Spontaneous preterm birth significantly increases the risk for a recurrent preterm birth. Only a few identifiable clinical risk factors can be referenced in counseling for recurrent preterm birth. Furthermore, treatment using progesterone supplementation has not consistently prevented preterm birth among high-risk patients, but it may be effective in a subset of those patients. Placental pathology from a previous pregnancy may be used to predict which patients will experience a recurrent preterm birth or to identify a subset of patients more likely to respond to treatment with antenatal progesterone.
Objective
This study aimed to determine if histologic patterns are associated with recurrent preterm birth among patients with an index spontaneous preterm birth. A secondary objective was to determine if placental histologic types and/or progesterone receptor density in the decidua are associated with the response to progesterone supplementation with intramuscular 17-hydroxyprogesterone caproate.
Study Design
This was a retrospective cohort study at a single institution of women with singleton pregnancies with an index spontaneous preterm birth and a subsequent birth within the same hospital system between 2009 and 2019. Patients were included if placental pathology was available for the index spontaneous preterm birth. A logistic regression was used to determine if there were independent associations between 4 histologic types (acute inflammation, maternal vascular malperfusion, fetal vascular malperfusion, chronic inflammation) and recurrent preterm birth. For the secondary endpoint, 17-hydroxyprogesterone caproate response was defined as prolonging gestation by >3 weeks beyond the gestational age at delivery in the index pregnancy. Patients who delivered <3 weeks beyond the gestational age in the index pregnancy but at ≥39 weeks' gestation were excluded. A logistic regression was used to assess the independent association between placental histology and 17-hydroxyprogesterone caproate response. Sensitivity analyses were completed using only patients with an index birth <36 weeks' gestation, and then excluding those with medically indicated preterm birth in a subsequent pregnancy. A nested case-control immunohistochemical study was done among 20 patients with a subsequent term birth and 20 patients with a subsequent spontaneous preterm birth. The percentage of cells in the maternal decidua positive for progesterone receptors was correlated with the subsequent pregnancy outcome.
Results
A total of 352 patients were included. Acute inflammation was the most common histologic type seen among patients with spontaneous preterm birth (44.1%), followed by chronic inflammation (40.9%) and maternal vascular malperfusion (31.3%). No histologic type was independently associated with recurrent preterm birth. A total of 155 patients received 17-hydroxyprogesterone caproate in a second pregnancy. Low-grade acute inflammation was significantly associated with a decreased likelihood of 17-hydroxyprogesterone caproate response. Low-grade maternal vascular malperfusion among those with an index pregnancy delivered at <36 weeks' gestation was significantly associated with a more than 4 times increased likelihood of 17-hydroxyprogesterone caproate response when excluding those with a subsequent iatrogenic preterm birth. Progesterone receptor staining was not associated with recurrent preterm birth.
Conclusion
Although acute inflammation was prevalent among spontaneous preterm births, more than half of the spontaneous preterm births were not associated with acute inflammation. Low-grade acute inflammation was associated with a significantly decreased response to 17-hydroxyprogesterone caproate supplementation. Low-grade maternal vascular malperfusion was associated with a 4-fold increased likelihood of 17-hydroxyprogesterone caproate response among those with index deliveries <36 weeks' gestation. Further work is needed to determine if placental pathologic examination can be used to target treatment in subsequent pregnancies to prevent recurrent preterm birth.
PMID 37751829 37751829 DOI 10.1016/j.ajog.2023.09.018 10.1016/j.ajog.2023.09.018
Cite this article
Suresh, S., Freedman, A., Adams, M., Hirsch, E., & Ernst, L. (2024). Placental histology for targeted risk assessment of recurrent spontaneous preterm birth. American journal of obstetrics and gynecology, 230(4), 452.e1-452.e11. https://doi.org/10.1016/j.ajog.2023.09.018
Suresh S, Freedman A, Adams M, Hirsch E, Ernst L. Placental histology for targeted risk assessment of recurrent spontaneous preterm birth. Am J Obstet Gynecol. 2024;230(4):452.e1-452.e11. doi:10.1016/j.ajog.2023.09.018
Suresh, Sunitha, et al. "Placental histology for targeted risk assessment of recurrent spontaneous preterm birth." American journal of obstetrics and gynecology, vol. 230, no. 4, 2024, pp. 452.e1-452.e11.
Endometriosis is a chronic, gynecologic condition in which tissue similar to the lining of the uterus implants throughout the body. Women with endometriosis have a higher prevalence of infertility and a greater risk of early natural menopause compared to those without endometriosis. This study aimed to evaluate preoperative serum AMH levels among women with and without incident endometriosis and to assess whether levels differ by surgical staging and typology. The ENDO (Endometriosis: Natural History, Diagnosis, and Outcomes) study was conducted between 2007 and 2009. The ENDO study consisted of an operative and population cohort (n=600). Only those in the ENDO operative cohort from the Utah site were used for this analysis, and included women aged 18 to 44 years who were scheduled for gynecologic surgery, irrespective of clinical indication (n=476). AMH levels were measured from stored serum collected before surgery using a quantitative enzyme-linked immunosorbent assay. After excluding participants with missing outcome data (n=51), unilateral oophorectomy (n=8), or those within the population cohort (n=69), 348 participants remained for the analysis. Surgically confirmed endometriosis diagnosis, staging (American Society for Reproductive Medicine I-IV), and typology (superficial, deep, ovarian) were ascertained by the operative report. Outliers for AMH (>14.0 ng/mL) were excluded from the analyses and AMH values were log-transformed. Multivariable linear regression models adjusted for age (squared and continuous), body mass index, serum cotinine levels, and exogenous hormonal contraceptive use were conducted. Percentage differences in AMH were calculated as (exp[β]-1)×100, and 95% confidence intervals were reported. Compared with no endometriosis, incident endometriosis diagnosis was associated with lower AMH levels (-19.8%; 95% confidence interval, -37.0 to 1.0); however, this association was not statistically significant. Stage III to IV disease was associated with 40.1% lower AMH levels (95% confidence interval, -58.9 to -12.7). Ovarian endometriomas were most strongly associated with lower AMH levels (-54.3%; 95% confidence interval, -69.4 to -31.8), with a more pronounced association among those with infertility (-72.6%; 95% confidence interval, -85.4 to -48.5). Deep (-24.1%; 95% confidence interval, -48.2 to 11.0) and superficial (-15.5%; 95% confidence interval, -34.6 to 9.3) endometriosis also showed a trend toward lower AMH levels, but these findings were not statistically significant. Compared with a postoperative diagnosis of a normal pelvis, incident endometriosis was associated with 26.8% lower AMH levels (95% confidence interval, -44.6 to -3.4). Stage III to IV disease was associated with 47.8% lower AMH levels (95% confidence interval, -65.8 to -23.2), and all subtypes of endometriosis were statistically significantly associated with lower levels of AMH compared with a postoperative diagnosis of a normal pelvis (ovarian: -60.8%; 95% confidence interval, -74.4 to -39.9; -34.3%; 95% confidence interval, -56.2 to -1.4; -24.8%; 95% confidence interval, -43.9 to -0.8). Ovarian and moderate to severe (stage III-IV) endometriosis were associated with markedly lower AMH levels compared with no endometriosis. Compared with a postoperative diagnosis of a normal pelvis, incident endometriosis and moderate to severe stages (stage III-IV) were associated with statistically significantly lower AMH levels. Additionally, typology (deep, ovarian, or superficial) was associated with statistically significantly lower AMH levels. However, this association was likely driven by the presence of ovarian endometriomas across all subtypes. These findings are consistent with previous studies and demonstrate that endometriosis lesions themselves, independent of surgical intervention, influence AMH levels.
General OB/GYNUterine Closure TechniqueHysterotomy RepairCesarean Scar Complications
Bujold E et al., 2026·American Journal of Obstetrics and Gynecology
Normal uterine function depends on cyclical regeneration and the capacity to sustain pregnancy. A cesarean incision represents an injury to this remarkable organ. Although the uterus possesses exceptional healing potential, cesarean delivery increases the risk of secondary infertility, pelvic pain, uterine rupture, and abnormal placentation in subsequent pregnancies. The two most important determinants of successful hysterotomy healing after cesarean delivery are the location of the incision and the surgical technique used for closure. The anatomic site of entry-whether the corpus, lower uterine segment, or cervix-defines the tissue composition, vascularity, and contractility at the wound margins, which in turn influence how the scar remodels and withstands subsequent pregnancies. Surgical technique is also important. A robust body of experimental and clinical evidence demonstrates that restoring anatomic integrity by reapproximating uterine layers while excluding the endometrium produces stronger scars and reduces late complications. The rationale for excluding the endometrium is to prevent displacement of endometrial tissue into the myometrium and to avoid mucosal tearing against a foreign body (i.e. suture material), both of which predispose to defective healing. When the endometrium is incorporated, healing is often impaired, leading to niches or isthmoceles, adenomyosis, and endometriosis at the scar site. Over time, these defects have been recognized as contributors to abnormal bleeding, pelvic pain, infertility, uterine rupture, and placenta accreta spectrum disorders. Despite this evidence, single-layer closures that incorporate endometrium became widely adopted because of their speed and simplicity, while their long-term sequels were initially underappreciated. This has prompted renewed scrutiny of closure techniques, including comparisons of single-layer vs double-layer closure, locking vs nonlocking sutures, type of sutures, and the direction of suture. Collectively, the data show that optimal closure respects uterine anatomy, restores the natural alignment of tissues, and achieves hemostasis without compromising perfusion or strangulating tissues. Building on these principles, we herein describe a refined 3-layer closure. The first layer approximates decidua and junctional myometrium while excluding surface endometrium to prevent tissue entrapment and bacterial contamination. The second layer restores anatomic wall integrity by reapproximating the bulk of the myometrium, thereby reinforcing strength and distributing tension across the scar. The third layer reapproximates superficial myometrium and serosa, smoothing the uterine surface and reducing adhesions. This technique is not simply a return to traditional double-layer methods or an extension of single-layer practice, but rather a refinement that integrates lessons from visceral surgery and contemporary obstetric data. Its rationale is to restore anatomy, secure hemostasis without ischemia, and preserve long-term uterine function. While short-term safety appears comparable across closure methods, evidence increasingly indicates that long-term reproductive outcomes depend on how closure respects tissue biology. We argue that appropriate repair is more meticulous restoration of uterine anatomy should take precedence over operative speed. The enduring success of a hysterotomy repair depends on the surgical technique employed, as it directly affects women's future reproductive health.
Whitley J et al., 2025·American journal of obstetrics and gynecology
Our objective was to determine if oxytocin discontinuation in the active phase of labor impacts the rate of cesarean delivery compared to continuation of oxytocin. This study was a systematic review and meta-analysis of randomized controlled trials. A research librarian performed a database search using a combination of standardized terms and keywords related to oxytocin discontinuation and stages of labor from database inception until February 2024. This protocol was registered in The International Prospective Register of Systematic Reviews (PROSPERO). Randomized controlled trials of pregnant patients who received oxytocin for induction or augmentation of labor, whose outcomes compared discontinuation and continuation of oxytocin in active labor, were included. We defined "active phase of labor" as defined by each trial. Nonrandomized trials, quasi-randomized trials, and animal models were excluded. The primary outcome was the rate of cesarean delivery. Secondary maternal outcomes included postpartum hemorrhage, total blood loss, and infectious outcomes. Secondary neonatal outcomes included Apgar score at 5 minutes <7, umbilical arterial pH <7.10, neonatal therapeutic hypothermia, neonatal intensive care unit admission, neonatal resuscitation at birth, and neonatal death. STUDY APPRAISAL The risk of bias in each study was assessed using the guidelines outlined in the Cochrane Handbook for Systematic Reviews of Interventions. Heterogeneity was measured using Higgins I2. Meta-analysis was performed in Review Manager 5.4.1 and StataSE 16 to determine summary treatment effects in terms of relative risk or mean difference with 95% confidence intervals. The adherence of each included trial to the trustworthiness criteria outlined by the OBGYN Editors' Integrity Group was assessed, and a leave-1-out analysis was performed to evaluate the effect of studies with concerns regarding trustworthiness. Fifteen randomized controlled trials, including 5734 patients, were ultimately included in the meta-analysis. The rate of cesarean delivery, reported in 13 studies, was lower with discontinuation of oxytocin in the active phase of labor (relative risk=0.80; 95% confidence interval, 0.66-0.97; 95% prediction interval, 0.38-1.22). Discontinuation of oxytocin was also associated with a lower risk of uterine tachysystole (relative risk=0.45; 95% confidence interval, 0.34-0.60; I2, 26%), and nonreassuring fetal heart rate tracing (relative risk=0.64; 95% confidence interval, 0.49-0.82; I2, 41%). Discontinuation of oxytocin increased the duration of active labor by an average of 30 minutes and second stage of labor by an average of 6 minutes. Although associated with an extension of labor by half an hour, discontinuation of oxytocin in the active phase of labor was associated with a 20% decreased risk of cesarean delivery and a lower risk of uterine tachysystole and nonreassuring fetal heart rate tracing. While the pooled analysis suggests a beneficial effect, this finding is dependent on the inclusion of studies with concerns regarding trustworthiness.