Cord Blood Banking - Recent Advances (MD Paper Note)

1. Introduction & Historical Context

2. Biological Basis - Why Cord Blood?

• Hematopoietic stem and progenitor cells (HSPCs) - more primitive, longer telomeres, higher proliferative potential than adult bone marrow or mobilized peripheral blood
• Mesenchymal stem cells (MSCs) - immunomodulatory, regenerative
• Immune effector cells - NK cells, T-regulatory cells, monocytes (candidates for cellular therapy manufacturing)
• Endothelial progenitor cells and other non-hematopoietic progenitors

3. Advantages over Other Stem Cell Sources

4. Types of Cord Blood Banks

4a. Public Banks

• Donated altruistically; used for unrelated allogeneic transplants
• Greater equity of access; facilitated most unrelated UCBTs globally
• Accredited by NetCord-FACT and AABB standards
• No cost to donor family; units available to any matched recipient

4b. Private Banks

• Autologous storage for family use; costly (collection + annual storage fees)
• Limited clinical indication for autologous use (autologous cells carry same genetic defect for inherited disease)
• Marketed heavily to parents despite low probability of personal use (estimated lifetime use probability: 1 in 2,700 per ACOG)
• Professional bodies (ACOG, AAP) do not recommend routine private banking

4c. Hybrid Banking (Emerging)

• Unit stored privately but made available for public use if not needed by family
• Laue et al. (Arch Gynecol Obstet 2024) reviewed this model as a middle-ground solution balancing family interests with public utility

5. Clinical Applications - Established

5a. Hematological Malignancies

• Acute leukemias (ALL, AML), CML, MDS
• UCBT comparable to or superior to BMT in pediatric patients
• In adults: alternative when HLA-matched unrelated donor is unavailable or transplant is urgently needed

5b. Non-malignant Hematological Disorders

• Aplastic anemia, thalassemia, sickle cell disease
• Bone marrow failure syndromes
• Hemoglobinopathies

5c. Immunological Deficiencies

• SCID (Severe Combined Immunodeficiency)
• Other primary immunodeficiencies

5d. Inherited Metabolic Disorders

• Hurler syndrome (MPS I), Krabbe disease, adrenoleukodystrophy

• Pediatric recipients (malignant conditions): overall survival 60-70%
• Adult recipients: overall survival 55-65%

6. Recent Advances - Key Areas

6a. Ex Vivo HSC Expansion - The Cell Dose Problem

• Nicotinamide (NAM) / StemRegenin 1 (SR1) - aryl hydrocarbon receptor antagonists that expand HSPCs while maintaining primitive phenotype; SR1 showed 330-fold expansion in Phase I/II trials
• UM171 - a pyrimidoindole derivative; combined with SR1 in clinical trials showing significant HSC expansion
• Notch ligand-based expansion (Delta1ext-IgG) - used in double UCB transplantation to boost cell dose
• Ferroptosis inhibition - a 2025 Nature Cell Biology study (PMID 41254392) showed that inhibiting ferroptosis (iron-dependent cell death) significantly enhances ex vivo expansion of human HSCs - a novel mechanism with translational potential
• Co-infusion strategies: Double UCB transplantation (two units) used in adults to overcome cell dose limitations

6b. Homing Enhancement

• UCB HSCs home less efficiently to bone marrow niches
• Fucosylation of cord blood cells (adding fucose groups to surface proteins) improves selectin-mediated homing - now in clinical trials
• Prostaglandin E2 (PGE2) pulsing (DMOG + PGE2): enhances CXCR4 expression, improving homing; showed improved outcomes in Phase I trial (CoRD study)

6c. UCB-Derived Cellular Therapies

• CAR-T cells from UCB: Compared to peripheral blood strategies, UCB-derived CAR-T cells may offer advantages in naivety and persistence (Rassek et al., Front Immunol 2025)
• NK cell therapies: UCB-derived NK cells as an "off-the-shelf" allogeneic product; several Phase I/II trials ongoing for hematological and solid tumors (PMID 42309519)
• Regulatory T cells (Tregs) from UCB: Investigated for GVHD prevention and autoimmune conditions
• iPSC generation: UCB units being reprogrammed to induced pluripotent stem cells (iPSCs) for banking as a universal source (Roslan et al., Int J Mol Med 2024)

6d. Non-Hematopoietic / Regenerative Applications (Investigational)

• Cerebral palsy: Autologous UCB infusion; multiple trials (Duke University); improvements in motor and cognitive function reported in early-phase studies
• Autism Spectrum Disorder (ASD): Autologous UCB infusions in small trials; immune modulation as proposed mechanism
• Type 1 Diabetes: UCB-MSCs may preserve beta-cell function
• Spinal cord injury: UC-MSC intrathecal/IV administration showing neurological improvements in clinical trials
• Ischemic stroke: NCT03004976 demonstrated clinical benefit of UC transplantation
• Hypoxic-Ischemic Encephalopathy (HIE) in neonates: Autologous UCB cells as neuroprotective agent; Phase II trial (Duke) showed improved outcomes

6e. Cryopreservation Advances

• Reduced DMSO concentration: Standard cryopreservation uses 10% DMSO (dimethyl sulfoxide), which carries infusion toxicity. A 2024 meta-analysis (PMID 38416086) evaluated lower DMSO concentrations (5%) with comparable viability outcomes and reduced toxicity
• Controlled-rate freezers and vapor-phase liquid nitrogen storage optimize long-term viability
• AXP II and PrepaCyte-CB automated processing systems improving volume reduction and cell recovery standardization

6f. Quality Control - New Standards

• AABB and NetCord-FACT now mandate CFU-GM assays (colony-forming unit - granulocyte/macrophage) for all banked units
• Recent data suggest also assessing CFU-E (erythroid) and CFU-Mk (megakaryocyte) for comprehensive viability prediction
• Total nucleated cell (TNC) dose, CD34+ cell count, and post-thaw viability remain key release criteria

6g. AI and Automation in Biobanking

• AI applied to donor-recipient HLA matching (improving speed and accuracy)
• Machine learning models predicting unit quality from pre-freeze parameters
• Automated processing, digital consent platforms, AI-assisted inventory management
• Reviewed in depth by PMC11626973

7. COVID-19 Impact on Cord Blood Banking

• Pandemic caused significant disruption: reduced collections, supply chain issues, staffing shortages, lower transplant volumes
• Roehsig & Nardi (Cell Tissue Bank 2024, PMID 38168846) reviewed the full impact - recovery ongoing
• Highlighted the fragility of global CBB supply chains, prompting resilience planning

8. Public Banking - Economic Analysis

• A 2026 scoping review (PMID 41235940) questioned cost-effectiveness models for public CBB and called for reassessment in light of declining UCBT volumes (due to haploidentical transplants competing)
• UCBT use has declined in adults over the past decade as haploidentical (half-matched family donor) transplantation has expanded, offering comparable outcomes at lower cost

9. Challenges & Limitations

10. Future Directions

• Gene-edited UCB cells (CRISPR/Cas9) as curative therapy for hemoglobinopathies before banking
• Universal off-the-shelf CAR-NK and CAR-T products derived from UCB
• iPSC banking from UCB as a renewable, patient-customizable resource
• Wharton's jelly MSC expansion (from umbilical cord tissue, not just blood) for broader regenerative applications
• Global harmonization of quality standards and registries
• Hybrid banking models expanding access while maintaining altruistic donation pools

Key References (for paper citation)

1. Mayani H. Umbilical Cord Blood Hematopoietic Cells: From Biology to Hematopoietic Transplants and Cellular Therapies. Arch Med Res. 2024;55:103042. PMID: 39003965
2. PMC12577836 - Comprehensive review: UCB protective and restorative clinical applications. 2025.
3. PMC11626973 - Advancements in Umbilical Cord Biobanking including AI. Stem Cell Cloning 2024.
4. Röhsig LM, Nardi NB. Impact of COVID-19 on cord blood banking. Cell Tissue Bank. 2024. PMID: 38168846
5. Bennett B et al. DMSO concentration meta-analysis for HSC cryopreservation. Cytotherapy. 2024. PMID: 38416086
6. Allan LE et al. Economic analyses of public cord blood banking. Transfusion. 2026. PMID: 41235940
7. Della Volpe L et al. Inhibiting ferroptosis enhances ex vivo HSC expansion. Nat Cell Biol. 2025. PMID: 41254392

Fertility Preservation in Transgender and Gender Diverse (TGD) Individuals

1. Definitions & Scope

• Transgender: A person whose gender identity differs from the sex assigned at birth
• Gender diverse (GD) / Gender nonconforming: Umbrella term including non-binary, genderqueer, genderfluid, and others whose identity does not fit binary categories
• Gender-affirming treatment (GAT): Medical or surgical interventions to align the body with gender identity - includes hormone therapy (GAHT) and gender-affirming surgery (GAS)
• RMAB: Registered/assigned male at birth (transgender women, transfeminine)
• RFAB: Registered/assigned female at birth (transgender men, transmasculine)

2. Why Fertility Preservation Matters

• TGD individuals desire parenthood at similar rates as cisgender people
• ~49% RFAB and ~48% RMAB adolescents report desire for future children (Stolk et al., J Sex Med 2025)
• Many have existing biological children before transitioning
• Gender-affirming treatments - hormonal and surgical - can impair or permanently eliminate reproductive capacity
• WPATH SOC8 (2022) and ASRM, ACOG, Endocrine Society all mandate fertility counseling prior to initiating any GAT
• Despite this, fertility counseling rates remain low - one 2025 study showed rates of only 31.5%, rising to 58.5% after implementing provider education tools (Pierce et al., JPAG 2025)

3. Impact of Gender-Affirming Treatments on Fertility

3a. Gender-Affirming Hormone Therapy (GAHT)

3b. Gender-Affirming Surgery (GAS)

4. Fertility Preservation Options - By Pubertal Status

4a. Post-Pubertal Individuals (Standard/Established Options)

For RFAB (Transgender Men / Transmasculine)

• Most preferred established method
• Requires ovarian stimulation (controlled ovarian hyperstimulation - COH) with gonadotropins
• Testosterone must be temporarily discontinued (~3 months) before stimulation in most protocols
• Recent data suggests oocyte yield and quality are comparable to cisgender women after testosterone cessation
• Random-start protocols (starting stimulation at any cycle phase) reduce time delay
• ASRM no longer labels this "experimental" (removed experimental label in 2022)
• A 2025 SWOT analysis (Barbe et al., J Assist Reprod Genet 2025) highlights strengths: established technology, no male partner needed; weaknesses: need for T cessation causing dysphoria, cost

• Oocytes fertilized with partner or donor sperm before freezing
• Higher success rate per cycle than unfertilized oocyte banking
• Requires a known sperm source at time of retrieval
• Same stimulation protocol as oocyte cryopreservation

• Laparoscopic removal and cryopreservation of ovarian cortical strips
• No longer considered experimental by ASRM (2019)
• Does not require testosterone cessation or ovarian stimulation
• Can be combined with GAS (oophorectomy)
• Future use requires reimplantation (orthotopic or heterotopic)
• Concern: reimplantation may require a receptive uterus (gestational carrier needed if hysterectomy performed)
• Live births reported in cisgender cancer patients; data in transgender men emerging

For RMAB (Transgender Women / Transfeminine)

• Gold standard - simple, non-invasive, highly effective
• Should be offered before starting estrogen or anti-androgen therapy
• Masturbation-based sample preferred; electroejaculation under anesthesia if needed
• Multiple samples recommended to maximize banked sperm count
• Long-term storage (decades) with maintained viability

• For individuals who are azoospermic due to prolonged GAHT
• Surgical retrieval of sperm directly from testicular tissue
• Sperm may still be present even after years of estrogen therapy
• Success rates variable; micro-TESE superior to conventional TESE

4b. Pre-Pubertal / Early Pubertal Individuals (Experimental Options)

• Can be performed pre-pubertally
• Tissue contains primordial follicles that may mature post-reimplantation
• No live births yet reported from pre-pubertal OTC in transgender individuals
• Considered "established but with limited data" in this age group

• Currently experimental - no live births reported globally from TTC
• Pre-pubertal testes contain spermatogonial stem cells (SSCs)
• Future use would require SSC transplantation or in vitro maturation of spermatids
• Offered at a few research centers (UCSF, Pittsburgh, Barcelona)
• WPATH SOC8 acknowledges as experimental but permits offering in research context

• Deriving functional gametes from somatic cells or iPSCs - entirely experimental, not yet in humans

5. Timing of Fertility Preservation - Key Principle

• Ideally, FP completed before puberty suppression, GAHT, or surgery
• If already on GAHT: assess reversibility; consider temporary hormone cessation
• If already post-GAS with gonadectomy: no FP options available (emphasizes pre-treatment counseling)

6. Family Building Options After Transition

7. Recent Advances (2024-2026)

7a. Oocyte Cryopreservation Outcomes in Transgender Men

• Studies by Ghofranian et al. (F&S Reports 2023, Transgender Health 2024) confirm oocyte yield after COH in transgender men is comparable to cisgender women age-matched
• Random-start stimulation protocols reduce the need for prolonged T cessation

7b. Gonadal Tissue Cryopreservation

• Ausavarungnirun & Orwig (Reproduction 2024, PMID 39331789) comprehensively reviewed OTC and TTC in TGD people - highlighting TTC as still experimental with SSC transplantation as the future route
• OTC now increasingly offered at gender clinics in combination with oophorectomy

7c. Effects of Long-Term Testosterone on Ovarian Reserve

• de Nie et al. (Hum Reprod 2020) showed preserved antral follicle counts and ovarian reserve markers in transgender men on long-term testosterone - reassuring for delayed FP
• Histology showed some morphological changes but functional reserve maintained

7d. Updated Recommendations (2025-2026)

• Wyns et al. (Hum Reprod 2025, PMID 40574354): Updated ESHRE-aligned recommendations on FP in TGD individuals
• French & Goldman (Obstet Gynecol Clin N Am 2026, PMID 42236067): Emphasize that all FP and infertility modalities available to cisgender individuals are equally available to TGD individuals; prioritize methods with highest live birth potential (mature oocyte/sperm cryopreservation)

7e. Uterine Transplantation for Transgender Women

• Ongoing research; technically feasible; no confirmed live births in transgender recipients yet
• Ethical frameworks being developed (WPATH SOC8 acknowledges as future option)

7f. iPSC-Derived Gametes

• Theoretical possibility of deriving oocytes from RMAB individuals and sperm from RFAB individuals using induced pluripotent stem cells - remains entirely pre-clinical

8. Barriers to Fertility Preservation

9. Ethical and Rights Framework

• UN Population Fund (2014): All humans have the reproductive right to decide whether or not to have children - explicitly includes transgender individuals
• WPATH SOC8: Mandates FP counseling before all GAT; no patient should be denied reproductive options
• ASRM Ethics Committee Opinion (Fertil Steril 2021): Access to fertility services should not be denied to TGD individuals
• ACOG (2021): Comprehensive reproductive counseling is part of affirming healthcare

10. Summary Table - FP Options by Population

Key References

1. French CB, Goldman RH. Fertility Considerations for Gender-Diverse People. Obstet Gynecol Clin N Am. 2026. PMID 42236067
2. Glodowski MB et al. Reproductive Considerations in the Transgender and Gender Diverse Population. Endocrinol Metab Clin N Am. 2024. PMID 39084820
3. Ausavarungnirun C, Orwig KE. Gonadal tissue cryopreservation in transgender and gender-diverse people. Reproduction. 2024. PMID 39331789
4. Barbe JE et al. Oocyte cryopreservation for fertility preservation in TGD individuals: a SWOT analysis. J Assist Reprod Genet. 2025.
5. Wyns C et al. Updated recommendations on fertility preservation. Hum Reprod. 2025. PMID 40574354
6. WPATH Standards of Care Version 8 (SOC8), 2022 - Chapter on Reproductive Health.

PPH Bundle Approach - Recent Advances (Exam Note)

1. Background

2. Definition of PPH

• Primary PPH: Blood loss ≥500 mL within 24 hours of vaginal delivery; or ≥1000 mL after caesarean section
• Severe PPH: Blood loss ≥1000 mL (new WHO threshold for triggering the bundle)
• Causes - 4 T's: Tone (70-80%), Trauma (20%), Tissue (retained placenta), Thrombin (coagulopathy)

3. The Bundle Concept

4. WHO PPH Care Bundles (Two Tiers)

BUNDLE 1 - First Response to PPH

• Examine for cause (4 T's)
• Escalate / call for help

BUNDLE 2 - Response to Refractory PPH

5. The E-MOTIVE Bundle (Landmark Trial)

What is E-MOTIVE?

The E-MOTIVE Trial (NEJM 2023)

• Design: International cluster-randomised trial
• Countries: Kenya, Nigeria, South Africa, Tanzania
• Size: 80 secondary-level hospitals; 210,132 vaginal deliveries
• Intervention: Calibrated drape (early detection) + MOTIVE bundle + implementation strategy (training, champions, data feedback)
• Primary outcome: Composite of severe PPH (≥1000 mL) + laparotomy for bleeding + maternal death from bleeding

Implementation Strategy (Key to Success)

• Simulation-based training with peer-assisted learning
• Local E-MOTIVE champions in each facility
• Calibrated blood-collection drape with "action line" at 500 mL
• MOTIVE emergency trolley / carry case (all drugs pre-packed)
• Feedback of real-time data to providers

6. Tranexamic Acid (TXA) in PPH

Mechanism

• Competitive inhibitor of plasminogen activation
• Prevents breakdown of fibrinogen and fibrin clots (antifibrinolytic)
• Does NOT promote clot formation; prevents clot dissolution

Dosing Protocol (WHO / WOMAN Trial)

• Dose: 1 g in 10 mL (100 mg/mL) IV at 1 mL/min (slow push over 10 minutes)
• Timing: As early as possible; no benefit if given >3 hours after bleeding onset
• Second dose: 1 g IV if bleeding continues after 30 min OR restarts within 24 h of first dose
• Route: IV only for PPH (not mixed with blood transfusion or mannitol/penicillin)
• Listed on WHO Essential Medicines List for PPH

Evidence Base

• WOMAN Trial (Lancet 2017): 20,060 women; TXA reduced death from PPH by 19% when given within 3 hours (RR 0.81, p=0.045); no benefit after 3 hours
• 2024 Lancet IPD Meta-analysis (Ker K et al., PMID 39461793): Confirmed early TXA reduces PPH mortality; greatest benefit when given within 60 minutes
• Prevention role (emerging): 2026 meta-analysis (PMID 42426676) shows prophylactic TXA at CS in high-risk women reduces blood loss

Key Points for Exam

• TXA reduces PPH mortality by ~20% when given early
• Time is critical - every 15-minute delay reduces efficacy
• No increase in thrombosis risk at 1 g dose (WOMAN trial)
• Part of BOTH first-response and refractory PPH bundles

7. Newer Uterine Tamponade and Vacuum Devices

A. Intrauterine Balloon Tamponade (IBT)

Types:

B. Novel Vacuum / Negative Pressure Devices - KEY ADVANCE

Jada System (Intrauterine Vacuum-Induced Hemorrhage Control)

• Principle: Uses low-level intrauterine vacuum suction rather than positive pressure/distension to induce uterine contraction
• Mechanism: Negative pressure (~70 mmHg) at the uterine fundus stimulates myometrial contraction (uterine collapse around the device)
• Advantage over balloons: Does NOT distend the uterus (which can theoretically impair uterine contraction). Instead, works WITH the uterus's natural contractile mechanism
• Design: Silicone loop inserted transcervically; connected to regulated suction
• Evidence: US FDA-approved (2020); multiple trials showing 94%+ success rate in uterine atony PPH
• Key trial: PEARLE trial (USA) - significant reduction in blood loss vs standard care

Panicker Vacuum Cannula

• Indian innovation - vacuum suction cannula for PPH
• Simple, low-cost device for atonic PPH

Compression/Suction Synergy

• Newer approach: combining vacuum suction (Jada) + uterotonic drugs + TXA simultaneously
• 2024 data shows combined approach reduces surgical intervention rates significantly

8. Other Newer Devices

9. Point-of-Care Viscoelastic Testing (POCT) - Emerging

• Devices: ROTEM (thromboelastometry) and TEG (thromboelastography)
• Real-time assessment of clot formation and fibrinolysis at the bedside
• Guides targeted blood product replacement (FFP, cryoprecipitate, platelets) in coagulopathic PPH
• 2026 narrative review (PMID 41084872) supports integration into PPH protocols
• Advantage: Avoids unnecessary transfusion of blood products; guides fibrinogen replacement early

10. Summary Algorithm

Blood loss ≥500 mL (detected by calibrated drape)
         ↓
TRIGGER: E-MOTIVE BUNDLE SIMULTANEOUSLY (within 15 min)
  • Massage uterus
  • Oxytocin 10 IU IV + infusion
  • TXA 1 g IV (within 3 hours!)
  • IV fluids (Ringer's lactate)
  • Examine (4 T's) + Escalate
         ↓
     Still bleeding?
         ↓
REFRACTORY PPH BUNDLE
  • Continue uterotonics + IV fluids
  • Second TXA 1 g IV
  • Bimanual compression OR aortic compression
  • NASG
  • Uterine balloon tamponade (Bakri / Jada vacuum)
  • Blood transfusion; ROTEM-guided blood products
         ↓
     Still bleeding?
         ↓
SURGICAL / INTERVENTIONAL
  • Compression sutures (B-Lynch, Hayman)
  • Uterine/ovarian artery ligation
  • Uterine artery embolization
  • Brace sutures
         ↓
     Last resort
         ↓
HYSTERECTOMY

11. Key Facts for Exam

Key References

1. Gallos I et al. E-MOTIVE Trial. N Engl J Med. 2023. PMID 37158447 - The landmark trial
2. Williams EV et al. Cost-effectiveness of E-MOTIVE. Nat Med. 2024. PMID 38844798
3. Ker K et al. TXA meta-analysis (IPD). Lancet. 2024. PMID 39461793
4. WHO Recommendations on PPH Bundle. December 2023.
5. FIGO-ICM Joint Statement on TXA for PPH. figo.org

Ultrasound in Labor (Intrapartum Ultrasound) - Exam Note

1. Introduction

• Subjective and poorly reproducible (inter-observer variation up to 30-40% for position)
• Inaccurate for head position (correct in only ~40-60% of cases vs. USG)
• Uncomfortable for the patient

2. Probes and Approaches Used in Labor

3. Parameters Assessed by Intrapartum Ultrasound

A. FETAL HEAD POSITION

Technique (Transperineal - Axial Plane):

• Probe placed transperineally, rotated to axial plane
• Identify midline echo (falx cerebri) → direction of occiput

B. FETAL HEAD STATION / DESCENT - The Key Parameters

1. Angle of Progression (AoP) - MOST IMPORTANT

• Definition: Angle between a line along the long axis of the pubic symphysis and a line tangent to the fetal skull, measured on midsagittal transperineal plane
• Measured on: Midsagittal transperineal view
• Interpretation: As head descends → AoP increases

• Sensitivity 67-91%, Specificity up to 100% for vaginal delivery

• Predict mode of delivery (vaginal vs. CS vs. operative)
• Guide decision for instrumental delivery (forceps/vacuum)
• Monitor labor progress objectively
• AoP <138° predicts difficult forceps delivery (sensitivity 85.7%, specificity 100%)

2. Head-Perineum Distance (HPD)

• Definition: Distance (in cm) from the outer bony edge of fetal skull to the perineal skin surface, measured in axial transperineal plane
• Inverse relationship with AoP - as head descends, HPD decreases
• Engagement threshold: HPD ≤35 mm = head engaged
• HPD <25 mm = head on perineum; imminent delivery

3. Head Direction Angle (HDA) / Angle of Descent

• Angle between infrapubic line of pelvis and a line perpendicular to the widest diameter of the fetal head
• Indicates whether head is directed anteriorly (favorable) or posteriorly (unfavorable)
• Anterior head direction → shorter second stage, higher vaginal delivery rate

4. Head-Symphysis Distance (HSD)

• Distance from fetal head bony surface to lower border of pubic symphysis
• Studied as marker of engagement and station

5. Head Progression Distance (HPrD)

• Distance from the level of the ischial spines (represented by the lower border of the pubic symphysis) to the leading edge of the fetal head
• Shows good performance but needs more validation before routine use

C. FETAL HEAD ATTITUDE (FLEXION / DEFLEXION)

• Why it matters: Well-flexed head (suboccipitobregmatic diameter 9.5 cm) is smallest presenting diameter. Deflexion increases diameter → obstructed labor.

Occiput-Spine Angle (OSA):

• Measured between line through occiput and fetal spine
• OSA >109° = well-flexed head (favorable)
• OSA <109° = deflexed head → larger diameter presenting → risk of obstructed labor / operative delivery
• Measured in fetuses in OA or OT position on sagittal transperineal view

D. CERVICAL ASSESSMENT

• Cervical length (transvaginal or transperineal): predicts preterm labor, labor progress
• Internal os dilatation and morphology
• Posterior cervical angle - predicts response to induction of labor
• Cervical dilatation can be measured directly by transperineal USG (semi-quantitative)

E. OTHER ASSESSMENTS IN LABOR

4. The Sonopartogram - Key Concept

An ultrasound-based partogram plotting serial objective measurements of:

• Fetal head position (angle)
• AoP / HPD over time
• Complementary maternal and clinical parameters

• Objective measurements (not subjective DVE)
• Reproducible across observers
• Better accuracy for head position (98% vs. 46% for DVE)
• Can be automated on modern US machines
• Enables individualized risk prediction models for labor outcome

5. Intrapartum USG in Specific Clinical Scenarios

5a. Prolonged / Obstructed Labor

• Objectively assess AoP, HPD, head position, attitude
• Identify malposition (OP/OT) causing dystocia
• Decide between expectant management, manual rotation, operative vaginal delivery, or CS

5b. Operative Vaginal Delivery (Forceps / Vacuum)

• Before: Confirm position, station (AoP), attitude - prevents failed instrumental delivery
• AoP >120° required for safe instrumental delivery
• AoP >145° associated with successful uncomplicated OVD
• Confirm occiput anterior position before applying forceps
• 2026 review on vacuum delivery (Malvasi et al., PMID 41897680): USG flexion point method guides optimal cup placement

5c. Occiput Posterior Position

• Detected reliably by USG (vs. DVE often misses OP)
• 2026 systematic review (PMID 41946068): Identified USG markers predicting persistent OP and mode of delivery
• AoP + head attitude predicts spontaneous rotation to OA or need for manual rotation
• Manual rotation of OP position under real-time USG guidance: demonstrated by Dall'Asta et al., UOG 2024 - guides rotation and confirms successful rotation

5d. Second Stage Monitoring

• Serial AoP measurements replace repeated painful DVEs
• USG biofeedback during pushing: Show mother real-time descent of fetal head on screen → improves pushing efforts → may shorten second stage
• Emerging area - trials underway

5e. Induction of Labor - Cervical Assessment

• Cervical length, posterior cervical angle, and head position predict success of induction
• Transperineal cervical angle <100° associated with successful induction

5f. Suspected Cord Presentation / Prolapse

• Color Doppler of presenting part in transperineal view
• Identifies cord ahead of presenting part before membranes rupture

5g. OASIS Detection (Postpartum)

• Transperineal or endoanal USG immediately postpartum
• Detects internal/external anal sphincter tears
• Superior to clinical examination alone in detecting occult sphincter injuries

6. Advantages of Intrapartum USG over Digital VE

7. Limitations of Intrapartum USG

• Learning curve: Training required for reliable measurements
• Maternal obesity reduces image quality
• Not yet standard of care: No large RCT showing improved outcomes compared to DVE alone
• No universal cut-off values agreed upon (AoP cut-offs vary by parity and stage of labor)
• Cannot fully replace DVE for all parameters (e.g., cervical effacement, membrane status)
• Equipment cost and availability in low-resource settings
• Time-consuming if unfamiliar

8. Summary Table - Parameters at a Glance

9. Key Points for Exam

• AoP is the single most important and well-validated intrapartum USG parameter
• AoP increases as head descends; >120° = engaged; >145° = vaginal delivery highly likely
• USG is ~2.5x more accurate than DVE for fetal head position
• Sonopartogram = USG-based partogram; objectifies labor progress
• OP position: USG diagnoses accurately; guides manual rotation decisions
• AoP before instrumental delivery is now widely recommended
• USG biofeedback during pushing = emerging innovation
• OASIS can be screened by immediate postpartum transperineal USG
• Limitation: No large RCT yet proving USG improves maternal/neonatal outcomes vs. standard care

Key References

1. Usman S et al. The sonopartogram. AJOG. 2023. PMID 37164504
2. Ghi T, Dall'Asta A. Sonographic evaluation of fetal head position and attitude during labor. AJOG. 2024. PMID 37278991
3. Nebel S et al. 2D-transperineal USG systematic review (AoP, HPD, OASIS). J Gynecol Obstet Hum Reprod. 2025. PMID 39814335
4. Turney M et al. USG markers for persistent OP position. Eur J Obstet Gynecol. 2026. PMID 41946068
5. Malvasi A et al. IUS in vacuum delivery. Diagnostics. 2026. PMID 41897680