cramping. After you perform a H&P, you order a beta-hCG and a transvaginal ultrasound.

Early Pregnancy Ultrasound

A (GS) can first be visualized at TV US @ 4.5-5.0 weeks of as a 2- 3mm rounded intrauterine fluid collection.

Early Pregnancy Ultrasound

Intradecidual sign Defined as an eccentrically located GS within the echogenic , with a relatively undisturbed collapsed uterine cavity visualized as a thin echogenic line.

2 1/10/2020

Early Pregnancy Ultrasound

Double sac sign Two concentric echogenic rings surrounding the fluid collection and separated by a thin crescent of endometrial fluid. The outer ring represents the decidua parietalis, and the inner ring represents the decidua capsularis and

Early Pregnancy Ultrasound Pseudosac • Fluid between the decidua layers • NOT eccentrically placed • NO double decidual sign

Early Pregnancy Ultrasound

Yolk Sac (YS) The is the earliest intragestational sac structure to be visualized at U/S that can absolutely confirm an IUP. It can be visualized at 5.5 weeks as a round 3-5 mm round structure, usually eccentrically located within the gestational sac.

3 1/10/2020

Early Pregnancy Ultrasound

Yolk Sac (YS) The YS may sometimes appear as two parallel lines, representing the leading edge and posterior wall (Figure 3b)

Early Pregnancy Ultrasound

The The embryo, or fetal pole, is first visible at approximately 6 weeks of gestational age as a 1-2 mm structure at the periphery of the yolk sac.

Early Pregnancy Ultrasound

4 1/10/2020

Early Pregnancy Ultrasound

• The embryo resides within the amniotic cavity, and the yolk sac resides within the chorionic cavity.

Early Pregnancy Ultrasound

Between 6.5 – 10 weeks of , a linear relationship exists between the diameter of the amniotic cavity and the CRL, with the mean diameter of the 10% larger than that of the CRL.

Early Pregnancy Ultrasound

In normal gestation, the chronic cavity, amniotic cavity, and CRL, grow proportionally until the onset of the fetal urine production at about 10 weeks.

The fetal urine disproportionately enlarges the amniotic cavity, which then grows faster than the chorionic cavity, with eventual fusion of the amnion and chorion at 14-16 weeks.

5 1/10/2020

PREGNANCY OF UNKNOWN LOCATION (PUL)

Early Pregnancy Ultrasound

• Pregnancy of Unknown Location (PUL)

– “A pregnant woman without a definitive finding of an intrauterine or on ultrasound examination has a pregnancy of unknown location”

Early Pregnancy Ultrasound

Early Pregnancy Loss (EPL) A nonviable, intrauterine pregnancy with either an empty gestational sac or a gestational sac containing an embryo or fetus without fetal heat activity within the first 12 6/7 weeks of gestation

6 1/10/2020

Early Pregnancy Ultrasound

If a GS was empty on initial scan, the absence of a visible yolk sac or embryo on a second scan performed 7 days or more after the first scan was always associated with pregnancy loss

Early Pregnancy Ultrasound

• Society of Radiologists in Ultrasound Guidelines – Findings Diagnostic of Pregnancy Failure • CRL ≥ 7mm and no heartbeat • Mean sac diameter of ≥ 25m and no embryo • Absence of embryo with heartbeat ≥ 2 weeks after a scan that showed a GS without a YS • Absence of embryo with heartbeat ≥ 11 days after a scan that showed a GS with a yolk sac

Early Pregnancy Ultrasound

• Findings Suspicious for, but Not Diagnostic of, Pregnancy Failure – CRL ≤ 7mm and no heartbeat – Mean sac diameter of 16-24 mm and no embryo – Absence of embryo with heartbeat 7-13 days after a scan that showed a GS without a YS – Absence of embryo with heartbeat 7-10 days after a scan that showed a GS with a yolk sac – Absence of embryo for 6 weeks or longer after LMP – Empty amnion – Enlarged yolk sac (≥ 7mm) – Small GS in relation to the size of the embryo (≤ 5mm difference between mean sac diameter and CRL)

7 1/10/2020

Early Pregnancy Ultrasound

Subchorionic Hematoma Reported to occur in 18- 22% of first-trimester with vaginal bleeding

Early Pregnancy Ultrasound

UNCOMMON ECTOPIC PREGNANCY SITUATIONS

8 1/10/2020

Early Pregnancy Ultrasound

Early Pregnancy Ultrasound

Fundal IUP Fundal IUP

Early Pregnancy Ultrasound

• Interstitial Ectopic Risk Factors – Prior ectopic pregnancy – Prior salpingectomy – Uterine anomalies – Use of ART techniques – Pelvic inflammatory disease

9 1/10/2020

Early Pregnancy Ultrasound

• Cornual/Interstitial Ectopic Diagnostic Criteria 1. An empty , AND 2. A gestational sac seen separately and < 1cm from the most lateral edge of the uterine cavity, AND 3. A thin myometrial layer surrounding the sac

Early Pregnancy Ultrasound

Early Pregnancy Ultrasound

10 1/10/2020

Early Pregnancy Ultrasound

• Options for Management of Cornual Ectopic – Surgical (Laparotomy or Laparoscopy) • Cornual resection • Hysterectomy • Uterine artery ligation and Salpingostomy – Medical • Systemic methotrexate (MTX) • Ultrasound or LSC-guided MTX or KCl injection

Early Pregnancy Ultrasound Cesarean Scar Ectopic

Early Pregnancy Ultrasound

• Ultrasound Findings – Empty uterine cavity with bright hyperechoic endometrial stripe – Empty cervical canal – Intrauterine mass in the anterior part of the uterine isthmus – Absence of the , absent or thin between the bladder and the gestational sac, measuring < 5mm

11 1/10/2020

Early Pregnancy Ultrasound

• Treatment Options – Medical Therapy • Patients who are pain-free, hemodynamically stable, and have an unruptured CSP < 8 weeks • Methotrexate – Systemic or local injection • Potassium Chloride (KCl)

Early Pregnancy Ultrasound

• Treatment Options – Surgical Therapy • Curettage – only after successful medical therapy • LSC-guided HSC curettage • Uterine artery embolization • Hysterectomy

Early Pregnancy Ultrasound

12 1/10/2020

Early Pregnancy Ultrasound

Cervical Ectopic • Risk Factors – Anatomic abnormalities – Fibroids – Prior endocervical canal instrumentation – Asherman’s syndrome – Intrauterine device – IVF pregnancy

Early Pregnancy Ultrasound

• Ultrasound Findings – Hourglass uterus – smaller than dates uterus with an enlarged cervix and narrowing at the internal os – Ballooned cervix with a closed internal os

Early Pregnancy Ultrasound

• Treatment Options – Suction D&C • AFTER placement of dilute vasopressin and cervical cerclage • Mechanical tamponade – Ultrasound guided transvaginal or transabdominal local injection of KCl or MTX

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