Dr. Chapa’s OBGYN Clinical Pearls

The ENG implant has data placing it as the most reversible, hormonal contraceptive agent available with a typical use failure rate of 0.05%. Unfavorable bleeding patterns, such as frequent or prolonged bleeding, affect approximately 40% of ENG implant users within the first 3 months but typically improve over time. Nonetheless, it is the main reason for patient discontinuation. In the past, various medications have shown to have at least some short-term reduction in bothersome breakthrough bleeding (BTB). These include doxycycline, ethinyl estradiol (EE), mefenamic acid, combined oral contraceptives (COCs), short term tamoxifen, norethindrone, and ulipristal acetate. In this episode, we will summarize a new RCT (AJOG, released as epub on Jan 7, 2026) which describes the use of TXA for ENG related BTB. Did it work? Listen in for details.1. Andrade, Maíra Cristina Ribeiro et al. Norethisterone for prolonged uterine bleeding associated with etonogestrel implant (IMPLANET): a randomized controlled trialAmerican Journal of Obstetrics & Gynecology, Volume 234, Issue 1, 101 - 1152. Edelman, Alison et al. Treatment of unfavorable bleeding patterns in contraceptive implant users with tranexamic acid: randomized clinical trial. American Journal of Obstetrics & Gynecology, Volume 0, Issue (Articles in Press January 07, 2026)

It’s a controversial topic: the impact of uterine incision (hysterectomy) on the neonate delivery interval (also called the U-D interval). Does it matter? Just to be clear, we’re talking about time from uterine entry to fetal extraction, not skin incision to fetal extraction. Past publications have produced conflicting results, often limited by small sample sizes, heterogeneous indications for delivery, and reliance on surrogate markers (like apgar scores) rather than clinical morbidity. But a new study published in the Gray journal at the end of 2025 (December 30, 2025) gives some new insights. In this episode, we will review this retrospective study and play the “Devil’s advocate” as we summarize the rebuttal data. As the reports are conflicting, we will end the podcast with a real-world interpretation and application of this data. Listen in for details. 1. Bart, Yossi et al. Uterine Incision-to-Delivery Interval and Neonatal Outcomes among Non-urgent, Term, Cesarean Deliveries. American Journal of Obstetrics & Gynecology, Volume 0, Issue 0. https://www.ajog.org/article/S0002-9378(25)00980-9/fulltext?rss=yes2. Maayan-Metzger A, Schushan-Eisen I, Todris L, Etchin A, Kuint J. The effect of time intervals on neonatal outcome in elective cesarean delivery at term under regional anesthesia. Int J Gynaecol Obstet. 2010 Dec;111(3):224-8. doi: 10.1016/j.ijgo.2010.07.022. Epub 2010 Sep 19. PMID: 20855070. https://pubmed.ncbi.nlm.nih.gov/20855070/3. Spain JE, Tuuli M, Stout MJ, Roehl KA, Odibo AO, Macones GA, Cahill AG. Time from uterine incision to delivery and hypoxic neonatal outcomes. Am J Perinatol. 2015 Apr;32(5):497-502. doi: 10.1055/s-0034-1396696. Epub 2014 Dec 24. PMID: 25539409.4. Bader AM, Datta S, Arthur GR, Benvenuti E, Courtney M, Hauch M. Maternal and fetal catecholamines and uterine incision-to-delivery interval during elective cesarean. Obstet Gynecol. 1990 Apr;75(4):600-3. PMID: 2107478.5. Tekin, E., Inal, H.A. & Isenlik, B.S. A Comparison of the Effect of Time from Uterine Incision to Delivery on Neonatal Outcomes in Women with One Previous and Repeat (Two or More) Cesarean Sections. SN Compr. Clin. Med. 5, 80 (2023). https://doi.org/10.1007/s42399-023-01427-x

In January 2026, the ACOG released its Practice Advisory on Screening for fetal Chromosomal Abnormalities. This comes after its Nov 2025 endorsement of the SMFM’s Consult Series #74, “Cell-free DNA screening for aneuploidies: Updated guidance”. In this episode we will review the key parts of this PA. Is screening for microdeletions recommended? PLUS, we will focus on cfDNA for sex chromosomal abnormalities. Should screening for sex chromosomal abnormalities (SCAs) be an “opt in” or “opt out” process for patients? What are nest steps after an abnormal SCA screening result? Are commercial tests available for fetal gender recommended? Listen in for details. 1. ACOG PA Jan 2026: https://www.acog.org/clinical/clinical-guidance/practice-advisory/articles/2026/01/screening-for-fetal-chromosomal-abnormalities?utm_source=higher-logic&utm_medium=email&utm_content=Jan-07&utm_campaign=acog2026-digest2. Society for Maternal-Fetal Medicine Consult Series #74: Cell-free DNA screening for aneuploidies: Updated guidance1 in November 2025.

Uterine rupture or dehiscence associated with TOLAC results in the most significant increase in the likelihood of additional maternal and neonatal morbidity. It should be noted that the terms “uterine rupture” and “uterine dehiscence” are not consistently distinguished from each other in the literature and often are used interchangeably. Furthermore, the reported incidence of uterine rupture varies in part because some studies have grouped true, catastrophic uterine rupture together with asymptomatic scar dehiscence. In January 2026, a new meta-analysis examines the relationship between oxytocin use with TOLAC and uterine rupture. In this episode, we will summarize the key findings in that study and review the data on the use of internal monitors during TOLAC. Do internal monitors (FSE, IUPC) offer a safer TOLAC compared with external monitors? Listen in for details.1. Nicolì, Pierpaolo et al.Oxytocin dosing during trial of labor after cesarean to minimize the risk of uterine rupture: a systematic review and meta-analysisAmerican Journal of Obstetrics & Gynecology MFM, Volume 8, Issue 1, 1018462. Practice Bulletin No. 184: Vaginal Birth After Cesarean Delivery. Obstetrics & Gynecology 130(5):p e217-e233, November 2017. | DOI: 10.1097/AOG.00000000000023983. ACOG Clinical Practice Guideline No. 10:Intrapartum Fetal Heart Rate Monitoring: Interpretation and Management. Obstetrics & Gynecology 146(4):p 583-599, October 2025. | DOI: 10.1097/AOG.00000000000060494. Bruno AM, Allshouse AA, Metz TD. Maximum Oxytocin Dose and Uterine Rupture During Trial of Labor After Cesarean. Obstet Gynecol. 2025 Dec 1;146(6):843-850. doi: 10.1097/AOG.0000000000006106. Epub 2025 Oct 30. PMID: 41325062.

Currently, as of today’s date, neither the ACOG nor SMFM currently support routine early induction of labor for suspected fetal macrosomia, instead recommending individualized counseling and reserving elective cesarean for extreme estimated fetal weights. However, a 2025 multicenter, open-label, randomized controlled trial was published in the Lancet comparing induction of labor versus standard care in pregnant women with fetuses suspected to be large for gestational age. The study used a parallel-group design with 1:1 randomization, enrolling women from 106 NHS hospitals across England, Scotland, and Wales. The per-protocol analysis demonstrated a significant reduction (40%) in shoulder dystocia with induction of labor at 38- 38 weeks and 4 days. Is this in conflict with the ACOG current guidance? In this episode, we will review the “Big Baby study” from the Lancet and provide 3 main limitations of this very large study, review the importance of PP vs ITT results, and explain why more data is still needed. Listen in for details. 1. ACOG PB 178; 2017 (reaffirmed 2024)2. Gardosi J, Ewington LJ, Booth K, Bick D, Bouliotis G, Butler E, Deshpande S, Ellson H, Fisher J, Gornall A, Lall R, Mistry H, Naghdi S, Petrou S, Slowther AM, Wood S, Underwood M, Quenby S. Induction of labour versus standard care to prevent shoulder dystocia in fetuses suspected to be large for gestational age in the UK (the Big Baby trial): a multicentre, open-label, randomised controlled trial. Lancet. 2025 May 17;405(10491):1743-1756. doi: 10.1016/S0140-6736(25)00162-X. Epub 2025 May 1. PMID: 40319899.3. Blaauwgeers, Anne N et al. Rethinking induction of labour for LGA fetuses: the Big Baby trial. The Lancet, Volume 406, Issue 10512, 1562