chapter 46 role of ultrasound in INFERTILITY

Purpose of Evaluation:

• To assess whether the cervix provides a sperm-friendly environment and to rule out structural issues that could impact fertility.

Key Things Being Evaluated:

• Cervical stenosis (narrowing <1 mm) — may hinder sperm passage

  • Detected via HSG (hysterosalpingography), not well assessed with ultrasound

• Nabothian cysts — usually benign, not typically related to infertility

• Cervical length — mainly evaluated in pregnancy for competence, limited utility in nongravid patients

Cervix

Purpose of Evaluation:

• To check for structural anomalies or masses that might impair implantation or gestation.

Key Things Being Evaluated:

• Structural anomalies:

  • Congenital uterine anomalies:

    • Septate uterus (associated with high infertility risk due to poor blood supply to septum)

    • Bicornuate uterus

    • Uterus didelphys

    • T-shaped uterus (related to DES exposure; no treatment available)

  • These are often visualized with 2D/3D ultrasound, HSG, or MRI

• Masses or irregularities:

  • Submucosal fibroids — can distort cavity, affect implantation

Uterus

Purpose of Evaluation:

• To assess lining thickness and appearance, which reflects hormonal response and implantation potential.

Key Things Being Evaluated:

• Endometrial thickness:

  • >6mm is associated with better implantation potential

  • Measured in sagittal plane

• Endometrial appearance:

  • Triple-line sign (proliferative phase, pre-ovulation)

  • Homogeneous, echogenic lining (secretory phase, post-ovulation)

• Abnormalities:

  • Polyps — hyperechoic, narrow base, vascular stalk (seen on SIS)

  • Fibroids — isoechoic with broad base, circumferential flow

  • Synechiae — adhesions from trauma/infection; appear as linear bands

Endometrium

Purpose of Evaluation:

• To determine whether the tubes are open (patent) and free of damage.

Key Things Being Evaluated:

• Hydrosalpinx — fluid-filled tube (50% lower pregnancy rate, higher miscarriage risk)

• Patency testing:

  • Saline infusion with air bubbles or contrast to check for spillage into the cul-de-sac

  • No spillage = possible obstruction

  • Tools used: SIS, HSG, or laparoscopy with chromopertubation

• Pre-assessment with transvaginal ultrasound:

  • Evaluate anatomy, ovarian-tubal relation, mobility

Fallopian Tubes

Purpose of Evaluation:

• To evaluate ovulatory function and detect PCOS or other ovulatory disorders.

Key Things Being Evaluated:

• Follicular development:

  • Antral follicles <5 mm

  • Dominant follicle ~22 mm = ready for ovulation

• Ovulation signs:

  • Follicular rupture

  • Corpus luteum cyst

  • Free fluid in cul-de-sac

  • Serum progesterone >3 ng/mL confirms ovulation

• Polycystic Ovary Syndrome (PCOS):

  • Diagnostic triad:

    1. Oligo- or anovulation

    2. Hyperandrogenism

    3. Polycystic ovaries

  • Sonographic sign: “String of pearls” — ≥25 small peripheral follicles (2–9 mm)

  • Thickened endometrium may also be present

Ovaries

Purpose of Evaluation:

• To identify external uterine or ovarian conditions (like adhesions or endometriosis) that impact fertility.

Key Things Being Evaluated:

• Endometriosis:

  • Especially when involving ovaries → forms endometriomas

  • Typical sonographic appearance: “ground glass” echoes, homogenous low-level echoes

• Adhesions:

  • May block tubes or restrict mobility

  • Difficult to assess via ultrasound alone; best seen with laparoscopy

• Peritoneal inclusion cysts:

  • Fluid trapped by adhesions

Peritoneal Factors

Summary Chart

Purpose:
Stimulate the ovaries to produce one or more follicles to increase the chance of ovulation and pregnancy.

Steps & Evaluation:

• Baseline Transvaginal Ultrasound (early cycle):

  • Rule out ovarian cysts (>15mm could interfere with meds)

  • Check for dominant follicle or intracavitary masses

• Medications Used:

  • Oral: Clomiphene citrate (Clomid) or Letrozole

  • Injectable: Human menopausal gonadotropins

• Monitoring:

  • Ultrasound on days 10–14 of cycle to:

    • Count and measure all follicles >1cm

    • Assess for mature follicles (target: ~20mm)

  • Estradiol levels may be checked for correlation

• Trigger Ovulation:

  • When follicles mature, hCG injection is given to mimic LH surge

Additional Evaluation:

• Antral Follicle Count (AFC):

  • Evaluates ovarian reserve by counting 2–6mm follicles in both ovaries

  • Low AFC (<5) = poor prognosis

  • High AFC = better response to stimulation

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2. Monitoring the Endometrium

Purpose:
To confirm the endometrial lining is receptive for implantation.

What is Evaluated:

• Thickness:

  • Should increase from 2–3 mm to 12–14 mm

  • Measured in sagittal plane from anterior to posterior interface

• Echogenicity/Pattern:

  • Trilaminar (triple-line) pattern is ideal

  • <6mm thickness or abnormal pattern = lower chance of implantation

Ovulation Induction Therapy (OIT)

Purpose:
Fertilize eggs outside the body and transfer embryos into the uterus.

Process:

1. Ovarian Monitoring (similar to OIT, but more aggressive):

   • Goal: Produce multiple mature follicles

2. Oocyte Retrieval:

   • Done via transvaginal ultrasound-guided aspiration

   • Needle inserted through vaginal wall into follicles

3. Fertilization & Incubation:

   • Oocytes are mixed with sperm in lab

4. Embryo Transfer:

   • Done under transabdominal ultrasound guidance with a full bladder

   • Embryo placed within 2 cm of fundus

   • Air bubble may be seen after release

In Vitro Fertilization (IVF)

Purpose:
Deliver sperm directly into the uterine fundus to bypass cervical or mild male factor issues.

Procedure:

• Catheter delivers washed sperm into the uterus

• Donor sperm may be used (donor insemination)

• Ultrasound not typically used during the insemination itself

Intrauterine Insemination (IUI)

complication

Cause:
Excessive response to ovulation induction drugs

Sonographic Findings:

• Enlarged ovaries (5–10 cm)

• Multiple cysts

• Ascites, possibly pleural effusion

• Seen more in young patients or those with PCOS

Symptoms:

• Abdominal pain, bloating, back pain

• Severe cases: hypotension, leg edema, hemoconcentration

Ovarian Hyperstimulation Syndrome (OHSS)

complication

Cause:
Transfer of multiple embryos (IVF) or overstimulation of ovaries (OIT)

Stats:

• ~30% of IVF pregnancies result in twins or higher

Risks:

• Higher chance of:

  • Preterm birth

  • Neonatal complications

  • Miscarriage

• Triplets or more may require fetal reduction

  • Done under ultrasound guidance by injecting potassium chloride into fetal heart

Multiple Gestations

complication

Cause:
Higher risk in ART patients due to manipulation of embryo transfer or tubal pathology

Location:
Usually in the fallopian tube

Ectopic Pregnancy

complication

Definition:
Coexistence of an intrauterine and ectopic pregnancy

Incidence:

• Natural: ~1 in 4,000

• ART Patients: ~1 in 100

Key Point:

• Even if an intrauterine pregnancy is seen, always check the adnexa for possible ectopic pregnancy

Heterotopic Pregnancy

complication summary chart

treatment summary chart

main organs evaluation chart