Ultrasound in early pregnancy is used to assess: 1. Normal aspects such as gestational sac size and viability by detecting a heartbeat. 2. Abnormalities including ectopic pregnancies, molar pregnancies, and hemorrhages. 3. Dating the pregnancy accurately in the first trimester by measuring the mean sac diameter or crown-rump length. 4. Detecting multiple pregnancies and diagnosing chorionicity and zygosity. 5. Screening for fetal abnormalities such as thickened nuchal translucency which is used to detect Down syndrome.

1. Ultrasound in early pregnancy
complications
Prepared by Baldandorj Kh
Resident, Urguu Maternity Hospital, Mongolia
Obs & Gynae Ultrasound rotation: December 2022

2. Points for discussion
• NORMAL
Aim of early obstetric ultrasound
• ABNORMAL
Location
Structure
Viability
Dating
Number
•Assessment of other pelvic masses ????
•Screening for fetal abnormalities ????
•Assisting CVS and amniocentesis????

3. Structure & Viability in 1st trimester pregnancy
 Gestational sac
 Yolk sac
 Embryo/fetus
 Presence of cardiac activity
Aim of early obstetric ultrasound

4. Structure & Viability in 1st trimester pregnancy
Aim of early obstetric ultrasound
Gestational sac
Visible at 4-5wks GA with TVUS & at 6 wks
GA with TAUS.
Eccentric echogenic ring with anechoic
center .
Measure by Mean Sac Diameter.
GS size increases by about 1mm/day in early
pregnancy
Discriminatory zone: serum hCG level in
which GS is expected to be visible by US :
hCG >2000 mIU/ml by TVUS& hCG >6000
mIU/ml by TAUS

5. Structure & Viability in 1st trimester pregnancy
Aim of early obstetric ultrasound
Yolk sac:
• bright ring with anechoic center located
inside GS seen at 5wk GA & persists to
11-12 weeks.
• Embryo/fetus: seen by TVUS as
thickening of yolk at 6wks GA.
• Presence of cardiac activity: usually
seen around the time fetal pole is
present, further confirming viability (6th
wks)

7. Structure & Viability in 1st trimester pregnancy
Aim of early obstetric ultrasound
Yolk sac:
• bright ring with anechoic center located
inside GS seen at 5wk GA & persists to
11-12 weeks.
• Embryo/fetus: seen by TVUS as
thickening of yolk at 6wks GA.
• Presence of cardiac activity: usually
seen around the time fetal pole is
present, further confirming viability (6th
wks)

8. Confirming IUP
Structure & Viability in 1st trimester pregnancy
1) Double decidual sac sign 2) Intradecidual sign 3) Double bleb sign
Хос бөгжний шинж

9. Dating
Structure & Viability in 1st trimester pregnancy
Early dating of pregnancy
 5 – 9 weeks : use of mean GS diameter
 6 – 12 weeks : use of CRL (most accurate dating of early
pregnancy)
 After 12 weeks : use of BPD

10. Dating
Structure & Viability in 1st trimester pregnancy
Formulas to Calculate gestational age
 MGSD (mm) + 30 = gestational age
(days) (between 5 and 9 weeks)
 CRL (mm) + 42 = gestational age
(days) (between 6 and 12weeks)

11. Diagnosis of multiple pregnancypregnancy
Structure & Viability in 1st trimester pregnancy
Types of multiple pregnancy

12. Diagnosis of multiple pregnancypregnancy
Structure & Viability in 1st trimester pregnancy
Zygosity= Conception type by DNA test
Chrionicity= Placentation type prenatally by Ultrasound &
postnatally by examining membranes

15. Diagnosis of multiple pregnancypregnancy
Structure & Viability in 1st trimester pregnancy
Chrionicity
• Number of sacs
• Placenta
• Sex
• Intertwin membrane
• Lambda sign & T sign

16. Diagnosis of multiple pregnancypregnancy

17. Other rules of Ultrasound
Structure & Viability in 1st trimester pregnancy
Confirm fetal number .
Confirm viability.
Diagnosis of vanishing twin syndrome.
Exclude any malformation or conjoined twins (especially at
age > 35y = genetic amniocentesis)
Needed with other procedures
CVS
fetal reduction

18. Other rules of Ultrasound
Structure & Viability in 1st trimester pregnancy
Confirm fetal number .
Confirm viability.
Diagnosis of vanishing twin syndrome.
Exclude any malformation or conjoined twins (especially at
age > 35y = genetic amniocentesis)
Needed with other procedures
• CVS
• fetal reduction

19. Abnormal early (first trimester) pregnancy
Structure & Viability in 1st trimester pregnancy
 Failed early pregnancy.Failed early pregnancy.
 Pregnancy of uncertain viability (i.e. IU pregnancy in a
situation with no enough criteria (usually on ultrasound
grounds) to confidently categorize a pregnancy as a
miscarriage).
 Pregnancy of unknown location.
 Ectopic pregnancy
 Trophoblastic disease
 Subchrionic hemorrhage
 Incomplete abortion (retained products of conception)

20. Failed early pregnancy & & Pregnancy of
uncertain viability
Structure & Viability in 1st trimester pregnancy
Doubilet et al., N Engl J Med. 2013 Oct 10;369(15):1443-51

21. Failed early pregnancy & & Pregnancy of uncertain viability
 TVUS criteria of :
Doubilet et al., N Engl J Med. 2013 Oct 10;369(15):1443-51

22. US poor prognostic indicators of pregnancy include:
 No yolk sac, where:
 MSD > 8 mm
 embryo seen
 Irregular gestational sac
 Low position of the gestational sac

23. Structure & Viability in 1st trimester pregnancy
Pregnancy of unknown location (PUL)
PUL = +ve pregnancy test + no IU or Ext.U
pregnancy in US scan
Differential diagnosis is:
1.Very early pregnancy, not detected with ultrasound
2.Complete miscarriage
3.Unidentified ectopic pregnancy

25. Structure & Viability in 1st trimester pregnancy
Ectopic pregnancy

26. Structure & Viability in 1st trimester pregnancy
Ectopic pregnancy
Specific for Etopic:
-Embryo in adnexa
Less specific (must correlate with B-hCG):
-Empty uterus
-Adnexal mass
• Classic=thick echogenic ring separate from ovary
• Tubal pregnancy >2-3cm at risk for rupture
-Pelvic free fluid
-Pseudogestational sac

27. True VS Pseudo-gestational sac

28. True Gs (DDSS) Pseudogestational sac of ectopic pregnancy
Sagittal view
VS
Pseudo Gestational sac
Beak sign
Fluid collection (or sac) shows a small “beak sign” that connects with or points
toward the uterine cavity line

29. HETEROTOPIC PREGNANCY

30. Hemorrhage and debris in Cul-de-sac
Free fluid
Debris
Transverse of Cul de sac & Uterus

31. Бусад төрлийн Умайн гаднах жирэмсэн
Hemorrhage and debris in Cul-de-sac

32. Умайн хүзүүний умайн гаднах жирэмсэн
 GS within the cervix .
 Abnormally low sac position.
 Colour Doppler: hypervascular trophoblastic ring in the cervical
region .

33. Sonographic features of Caesarean scar ectopic pregnancy (CSEP)
 Empty uterus
 Empty cervical
canal
 GS in the anterior
part of the lower
uterine segment
 Absence of
myometrium
between the
bladder wall and
the GS

34. Molar pregnancy

35. ( Snow storm+ Theca-lutein cysts )

36. Subchorionic hematoma

37. Retained products of conception (incomplete abortion)

38. Thickened Nuchal Tanslucency (NT):

39. Thickened Nuchal Tanslucency (NT):
 Used for screening (SS) for Down’s
syndrome in first trimester
 Serial screening: Pregnancy associated
plasma protein levels, hCG levels, NT
thickness
 Measured during 11-14 wks gestational age
 Seen on sagittal image as increased
subcutaneous non-septated fluid in posterior
fetal neck
 Measurement >3mm usually considered
abnormal, however exact cut off
measurements are dependent on maternal
age/gestational age
 Detection rate of screening for Down’s
Syndrome in first trimester:
 Sequential screening with nt: 82-87%
 Nt alone: 64-70%

40. Safety of ultrasound in pregnancy
 General perception is that ultrasound is safe (It is not ionising radiation)
 However, bioeffects can be either thermal or mechanical (i.e. cavitations) with high
power ultrasound
 One RCT of repeated routine ultrasound with Dopplers in the 3rd trimester found a
small but significant decrease in birth weight in the exposed cohort
 A meta analysis showed males exposed to ultrasound in uterus are more likely to
be left-handed
 Ultrasound is no substitute for a good history
 ALWAYS do an abdominal scan with ( Full bladder) before using the vaginal probe
with ( Empty bladder)
 You will always be better than sonographers because you know the anatomy and
pathology
 Avoid premature conclusions
 Systematic scan should be performed
 US scans are useful to be combined with HCG tests before decision.
 With ultrasound , an early intervention or conservative management in pregnancy
can be determined.
 General perception is that ultrasound scan is safe in pregnancy.

41. The cross-over sign (COS)
In a sagittal view of the uterus, a
straight longitudinal line is drawn
connecting the internal cervical os and
the uterine fundus trough the
endometrium, the gestational sac is
identified and its superior–inferior (S–I)
diameter perpendicular to the
endometrial line is traced.
• COS-1 – the gestational sac is implanted within the Cesarean scar (CS) and at least two-
thirds of the S–I diameter of the gestational sac is above the endometrial line towards the
anterior uterine wall.
• COS-2 – the gestational sac is implanted within the CS and less than two-thirds of the S–I
diameter of the gestational sac is above the endometrial line.
 Cases in the latter group are further divided into the presence (COS-2+) or absence (COS-2–) of an
intersection between the S-I diameter of the ectopic gestational sac and the endometrial line.
First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018

42. First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018
 COS-1=higher
risk of
developing
placenta
percreta (More
AIP)
 COS-2=less
severe types of
AIP, such as
placenta accreta.

43. Introduction
• The COS has been suggested to have the potential to stratify the risk of women with CSP
evolving towards AIP:
 Women with COS-1 were shown to be at higher risk of developing placenta percreta
 Women with COS-2 were more likely to be affected by less severe types of AIP, such
as placenta accreta.
• Evidence for whether first-trimester ultrasound can identify women affected by AIP who
are at higher risk of intra- and postsurgical complications is still lacking.
First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018

44. Aim of the study
To ascertain whether ultrasound assessment of COS in the
first-trimester can predict surgical outcome in women with AIP
First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018

45. Methods
• Study Design
Retrospective study
• Setting
Single-center trial, Arnas Civico Hospital, Palermo, Italy. (Jan. 2007–Dec.
2015)
• Participants
All women referred with AIP during the study period for whom early first-
trimester ultrasound images (6–8 weeks’ gestation) indicated CSP.
First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018

46. Methods
• Study protocol
- Assessment of COS was carried out as reported previously.
- After prenatal diagnosis of AIP, parents were counseled regarding the
severity of their clinical condition, treatment options and related risk.
- In general, women with severe types of AIP were delivered at around 34
weeks of gestation and those with a less severe variants at 36 weeks.
- All cases of AIP included in the study were treated with Cesarean
hysterectomy and preoperative temporary occlusion of internal iliac arteries
with a balloon catheter and insertion of a ureteral stent.
- Final diagnosis of the type of AIP was made after surgery and hysterectomy,
based on pathological examination of the removed uterus.
First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018

47. First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018
Methods
• Primary Outcomes
- Estimated blood loss during surgery.
- Need for and amount of packed red blood cells and fresh frozen plasma units
required either during or after surgery.
- Operative time.
- Intra-surgical complications.
- Gestational age at birth.
- Delivery at <34 weeks of gestation.
- Length of hospital stay and maternal admission to intensive care unit.

48. First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018
Results - General characteristics of 68 women with AIP
according to type of COS
The three groups did not show any significant difference with
respect to: maternal age, parity and number of previous CS
(P = 0.0001)

50. First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018
Results - Pregnancy and operative outcomes
• Pregnancies with COS-1 were delivered earlier than those with either COS-2+ (P
= 0.0001) or COS-2− (P = 0.0001)
• Pregnancies with COS-2+ were delivered earlier than those with COS-2– (P =
0.01).
• Iatrogenic preterm birth at <34 weeks’ gestation was higher in pregnancies with
COS-1 than those with COS-2+ (P = 0.0001) or COS-2− (P = 0.0001).
• There was no difference in the length of hospital stay among COS categories.
• None of the women who underwent surgery was admitted to an intensive care
unit.

51. First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018
Discussion
• Key findings
- Assessment of COS in the first trimester may help in stratifying women at higher
risk for intra- and postoperative complications.
• Implications for practice= практик зөвлөмж
- First-trimester diagnosis is critical, as many CSPs are misdiagnosed as
threatened miscarriage, miscarriage or simply intrauterine pregnancy. This may
lead to curettage for presumed failed pregnancy, resulting in profuse bleeding and
emergency surgical interventions.
- Assessment of COS can be used to predict the evolution of CSP towards the
most severe variants of AIP, such as placenta percreta, and assist in solving the
dilemma whether termination of pregnancy should be the only therapeutic option
offered to women with a first-trimester diagnosis of CSP.

52. First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018
Discussion
• Implications for practice (continued)
- Classification of AIP according to the degree of placental invasion is
retrospective and not always useful in clinical practice.
- The likelihood of intra- or pos-tsurgical complications is strictly dependent
upon the extent and location, rather than depth, of placental invasion.
- Assessment of the topography of placental is therefore fundamental and
constitutes the optimal approach to identify women at higher risk of intra-
surgical complications.

53. First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign
Calì et al., UOG 2018
Discussion
• Strengths of study
- All cases were managed according to an established protocol for AIP
- All women were operated on by a single surgeon with decades of experience in
managing AIP disorders, thus considerably reducing the heterogeneity in the
outcome measures explored.
• Limitations of study
- Small number of included cases.
- Retrospective design of the study.
- Inclusion of only women with CSP progressing through the second and third
trimesters – study does not address how to identify cases with CSP that will need
intervention during the first- or early second-trimester of pregnancy.
- All cases were operated on by the same team, thus reducing the external validity
of the reported findings.

54. Thank you for your time