To evaluate the feasibility of the use of serial ultrasound measurements of cervical length, membrane protrusion, and dilatation to discriminate between the competent and the incompetent cervix, 107 at-risk patients and 30 control subjects were examined prospectively. Patients were divided into five groups based on treatment and method of diagnosis. Epidemiologic, ultrasound, and outcome data were analyzed. Means and standard deviations for ultrasound measurements were established. Highly significant differences between all prediagnostic and postdiagnostic-pretreatment measurements were found (p less than 0.001). Highly significant differences were also found between all postdiagnostic-pretreatment and postdiagnostic-posttreatment measurements (p less than 0.001). No significant differences between prediagnostic and postdiagnostic-posttreatment measurements were noted. The incidence of preterm delivery was significantly higher among untreated diagnosed patients (p less than 0.01). By combined clinical and ultrasound criteria 51 patients (47.7%) were identified as not having cervical incompetency. Fifty-six patients (52.3%) were diagnosed.
PMID 3513583 3513583 DOI 10.1016/0002-9378(86)90598-3 10.1016/0002-9378(86)90598-3
Cite this article
Michaels, W. H., Montgomery, C., Karo, J. J., Temple, J. G., Ager, J., & Olson, J. M. (1986). Ultrasound differentiation of the competent from the incompetent cervix: prevention of preterm delivery. American journal of obstetrics and gynecology, 154(3), 537-546. https://doi.org/10.1016/0002-9378(86)90598-3
Michaels WH, Montgomery C, Karo JJ, Temple JG, Ager J, Olson JM. Ultrasound differentiation of the competent from the incompetent cervix: prevention of preterm delivery. Am J Obstet Gynecol. 1986;154(3):537-546. doi:10.1016/0002-9378(86)90598-3
Michaels, William H., et al. "Ultrasound differentiation of the competent from the incompetent cervix: prevention of preterm delivery." American journal of obstetrics and gynecology, vol. 154, no. 3, 1986, pp. 537-546.
Although shortened cervical length has been consistently associated with spontaneous preterm birth, it is not known when in gestation this risk factor becomes apparent. To determine whether sonographic cervical findings between 16 weeks' and 18 weeks 6 days' gestation predict spontaneous preterm birth and whether serial evaluations up to 23 weeks 6 days' gestation improve prediction in high-risk women. DESIGN, SETTING, Blinded observational study performed between March 1997 and November 1999 at 9 university-affiliated medical centers in the United States in 183 women with singleton gestations who previously had experienced a spontaneous birth before 32 weeks' gestation. Certified sonologists performed 590 endovaginal sonographic examinations at 2-week intervals. Cervical length was measured from the external os to the functional internal os along a closed endocervical canal. Funneling and dynamic cervical shortening were also recorded. Spontaneous preterm birth before 35 weeks' gestation, analyzed by selected cutoff values of cervical length. Forty-eight women (26%) experienced spontaneous preterm birth before 35 weeks' gestation. A cervical length of less than 25 mm at the initial sonographic examination was associated with a relative risk (RR) for spontaneous preterm birth of 3.3 (95% confidence interval [CI], 2.1-5.0; sensitivity = 19%; specificity = 98%; positive predictive value = 75%). After controlling for cervical length, neither funneling (P =.24) nor dynamic shortening (P =.054) were significant independent predictors of spontaneous preterm birth. However, using the shortest ever observed cervical length on serial evaluations, after any dynamic shortening, the RR of a cervical length of less than 25 mm for spontaneous preterm birth increased to 4.5 (95% CI, 2.7-7.6; sensitivity = 69%; specificity = 80%; positive predictive value = 55%). Compared with a single cervical measurement at 16 weeks' to 18 weeks 6 days' gestation, serial measurements at up to 23 weeks 6 days significantly improved the prediction of spontaneous preterm birth in a receiver operating characteristic curve analysis (P =.03). Cervical length assessed by endovaginal sonography between 16 weeks' and 18 weeks 6 days' gestation, augmented by serial evaluations, predicts spontaneous preterm birth before 35 weeks' gestation in high-risk women.
PregnancyCerclagePreventionCervical Length Measurement
Open Access
To determine changes in length of incompetent cervices after cerclage, using transvaginal ultrasound. Patients were enrolled in a prospective, observational study under an Institutional Review Board-approved protocol. McDonald or Shirodkar sutures were placed according to physician preference. Pre- and postcerclage cervical lengths were measured within 72 hours of the procedure. At each examination, the first measurement was discarded, and a mean of the subsequent three measurements was calculated. Twenty-one Shirodkar and ten McDonald operations were done. The mean (+/- standard deviation) precerclage cervical length was 2.7+/-0.9 cm and the postcerclage cervical length was 3.6+/-0.9 cm (P<.001, paired t test). Prophylactic cerclage results in measurable increases in cervical length, which might contribute to the success of the procedure. Further study is needed to determine whether the degree of cervical lengthening after cerclage predicts term delivery.
EndometriosisAMH and Ovarian ReserveSurgical Staging and TypologyAnti-Müllerian Hormone
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.