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ob.cervical-insufficiency.v1

Cervical Insufficiency (Painless 2nd-Trimester Cervical Dilation)

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NEW Phase C wave 12 dossier — authored 2026-05-15 for shard-5-obped-id. Covers cervical insufficiency (formerly "incompetent cervix") — painless cervical dilation in the 2nd trimester (16-24 wk) without contractions → mid-trimester loss or extreme-preterm birth. True CI ~ 0.1-1 % of pregnancies; mid-trimester loss ~ 1-2 % of all pregnancies; recurrence ~ 30 % without cerclage vs ~ 15 % with cerclage. Cerclage placed in ~ 1 % of US deliveries. Manifest field intentionally blanked (manifest: "") per shard-5 precedent on peds.febrile-infant.core.v1, id.influenza.core.v1, id.neonatal-sepsis.early-late.v1, peds.neonatal-abstinence-syndrome.v1, ob.chorioamnionitis.v1, ob.placental-abruption.v1, ob.amniotic-fluid-embolism.v1, ob.uterine-rupture.v1, ob.shoulder-dystocia.v1, ob.preterm-labor.v1 — seed manifest authoring at prisma/seed/manifests/ob.cervical-insufficiency.v1.{ts,atoms.ts} is out-of-shard scope and deferred to a future shard. Cross-engine manifest reuse (orchestrator suggested pointing to id.sepsis.core.v1 manifest) considered but rejected — semantically misleading (sepsis manifest does not describe CI-specific atoms — cerclage indications + technique + timing, vaginal progesterone, pessary, rescue cerclage with pre-procedural antibiotics + indomethacin). _registry.ts NOT modified per refined shard-5 pattern (3-file set only: dossier TS + brief + research bundle). Registry edit deferred to a future shard. Distinct from ob.preterm-labor.v1 (sibling — PTL has regular contractions at 20-37 wk; CI is painless at 16-24 wk; CI patients can transition to PTL after cerclage → emergent removal if refractory tocolysis), ob.chorioamnionitis.v1 (sibling — cerclage in chorio mandates removal; foreign body in infected field), ob.pre-eclampsia.core.v1 (sibling — PE-indicated preterm birth is separate pathway), ob.placental-abruption.v1 (sibling — painful + bleeding excludes pure CI). Sibling differentiation explicitly encoded for four. Phenotype matrix (5-axis indication-tier × GA × cervical-exam × singleton-vs-multifetal × complication-state — collapsed to 11 anchor combinations) encoded indirectly via regimen_axes.cervical_insufficiency_management.steps (history_indicated_cerclage_elective_12_to_14wk / ultrasound_indicated_cerclage_16_to_23_6wk / rescue_cerclage_physical_exam_indicated_with_antibiotics_and_indomethacin / vaginal_progesterone_short_cervix_no_prior_ptb / twin_rescue_cerclage_at_advanced_dilation / transabdominal_cerclage_for_failed_transvaginal / cervical_pessary_alternative / cerclage_removal_elective_or_emergent) + severity_triggers (10 triggers) + setting playbooks (outpatient / ed / inpatient). First-class TS phenotype field is schema-blocked. Severity triggers (10): history_indicated_cerclage_at_13_14wk (mild — elective procedure 12-14 wk per ACOG PB 234), ultrasound_indicated_cerclage_short_cervix (severe — prior PTB + CL < 25 mm singleton 16-23+6 wk per Berghella 2011 PMID 21446209 + Owen 2009 PMID 19788970), rescue_cerclage_dilated_cervix_with_bulging_membranes (severe — emergent rescue 16-23+6 wk with pre-procedural antibiotics + indomethacin per CIPRACT Althuisius 2003 PMID 14586323; efficacy controversial), cerclage_complication_with_ptl_or_chorio_or_pprom (severe — routes to ob.preterm-labor.v1 or ob.chorioamnionitis.v1 with cerclage carryover; mandatory removal at chorio; case-by-case at PTL/PPROM), vaginal_progesterone_short_cervix_no_prior_ptb (moderate — 200 mg PV nightly per Hassan 2011 PMID 21472815 + Romero 2017 PMID 29630885; NOT cerclage indication per Berghella 2017 IPD meta-analysis), twin_pregnancy_with_short_cervix (moderate — rescue cerclage at advanced dilation per Roman 2020 PMID 32592693; routine cerclage NOT recommended; vaginal progesterone NOT effective for multifetal), cervical_pessary_alternative (mild — Goya 2012 PMID 22475493 positive trial NOT replicated in OPPTIMUM 2016 or ProTwin 2013; informed consent re uncertain benefit), preconception_counseling_with_history (moderate — MFM preconception consult for next pregnancy; uterine-anomaly workup; recurrence counseling), recurrent_loss_despite_cerclage (severe — transabdominal cerclage consideration; uterine-anomaly + connective-tissue workup), pprom_after_cerclage_decision (severe — case-by-case removal usually within 24-48 h of PPROM diagnosis given ascending infection risk; routes to ob.preterm-labor.v1 PPROM branch with cerclage carryover). Bayesian linkage (per §5.5.2): pre-test priors documented in _research-bundles/ob.cervical-insufficiency.v1.md — true CI ~ 0.1-1 % of pregnancies; mid-trimester loss ~ 1-2 % overall; recurrence ~ 30 % without cerclage vs ~ 15 % with; short cervix CL < 25 mm at 18-24 wk in prior PTB singletons ~ 30-40 %. Key LRs: prior 2nd-trimester loss attributable to painless dilation LR+ ~ 5-10 for recurrence (history-indicated cerclage basis); TVUS CL < 25 mm at 16-23 wk + prior PTB LR+ ~ 5-7 for PTB < 34 wk (US-indicated cerclage threshold per Berghella 2011); TVUS CL < 20 mm singleton no prior PTB LR+ ~ 4-6 for preterm birth (vaginal progesterone threshold); dilated cervix + bulging membranes 16-24 wk without contractions → high LR+ for mid-trimester loss (rescue cerclage substrate); cerclage in situ + PPROM LR+ ~ 5 for chorio (foreign body in infected field). Conditional dependencies modeled: indication tier × cerclage benefit coupling (history-indicated > US-indicated > exam-indicated in NNT); singleton vs multifetal × cerclage coupling (routine cerclage NOT effective in twins; rescue cerclage at advanced dilation per Roman 2020); prior PTB × short cervix coupling (US-indicated cerclage substrate per Berghella 2011); cerclage × complication coupling (PTL refractory → removal; chorio → mandatory removal; PPROM → usually within 24-48 h; bleeding → case-by-case). Decision thresholds: T_history-indicated-cerclage = ≥ 1 prior 2nd-trimester loss + no other cause + singleton + 12-14 wk; T_ultrasound-indicated-cerclage = prior sPTB + singleton + CL < 25 mm before 24 wk; T_rescue-cerclage = dilated cervix + bulging membranes 16-23+6 wk WITHOUT contractions/infection/bleeding; T_vaginal-progesterone = asymptomatic CL < 25 mm at 18-24 wk WITHOUT prior PTB; T_cerclage-removal = elective 36-37 wk OR emergent at PTL refractory / chorio / PPROM / bleeding; T_transabdominal-cerclage = failed prior transvaginal OR anatomically short/scarred cervix; T_twin-rescue-cerclage = twin + asymptomatic cervical dilation ≥ 1 cm at 16-23+6 wk per Roman 2020. Cross-dossier routing: ob.preterm-labor.v1 (PTL emergence after cerclage with cerclage carryover), ob.chorioamnionitis.v1 (chorio in cerclage patient; mandatory removal), ob.placental-abruption.v1 (bleeding excludes pure CI), ob.pre-eclampsia.core.v1 (PE overlay; distinct pathway). ROS/DDx LR seed data NOT touched (cross-cutting; not in shard scope). Settings (3): Outpatient (antepartum MFM clinic for pre-conception + surveillance + elective cerclage scheduling + vaginal progesterone + 6-week postpartum), ED (triage 2nd-trimester pelvic pressure / incidental painless cervical dilation; sterile speculum + TVUS CL + immediate OB consult + L&D / antepartum transfer), Inpatient L&D / antepartum (definitive cerclage placement — history-, US-, or exam-indicated rescue; pre-procedural infection screen + treat; post-procedural observation; emergent removal at PTL refractory / chorio / PPROM / bleeding). ICU not authored separately (CI rarely ICU-requiring; complications route to sibling ICU pathways). Drug guidance grounded in ACOG PB 234 + PB 130 + SMFM Consult Series #20 (2020) + Berghella 2011 + Owen 2009 + Hassan 2011 + Romero 2017/2018 + Roman 2020 + CIPRACT 2003 + Goya 2012 + Cochrane 2017 (Alfirevic). RxCUIs referenced: progesterone (8727 reused from ob.preterm-labor.v1), cefazolin (2180 — RxNav-verified live 2026-05-25; prior 2191 resolved to ceftazidime and was corrected), indomethacin (5781 reused), acetaminophen (161 reused), aspirin (1191 reused). RxCUI validation via npm run research:rxnav deferred to next research loop (out-of-shard gate dependency; codes carried over from sibling dossiers). Open gaps: (1) Phenotype matrix not first-class TS field — schema-blocked. (2) Bayesian LR seed data not encoded — lives in narrative + research bundle only this pass; ROS/DDx seed edit cross-cutting. (3) Cross-engine manifest reuse considered for INTEGRATED promotion but rejected — semantically misleading; safer pattern is blank-manifest + PLANNED. (4) Manifest file not authored this pass — shard precedent for manifest: "" with seed deferred. (5) Co-located test file (ob.cervical-insufficiency.test.ts) not authored — coverage via canonical tests/dossiers/dossier-contract.test.ts only. (6) _registry.ts NOT modified per refined shard-5 pattern — registry edit deferred to a future shard. (7) ACOG Practice Bulletin 234 does not carry a stable PubMed PMID — cited by year + bulletin number; closest indexed PMIDs are the underlying trial papers (Berghella 2011, Owen 2009, Hassan 2011, Romero 2017/2018, Roman 2020, CIPRACT 2003, Goya 2012, Cochrane 2017). (8) Transabdominal cerclage technique-specific evidence (laparoscopic vs laparotomy) not deeply captured — flagged in severity_triggers + research bundle; MAVRIC 2020 emerging evidence base. (9) Pessary alternative — emerging evidence; CIPRACT + ProTwin + OPPTIMUM mixed; not encoded as first-line. Status declared PLANNED with manifest: "" — audit surfaces "missing manifest pointer" as a next-tier requirement; broken_pointers should be empty since blank pointer is skipped by audit. Per shard precedent, this is acceptable for new Phase C dossiers awaiting manifest authoring in a future shard.

Entry points (8)

  • history
    ≥ 1 prior 2nd-trimester pregnancy loss attributable to painless cervical dilation with no other identifiable cause (ACOG PB 234 history-indicated cerclage substrate)
    prior_second_trimester_loss_painless_dilation
  • imaging
    TVUS cervical length < 25 mm before 24 wk in singleton with prior spontaneous preterm birth (US-indicated cerclage substrate per Berghella 2011 PMID 21446209; Owen 2009 PMID 19788970)
    transvaginal_cervical_length_under_25mm_with_prior_ptb
  • imaging
    TVUS cervical length < 25 mm at 18-24 wk in asymptomatic singleton WITHOUT prior preterm birth — vaginal progesterone indication per Hassan 2011 PMID 21472815; Romero 2017 PMID 29630885
    transvaginal_cervical_length_under_25mm_no_prior_ptb
  • symptom
    Painless cervical dilation ≥ 1-2 cm + visible / bulging amniotic membranes on speculum or digital exam at 16+0 to 23+6 wk WITHOUT contractions or infection (rescue cerclage substrate per CIPRACT Althuisius 2003 PMID 14586323; ACOG PB 234)
    painless_cervical_dilation_on_exam_16_to_24wk
  • symptom
    New pelvic pressure / vaginal pressure / increased discharge at 16-24 wk without contractions — supportive feature warranting speculum + TVUS evaluation
    pelvic_pressure_or_vaginal_discharge_mid_trimester
  • history
    History of cervical surgery (LEEP, cone biopsy, D&C with cervical injury) — iatrogenic CI risk factor (ACOG PB 234)
    cervical_procedure_history_loop_cone_dnc
  • history
    Connective tissue disorder (Ehlers-Danlos), congenital uterine anomaly (Mullerian fusion defect), or DES exposure — structural CI risk factors
    connective_tissue_or_uterine_anomaly_history
  • history
    Twin / triplet pregnancy + cervical dilation ≥ 1 cm at 16-23+6 wk → rescue cerclage candidate per Roman 2020 PMID 32592693; routine cerclage NOT recommended in multifetal
    twin_or_multifetal_pregnancy_with_short_cervix

Required inputs (20)

  • gestational_age_weeksrequired
    demographic • used at FRAME
    GA partitions decision branches: pre-conception (counseling); 12-14 wk (elective history-indicated cerclage); 16-23+6 wk (US- or exam-indicated cerclage); ≥ 24 wk (cerclage too late typically); 36-37 wk (elective removal)
  • prior_second_trimester_loss_count_and_featuresrequired
    history • used at CONTEXT
    Prior 2nd-trimester loss attributable to painless dilation (rather than abruption / abnormal placentation / infection) is the substrate for history-indicated cerclage; ≥ 1 prior loss (some criteria ≥ 2) drives elective cerclage at 12-14 wk
  • prior_spontaneous_preterm_birth_count_and_GArequired
    history • used at CONTEXT
    Prior spontaneous preterm birth + current short cervix < 25 mm singleton drives US-indicated cerclage decision per Berghella 2011 + Owen 2009
  • multifetal_gestation_statusrequired
    history • used at CONTEXT
    Twin / triplet — routine cerclage NOT recommended (Berghella 2017 IPD meta-analysis); rescue cerclage at advanced dilation per Roman 2020 reduces sPTB subgroup; vaginal progesterone NOT effective for multifetal (Romero 2018 PMID 29630885)
  • cervical_procedure_history
    history • used at CONTEXT
    LEEP / cone biopsy / D&C with cervical injury — iatrogenic CI risk factor; informs cerclage decision threshold (ACOG PB 234)
  • uterine_anomaly_or_connective_tissue_history
    history • used at CONTEXT
    Congenital uterine anomaly (Mullerian fusion defect; bicornuate / septate uterus) or connective tissue disorder (Ehlers-Danlos) — structural CI risk factor; mandates workup post-loss for next-pregnancy planning
  • prior_cerclage_history_and_outcome
    history • used at CONTEXT
    Prior transvaginal cerclage failure → transabdominal cerclage consideration in next pregnancy (laparoscopic or laparotomy); mandates cesarean delivery and left in situ for future pregnancies
  • maternal_temperaturerequired
    vital • used at RED_FLAGS
    Fever screens for chorio (Higgins 2016) — chorio is a contraindication to rescue cerclage and mandates removal of cerclage in situ
  • maternal_hrrequired
    vital • used at CONTEXT
    Maternal tachycardia + fever supports chorio; sepsis screen if disproportionate
  • maternal_bprequired
    vital • used at CONTEXT
    BP screens for pre-eclampsia overlay (rare in CI population given GA but indicated-preterm-birth ddx); informs anesthesia planning for cerclage
  • contractions_statusrequired
    symptom • used at FRAME
    CI is by definition PAINLESS dilation; presence of regular contractions reclassifies as PTL and routes to ob.preterm-labor.v1
  • vaginal_bleeding_amount_and_patternrequired
    symptom • used at RED_FLAGS
    Vaginal bleeding excludes pure CI diagnosis — abruption ddx routes to ob.placental-abruption.v1; light bloody show acceptable at advanced cervical dilation
  • rupture_of_membranes_statusrequired
    symptom • used at RED_FLAGS
    PPROM (ROM at < 37 wk) after cerclage placement — case-by-case removal decision usually within 24-48 h given ascending infection risk; routes to ob.preterm-labor.v1 (PPROM branch)
  • transvaginal_cervical_length_ultrasoundrequired
    imaging • used at INITIAL_WORKUP
    TVUS CL is the gold-standard cervical assessment; thresholds: < 25 mm at 16-23 wk + prior PTB → US-indicated cerclage (Berghella 2011); < 25 mm at 18-24 wk no prior PTB → vaginal progesterone (Hassan 2011); serial surveillance q1-2 wk in high-risk
  • speculum_examination_cervical_visualizationrequired
    imaging • used at INITIAL_WORKUP
    Sterile speculum to visualize cervical dilation and amniotic membranes — bulging membranes through dilated os at 16-24 wk without contractions is physical-exam-indicated rescue cerclage substrate (CIPRACT 2003)
  • obstetric_ultrasound_growth_and_anatomyrequired
    imaging • used at INITIAL_WORKUP
    Confirm GA + viability + anatomy + amniotic fluid volume + placenta location (abruption ddx); guide cerclage decision
  • maternal_cbc_with_diffrequired
    lab • used at INITIAL_WORKUP
    WBC > 15K without antenatal steroids supports chorio (Higgins 2016) — chorio is cerclage contraindication; baseline pre-procedural
  • maternal_urine_culture_and_uarequired
    lab • used at INITIAL_WORKUP
    Asymptomatic bacteriuria / UTI is a PTB risk factor — treat to reduce preterm birth and pre-procedural infection risk before cerclage (ACOG PB 130)
  • cervicovaginal_swab_gbs_chlamydia_gonorrhea_bvrequired
    lab • used at INITIAL_WORKUP
    STI / BV screen — pre-procedural cerclage workup; treat positive infections before cerclage placement
  • maternal_coagulation_panel
    lab • used at INITIAL_WORKUP
    Pre-procedural workup for cerclage anesthesia (regional preferred)

12-phase flow (12)

  1. 1FRAME
    Cervical insufficiency = painless cervical dilation in 2nd trimester (typically 16-24 wk) without contractions, with risk of mid-trimester loss or extreme-preterm birth. Pathophysiology is mechanical (cervical structural weakness) rather than the contraction-driven mechanism of PTL. Partition by indication tier: history-indicated (prior 2nd-trimester loss) vs ultrasound-indicated (prior PTB + current CL < 25 mm) vs physical-exam-indicated (dilated cervix + bulging membranes) vs asymptomatic-short-cervix-no-prior-PTB (vaginal progesterone). Distinguishes from preterm labor (regular contractions + cervical change at 20-37 wk; routes to ob.preterm-labor.v1), placental abruption (painful bleeding; ob.placental-abruption.v1), chorioamnionitis (fever + Higgins criteria; ob.chorioamnionitis.v1).
    inputs: gestational_age_weeks, contractions_status
    advance: GA + indication-tier classification + contractions absent (defining CI feature) confirmed
  2. 2ENTRY
    Recognise CI via (a) ≥ 1 prior 2nd-trimester loss attributable to painless dilation (history-indicated substrate); (b) prior PTB + current TVUS CL < 25 mm singleton before 24 wk (US-indicated substrate); (c) speculum exam showing dilated cervix + visible / bulging amniotic membranes 16-24 wk without contractions (rescue / physical-exam-indicated substrate); (d) incidental short cervix < 25 mm at 18-24 wk in singleton WITHOUT prior PTB (vaginal-progesterone substrate, NOT cerclage); (e) twin / multifetal + dilated cervix at advanced GA (rescue cerclage candidate per Roman 2020).
    inputs: gestational_age_weeks
    advance: Indication tier diagnosed; speculum + TVUS confirmation documented; PTL + abruption + chorio excluded
  3. 3CONTEXT
    GA exact + prior 2nd-trimester loss count + prior PTB count + multifetal status + cervical procedure history (LEEP / cone / D&C) + uterine anomaly + connective tissue disorder + prior cerclage history and outcome + comorbidities (DM, autoimmune) + medications (anticoagulants pre-procedural). Critical decision context for cerclage technique (McDonald vs Shirodkar vs transabdominal) and timing (elective 12-14 wk vs 16-23+6 wk vs emergent rescue).
    inputs: gestational_age_weeks, prior_second_trimester_loss_count_and_features, prior_spontaneous_preterm_birth_count_and_GA, multifetal_gestation_status, cervical_procedure_history, uterine_anomaly_or_connective_tissue_history, prior_cerclage_history_and_outcome, maternal_hr, maternal_bp
    advance: Risk-factor profile + cerclage-eligibility-specific decision context captured
  4. 4RED_FLAGS
    Maternal fever ≥ 39.0 °C OR 38.0-38.9 °C × 2 + secondary criteria → ob.chorioamnionitis.v1 (chorio is cerclage CONTRAINDICATION; mandates removal if cerclage in situ). Regular contractions → reclassify as PTL → ob.preterm-labor.v1 with cerclage carryover. Painful vaginal bleeding + tachysystole → ob.placental-abruption.v1. PPROM → ob.preterm-labor.v1 (PPROM branch) with cerclage carryover (removal usually within 24-48 h). Significant vaginal bleeding without abruption features → case-by-case observation.
    inputs: maternal_temperature, contractions_status, vaginal_bleeding_amount_and_pattern, rupture_of_membranes_status
    advance: Red-flag routing decisions documented (chorio / PTL / abruption / PPROM emergence + cerclage removal decision if in situ)
  5. 5INITIAL_WORKUP
    Sterile speculum (visualize cervical dilation + amniotic membranes — no digital exam if PPROM suspected), TVUS cervical length, obstetric ultrasound for growth + anatomy + amniotic fluid + placenta location. Pre-procedural workup before cerclage: CBC + CMP + coagulation panel + UA + urine culture + cervicovaginal GBS / chlamydia / gonorrhea / BV swabs. Treat any positive infection BEFORE cerclage placement. Document GA exactly + cervical exam findings + TVUS CL + amniotic fluid + placenta location.
    inputs: transvaginal_cervical_length_ultrasound, speculum_examination_cervical_visualization, obstetric_ultrasound_growth_and_anatomy, maternal_cbc_with_diff, maternal_urine_culture_and_ua, cervicovaginal_swab_gbs_chlamydia_gonorrhea_bv
    actions: panel.cbc, panel.ua, panel.coag
    advance: Diagnostic imaging + pre-procedural labs drawn; indication tier confirmed; infections ruled out or treated
  6. 6BRANCHING_WORKUP
    Branching by indication tier + GA: (1) history-indicated → schedule elective McDonald or Shirodkar cerclage at 12-14 wk; (2) US-indicated (prior PTB + CL < 25 mm singleton) → cerclage at 16-23+6 wk per Berghella 2011 + Owen 2009; (3) physical-exam-indicated (dilated cervix + bulging membranes 16-23+6 wk without contractions / infection / bleeding) → emergent rescue cerclage with pre-procedural antibiotics + indomethacin tocolysis (CIPRACT pattern); informed consent re uncertain efficacy; (4) asymptomatic short cervix < 25 mm at 18-24 wk singleton WITHOUT prior PTB → vaginal progesterone 200 mg PV nightly (NOT cerclage; Hassan 2011 + Romero 2017); (5) twin / multifetal + dilated cervix at advanced GA → rescue cerclage per Roman 2020 (subgroup benefit; routine cerclage NOT recommended); (6) recurrent loss despite prior transvaginal cerclage → transabdominal cerclage consideration pre-conception or in early pregnancy (mandates cesarean delivery).
    advance: Indication-tier-specific management plan documented; cerclage technique + timing decision made
  7. 7DIFFERENTIAL
    Preterm labor (regular contractions + cervical change → ob.preterm-labor.v1), placental abruption (painful bleeding + tachysystole → ob.placental-abruption.v1), chorioamnionitis (fever + Higgins 2016 → ob.chorioamnionitis.v1), PPROM (ROM at < 37 wk → ob.preterm-labor.v1 PPROM branch), congenital uterine anomaly as primary cause of loss (MFM / REI referral for surgical correction), abnormal placentation (placenta previa / accreta — separate management).
    advance: Mimics excluded; pure CI diagnosis confirmed for cerclage decision OR complication overlay routed to appropriate sibling engine
  8. 8RISK_STRATIFICATION
    Indication tier + GA + singleton vs multifetal + cervical length + complication status drive recurrence risk + cerclage benefit + delivery timing. Highest benefit: history-indicated (NNT lowest for recurrence reduction). Moderate benefit: US-indicated (Berghella 2011 RR 0.70). Uncertain benefit: physical-exam-indicated rescue (CIPRACT cohort; informed consent essential). Twin pregnancy: rescue cerclage at advanced dilation per Roman 2020; routine cerclage NOT effective. Recurrent loss despite prior transvaginal cerclage: transabdominal cerclage consideration.
    inputs: gestational_age_weeks, transvaginal_cervical_length_ultrasound, multifetal_gestation_status
    advance: Risk-stratification tier set; cerclage candidacy + technique + timing finalized; informed consent obtained
  9. 9TREATMENT
    CERCLAGE PLACEMENT (history-indicated 12-14 wk McDonald or Shirodkar elective; US-indicated 16-23+6 wk; physical-exam-indicated rescue 16-23+6 wk with pre-procedural antibiotics + indomethacin tocolysis if < 32 wk). PRE-PROCEDURAL ANTIBIOTICS at rescue cerclage: cefazolin 2 g IV pre-op + post-op course typical (low-quality evidence; commonly used). INDOMETHACIN TOCOLYSIS for rescue cerclage: 50-100 mg PO load → 25-50 mg PO q6h × 48 h (only at < 32 wk; ductus closure risk after). VAGINAL PROGESTERONE 200 mg PV nightly from diagnosis (CL < 25 mm at 18-24 wk singleton no prior PTB) through 36+6 wk per Hassan 2011 + Romero 2017. CERCLAGE REMOVAL elective at 36-37 wk antepartum to allow vaginal delivery; emergent for PTL refractory tocolysis (avoids cervical laceration) / chorio confirmed (mandatory) / PPROM (usually within 24-48 h) / significant vaginal bleeding (case-by-case). TRANSABDOMINAL CERCLAGE for failed transvaginal cerclage OR anatomically short / scarred cervix (laparoscopic or laparotomy; pre-conception or first-trimester placement; mandates cesarean delivery; left in situ for future pregnancies). PESSARY alternative in select cases where cerclage declined or contraindicated (CIPRACT + ProTwin + OPPTIMUM mixed evidence; not first-line).
    inputs: gestational_age_weeks, transvaginal_cervical_length_ultrasound
    advance: Cerclage placed (or vaginal progesterone started, or pessary placed) per indication-tier plan; pre-procedural antibiotics + tocolysis given for rescue cases; informed consent documented
  10. 10DISPOSITION
    Outpatient antepartum MFM follow-up for history-indicated cerclage (post-op observation 1-2 days). Inpatient L&D admission for rescue cerclage + 24-48 h observation. Outpatient for asymptomatic short cervix on vaginal progesterone (serial TVUS q1-2 wk). Tertiary transfer if rescue cerclage needed and current facility lacks MFM / OR. ICU rarely required (only if rescue cerclage complicated by maternal sepsis from chorio overlay OR severe hemorrhage OR anesthesia complications).
    inputs: gestational_age_weeks
    advance: Disposition determined; post-procedural monitoring plan in place; outpatient follow-up arranged
  11. 11MONITORING
    Post-cerclage observation: maternal vitals q4 h × 24 h (more frequent if rescue / indomethacin tocolysis); maternal temperature q4 h (chorio surveillance); fetal HR confirmation post-procedure. Serial TVUS cervical length q1-2 wk during expectant management. Antepartum surveillance: daily fetal kick counts after 24 wk; NST / BPP per MFM protocol from 28-32 wk in high-risk; weekly amniotic fluid index. Symptom monitoring: contractions (PTL emergence), fever (chorio), bleeding (abruption), rupture of membranes (PPROM). At 36-37 wk: elective cerclage removal antepartum to allow vaginal delivery.
    inputs: maternal_temperature, maternal_hr, transvaginal_cervical_length_ultrasound
    actions: panel.cbc
    advance: Maternal-fetal status stable; cerclage in place (or progesterone ongoing); 36-37 wk reached for elective removal OR earlier emergent removal indication arisen
  12. 12FOLLOWUP
    6-week postpartum visit + CI-specific anticipatory guidance: recurrence ~ 15-30 % in subsequent pregnancy; preconception MFM consult for next pregnancy planning (cerclage indication review; uterine-anomaly workup with 3D US / saline-infusion sonohysterogram if recurrent loss despite cerclage; connective-tissue / autoimmune review). Mental health screen (EPDS for postpartum depression; PCL-5 for peripartum PTSD especially after mid-trimester loss or extreme preterm). Contraception counseling + interpregnancy interval ≥ 18 mo. Immunization audit (Tdap, flu, COVID per ACIP). Newborn outpatient peds follow-up if delivery occurred preterm.
    advance: Postpartum visit complete; preconception MFM counseling delivered; mental health + immunization + newborn follow-up arranged