38–39wk
Normal Doppler
EFW 3rd–10th percentile, or severe FGR below 3rd percentile with no absent/reversed flow: 37 0/7–39 0/7 weeks.
OpenMFM Clinical Reference
SMFM / ACOG
Delivery Timing Master Table
Evidence-based gestational-age windows for delivery across twelve major maternal, fetal, and placental conditions — a quick-reference tool for physicians, residents, and advanced practice providers.
ACOG & SMFM sourced12 clinical categoriesPhysician & APP education
Atlanta Perinatal AssociatesMaternal-Fetal Medicine
Before you use this table
These windows assume a stable, reliably dated pregnancy — read the assumptions first
- Reliable pregnancy dating
- Stable maternal condition
- Reassuring fetal surveillance
- No labor and intact membranes
- No significant vaginal bleeding
- No separate indication for earlier delivery
!
Maternal or fetal deterioration supersedes routine gestational-age recommendations at every point in this table.
i
Gestational ages are expressed as completed weeks and days — e.g., 37 0/7 weeks = 37 weeks 0 days; 37 6/7 weeks = 37 weeks 6 days. Timing does not determine mode of delivery; that requires separate assessment.
Atlanta Perinatal Associates2 / 19
1. Hypertensive disorders — routine timing
Preeclampsia and gestational hypertension without severe features: deliver at 37 weeks
| Condition | Clinical status | Recommended delivery |
|---|---|---|
| Gestational hypertension | No severe features | 37 0/7 weeks |
| Preeclampsia | No severe features | 37 0/7 weeks |
| Superimposed preeclampsia | Without severe features | 37 0/7 weeks |
| Chronic hypertension | Not requiring medication | 38 0/7–39 6/7 weeks |
| Chronic hypertension | Controlled with medication | 37 0/7–39 6/7 weeks |
| Chronic hypertension | Difficult to control | 36 0/7–37 6/7 weeks, individualized |
Primary source: ACOG Practice Bulletin No. 222; ACOG Committee Opinion No. 831.
Atlanta Perinatal Associates3 / 19
1. Hypertensive disorders — severe disease
Severe features, eclampsia, and HELLP: deliver after stabilization, not on a fixed date
| Condition | Status | Recommended delivery |
|---|---|---|
| Preeclampsia with severe features | At or beyond 34 0/7 weeks | Delivery after maternal stabilization |
| Preeclampsia with severe features | Before 34 0/7 weeks, stable | Selected inpatient expectant management may be considered |
| Eclampsia | Any viable gestational age | Delivery after stabilization |
| HELLP syndrome | Any viable gestational age | Delivery after stabilization |
| Gestational hypertension | Severe-range blood pressure | Manage as preeclampsia with severe features |
!
Deliver earlier for: uncontrolled severe hypertension, eclampsia, pulmonary edema, stroke, MI, HELLP, progressive renal dysfunction, refractory headache or visual symptoms, RUQ/epigastric pain, abruption, or nonreassuring fetal status.
!
An indicated delivery at or beyond 34 weeks for severe features should not be delayed solely to complete antenatal corticosteroids.
Primary source: ACOG Practice Bulletin No. 222; ACOG Committee Opinion No. 831.
Atlanta Perinatal Associates4 / 19
2. Diabetes in pregnancy
Delivery windows track glycemic control and vascular risk, not diagnosis alone
| Condition | Glycemic status | Recommended delivery |
|---|---|---|
| GDM, A1GDM | Diet controlled | 39 0/7–40 6/7 weeks |
| GDM, A2GDM | Well controlled with medication | 39 0/7–39 6/7 weeks |
| GDM | Poorly controlled | Individualize; commonly 37 0/7–38 6/7 weeks |
| Pregestational T1/T2 diabetes | Well controlled, no vascular disease | 39 0/7–39 6/7 weeks |
| Pregestational diabetes | Poor control, vascular disease, or prior stillbirth | 36 0/7–38 6/7 weeks, individualized |
i
Suspected macrosomia alone does not automatically establish an indication for delivery before 39 weeks.
Primary sources: ACOG Practice Bulletins on Gestational and Pregestational Diabetes Mellitus; ACOG Committee Opinion No. 831.
Atlanta Perinatal Associates5 / 19
3. Fetal growth restriction
Delivery timing tracks umbilical-artery Doppler severity
37wk
Decreased diastolic flow
Reduced but not absent or reversed umbilical-artery flow.
33–34wk
AEDV
Absent end-diastolic velocity.
30–32wk
REDV
Reversed end-diastolic velocity.
i
SMFM does not recommend routine MCA, ductus venosus, or uterine-artery Doppler for otherwise uncomplicated FGR. Timing also integrates interval growth, fetal testing, amniotic fluid, and associated anomalies.
Primary source: SMFM Consult Series No. 52; ACOG Practice Bulletin No. 227.
Atlanta Perinatal Associates6 / 19
4. Amniotic-fluid disorders
Isolated oligohydramnios: deliver by term; polyhydramnios rarely justifies early delivery
| Condition | Status | Recommended delivery |
|---|---|---|
| Isolated oligohydramnios | Otherwise uncomplicated | 36 0/7–37 6/7 weeks, or at diagnosis if later |
| Mild idiopathic polyhydramnios | Otherwise uncomplicated | Allow spontaneous labor at term; avoid planned delivery before 39 0/7 weeks without another indication |
| Moderate–severe polyhydramnios | Stable | Individualize by etiology, fetal condition, symptoms, surveillance |
!
Deliver earlier for: abnormal surveillance, ROM, labor, significant maternal respiratory symptoms, cord prolapse, abruption, or an anomaly requiring coordinated delivery.
Primary sources: ACOG Committee Opinion No. 831; SMFM Consult Series on polyhydramnios.
Atlanta Perinatal Associates7 / 19
5. Multiple gestation
Chorionicity — not simply twinning — drives the delivery window
| Pregnancy type | Recommended delivery |
|---|---|
| Dichorionic diamniotic twins | 38 0/7–38 6/7 weeks |
| Monochorionic diamniotic twins | 36 0/7–37 0/7 weeks |
| Monochorionic monoamniotic twins | 32 0/7–34 0/7 weeks, planned cesarean |
| Trichorionic triamniotic triplets, uncomplicated | Commonly planned during the 35th week |
| Other triplet / higher-order gestations | Individualize with MFM input |
i
These windows apply to uncomplicated pregnancies. Deliver earlier for TTTS, TAPS, selective FGR, abnormal Doppler, discordant growth with compromise, preeclampsia, preterm labor, ROM, abnormal surveillance, or fetal demise. Complicated monochorionic gestations require condition-specific planning.
Primary sources: ACOG Practice Bulletin No. 231; SMFM 2026 Updated Checklists for Management of Monochorionic Twin Pregnancy; ACOG Committee Opinion No. 831.
Atlanta Perinatal Associates8 / 19
6. Intrahepatic cholestasis of pregnancy
Peak bile acids — not symptoms alone — set the delivery window
| Peak total bile acids | Recommended delivery |
|---|---|
| ≥ 100 µmol/L | 36 0/7 weeks |
| < 100 µmol/L | 36 0/7–39 0/7 weeks |
| Clinical symptoms without lab confirmation | Do not deliver before 37 weeks solely for suspected ICP |
i
Within the 36–39-week window below 100 µmol/L, individualize using peak bile-acid concentration, severity/persistence of pruritus, prior ICP-associated stillbirth, coexisting preeclampsia or diabetes, fetal surveillance, and shared decision-making.
!
SMFM recommends antenatal corticosteroids when delivery before 37 0/7 weeks is planned and a prior course has not been given.
Primary source: SMFM Consult Series No. 53, endorsed by ACOG.
Atlanta Perinatal Associates9 / 19
7. Placental and fetal-vessel disorders
Placenta previa, accreta spectrum, and vasa previa each have distinct windows
| Condition | Stable status | Recommended delivery |
|---|---|---|
| Placenta previa | No active bleeding/complication | 36 0/7–37 6/7 weeks |
| Placenta accreta spectrum | Planned cesarean or cesarean hysterectomy | 34 0/7–35 6/7 weeks |
| Vasa previa | Prenatally diagnosed, stable | Planned cesarean, 34 0/7–37 0/7 weeks |
| Chronic placental abruption | Stable maternal/fetal status | Individualize; no single universal recommendation |
| Acute placental abruption | Maternal or fetal compromise | Immediate delivery as indicated |
!
With known vasa previa, labor or rupture of membranes generally requires urgent cesarean delivery, regardless of gestational age.
Primary sources: ACOG–SMFM Obstetric Care Consensus No. 7; SMFM Consult Series No. 37; ACOG Committee Opinion No. 831.
Atlanta Perinatal Associates10 / 19
8. Prelabor rupture of membranes
Term PROM: deliver. PPROM: expectant management, with a 37-week ceiling
| Membrane status | Gestational age | Recommended approach |
|---|---|---|
| Term PROM | ≥ 37 0/7 weeks | Recommend delivery |
| PPROM | 24 0/7–33 6/7 weeks | Expectant inpatient management if no contraindication |
| Late-preterm PPROM | 34 0/7–36 6/7 weeks | Delivery or expectant management after counseling; do not continue beyond 37 0/7 weeks |
| Previable/periviable PPROM | Before resuscitation threshold | Individualized counseling and management |
!
Contraindications to expectant management: intraamniotic infection, abruption, nonreassuring fetal status, advanced labor, cord prolapse, significant hemorrhage, or maternal instability.
i
Management should also address latency antibiotics, antenatal corticosteroids, magnesium sulfate for neuroprotection when indicated, and GBS prophylaxis.
Primary source: ACOG Practice Bulletin No. 217.
Atlanta Perinatal Associates11 / 19
9. Prior uterine surgery
Prior classical incisions and myomectomy both call for planned early-term delivery
| Uterine history | Recommended delivery |
|---|---|
| Prior classical cesarean incision | 36 0/7–37 0/7 weeks |
| Prior T-shaped uterine incision | 36 0/7–37 0/7 weeks |
| Prior uterine rupture | 36 0/7–37 0/7 weeks, individualized |
| Prior myomectomy requiring cesarean delivery | 37 0/7–38 6/7 weeks |
| Prior low-transverse cesarean, no contraindication to labor | Usual obstetric indications and TOLAC plan |
i
Myomectomy timing depends on whether the endometrial cavity was entered, fibroid number/size/location, surgical approach, extent of myometrial dissection, the operative report, surgeon's recommendation, and prior pregnancy outcomes. More extensive surgery favors delivery closer to 37 weeks; less extensive surgery may permit delivery closer to 38 6/7 weeks.
Primary source: ACOG Committee Opinion No. 831; ACOG Practice Bulletin on Vaginal Birth After Cesarean Delivery.
Atlanta Perinatal Associates12 / 19
10. Fetal anemia and alloimmunization
Stable at-risk fetuses deliver near 37–38 weeks; hydrops changes the calculus
| Clinical status | Recommended delivery |
|---|---|
| Significant anemia risk, stable | 37 0/7–38 0/7 weeks |
| Pregnancy following intrauterine transfusion | Individualize by timing of final transfusion, fetal condition, center protocol |
| Hydrops or severe fetal anemia | Fetal therapy or delivery based on gestational age and comparative procedural risk |
!
Deliver earlier for: hydrops, MCA peak systolic velocity suggesting severe anemia, abnormal surveillance, or inability to safely continue fetal therapy.
Primary source: SMFM Clinical Guideline No. 8, reaffirmed 2025.
Atlanta Perinatal Associates13 / 19
11. Advanced maternal age
Age ≥ 40 alone supports delivery at 39 weeks — younger age does not change routine timing
| Maternal age at anticipated delivery | Recommended approach |
|---|---|
| 35–39 years, no other complication | Routine obstetric timing; age alone does not mandate early-term delivery |
| ≥ 40 years | 39 0/7–39 6/7 weeks in a well-dated pregnancy |
i
Earlier delivery should be based on an additional maternal, fetal, or obstetric indication — not chronological age alone.
Primary source: ACOG–SMFM Obstetric Care Consensus: Pregnancy at Age 35 Years or Older.
Atlanta Perinatal Associates14 / 19
12. Conditions requiring individualized timing
No universal window exists for these conditions — multidisciplinary planning is the standard
Maternal cardiac disease
Lesion, ventricular function, symptoms, anticoagulation, hemodynamic risk
Chronic kidney disease
Renal function, hypertension, proteinuria, fetal growth
Lupus (SLE)
Disease activity, nephritis, hypertension, fetal condition
Antiphospholipid syndrome
Thrombosis history, anticoagulation, placental dysfunction
Pulmonary hypertension
Maternal hemodynamics, tertiary-care planning
Major fetal anomaly
Prognosis, need for neonatal surgery, center capability
Hydrops fetalis
Etiology, fetal therapy options, surveillance
Prior stillbirth
Etiology, recurrence risk, neonatal risk of early delivery
i
Also individualized: chronic placental abruption, severe polyhydramnios, IVF pregnancy, and extreme obesity. This table does not substitute for MFM consultation, relevant subspecialty consultation, anesthesia and neonatology planning, or institutional protocol.
Atlanta Perinatal Associates15 / 19
General delivery principles
Four rules apply across every condition in this table
Deterioration overrides the table
Eclampsia, stroke, pulmonary edema, uncontrolled severe hypertension, hemorrhage, abruption, intraamniotic infection, cord prolapse, persistent Category III tracing, abnormal surveillance, or fetal death all supersede routine timing.
Corticosteroids and magnesium sulfate
Give antenatal corticosteroids when delivery is expected within the recommended interval — but never delay an indicated delivery solely to complete the course. Give magnesium sulfate for maternal seizure prophylaxis or fetal neuroprotection when indicated.
Timing is not mode of delivery
Gestational-age recommendations do not determine induction versus cesarean, TOLAC eligibility, operative-vaginal delivery, need for classical cesarean, or delivery location.
Avoid nonmedically indicated early delivery
Without a maternal, fetal, placental, or obstetric indication, avoid delivery before 39 0/7 weeks. Fetal lung-maturity testing should not be used to justify an otherwise nonmedically indicated early-term delivery.
Atlanta Perinatal Associates16 / 19
Clinical pearls
Ten things to remember about delivery-timing decisions
- Deterioration always overrides the table: eclampsia, stroke, abruption, and Category III tracings mandate delivery regardless of the "target" week.
- Preeclampsia without severe features: 37 weeks. With severe features at or beyond 34 weeks: deliver after stabilization, not on a fixed date.
- Don't delay an indicated ≥34-week delivery solely to complete a corticosteroid course.
- Diabetes windows run 36–40 weeks depending on control and vascular disease — suspected macrosomia alone is not an indication for early delivery.
- FGR timing tracks Doppler severity: AEDV at 33–34 weeks, REDV at 30–32 weeks. Routine MCA/DV/UtA Doppler is not recommended for uncomplicated FGR.
- Chorionicity drives twin timing: MCDA (36–37 weeks) delivers earlier than DCDA (38–38 6/7 weeks); MCMA by planned cesarean at 32–34 weeks.
- ICP timing hinges on peak bile acids: ≥100 µmol/L mandates 36 weeks; below that, individualize within a 36–39-week window.
- Vasa previa in labor or with ROM is a cesarean emergency regardless of gestational age.
- Avoid nonmedically indicated delivery before 39 0/7 weeks, and never use fetal lung-maturity testing to justify one.
- Delivery timing never determines delivery mode — TOLAC eligibility, operative delivery, and route require separate assessment.
Atlanta Perinatal Associates17 / 19
Evidence & controversies
What's established, what's individualized, and where guidance keeps evolving
Known
Delivery-timing windows for major conditions — preeclampsia, diabetes, staged FGR, twin chorionicity — are grounded in consistent, current ACOG/SMFM guidance.
Uncertain
Optimal timing within broad individualized windows (chronic hypertension 36–39 6/7 weeks; ICP below 100 µmol/L) where a single threshold does not fully predict risk.
Contested
How aggressively to expand routine Doppler surveillance — MCA, ductus venosus, uterine artery — beyond the umbilical artery in FGR management.
Research need
Long-term maternal and offspring outcomes tied to specific timing thresholds, particularly for conditions requiring individualized, multidisciplinary planning.
i
This is a living reference — version 1.0, guideline review July 2026, next scheduled review January 2027. Verify current guidance before applying to an individual patient.
Atlanta Perinatal Associates18 / 19
References
Abbreviations and selected references
| ACOG | American College of Obstetricians and Gynecologists | AEDV | Absent end-diastolic velocity |
| SMFM | Society for Maternal-Fetal Medicine | REDV | Reversed end-diastolic velocity |
| EFW | Estimated fetal weight | FGR | Fetal growth restriction |
| ICP | Intrahepatic cholestasis of pregnancy | PPROM | Preterm prelabor rupture of membranes |
- ACOG. Medically Indicated Late-Preterm and Early-Term Deliveries. Committee Opinion No. 831. 2021.
- ACOG. Gestational Hypertension and Preeclampsia. Practice Bulletin No. 222. 2020.
- ACOG. Prelabor Rupture of Membranes. Practice Bulletin No. 217.
- ACOG. Gestational Diabetes Mellitus. Practice Bulletin No. 190.
- ACOG. Pregestational Diabetes Mellitus. Practice Bulletin No. 201.
- ACOG. Fetal Growth Restriction. Practice Bulletin No. 227.
- ACOG. Multifetal Gestations: Twin, Triplet, and Higher-Order Multifetal Pregnancies. Practice Bulletin No. 231.
- ACOG and SMFM. Placenta Accreta Spectrum. Obstetric Care Consensus No. 7.
- ACOG and SMFM. Pregnancy at Age 35 Years or Older. Obstetric Care Consensus.
- SMFM. Diagnosis and Management of Fetal Growth Restriction. Consult Series No. 52. Reaffirmed 2024.
- SMFM. Intrahepatic Cholestasis of Pregnancy. Consult Series No. 53. Reaffirmed 2024, endorsed by ACOG.
- SMFM. Diagnosis and Management of Vasa Previa. Consult Series No. 37. Reaffirmed 2024.
- SMFM. The Fetus at Risk for Anemia: Diagnosis and Management. Clinical Guideline No. 8. Reaffirmed 2025.
- SMFM. Updated Checklists for Management of Monochorionic Twin Pregnancy. Special Statement. 2026.
Educational reference for physicians, residents, and advanced practice providers. Individualize according to maternal condition, fetal condition, dating accuracy, labor status, and institutional capability. Maternal or fetal deterioration supersedes routine gestational-age recommendations.
Atlanta Perinatal Associates19 / 19