Dr. Chapa’s OBGYN Clinical Pearls

Well podcast family, we are back with another installment of our “You ask, We answer” edition. We've got 2 fascinating and real-world clinical conundrums in this episode, both suggested by two separate podcast family members. The first has to do with RH IG maternal administration. Here's the question: If a patient receives routine, prophylactic RH IG at 28 weeks but then has maternal trauma say 1 or 2 weeks after, does she still require an additional dose of RH IG? That's a good question because it's not as intuitive as you would think. We will explain in this episode and there is a bit of a contradiction in the guidance. The second question has to do with finding an asymptomatic uterine rupture at cesarean section. Is there such a thing as a “partial” (silent) uterine rupture? There's recent data from 2025 about this. Listen in for details.

1. ACOG PB 181; 2017.
2. Baek S, Froese V, Morgenstern B. Risk Profiles and Outcomes of Uterine Rupture: A Retrospective and Comparative Single-Center Study of Complete and Partial Ruptures. J Clin Med. 2025 Jul 15;14(14):4987. doi: 10.3390/jcm14144987. PMID: 40725680; PMCID: PMC12295210.
3. Vandenberghe G, Bloemenkamp K, Berlage S, Colmorn L, Deneux-Tharaux C, Gissler M, Knight M, Langhoff-Roos J, Lindqvist PG, Oberaigner W, Van Roosmalen J, Zwart J, Roelens K; INOSS (the International Network of Obstetric Survey Systems). The International Network of Obstetric Survey Systems study of uterine rupture: a descriptive multi-country population-based study. BJOG. 2019 Feb;126(3):370-381. doi: 10.1111/1471-0528.15271. Epub 2018 Jun 12. PMID: 29727918.

Fetal Microcephaly has an incidence of 2 to 12 in10,000 births in the USA and can be diagnosed prenatally via ultrasound (in second or early third trimester) or postnatally via measurement of head circumference (HC).  Antepartum, this is a unique diagnosis since we are mainly used to using PERCENTAGES for biometrics and for fetal weight, butmicrocephaly is not diagnosed by HC percentage- but by Standard Deviation (SD). Microcephaly has been linked to developmental delay, seizures, as well as feeding, vision and hearing problems.  Prognosis depends on the severityof the microcephaly and whether it is associated with other anomalies. What SD is diagnostic of microcephaly? What are the potential etiologies? What genetic syndromes are most associated with true microcephaly? Is fetal cranial MRIrecommended? Listen in for details.

1.     Sukenik-Halevy R, Golbary Kinory E, Laron KenetT, Brabbing-Goldstein D, Gilboa Y, Basel-Salmon L, Perlman S. Prenatalgender-customized head circumference nomograms result in reclassification ofmicrocephaly and macrocephaly. AJOG Glob Rep. 2023 Jan 29;3(1):100171. doi:10.1016/j.xagr.2023.100171. PMID: 36864987; PMCID: PMC9972400.
2.     SOGC CO (2019) No. 380-Investigation andManagement of Prenatally Identified Microcephaly
3.     Fetal Medicine Foundation: Microcephaly; https://fetalmedicine.org/education/fetal-abnormalities/brain/microcephaly

Stress fractures are common injuries in athletes and military recruits, that’s’ understandable- based on the physical forces placed on the long bones. A stress fracture can be defined as a partial or complete fracture of the bone that is a result from repeated application of stress lower than that required to fracture the bone in a single loading situation. In pregnancy, the body is subjected to various physiological changes that make women more vulnerable. In this pregnancy, we will highlight a REAL patient case which our team cared for on the inpatient service where a simple cough at 34 weeks leads to a painful spontaneous rib fracture! Is there any data published on this? Are serum tests for bone turn-over required as part of this workup? Listen in for clinical pearls!
1. 1962: Long A.E.: “Stress fracture of the ribs associated with pregnancy”. Surg. Clin. North Am., 1962, 42, 909.
2. 2000: Baitner AC, Bernstein AD, Jazrawi AJ, Della Valle CJ, Jazrawi LM. Spontaneous rib fracture during pregnancy. A case report and review of the literature. Bull Hosp Jt Dis. 2000;59(3):163-5. PMID: 11126720. https://pubmed.ncbi.nlm.nih.gov/11126720/
3. 2015: Rib stress fractures in pregnancy: a case report and review of literature. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/file:///C:/Users/hchapa/Downloads/1575956493464-5157163%20(1).pdf
4. Zhang Y, Li R, Zhang J, Zhou W, Yu F. Changes in Serum Concentrations of Bone Turnover Markers in Healthy Pregnant Women. International Journal of Clinical Practice. 2023.

We have learned a lot about extended spectrum coverage of prophylactic antibiotics for cesarean section. The landmark C/SOAP trial randomized 2,013 women undergoing nonelective cesarean delivery to azithromycin 500 mg IV plus standard prophylaxis versus placebo, demonstrating a 51% reduction in the composite outcome of endometritis, wound infection, or other infection. Adjuvant Zmax (plus standard first-generation cephalosporin) is now recognized as evidence-based antibiotic coverage for intrapartum cesarean, cesarean with ruptured membranes, and patients with obesity. This last patient characteristic comes from the ERAS latest update. But what is ZMAX is not available? Is there an evidence-based peri-op alternative in these cases? Does Gent and Clinda cover mycoplasma/Ureaplasma? What about postop flagyl? Listen in for details.

1. Tita AT, Szychowski JM, Boggess K, et al. Adjunctive Azithromycin Prophylaxis for Cesarean Delivery. The New England Journal of Medicine. 2016. 2. Yang M, Yuan F, Guo Y, Wang S. Efficacy of Adding Azithromycin to Antibiotic Prophylaxis in Caesarean Delivery: A Meta-Analysis and Systematic Review. International Journal of Antimicrobial Agents. 2022.
2. ACOG Practice Bulletin No. 199: Use of Prophylactic Antibiotics in Labor and Delivery.
Obstetrics and Gynecology. 2018. Committee on Practice Bulletins-Obstetrics
3. Martingano D, Nguyen A, Nkeih C, Singh S, Mitrofanova A. Clarithromycin Use for Adjunct Surgical Prophylaxis Before Non-Elective Cesarean Deliveries to Adapt to Azithromycin Shortages in COVID-19 Pandemic. PloS One. 2020.
4. Valent AM, DeArmond C, Houston JM, et al. Effect of Post–Cesarean Delivery Oral Cephalexin and Metronidazole on Surgical Site Infection Among Obese Women: A Randomized Clinical Trial. The Journal of the American Medical Association. 2017.
5. Wood, G. E., et al. "In Vitro Susceptibility of Mycoplasma genitalium to Nitroimidazoles." Antimicrobial Agents and Chemotherapy
6. https://www.cdc.gov/std/treatment-guidelines/mycoplasmagenitalium.htm

We have covered the subject of whether to include the decidual (innermost) layer when closing the uterine incision during cesarean section (CS) on at least 2 episodes. The most recent was in September 2025, when we focused on a published (September 2025) systematic review and meta-analysis from the Green Journal. Back then, we compared those new findings to our prior episode from 2023 on the same matter. Well, we are back at it again with the same subject as there is a new EXPERT REVIEW from the AJOG on hysterotomy closure technique which just came out January 2026. What did these authors conclude? There are also some controversial suggestions made by the authors. Listen in for details.

1. Antoine C, Meyer JA, Silverstein J, Buldo-Licciardi J, Lyu C, Timor-Tritsch IE. Endometrium-Free Closure Technique During Cesarean Delivery for Reducing the Risk of Niche Formation and Placenta Accreta Spectrum Disorders. Obstet Gynecol. 2025 Jun 1;145(6):674-682. doi: 10.1097/AOG.0000000000005813. Epub 2025 Jan 9. PMID: 39787602.
2. Gialdini, Celina et al.Evidence-based surgical procedures to optimize caesarean outcomes: an overview of systematic reviews. eClinicalMedicine- Lancet (June 2024), Volume 72, 102632
3. Dahlke, Joshua D. MD; Mendez-Figueroa, Hector MD; Maggio, Lindsay MD, MPH; Sperling, Jeffrey D. MD, MS; Chauhan, Suneet P. MD, Hon DSc; Rouse, Dwight J. MD. The Case for Standardizing Cesarean Delivery Technique: Seeing the Forest for the Trees. Obstetrics & Gynecology 136(5):p 972-980, November 2020. | DOI: 10.1097/AOG.0000000000004120
4. Antoine C, Timor-Tritsch IE, Bujold E, Young BK, Reece EA. Endometrium-free closure technique for hysterotomy incision at cesarean delivery. Am J Obstet Gynecol. 2026 Jan;233(6S):S103-S114. doi: 10.1016/j.ajog.2025.07.009. PMID: 41485813.