Dr. Chapa’s OBGYN Clinical Pearls

Episode: TOLAC, PIT, and Internals: The Latest

Host: Dr. Chapa
Date: January 8, 2026

Episode Overview

This energized and evidence-focused episode dives into the latest developments in the management of Trial of Labor After Cesarean (TOLAC), specifically examining two essential questions for contemporary obstetric practice:

• What is the newest evidence on Pitocin (oxytocin) dosing during TOLAC and its relationship to uterine rupture risk?
• Are internal monitors superior to external monitors in detecting early signs of uterine rupture during TOLAC?

Dr. Chapa, bringing his signature engaging and approachable tone, blends clinical pearls, guideline updates, and practical wisdom, referencing a brand-new systematic review from the “Pink Journal” (AJOG MFM, January 2026) as well as recent ACOG bulletins.

Key Discussion Points & Clinical Insights

1. Setting the Stage: TOLAC, Risk & Clinical Context

• TOLAC Eligibility: Per ACOG, patients with one or two prior low transverse C-sections may be offered TOLAC after shared decision-making, as the absolute risk of uterine rupture remains low but increases with the number of prior C-sections.
  • "ACOG says after one and reasonable up to two...if the patient understands the risk, understands what's at stake, and is willing to take that risk." (05:05)
• Risk Numbers: Uterine rupture risk is about 0.5–0.9% after one C-section, and roughly doubles after two (up to ~1.8%), but some studies report up to 3.5% (selection bias acknowledged).

2. The Latest Evidence: Pink Journal Systematic Review on Oxytocin & TOLAC

Main findings from the January 2026 meta-analysis:

• Oxytocin (Pitocin) Use During TOLAC:

  • Consistently associated with an increased risk of uterine rupture compared to spontaneous labor. Odds ratio ≈ 1.94 (CI 1.36–2.77).
    • "Oxytocin used during TOLAC is consistently associated with a significantly higher risk of uterine rupture across all analyses." (12:43)
  • Still, the absolute risk remains low, and oxytocin use is not contraindicated.

• Dose-Related Risk:

  • Higher dosing protocols (>20 milliunits/minute) are associated with greater rupture risk.
    • "Is it better to use a lower dose of oxytocin or a higher dose? ... Higher dose protocols, especially going over 20 milliunits per minute, may enhance the risk of rupture." (13:46)

• Interval & Escalation Matters:

  • Increasing the oxytocin dose at intervals shorter than every 30 minutes also raises risk.
    • "When dose escalation was at less than 30 minutes, a higher risk of uterine rupture was uniformly observed." (15:55)

• Cumulative (Total) Exposure:

  • Prolonged exposure to oxytocin, regardless of individual dose increments, further adds to risk. Consider stopping Pitocin once active labor is achieved (e.g., ≥6–7 cm), as some patients will continue progressing without it.
    • "Cumulative exposure of oxytocin, rather than just the initial or incremental dose... may also contribute." (17:40)

• Clinical Pearl: Use oxytocin judiciously—lowest effective dose, slow escalation, shortest necessary duration.

3. Real-World Application & Shared Decision-Making

• Pitocin is acceptable in TOLAC, with clear documentation and informed patient consent:

  • "Pitocin and TOLAC is not contraindicated... The catch is understand that Pitocin in a TOLAC does increase the risk of rupture, even though it's manageable." (20:42)

• Shared decision-making is vital. When a labor stalls, the risks and options (continue TOLAC with Pitocin versus repeat C-section) should be discussed transparently.

  • Memorable quote:
    "You gotta do something. So if she's just sitting there... you have to have the bedside conversation of, are you okay with getting Pitocin? How bad you want to do the vaginal delivery?" (21:18)

4. Pitocin Protocols: Historical Perspectives and Modern Updates

• Traditional high-dose protocols (e.g., Parkland: 6 milliunits every 30 minutes to 42) increase hyperstimulation—should be avoided in TOLAC.

  • "These are the patients you probably don't want to do the Pitocin Parkland Protocol, because higher duration, higher total exposure, and especially intervals that are less than 30 minutes tend to increase uterine rupture risk." (22:39)

• Protocols should now focus on slow titration and careful monitoring, limiting escalation and duration.

5. Internal vs. External Monitoring in TOLAC

Does internal monitoring (FSE, IUPC) improve detection of uterine rupture?

• Current Guidelines:

  • Continuous fetal monitoring is required for all TOLAC patients, but internal monitors are NOT superior to external monitors for detecting uterine rupture unless there are specific indications (e.g., poor external signal, high BMI, amnioinfusion need).

    • "Internal fetal monitors are not routinely recommended or proven superior to external monitors just because she is TOLACing." (27:25)

  • The most sensitive sign of uterine rupture is a sudden fetal heart rate deceleration or bradycardia (seen in 70–80% of ruptures), not changes in intrauterine pressure via IUPC.

    • "The biggest indication of rupture is not the drop in intrauterine pressure... It is a drop in the fetal heart rate tracing." (28:53)

  • Memorable quote:

    • “So, are internals required for TOLAC? No... just because it is a TOLAC.” (31:29)

When are Internals Indicated?

• Poor signal quality with externals (e.g., maternal movement, obesity)
• Need for intrauterine intervention (e.g., amnioinfusion)
• Not justified solely based on TOLAC status.
  • "If your idea is, I need the AROM to put internals because it's safer for TOLAC, if that's your reasoning, that's not evidence based, nor is that college guidance." (27:27)

Intermittent Auscultation:

• TOLAC does NOT qualify for intermittent monitoring; requires continuous monitoring due to higher risk profile.

Notable Quotes & Moments

• British Humor & Monty Python in Medicine:
  Dr. Chapa uses a Monty Python “Meaning of Life” birth sketch to highlight the complexity and absurdity sometimes present in OB, drawing a laugh and setting his conversational tone.

  • "You either get British humor or you don't. And I'm kind of in the middle... But it does highlight the complexity of birth." (01:32)

• On OB Protocols:

  • “How do you monitor labor and delivery? Very carefully. That's my professional physician dad joke.” (25:35)

• Guideline Emphasis:

  • “No major obstetrical organizations... have published evidence demonstrating that internal monitors improves detection of uterine rupture during TOLAC.” (31:05)

Timestamps for Key Segments

• [05:05] – Who can TOLAC? Reviewing ACOG guidance and rupture data.
• [12:43] – Pink Journal meta-analysis: Pitocin and uterine rupture risk.
• [13:46] – Dose and escalation protocols: What the data shows.
• [15:55] – Importance of dosing intervals (>30 minutes).
• [17:40] – Total oxytocin exposure: Rationale for reducing/turning off after active phase.
• [20:42] – Clinical implications: Pitocin in TOLAC is allowed, informed consent is vital.
• [22:39] – Parkland protocol and why to avoid high-dose regimens in TOLAC.
• [25:35] – Continuous fetal monitoring: Dad joke and clinical nuance.
• [27:25] – Why internals are not mandatory for TOLAC.
• [28:53] – What’s actually the best indicator of uterine rupture? (Fetal heart rate dropping).
• [31:05] – No evidence for internal monitoring superiority in TOLAC.

Take-Home Pearls

• Pitocin in TOLAC: Not contraindicated, but risk of uterine rupture increases modestly. Use the lowest effective dose, with slow escalation, and shortest possible duration.
• Monitoring: Continuous fetal monitoring is a must for TOLAC. Internal monitors (IUPC, spiral electrode) should only be used for standard indications (not routinely for TOLAC).
• Detecting Uterine Rupture: Sudden fetal heart rate changes are the most sensitive and immediate indicators, not pressure readings.
• Shared Decision-Making: Always involve the patient in discussions about labor management choices, risks, and benefits—with careful documentation.
• Stay Current: Pink Journal (AJOG MFM, Jan 2026) and ACOG Practice Bulletins 184 & CPG 10 are key resources for evidenced-based OB care.

“As always, podcast family, we're thankful for you… I think I've done what I'm supposed to do. I'm going to try to simmer my brain down, simmer down, take a nap, because I got to go back in a few hours.” (32:42)
— Dr. Chapa

For more updates and practical insights, stay tuned for the next episode of Dr. Chapa’s OBGYN Clinical Pearls – the No Spin Podcast!