Indications for a first-trimester sonogram

1. Confirmation of the presence of an intrauterine pregnancy

2. Evaluation of a suspected ectopic pregnancy

3. Defining the cause of vaginal bleeding

4. Evaluation of pelvic pain

5. Estimation of gestational (menstrual) age

6. Diagnosis or evaluation of multiple gestations

7. Confirmation of cardiac activity

8. Imaging as an adjunct to chorionic villus sampling, embryo transfer.

9. Assessing for certain fetal anomalies, such as anencephaly, in high-risk patients

10. Evaluation of maternal pelvic masses and/or uterine abnormalities

11. Measuring the nuchal translucency (NT) when part of a screening program for fetal

12. Aneuploidy

13. Evaluation of a suspected Hydatidiform mole

14. Localization and removal of an intrauterine device

1. Confirmation of the presence of an intrauterine pregnancy

Confirmation of an intrauterine pregnancy (IUP) is typically done through ultrasound and clinical evaluation. The key criteria for confirming an IUP include:

1. Ultrasound Findings

A transvaginal ultrasound (TVUS) is the most reliable method for early pregnancy confirmation. An intrauterine pregnancy is confirmed when the following are seen:

• Gestational sac within the uterus
• Yolk sac (confirms a true gestational sac, differentiating it from a pseudogestational sac seen in ectopic pregnancy)
• Fetal pole with cardiac activity (heartbeat), usually detected by 5.5–6 weeks of gestation

2. β-hCG Levels and Ultrasound Correlation

• β-hCG > 1500–2000 mIU/mL: A gestational sac should be visible on transvaginal ultrasound (discriminatory zone). If not seen, an ectopic pregnancy must be considered.
• Serial β-hCG measurements: In a normal IUP, β-hCG levels should double every 48 hours in early pregnancy. Slower rises or plateaus may indicate an ectopic or non-viable pregnancy.

3. Clinical Correlation

• History of a missed period, positive pregnancy test, and pregnancy symptoms (nausea, breast tenderness, fatigue).
• Absence of severe abdominal pain or abnormal bleeding, which may suggest an ectopic pregnancy.

2. Evaluation of a suspected ectopic pregnancy

Evaluation of a suspected ectopic pregnancy involves a combination of clinical assessment, laboratory tests, and imaging to confirm the diagnosis and guide management. Here’s a step-by-step approach:

1. Clinical Assessment

• History:

  • Missed period
  • Vaginal bleeding (often light or spotting)
  • Abdominal or pelvic pain (often unilateral)
  • Shoulder pain (if rupture causes diaphragmatic irritation)
  • Symptoms of hemodynamic instability (dizziness, syncope, hypotension in case of rupture)

• Physical Examination:

  • Abdominal tenderness
  • Adnexal tenderness or mass on bimanual exam
  • Cervical motion tenderness
  • Signs of shock (if ruptured ectopic pregnancy)

2. Laboratory Tests

• Serum β-hCG Levels:

  • Serial β-hCG measurements (every 48 hours)
  • In a normal intrauterine pregnancy, β-hCG should double every 48 hours.
  • In ectopic pregnancy, rise is slower or plateaus.
  • If β-hCG > 2000 IU/L (discriminatory zone) and no intrauterine pregnancy is seen on ultrasound, an ectopic pregnancy is likely.

• Complete Blood Count (CBC):

  • Check for anemia if bleeding is suspected.

• Blood Type & Rh Factor:

  • Rh-negative patients may need Rho(D) immune globulin (RhoGAM) to prevent alloimmunization.

3. Imaging Studies

• Transvaginal Ultrasound (TVUS):
  • The gold standard for diagnosing ectopic pregnancy.
  • Look for an empty uterus (no intrauterine gestational sac) when β-hCG is above the discriminatory zone.
  • Possible findings of ectopic pregnancy:
    • Adnexal mass with a gestational sac
    • Free fluid in the pelvis (suggests rupture)
    • Pseudogestational sac (fluid collection in the uterus)

4. Diagnostic Procedures (if unclear diagnosis)

• Uterine Aspiration (Endometrial Sampling):

  • Used in rare cases to differentiate miscarriage from ectopic pregnancy.

• Laparoscopy:

  • Performed if diagnosis remains unclear and there is high suspicion.
  • Allows direct visualization and potential treatment.

5. Differential Diagnosis

• Miscarriage (incomplete, threatened)
• Corpus luteum cyst rupture
• Ovarian torsion
• Pelvic inflammatory disease (PID)

6. Management Based on Stability

• Hemodynamically Unstable: Emergency surgery (laparoscopic or open)
• Hemodynamically Stable:
  • Medical Management: Methotrexate (if criteria are met)
  • Surgical Management: Laparoscopic salpingostomy/salpingectomy if necessary

3. Defining the cause of vaginal bleeding

Vaginal bleeding can be caused by various factors, ranging from normal physiological processes to medical conditions. The cause depends on the person's age, reproductive status, and accompanying symptoms. Below are some common causes:

1. Normal Causes

• Menstruation – Regular shedding of the uterine lining
• Ovulation spotting – Light bleeding around ovulation
• Implantation bleeding – Early pregnancy sign when a fertilized egg attaches to the uterus

2. Gynecological Conditions

• Polycystic Ovary Syndrome (PCOS) – Irregular cycles and hormonal imbalance
• Uterine fibroids or polyps – Noncancerous growths that can cause bleeding
• Endometriosis or adenomyosis – Abnormal tissue growth causing irregular bleeding
• Pelvic inflammatory disease (PID) – Infection of the reproductive organs
• Cervical or uterine cancer – Unusual bleeding, often postmenopausal

3. Pregnancy-Related Causes

• Miscarriage – Early pregnancy loss
• Ectopic pregnancy – Pregnancy outside the uterus, which can be life-threatening
• Placenta previa or placental abruption – Late pregnancy complications causing bleeding

4. Hormonal and Medication-Related Causes

• Birth control pills or IUDs – Hormonal changes can cause spotting
• Hormone replacement therapy (HRT) – Can lead to breakthrough bleeding
• Blood thinners – Medications affecting clotting may lead to bleeding

5. Trauma or Infections

• Sexual intercourse or injury – May cause vaginal tears and bleeding
• Sexually transmitted infections (STIs) – Some, like chlamydia or gonorrhea, may cause bleeding
• Vaginal atrophy (postmenopausal) – Thinning vaginal walls can lead to bleeding

4. Evaluation of pelvic pain

Ultrasound is a critical tool for evaluating pelvic pain in early pregnancy. It helps differentiate between normal intrauterine pregnancy, ectopic pregnancy, miscarriage, and other gynecological conditions. Here’s a structured approach to ultrasound evaluation in this context:

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1. Clinical Indications

• Pelvic pain (unilateral or bilateral)
• Vaginal bleeding
• Suspicion of ectopic pregnancy
• Rule out miscarriage
• Assess viability of pregnancy
• Evaluate ovarian pathology (e.g., corpus luteum cyst, ovarian torsion)

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2. Ultrasound Modalities

• Transabdominal Ultrasound (TAS)
  • Provides an overview of the pelvic structures.
  • Limited in early pregnancy due to low resolution.
• Transvaginal Ultrasound (TVUS)
  • Gold standard for early pregnancy evaluation.
  • Provides high-resolution images of the uterus, adnexa, and gestational sac.

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3. Key Ultrasound Findings

A. Normal Intrauterine Pregnancy

• Gestational sac within the endometrium (intrauterine)
• Double decidual sac sign
• Yolk sac visible at ~5 weeks
• Fetal pole with cardiac activity (~6 weeks)
• Crown-rump length (CRL) used to estimate gestational age

B. Ectopic Pregnancy

• No intrauterine pregnancy despite positive hCG
• Adnexal mass with or without yolk sac/fetal pole
• Free fluid in the pelvis (suggestive of rupture)
• Pseudogestational sac (fluid collection in the uterus)

C. Miscarriage (Pregnancy Loss)

• Gestational sac without fetal pole beyond 6 weeks
• Absence of fetal cardiac activity
• Irregular or collapsing gestational sac
• Subchorionic hemorrhage (if significant, may indicate impending loss)

D. Other Causes of Pelvic Pain

• Ovarian cysts (simple, hemorrhagic, corpus luteum)
• Ovarian torsion (enlarged ovary, peripheral follicles, absent blood flow)
• Uterine fibroids (degenerating fibroids may cause pain)
• Pelvic inflammatory disease (tubo-ovarian abscess, fluid in the pelvis)

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4. Role of Serial hCG & Ultrasound

• If the initial ultrasound is inconclusive, serial beta-hCG levels help guide further management.
• A gestational sac should be seen when hCG > 1500-2000 mIU/mL (discriminatory zone).
• If hCG rises <53% in 48 hours, consider ectopic pregnancy or non-viable pregnancy.

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5. Urgent Findings Requiring Immediate Intervention

• Ruptured ectopic pregnancy (free fluid with debris, hypotension, severe pain)
• Non-viable pregnancy with retained products of conception (requires follow-up)
• Ovarian torsion (surgical emergency)

5. Estimation of gestational (menstrual) age

Gestational age (or menstrual age) is typically estimated in several ways, depending on the

available clinical data. Here are the most common methods:

1. Last Menstrual Period (LMP) Method

• Gestational age is counted from the first day of the last menstrual period (LMP).
• This method assumes a 28-day cycle with ovulation occurring on day 14.
• Formula: $$\text{Gestational Age (weeks)} = \frac{\text{Days since LMP}}{7}$$
• Limitations: Can be inaccurate if cycles are irregular or if LMP is uncertain.

2. Ultrasound Dating

• More accurate than LMP, especially in cases of irregular cycles.
• First-trimester ultrasound (≤13+6 weeks):
  • Uses Crown-Rump Length (CRL) to estimate age.
  • Most accurate ±5-7 days.
• Second-trimester ultrasound (14-28 weeks):
  • Uses Biparietal Diameter (BPD), Femur Length (FL), Head Circumference (HC), and Abdominal Circumference (AC).
  • Accuracy: ±7-10 days in early second trimester, ±14 days later.
• Third-trimester ultrasound (>28 weeks):
  • Least accurate due to fetal growth variations.
  • Accuracy: ±21 days.

3. Naegele’s Rule (For Estimated Due Date, EDD)

• Used if LMP is known.
• Formula: $$\text{EDD} = \text{LMP} + 280 \text{ days} (or 40 weeks)$$
  • Example: If LMP = January 1, EDD = October 8.

4. Fundal Height Measurement (After 20 Weeks)

• Fundal height in cm ≈ Gestational age in weeks (±2 cm).
• Less accurate compared to ultrasound.

5. Postnatal Assessment

• If gestational age is unknown, Ballard Score (physical and neuromuscular maturity) can be used after birth.

6. Diagnosis or evaluation of multiple gestations

Multiple gestations (twins, triplets, or higher-order multiples) require early and accurate diagnosis to optimize prenatal care. Here’s how they are evaluated:

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1. Diagnosis of Multiple Gestations

A. Clinical Signs & Symptoms

• Larger-than-expected uterine size (fundal height greater than gestational age).
• Excessive weight gain in early pregnancy.
• More severe pregnancy symptoms, such as nausea and vomiting due to higher β-hCG levels.
• Increased fetal movements earlier than expected.
• Detection of more than one fetal heart rate using Doppler (typically after 10-12 weeks).

B. Ultrasound Confirmation (Gold Standard)

• First-trimester ultrasound (best for accurate diagnosis and chorionicity determination).
• Transvaginal ultrasound is preferred in early pregnancy.
• Findings:
  • Two or more gestational sacs (early pregnancy).
  • Two or more fetuses with separate heartbeats.
  • Lambda (Δ) sign: Suggests dichorionic diamniotic (DCDA) twins (separate placentas).
  • T-sign: Suggests monochorionic diamniotic (MCDA) twins (shared placenta).

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2. Evaluation of Chorionicity and Amnionicity

• Essential for risk stratification (monochorionic twins have higher risks).
• Determined by ultrasound, ideally before 14 weeks.
• Types of Twin Pregnancies:

Type	Chorionicity & Amnionicity	% of Twins	Key Features
Dichorionic Diamniotic (DCDA)	2 placentas, 2 amniotic sacs	75%	Lowest risk, can be fraternal or identical
Monochorionic Diamniotic (MCDA)	1 placenta, 2 amniotic sacs	20%	Risk of twin-twin transfusion syndrome (TTTS)
Monochorionic Monoamniotic (MCMA)	1 placenta, 1 amniotic sac	1-2%	High risk of cord entanglement, TTTS
Conjoined Twins	Incomplete division	<1%	Severe complications, requires surgical planning

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3. Serial Ultrasound Monitoring

• DCDA Twins: Growth scans every 4 weeks from 24 weeks.
• MCDA Twins: Every 2 weeks from 16 weeks (monitor for TTTS).
• MCMA Twins: Weekly monitoring from 24 weeks (high risk of cord entanglement).

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4. Complications to Monitor

• Twin-Twin Transfusion Syndrome (TTTS) (MCDA twins)
• Twin Reversed Arterial Perfusion (TRAP) Sequence (MCDA)
• Selective Intrauterine Growth Restriction (sIUGR)
• Preterm Labor (PTL) (50% of twins deliver before 37 weeks)
• Preeclampsia (higher incidence in multiple pregnancies)

7. Confirmation of cardiac activity

Confirming fetal cardiac activity is a crucial step in assessing viability and ensuring appropriate pregnancy management.

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1. Methods of Confirmation

A. Ultrasound (Gold Standard)

• Transvaginal Ultrasound (TVUS)

  • Detects fetal cardiac activity as early as 5.5 to 6 weeks gestation.
  • Best method for early pregnancy viability assessment.

• Transabdominal Ultrasound (TAUS)

  • Typically detects cardiac activity around 6.5 to 7 weeks.
  • Less sensitive than TVUS in early pregnancy.

• Cardiac Activity Confirmation:

  • M-mode ultrasound (preferred) measures fetal heart rate (FHR) while minimizing energy exposure.
  • Doppler ultrasound can detect fetal heartbeats, but is usually avoided early in pregnancy due to potential thermal effects.

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B. Fetal Doppler Device

• Detects heart sounds starting around 10-12 weeks.
• Used in clinical settings but not as reliable as ultrasound for early detection.

C. Fetal Heart Rate (FHR) via Ultrasound

• Normal FHR varies by gestational age:
  • 5-6 weeks: ~90-110 bpm
  • 8-9 weeks: Peaks at ~170 bpm
  • After 10 weeks: 120-160 bpm (normal range for mid-to-late pregnancy)
• Bradycardia (<100 bpm before 6 weeks) may indicate a higher risk of miscarriage.

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2. Clinical Considerations

• If cardiac activity is absent but a gestational sac is seen:
  • Repeat ultrasound in 7-10 days to confirm viability.
• If pregnancy is ≥7 weeks without cardiac activity, it may indicate a nonviable pregnancy.
• If a fetal pole is ≥7 mm without a heartbeat, diagnosis of early pregnancy loss can be made.

8. Imaging as an adjunct to chorionic villus sampling, embryo transfer.

Medical imaging plays a crucial role in guiding and improving the safety and accuracy of chorionic villus sampling (CVS) and embryo transfer.

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1. Imaging in Chorionic Villus Sampling (CVS)

Chorionic Villus Sampling (CVS) is a prenatal diagnostic procedure performed between 10-13 weeks of gestation to obtain placental tissue for genetic testing. Imaging is essential for:

A. Ultrasound Guidance (Gold Standard)

• Before the Procedure:

  • Confirms gestational age and fetal viability.
  • Determines placental location (anterior vs. posterior) to select the best sampling approach.
  • Assesses chorionicity in multiple gestations.

• During the Procedure:

  • Guides the needle or catheter placement to avoid fetal structures.
  • Ensures an adequate sample is obtained from the correct placental region.
  • Monitors for complications (e.g., bleeding, hematoma).

• After the Procedure:

  • Confirms fetal well-being (cardiac activity, amniotic fluid assessment).

Approaches Based on Ultrasound Findings:

Placental Location	Preferred Sampling Route
Anterior Placenta	Transabdominal CVS
Posterior Placenta	Transcervical CVS
Low-Lying Placenta	Transcervical CVS (if accessible)

B. Potential Role of Doppler Ultrasound

• Assesses uteroplacental blood flow to minimize vascular injury.
• Helps identify umbilical cord insertion site in complex cases.

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2. Imaging in Embryo Transfer (ET)

Embryo Transfer (ET) is a critical step in in vitro fertilization (IVF) where an embryo is placed into the uterine cavity. Imaging significantly improves pregnancy rates by ensuring precise placement and minimizing uterine trauma.

A. Transabdominal Ultrasound Guidance (Standard Practice)

• Provides real-time visualization of the catheter entering the uterus.
• Ensures optimal placement (~1.5-2 cm from the fundus).
• Reduces the risk of endometrial trauma and improper embryo deposition.

B. 3D Ultrasound (Emerging Role)

• Improves endometrial evaluation and catheter positioning.
• Helps detect uterine anomalies (e.g., septate uterus, fibroids).

C. Hysteroscopic Guidance (Alternative for Difficult Cases)

• Used in patients with previous failed embryo transfers or abnormal endometrial cavities.
• Allows direct visualization of the endometrial surface.

D. Doppler Ultrasound (Adjunct for Endometrial Receptivity)

• Assesses endometrial blood flow, which may predict implantation success.

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Summary Table: Role of Imaging in CVS and Embryo Transfer

Procedure	Imaging Modality	Purpose
Chorionic Villus Sampling (CVS)	Ultrasound (2D, Doppler)	Guides needle/catheter, confirms fetal viability, ensures correct sampling, avoids complications
Embryo Transfer (ET)	Transabdominal ultrasound	Ensures precise embryo placement, improves pregnancy rates
Embryo Transfer (ET) – Advanced	3D ultrasound, Doppler	Assesses endometrial receptivity, detects uterine abnormalities

9. Assessing for certain fetal anomalies, such as anencephaly, in high-risk patients

For high-risk pregnancies, early and accurate assessment of fetal anomalies is crucial for proper management. Ultrasound is the primary imaging modality for detection, while additional testing (e.g., maternal serum screening, fetal MRI, genetic testing) may be used for confirmation and further evaluation.

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1. High-Risk Factors for Fetal Anomalies

• Maternal history of neural tube defects (NTDs)
• Previous pregnancy with a congenital anomaly
• Maternal diabetes (poorly controlled)
• Teratogen exposure (e.g., valproic acid, isotretinoin)
• Obesity (linked to increased NTD risk)
• Low folic acid intake (before conception and early pregnancy)
• Chromosomal abnormalities (e.g., trisomy 18, trisomy 13)

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2. Imaging Modalities for Fetal Anomaly Detection

A. First-Trimester Ultrasound (11-14 Weeks)

• Transvaginal ultrasound (TVUS) provides high-resolution images for early detection.
• Anencephaly detection:
  • Absence of the cranial vault and brain tissue above the orbits.
  • "Frog-eye sign" (prominent orbits due to absent frontal skull).
  • Typically detectable by 11 weeks.

B. Second-Trimester Anatomy Scan (18-22 Weeks)

• Transabdominal ultrasound (TAUS) is the standard for fetal anomaly screening.
• Detects structural abnormalities such as:
  • Anencephaly (absence of skull and brain).
  • Spina bifida (open or closed).
  • Congenital heart defects (CHDs).
  • Limb anomalies (e.g., clubfoot, limb reduction defects).

C. Fetal MRI (Adjunct in Complex Cases)

• Used for better visualization of the brain, spine, and soft tissues in complex anomalies.
• Usually performed after 22 weeks.

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3. Specific Anomaly: Anencephaly

Definition

• A neural tube defect (NTD) caused by failure of the cranial neuropore to close around day 23-26 of embryonic development.
• Results in absence of the skull (calvarium) and most of the brain tissue.
• Lethal condition, with no postnatal survival.

Ultrasound Findings

➤ First-Trimester (11-14 weeks)

• Absent cranial vault.
• "Frog-eye" appearance (prominent orbits with absent forehead).
• Polyhydramnios (due to impaired fetal swallowing).

➤ Second-Trimester (18-22 weeks)

• No skull above the orbits.
• Exposed brain tissue, which may degenerate ("exencephaly → anencephaly sequence").
• Increased amniotic fluid (polyhydramnios).

Differential Diagnoses

• Exencephaly (brain exposed but not degenerated yet).
• Microcephaly (small but intact brain and skull).
• Acrania (absent skull with abnormal but present brain).

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4. Additional Diagnostic Tests

➤ Maternal Serum Alpha-Fetoprotein (MSAFP)

• Elevated in neural tube defects (NTDs), including anencephaly.
• Performed between 15-20 weeks.

➤ Amniocentesis

• Detects chromosomal abnormalities or genetic syndromes linked to anomalies.
• Assesses acetylcholinesterase (AChE) (elevated in NTDs).

➤ Genetic Testing

• Whole-exome sequencing (WES) for suspected syndromic causes.
• Karyotyping for trisomy associations.

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5. Management of Anencephaly

• Counseling: Families should receive prenatal counseling about prognosis.
• Pregnancy Options:
  • Termination (in many cases, parents may opt for this).
  • Continued pregnancy with palliative care planning.
• Folic Acid Supplementation:
  • High-dose folic acid (4 mg/day) is recommended for future pregnancies.
  • Reduces the risk of recurrent NTDs by ~70%.

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Summary Table: Imaging in Fetal Anomaly Assessment

Imaging Modality	Timeframe	Use
First-Trimester Ultrasound (TVUS/TAUS)	11-14 weeks	Early detection of anencephaly, acrania, exencephaly
Second-Trimester Anatomy Scan (TAUS)	18-22 weeks	Detailed evaluation of brain, spine, heart, limbs
Fetal MRI	>22 weeks	Adjunct for complex anomalies
Maternal Serum Alpha-Fetoprotein (MSAFP)	15-20 weeks	Screening for NTDs
Amniocentesis	>15 weeks	Genetic confirmation and AChE levels

10. Evaluation of maternal pelvic masses and/or uterine abnormalities

1. Introduction

Pelvic masses and uterine abnormalities in pregnancy are important considerations due to their potential impact on maternal and fetal outcomes. These conditions can range from benign findings to more serious pathological concerns requiring close monitoring or intervention.

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2. Clinical Presentation and Risk Factors

Symptoms:

• Pelvic pain or pressure (fibroids, ovarian torsion, cyst rupture)
• Abnormal bleeding (submucosal fibroids, uterine anomalies)
• Urinary or bowel symptoms (large masses causing compression)
• Incidental findings on routine prenatal ultrasound

Risk Factors:

• Prior gynecological history: History of fibroids, ovarian cysts, or endometriosis
• Infertility treatments: Increased risk of ovarian hyperstimulation syndrome (OHSS) and large ovarian cysts
• Congenital uterine anomalies: May be associated with pregnancy loss or complications

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3. Imaging Modalities

Ultrasound (US) – First-line Modality

• Transabdominal Ultrasound (TAS): Best for large masses
• Transvaginal Ultrasound (TVS): Higher resolution for early pregnancy and smaller masses
• Key Features to Evaluate:
  • Size and consistency (solid, cystic, mixed)
  • Location (uterine, ovarian, or extra-adnexal)
  • Vascularity (Doppler flow for malignancy suspicion or torsion)

Magnetic Resonance Imaging (MRI) – Second-line Modality

• Used when ultrasound is inconclusive or to assess complex masses
• Safe in pregnancy (avoiding contrast agents)
• Helps differentiate fibroids from neoplasms or congenital anomalies

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4. Differential Diagnosis

A. Uterine Abnormalities

1. Fibroids (Leiomyomas)

   • Most common uterine masses in pregnancy (seen in ~10% of pregnancies)
   • Can cause pain (red degeneration), preterm labor, malpresentation, or postpartum hemorrhage
   • Growth varies with hormonal influence

2. Congenital Uterine Anomalies (Müllerian Anomalies)

   • Includes septate, bicornuate, unicornuate, and didelphic uterus
   • Associated with recurrent miscarriage, preterm birth, or fetal growth restriction
   • Diagnosed via 3D ultrasound, MRI, or hysteroscopy (postpartum)

B. Adnexal (Ovarian and Tubal) Masses

1. Functional Ovarian Cysts (Corpus Luteum or Theca Lutein Cysts)

   • Common in early pregnancy, usually regress spontaneously
   • Large or persistent cysts may cause pain or torsion

2. Benign Ovarian Tumors (Dermoid Cyst, Cystadenomas)

   • Can grow during pregnancy; risk of torsion with larger sizes (>5 cm)

3. Ovarian Malignancies (Rare but Important)

   • May present as a complex solid-cystic mass with vascular flow
   • Tumor markers (e.g., CA-125) may be elevated but less reliable in pregnancy

4. Ectopic Pregnancy (if early gestation with adnexal mass)

   • Always consider in the differential if associated with positive β-hCG and no intrauterine gestation on US

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5. Management Strategies

A. Expectant Management

• Most small, asymptomatic masses (<5 cm simple cysts, small fibroids) are monitored with serial ultrasounds
• Most functional cysts resolve postpartum

B. Indications for Surgical Intervention

• Ovarian torsion – Requires emergency surgery (laparoscopy if feasible)
• Ruptured ovarian cyst with hemorrhage
• Rapidly growing or suspicious adnexal mass (malignancy concern)
• Large fibroids causing obstruction, fetal malpresentation, or severe pain unresponsive to conservative measures

C. Mode of Delivery Considerations

• Fibroids: If obstructing the lower uterine segment, cesarean delivery may be required
• Uterine anomalies: May need cesarean section due to abnormal uterine contractility

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6. Follow-up and Prognosis

• Most benign masses regress postpartum
• Persistent or complex masses warrant post-delivery imaging and possible surgical intervention
• Close fetal monitoring may be required for uterine anomalies associated with growth restriction or malpresentation

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7. Summary Table

Condition	Common Features	Impact on Pregnancy	Management
Fibroids	Well-defined, hypoechoic, solid mass	Pain, preterm labor, fetal malpresentation	Conservative unless complications arise
Congenital Uterine Anomalies	Abnormal uterine shape	Recurrent miscarriage, fetal growth issues	Monitor pregnancy, possible C-section
Corpus Luteum Cyst	Simple cyst, usually <5 cm	Rarely symptomatic, self-resolving	Observation
Ovarian Torsion	Enlarged ovary, decreased blood flow	Acute pain, surgical emergency	Laparoscopic detorsion if possible
Ovarian Tumors (Benign/Malignant)	Solid-cystic complex masses	Potential for malignancy	Further imaging, surgery if needed

11. Measuring the nuchal translucency (NT) when part of a screening program for fetal

1. Introduction

Nuchal translucency (NT) measurement is a key component of first-trimester screening for fetal aneuploidies, primarily Down syndrome (Trisomy 21), Trisomy 18, and Trisomy 13. It assesses the fluid-filled space at the back of the fetal neck between 11+0 and 13+6 weeks of gestation.

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2. Indications for NT Measurement

NT is performed as part of the first-trimester combined screening, which includes:

• NT ultrasound measurement
• Maternal serum markers: Pregnancy-associated plasma protein A (PAPP-A) and human chorionic gonadotropin (β-hCG)
• Maternal age and history

It helps estimate the risk of chromosomal abnormalities and structural defects such as congenital heart disease.

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3. NT Measurement Protocol

A. Timing:

• Gestational Age: Between 11 weeks and 13 weeks + 6 days
• Crown-Rump Length (CRL) Criteria: 45–84 mm

B. Ultrasound Technique:

• Imaging Approach: Transabdominal or transvaginal ultrasound
• Key Criteria for Accurate NT Measurement:
  • Mid-sagittal plane: Fetal profile should be in a neutral position (not hyperextended or flexed).
  • Calipers Placement: Inner-to-inner measurement of the maximum thickness of the translucent space.
  • No amniotic membrane overlap: Ensures accurate measurement of fluid space, avoiding false increases.

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4. NT Normal Values and Risk Assessment

A. Normal vs. Increased NT:

• Normal NT: ≤3.0 mm (varies by gestational age)
• Increased NT: >3.0 mm (higher risk of aneuploidy and structural anomalies)
• Very high NT (>3.5 mm): May indicate chromosomal defects, cardiac defects, or genetic syndromes (e.g., Noonan syndrome).

B. NT and Trisomy Risk:

NT Thickness (mm)	Risk of Trisomy 21 (Down Syndrome)	Additional Risk Factors
< 2.5 mm	Low risk	None
2.5 – 3.0 mm	Mildly increased	Needs combined screening results
3.0 – 3.5 mm	Moderately increased	Offer additional testing
> 3.5 mm	High risk	Consider invasive testing (CVS/Amniocentesis)

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5. Additional Diagnostic Testing

If NT is increased or if combined screening shows high risk, further testing may be recommended:

A. Non-Invasive Prenatal Testing (NIPT) (cfDNA Screening):

• Detects fetal aneuploidies via maternal blood test
• Recommended for high-risk cases before invasive procedures

B. Invasive Testing:

• Chorionic Villus Sampling (CVS): Performed at 11–14 weeks for definitive genetic diagnosis
• Amniocentesis: Done at 15+ weeks for karyotyping and genetic analysis

C. Fetal Echocardiography:

• If NT >3.5 mm, a fetal echocardiogram at 18–22 weeks is recommended to evaluate congenital heart defects.

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6. NT in Association with Structural and Genetic Syndromes

Apart from chromosomal abnormalities, an increased NT may indicate:

• Congenital heart defects
• Noonan syndrome
• Skeletal dysplasias
• Diaphragmatic hernia

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7. Summary

Aspect	Key Information
Best Timing	11+0 – 13+6 weeks (CRL 45–84 mm)
Measurement Technique	Mid-sagittal plane, neutral fetal position, inner-to-inner caliper placement
Normal NT Range	≤3.0 mm
Increased NT (>3.0 mm)	Higher risk of aneuploidy or structural defects
Follow-up for High NT	NIPT, CVS/Amniocentesis, Fetal Echocardiogram

12. Aneuploidy

1. Definition

Aneuploidy refers to an abnormal number of chromosomes, where a cell has extra or missing chromosomes instead of the normal diploid number (46, XX or 46, XY). It is one of the most common chromosomal abnormalities and can lead to miscarriage, congenital disabilities, and developmental disorders.

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2. Types of Aneuploidy

Aneuploidies can involve autosomes (non-sex chromosomes) or sex chromosomes.

A. Autosomal Aneuploidies

1. Trisomy 21 (Down Syndrome) – Extra copy of chromosome 21

   • Prevalence: Most common liveborn aneuploidy (~1 in 700 births)
   • Clinical Features: Intellectual disability, hypotonia, characteristic facial features, congenital heart defects, and increased risk of leukemia and Alzheimer’s disease.
   • Screening: Increased nuchal translucency (NT), low PAPP-A, high β-hCG in first-trimester screening.

2. Trisomy 18 (Edwards Syndrome) – Extra copy of chromosome 18

   • Prevalence: ~1 in 5,000 births; high mortality (most die within the first year).
   • Clinical Features: Severe intellectual disability, clenched fists with overlapping fingers, rocker-bottom feet, congenital heart defects, intrauterine growth restriction (IUGR).
   • Screening: Markedly low PAPP-A and β-hCG, increased NT.

3. Trisomy 13 (Patau Syndrome) – Extra copy of chromosome 13

   • Prevalence: ~1 in 10,000 births; high mortality (most die within days or weeks).
   • Clinical Features: Severe intellectual disability, holoprosencephaly, cleft lip/palate, polydactyly, congenital heart defects.
   • Screening: Very low PAPP-A, β-hCG, and increased NT.

B. Sex Chromosome Aneuploidies

1. Monosomy X (Turner Syndrome – 45, X)

   • Prevalence: ~1 in 2,500 female births.
   • Clinical Features: Short stature, webbed neck, gonadal dysgenesis (infertility), cardiac anomalies (coarctation of the aorta).
   • Screening: Increased NT, abnormal ductus venosus Doppler flow.

2. Klinefelter Syndrome (47, XXY)

   • Prevalence: ~1 in 600 male births.
   • Clinical Features: Tall stature, small testes, infertility, mild learning disabilities, gynecomastia.
   • Often undiagnosed until puberty or adulthood.

3. Other Sex Chromosome Aneuploidies

   • 47, XXX (Triple X Syndrome): Generally mild phenotype, sometimes associated with learning disabilities.
   • 47, XYY Syndrome: Usually tall stature, may have mild learning and behavioral differences.

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3. Causes and Mechanisms

• Nondisjunction: Failure of chromosomes to separate during meiosis, leading to extra or missing chromosomes.
• Mosaicism: Some cells have normal chromosome numbers, while others have aneuploidy due to post-fertilization mitotic errors.
• Translocations: Unbalanced chromosome rearrangements can result in extra genetic material (e.g., Robertsonian translocation in Down syndrome).

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4. Prenatal Screening for Aneuploidy

Aneuploidy risk is assessed using maternal age, ultrasound markers, biochemical screening, and genetic testing.

A. First-Trimester Screening (11-14 Weeks)

• Ultrasound: Nuchal translucency (NT) >3.0 mm increases risk.
• Serum markers:
  • PAPP-A (Pregnancy-Associated Plasma Protein A): Low in aneuploidies.
  • β-hCG (Human Chorionic Gonadotropin):
    • High in Trisomy 21
    • Low in Trisomy 18 & 13

B. Second-Trimester Screening (Quad Screen, 15-20 Weeks)

• AFP (Alpha-fetoprotein): Low in Down syndrome, high in neural tube defects.
• Estriol (uE3): Low in aneuploidies.
• β-hCG: High in Down syndrome, low in other trisomies.
• Inhibin A: High in Down syndrome.

C. Non-Invasive Prenatal Testing (NIPT) (Cell-Free DNA Test)

• Uses fetal DNA in maternal blood to detect trisomy 21, 18, 13, and sex chromosome aneuploidies.
• High accuracy (>99% for trisomy 21).
• Recommended for high-risk pregnancies (e.g., advanced maternal age, abnormal ultrasound).

D. Diagnostic Tests (Definitive Diagnosis)

1. Chorionic Villus Sampling (CVS) (10-13 Weeks):

   • Takes placental tissue for karyotyping.
   • Risk of miscarriage ~0.5%.

2. Amniocentesis (15-20 Weeks):

   • Analyzes fetal cells from amniotic fluid.
   • Lower risk of miscarriage (~0.1-0.3%) compared to CVS.

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5. Management of Aneuploidy

• Genetic counseling: Essential for parents to understand risks and options.
• Pregnancy options:
  • Continue with specialized prenatal care.
  • Termination may be considered based on the severity of the condition.
• Postnatal care:
  • Down syndrome: Early intervention, cardiac and developmental monitoring.
  • Turner syndrome: Hormone therapy, cardiac screening.
  • Klinefelter syndrome: Testosterone therapy in adolescence.

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6. Summary Table

Aneuploidy	Karyotype	Key Features	Prenatal Screening Clues
Down Syndrome (Trisomy 21)	47, XX+21 or XY+21	Intellectual disability, flat facial profile, heart defects	↑ NT, ↑ β-hCG, ↓ PAPP-A
Edwards Syndrome (Trisomy 18)	47, XX+18 or XY+18	Clenched fists, IUGR, heart defects	↑ NT, ↓ β-hCG, ↓ PAPP-A
Patau Syndrome (Trisomy 13)	47, XX+13 or XY+13	Polydactyly, holoprosencephaly, cleft lip	↑ NT, ↓ β-hCG, ↓ PAPP-A
Turner Syndrome (45, X)	45, X	Short stature, webbed neck, infertility	↑ NT, abnormal ductus venosus flow
Klinefelter Syndrome (47, XXY)	47, XXY	Tall male, small testes, gynecomastia	Often undetected prenatally

13. Evaluation of a suspected Hydatidiform mole

A hydatidiform mole (molar pregnancy) is a type of gestational trophoblastic disease (GTD) that results from abnormal fertilization, leading to abnormal placental development. It is classified as:

1. Complete Hydatidiform Mole (CHM): No fetal tissue, diffuse trophoblastic proliferation.
2. Partial Hydatidiform Mole (PHM): Some fetal tissue, focal trophoblastic proliferation.

1. Risk Factors

• Maternal Age: <15 years or >40 years.
• Previous Molar Pregnancy: Recurrence risk ~1%.
• Nutritional Deficiencies: Low folate, vitamin A.
• Ethnicity: Higher in Asian populations.

2. Clinical Presentation

• Abnormal vaginal bleeding (most common sign).
• Excessive nausea/vomiting (hyperemesis gravidarum).
• Uterine size greater than expected for gestational age.
• Early preeclampsia (<20 weeks) (suggestive of CHM).
• Hyperthyroidism symptoms (rare, due to high hCG).

3. Diagnostic Evaluation

A. Laboratory Tests

• β-hCG:
  • Markedly elevated (>100,000 mIU/mL) in complete mole.
  • Moderately elevated in partial mole.
• Thyroid function tests: Hyperthyroidism (high free T4, suppressed TSH) due to hCG stimulation.
• CBC, liver, and renal function tests: To assess complications.

B. Ultrasound (Gold Standard Imaging)

• Complete Mole (CHM):
  • "Snowstorm" or "cluster of grapes" appearance (diffuse echogenic tissue, no fetus).
  • No amniotic sac or embryo.
  • Theca-lutein ovarian cysts (>6 cm) in 50% of cases.
• Partial Mole (PHM):
  • Thickened, cystic placenta with abnormal vesicles.
  • Fetal parts may be visible but appear abnormal.
  • Growth restriction, triploidy features.

C. Histopathology (Definitive Diagnosis)

• Complete Mole: Diffuse hydropic villi, no fetal tissue, trophoblastic proliferation.
• Partial Mole: Focal hydropic changes, presence of fetal tissue, less trophoblastic proliferation.

D. Additional Workup for Metastatic Disease

• Chest X-ray (if concern for metastatic gestational trophoblastic neoplasia, GTN).
• Pelvic MRI/CT if high-risk GTN is suspected.

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4. Management of Hydatidiform Mole

A. Uterine Evacuation (First-Line Treatment)

• Suction dilation & curettage (D&C) is the preferred method.
• Oxytocin after D&C (to reduce bleeding, avoid before evacuation).
• Hysterectomy for patients who do not desire future fertility.

B. Post-Evacuation Monitoring

• Serial β-hCG testing every 1–2 weeks until undetectable.
• Monitor for at least 6 months (risk of persistent GTN).
• Contraception (OCPs, IUDs) recommended during follow-up (avoid pregnancy for 6 months).

C. Management of Persistent GTN

• If β-hCG plateaus or rises, GTN is suspected.
• Single-agent chemotherapy (Methotrexate or Actinomycin D) for low-risk cases.
• Multi-agent chemotherapy for metastatic/high-risk disease.

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5. Prognosis & Follow-Up

• 80% of molar pregnancies resolve after D&C.
• Persistent GTN occurs in ~15-20% of complete moles, ~5-10% of partial moles.
• Recurrence risk: ~1% in future pregnancies (monitor with early ultrasound).

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6. Summary Table

Feature	Complete Mole	Partial Mole
Karyotype	46, XX or XY (paternal origin)	69, XXX or XXY (triploidy)
Fetal Tissue	Absent	Present (but abnormal)
Ultrasound	"Snowstorm" pattern, no fetus	Enlarged placenta, fetal parts may be seen
hCG Levels	Very high (>100,000 mIU/mL)	Mild to moderate elevation
Risk of GTN	15-20%	5-10%
Treatment	D&C, serial hCG follow-up	D&C, serial hCG follow-up

14. Localization and removal of an intrauterine device

1. Introduction

An intrauterine device (IUD) is a widely used long-acting reversible contraceptive (LARC). Occasionally, complications may arise, requiring localization and removal due to:

• Missing IUD strings
• Expulsion or displacement
• Embedded or perforated IUD
• Pain, bleeding, or infection

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2. Indications for IUD Removal

• Routine removal (end of lifespan: Copper IUD = 10 years, LNG IUD = 3-8 years).
• Desire for pregnancy.
• Menstrual irregularities or heavy bleeding.
• Pain or discomfort.
• Pelvic inflammatory disease (PID) or infection unresponsive to antibiotics.
• Perforation or embedment.
• Ectopic or intrauterine pregnancy with an IUD in place.

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3. Localization of an IUD

If the IUD strings are not visible at the cervical os, further evaluation is required.

A. Initial Evaluation

• Pelvic Examination: Check for strings at the cervix.
• Speculum Examination: Sometimes, strings are curled in the cervical canal and can be retrieved with forceps.

B. Imaging Modalities

1. Transvaginal Ultrasound (TVUS) (First-Line Imaging)

   • Confirms intrauterine location.
   • Detects malpositioned, embedded, or perforated IUD.
   • Helps determine depth of embedment in the myometrium.

2. Abdominal X-ray (If IUD Not Found on Ultrasound)

   • Rules out perforation and migration into the peritoneal cavity.
   • Used if IUD is not visualized within the uterus on TVUS.

3. CT or MRI (Rarely Needed)

   • For deeply embedded or migrated IUDs in complex cases.

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4. Removal of an IUD

A. Uncomplicated IUD Removal

• Performed in an outpatient setting.
• Steps:
  1. Speculum insertion to visualize the cervix.
  2. Grasp the IUD strings with ring forceps.
  3. Apply gentle traction to remove the IUD.
  4. Inspect the device for completeness.

B. Removal of an IUD with Missing Strings

If the strings are not visible:

• Use cytobrush or forceps to retrieve them from the cervical canal.
• Ultrasound-guided removal may be necessary.

C. Embedded IUD Removal

• If embedded in the endometrium or myometrium, removal is done:
  • With ultrasound guidance.
  • Using hysteroscopy for deeper embedment.
  • Dilation and curettage (D&C) if necessary.

D. Perforated or Extrauterine IUD Removal

• Laparoscopy is required for peritoneal cavity migration.
• Hysteroscopy or laparoscopy is preferred for partial perforations.

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5. Post-Removal Considerations

• Immediate contraception counseling (if pregnancy prevention is desired).
• Monitor for pain, infection, or bleeding.
• Follow-up ultrasound if concerns about incomplete removal.

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6. Summary Table

Scenario	Recommended Localization	Preferred Removal Method
Strings visible at os	None needed	Forceps removal
Strings not visible	TVUS (first-line)	Speculum-guided retrieval
IUD embedded in myometrium	TVUS or hysteroscopy	Hysteroscopic removal
Suspected perforation	Abdominal X-ray or CT	Laparoscopic removal