1st TRIMESTER
PREGNANCY FAILURE
Shortened to emphasize
medical student curriculum
requirements
Carlos M. Fernandez, M.D
Department of Obstetrics and Gynecology
Advocate Illinois Masonic and Medical Center
ULTRASOUND DIAGNOSIS OF
INTRAUTERINE PREGNANCY
Diagnosis of IUP
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“Double decidual sign” at 4½ to 5 wks
Gestational sac + yolk sac at 5 wks
(a definitive sign of IUP)
GS + yolk sac + embryo at 5½ to 6 wks
CRL >5 mm – fetal cardiac activity present
Seeber BE and Barnhart KT. Obstet Gynecol 2006;107:339-413
First sign of IUP: double
decidual sign
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Earliest finding is the
“double decidual sign”
(arrows)
seen around 4½-5 wks
gestation
initially eccentric in
location
It excludes
pseudogestational sac
(free fluid or blood within
endometrium)
Gestational Sac (confirmed by
double decidual sign)
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Grows 1 mm per day
Usually seen by 4 ½ to 5 weeks of gestation
Discriminatory ß-hCG with TVS: usually quoted 1000 2000 ß-hCG IU/L. Depends upon:
 Skill of the sonographer and image magnification
 Frequency (5-10mHz) and resolution of the
transducer
 Uterine abnormalities, fibroids
 Multiple gestation
Gestational Sac
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Discriminatory ß-hCG with TVS :
1000 - 2000 ß-hCG IU/L
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Discriminatory ß-hCG with TAS:
≥ 6500 ß-hCG IU/L
Bhatt & Dogra, Radiol Clin N Am 45 (2007) 549-560
The gestational sac diameter is
used to calculate gestational age
Long axis
Short axis
Second sign of IUP: Yolk Sac
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First structure visualized within
the gestational sac
Round , bright ring <6mm
A definitive sign of IUP
Involutes after 11 weeks
Can be seen half a week before
normal embryo is seen
When enlarged (“hydropic”), solid
or duplicated, it is a very poor
prognosis sign
Third sign of IUP: GS + yolk sac
+ embryo
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GS + yolk sac + fetal
pole at 5½ to 6 wks
The fetal pole (arrow) is
better seen on the
zoomed in image
GS grows 1mm/day
Embryo grows
1mm/day
Fourth sign of IUP: GS + YS +
embryo + cardiac activity
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Double decidual sign +yolk
sac+ fetal pole +cardiac
activity
Cardiac activity confirms a
live intrauterine pregnancy
Cardiac activity is usually
detected at 5 ½ to 6 weeks
from last menstrual period
CRL ≥5 mm – fetal cardiac
activity present
BHCG AND PROGESTERONE
IN EARLY PREGNANCY
Serum concentrations of ß-hCG in 443 normal pregnancies
ß-hCG is first detected in maternal serum
6 to 9 days after conception. The levels rise
in a logarithmic fashion, peaking 8 to 10
weeks after the last menstrual period,
followed by a decline to a nadir at 18
weeks, with subsequent levels remaining
constant until delivery
Second International Standard ß-hCG
Braunstein G D, et al. Am J Obstet Gynecol 1976; 126:678-81.
Serial ß-hCG
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The doubling time for a normal IUP is 2
days, with a range of 1.4 to 2.1 days
Doubling of ß-hCG is less reliable after
10,000 mIU/ml , at this level pregnancy is
better evaluated with U/S
15% of normal IUP can demonstrate an
abnormal rise of ß-hCG
Kadar N, et al. Obstet Gynecol 1981;52:162-6
ß-hCG up to 10000 mIU/ml
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The minimal rise in ß-hCG for a viable
pregnancy is 53% in 48 hours
The minimal decline of a spontaneous
abortion is 21-35% in 48 hours
A rise or fall in serial ß-hCG values that is
slower than this is suggestive of an ectopic
pregnancy
Seeber BE and Barnhart KT. Obstet Gynecol 2006;107:339-413
Hypothetical illustration of the rise, or fall, of
serial hCG values in women with an EP
53%
21-35%
Seeber BE and Barnhart KT. Obstet Gynecol 2006;107:339-413
SPONTANEOUS ABORTION:
BACKGROUND, ETIOLOGY
Spontaneous abortion or miscarriage
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Spontaneous abortion is a fetal loss before week
20 of pregnancy
Early loss is before menstrual week 12
 Late loss refers to losses from weeks 12 to
20
 80% of miscarriages occurring in the first
trimester
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Ferri: Ferri's Clinical Advisor 2012, 1st ed.
Miscarriage
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Miscarriage is the most common serious pregnancy
complication affecting approximately 30% of
biochemical pregnancies and 11–20% of clinically
recognized pregnancies
The diagnosis of miscarriage is made most commonly
by trans-vaginal ultrasound (TVS) assessment
After a diagnosis of miscarriage, half the women
undergo significant psychological effects, which may
last for up to 12 months
Cecilia Bottomley, Tom Bourne. Diagnosing miscarriage. Best Practice & Research
Clinical Obstetrics & Gynecology 2009; 23:463-77
Miscarriage
The crucial role of chromosomal imbalance in
abnormal early human development is well
established
 Approximately 50–60% of first-trimester
spontaneous abortions have karyotype
abnormalities
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Igor N Lebedev, Nadezhda V Ostroverkhova, Tatyana V Nikitina, Natalia N Sukhanova
and Sergey A Nazarenko. Features of chromosomal abnormalities in spontaneous
abortion cell culture failures detected by interphase FISH analysis. European Journal of
Human Genetics 2004; 12:513–20
Miscarriage
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The most frequent type of chromosomal
abnormalities detected are:
Autosomal trisomies ─ 52 %
2. Monosomy X ─ 19 %
3. Polyploidies ─ 22 %
4. Other ─ 7 %
1.
Hsu, LYF. Prenatal diagnosis of chromosomal abnormalities through amniocentesis. In:
Genetic Disorders and the Fetus, 4th ed, Milunsky, A (Ed), The Johns Hopkins University
Press, Baltimore 1998. p.179
CLASSIFICATION OF
MISCARRIAGE
Clinical classification of spontaneous abortion
Laifer-Narin SL. Ultrasound for Obstetrics Emergencies. Ultrasound Clin . 2011; 6: 177-193
Type
Definition
Threatened abortion Vaginal bleeding during the first 20 weeks of pregnancy and no
evidence of cervical dilation <50% of threatened abortions will
progress to loss of pregnancy
Missed abortion
Intrauterine demise of the conceptus without either vaginal bleeding
or expulsion of the products of conception
Incomplete abortion Vaginal bleeding with dilation of the cervix and partial expulsion of
the conceptus
Complete abortion
Vaginal bleeding with expulsion of all of the products of
conception
Inevitable abortion
Abortion in progress in which the bleeding is profuse with cervical
dilation but a maintained intrauterine pregnancy
Differential Diagnosis of
Threatened Abortion
1. Undetermined or physiologic (implantation
2.
3.
4.
5.
6.
related)
Ectopic pregnancy
Sub-chorionic bleed, found in ~20% of
threatened Ab
Gestational trophoblastic disease
Impending spontaneous miscarriage
Cervix, vaginal or uterine pathology
This section is too in-depth for most medical students; use it only for the
most interested students!
ULTRASOUND DIAGNOSIS OF
MISCARRIAGE (COMPARING
INTERNATIONAL CRITERIA)
How to define miscarriage using ultrasound-comparing and contrasting national guidelines
Royal College of Obstetricians and Gynaecologists.
The Management of Early Pregnancy Loss. GreenTop Guideline No. 25. October 2006
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Miscarriage:
 Miscarriage is defined at first scan when gestational
sac with MSD greater than 20 mm an no embryonic
contents or CRL > 6 mm with no heart beat
 Or subsequently if sac remain empty after at least
one week or still no cardiac activity 1 week after
initial
How to define miscarriage using ultrasound-comparing and contrasting national guidelines
The Institute of Obstetricians and
Gynaecologists
Royal College of Physicians of Ireland
Transvaginal
Ultrasound
Embryo > 7 mm
No cardiac activity
Miscarriage
Gestational sac > 20 mm
No embryo or yolk sac
Miscarriage
What is the evidence to support the cut-offs used to
diagnose miscarriage?
Conclusions
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First systematic review of ultrasound diagnosis of miscarriage
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Studies are 15–20 years old, small numbers of miscarriage, reference standards
were poor (method of miscarriage confirmation)
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Various cut-off values used (4–6mm for CRL, 13–25mm for MSD), making
pooling of data impossible
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Best (most specific) criteria appeared to be MSD > 25mm with a missing
embryo or MSD > 20mm with a missing yolk sac
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These criteria had a 95% CI of 0.96–1.00, therefore up to 4 out of 100
diagnoses of early fetal demise may be wrong. A single incorrect diagnosis of
miscarriage is one too many
Jeve Y et al., UOG 2011 Nov
Abdallah Y, et al. Limitations of current definitions of miscarriage using mean
gestational sac diameter and crown–rump length measurements: a multicenter
observational study. Ultrasound Obstet Gynecol 2011; 38: 497–502
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Prospective multicenter study
1060 patients of IPUV
Conclusions
Current definitions used to diagnose miscarriage by ultrasound
are potentially unsafe
In order to minimize the risk of a false-positive diagnosis of
miscarriage the following cut-off could be introduced
 Empty gestational sac or sac with a yolk sac but no
embryo seen with MSD >25 mm
 Embryo with an absent heartbeat and CRL > 7 mm
Summary
Summary
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Data from these studies show that current definitions
used to diagnose miscarriage are potentially unsafe
Significant interobserver variability may be associated
with a misdiagnosis of miscarriage
Current national guidelines should be reviewed to avoid
inadvertent termination of wanted pregnancy
Large prospective studies with agreed reference
standards are urgently required
ECTOPIC PREGNANCY
Risk Factors for Ectopic Pregnancy
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Prior ectopic
Previous tubal surgery
History of tubal ligation
Intra-uterine contraceptive device
History of infertility
History of PID
History of chlamydia or gonorrhea
Smoking
PREGNANCY OF UKNOWN
LOCATION
RETAINED PRODUCTS OF
CONCEPTION
Retained Products of Conception (RPOC)
Oscar Sadan, Abraham Golan, Ofer Girtler, Samuel Lurie, Abraham Debby, Ron Sagiv,
Shmuel Evron, Marek Glezerman. Role of Sonography in the Diagnosis of Retained
Products of Conception. JUM 2004 23:371-4
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RPOC are well-known and troublesome complications after
spontaneous or induced abortion and parturition
Patients usually have abdominal pain, bleeding, fever, and an
open cervical external os
The diagnosis is based on the sonographic appearance of
intrauterine echogenic material
Retained products of conception are generally treated by D&C
to empty the uterine cavity. This exposes the uterus to
additional potential trauma, with immediate risks such as
bleeding, perforation, and infection and late sequelae such as
intrauterine adhesions
Retained products of conception. Intrauterine heterogeneous, mixed
echogenic mass with marked internal vascularity in a patient who recently
underwent spontaneous abortion
Transvaginal sagittal sonogram of a uterus immediately after
repeated D&C. A thin hyperechoic echo is shown, characteristic of
an empty uterus.