early pregnancy- dorma ghana
TRANSCRIPT
Early Pregnancy
Dr S ChawlaDorma, GhanaNovember 2013
Role of US in Early pregnancy
Confirm:• Presence of live intra-uterine pregnancy• Gestational age• Number of fetuses
Exclude:• Early pregnancy failure• Ectopic pregnancy• Molar pregnancy• Other pathology
Technique
Transabdominal scan• 3.5 – 5 MHz• Full bladder• Entire pelvis visible
Transvaginal scan• 7.5 MHz• Empty bladder• 8 – 10 cm depth
only
Technique
• Begin in LS plane• Use wide FOV• Identify bladder• Look for gestation sac• Look for yolk sac or embryo• Check for heart pulsatations• Transverse• Scan out towards both adnexa
Anatomy
Bladder
Cervix
Body ofUterus
Gestation sac
Sac containing yolk sac andFetal pole
Estimating gestational age
1. Gestational sac size
Add 3 measurements, divide by 3, add 30, divide by 7
Estimating gestational age
2. Crown rump length (CRL)
• Zoom the image• Find the longest axis of the embryo• Measure from crown to rump
• If CRL > 85mm, measureHC instead
Early pregnancy abnormalities
• Embryonic demise• Multifetal pregnancy• Retained products of conception• Molar pregnancy • Ectopic pregnancy• Subchorionic haemorrhage• Some fetal abnormalities
Embryonic demise (EPF)
1. Empty sac sign• MSD > 20mm with no visible yolk sac
CAUSES:• Missed miscarriage• Anembryonic pregnancy• Pseudo sac from ectopic pregnancy
20mm
Embryonic demise (EPF)
2. Absent fetal heart pulsatation
• Embryo CRL > 10mm with no FH = EPF(Transabdominal)
If unsure:• Use M mode• Use Doppler• Get a second opinion
Ectopic pregnancy (1)
• Implantation of pregnancy outside endometrium• 0.3-1.6% of pregnancies, 10% of maternal deaths• Role of ultrasound is to locate pregnancy• Intra-uterine pregnancy = ectopic excluded
IMPORTANT FACTS:• Normal ultrasound does not exclude ectopic• Must be correlated with clinical findings• ß-hCG > 1000 iu = embryo should be visible• If the patient is collapsed, do not delay treatment
Ectopic pregnancy (2)Possible ultrasound features of ectopic
Intra-uterinepseudo sac
Solid adnexalmass with ‘doughnutappearance’
Ectopic pregnancy (3)
Possible ultrasound features of ectopic
Thickened echobright endometrium
Ectopic pregnancy (4)
Possible ultrasound features of ectopic
Solid adnexalmass
Bladder
Ectopic pregnancy (5)
Possible ultrasound features of ectopic
Molar pregnancy
• Present with bleeding and hyperemesis• Caused by excessive proliferation of
placental tissue• Occasionally fetal tissue forms (non-viable)• Elevated ßhCG levels• 10% develop into malignant choriocarcinoma
Molar pregnancyAppearance of molar pregnancy
Enlarged echobright endometrium Multiple cystic spaces
Retained products of conception
Echobright or heterogenous material within endometrial cavity
Multifetal pregnancy
• Assess viability of all fetuses
• Identify presence or absence of dividing septum
• Look for lambda sign
THICK DIVIDING MEMBRANE = DCDA
THIN DIVIDING MEMBRANE= MCDA
Associated findings• Intra-uterine fibroids
Associated findings
• Ovarian cysts
Early fetal abnormalities
• Anencephaly
Early fetal abnormalities
• Megacystic baldder
Early fetal abnormalities
• Gastroschisis/omphalocele
Troubleshooting
To improve image quality:1. Ensure patient has full bladder2. Use multiple focal zones3. Narrow FOV and use zoom4. Use M mode, Doppler and Transvaginal
scanning if available
TroubleshootingTo help visualise ovaries:• Use the bladder as a window
Scan right ovaryfrom the left
Scan left ovary from the right
Face
Nasal Bone
Heart
Kidneys
Spine
Limb
Calvarium, choroids and midline
Placenta
Troubleshooting
REMEMBER:Always consider the clinical picture and
not just the ultrasound picture!