Reproductive history combining late first full-term pregnancy (age ≥30) OR nulliparity, A...

Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.

ID	`RF-REPRODUCTIVE-LATE-FIRST-PREGNANCY-PREVENTION`
Type	Red flag
Status	reviewed 2026-05-18 \| pending_clinical_signoff
Diseases	`DIS-BREAST`
Sources	`SRC-NCCN-BCELL-2025` `SRC-NCCN-BREAST-2025`

Red Flag Origin

Definition	Reproductive history combining late first full-term pregnancy (age ≥30) OR nulliparity, AND short cumulative lifetime breastfeeding duration (<6 months total). Both factors independently confer modest increases in hormone-receptor-positive breast cancer risk (RR ~1.2-1.4 each) per Collaborative Group on Hormonal Factors in Breast Cancer + WCRF/AICR. Breastfeeding is protective in dose- dependent fashion (~4% breast cancer risk reduction per 12 months of cumulative breastfeeding). Mechanism: cumulative ovulatory cycles + unopposed estrogen exposure + delayed terminal differentiation of breast ductal epithelium. Effect cumulative with other reproductive factors (early menarche, late menopause, nulliparity, HRT). Prevention-persona RedFlag (§20 v0.3 reproductive pilot).
Clinical direction	investigate
Category	other

Trigger Logic

{
  "any_of": [
    {
      "finding": "nulliparous_or_first_pregnancy_age_ge_30",
      "value": true
    },
    {
      "finding": "cumulative_breastfeeding_lt_6_months",
      "value": true
    },
    {
      "finding": "combined_late_pregnancy_short_breastfeeding",
      "value": true
    }
  ],
  "type": "lab_value"
}

Notes

Prevention-persona RedFlag for late-first-pregnancy + short-breastfeeding combination. Modest individual effect sizes; cumulative effect non-trivial. Cannot retroactively modify primary trigger (timing of reproductive events) — counseling is forward-looking (encourage breastfeeding when feasible in subsequent pregnancies) + tightened breast cancer screening. STUB pending two-Clinical-Co-Lead signoff per CHARTER §6.1 dev-mode.

Used By

Indications

IND-REPRODUCTIVE-LATE-FIRST-PREGNANCY-PREVENTION-COUNSELING - IND-REPRODUCTIVE-LATE-FIRST-PREGNANCY-PREVENTION-COUNSELING
IND-REPRODUCTIVE-LATE-FIRST-PREGNANCY-PREVENTION-OBSERVATION - IND-REPRODUCTIVE-LATE-FIRST-PREGNANCY-PREVENTION-OBSERVATION