Ultrasonographic assessment of cervix size and its correlation with female characteristics, pregnancy, BMI, and other anthropometric features

Cervical length measurement between 11 and 13 + 6 weeks of pregnancy: Comparison of maternal and ultrasonographic characteristics between term and preterm deliveries

OBJECTIVE

The aim of this study was to evaluate the maternal and ultrasonographic characteristics of pregnant women who underwent cervical length (CL) measurement by transvaginal ultrasound between 11 and 13 + 6 weeks of gestation and who delivered at term or preterm.

METHODS

A retrospective cohort study was carried out between March 2013 and December 2018 by analyzing ultrasound data of singleton pregnant women who underwent CL measurement by transvaginal ultrasound during the first trimester scan. CL was compared between the two groups (full-term and preterm birth [PB]) using Student's t-test.

RESULTS

A total of 5097 pregnant women were enrolled, of whom 5061 (99.3%) had term and 36 (0.7%) had PB < 34 weeks. CL measurements did not differ between the term and preterm groups (36.62 vs. 37.83 mm, p = 0.08). Maternal age showed a significant and linear association with CL (r = 0.034, p = 0.012) and CRL (r = 0.086, p < 0.001). Smoking status was associated with shorter CL (36.64 vs. 35.09 mm, p = 0.003). When we analyzed the CL of the pregnant women in the term and preterm groups, according to the gestational age cut-offs for prematurity (28, 30, 32, and 34 weeks), we found that there was no significant difference between the measurements in all groups (p > 0.05).

CONCLUSION

We observed no significant differences between CL measurements between 11 and 13 + 6 weeks in pregnant women who had preterm and term deliveries. Gestational age and CRL showed a significant and linear association with CL measurement.

Biomechanically Compliant Gynecologic Training Simulator

INTRODUCTION

Pap smear training is commonly conducted using simulators before practicing with humans. Unfortunately, existing simulators do not well simulate the biomechanical properties of pelvic tissues, and this may negatively impact the training outcome. In this study, we used finite element analysis (FEA) to identify a material that most accurately simulates pelvic tissues in terms of biomechanical properties for fabricating gynecologic training simulators. The selected material was then used to fabricate a vagina and cervix model using a hybrid technique of fused deposition modeling and molding to qualitatively confirm the structural integrity of the simulator.

METHODS

The vagina and cervix were reconstructed in a 3-dimensional feature according to geometrical parameters reported in the literature. The biomechanical compliance of the simulators was investigated by comparing 5 materials-RTV615, Dragon Skin 10, Dragon Skin 30, Dragon Skin FX-Pro, and Ecoflex 00-30-and a pelvic tissue model (control) using 2 FEA modules. The structural mechanics module simulated the insertion and opening of a vaginal speculum, and the (1) horizontal opening of the vagina and peak von Mises stress at the anterior and (2) posterior walls of the vagina were obtained. The explicit dynamics module estimated (1) the fracture stress during punch biopsies and (2) maximum perpendicular deformation of the cervix before break. The most biomechanically compliant material was subsequently used to fabricate the simulator using the hybrid technique.

RESULTS

From the FEA, the horizontal opening of the vagina, peak von Mises stress at the anterior wall of the vagina, peak von Mises stress at the posterior wall of the vagina fracture stress, and maximum perpendicular deformation of the cervix before break were obtained; the results of Dragon Skin 10 and the control were most similar. Therefore, the simulator was fabricated using the material. A qualitative evaluation of the simulator by the naked eye verified its structural integrity.

CONCLUSIONS

Of the materials studied, the FEA results showed that Dragon Skin 10 was the most accurate material for simulating pelvic tissues in terms of the biomechanical properties in a gynecologic training simulator. The simulator was also successfully fabricated using the hybrid technique. Further studies may also involve experimental testing to support the simulation results.

Ultrasound guidance versus the classical method for intrauterine insemination in oral medication-stimulated cycles: A randomized, single-blind, controlled trial

OBJECTIVE

This study was conducted to compare the pregnancy rates of ultrasound-guided intrauterine insemination (UG-IUI) and classical intrauterine insemination (C-IUI) cycles.

STUDY DESIGN

A total of 320 infertile women were enrolled and randomized into an UG-IUI group, and a C-IUI group. All participants received an oral medication for ovarian stimulation. With both groups, the IUIs were scheduled and performed by doctors in their residency and fellowship training, under supervision. The duration and difficulty of the procedures were assessed. A pregnancy test was offered 3 weeks later if the participants did not have menstruation.

RESULTS

The demographic and other baseline characteristics of the groups (baseline hormone levels, cervical length, uterine position, endometrial thickness, and expertise of the providers) were comparable. The pregnancy rates were similar, with 6.9 % and 6.3 % for the UG-IUI and C-IUI groups, respectively. In the UG-IUI group, the pregnancy rate of the multigravida women was three times higher than that of the nulligravida women (15.4 % vs. 5.0 %; p = 0.13). Although the duration of the procedure was shorter for the UG-IUI group (p < 0.05), the level of difficulty was similar for the two groups.

CONCLUSIONS

For oral-medication stimulated cycles, UG-IUI did not increase the pregnancy rate more than with C-IUI. However, the pregnancy rate tended to increase with UG-IUI for multigravida women.

The impact of preconception body mass index on cervical length: a prospective cohort study in China

Objective: To assess the relationship between preconception body mass index (BMI) and cervical length (CL).Methods: Data was collected from a prospective cohort study conducted in Beijing, China. A total of 4843 qualified women participated in this study, whose health-related information was recorded at the very beginning and their cervical length was measured with transvaginal ultrasound examination during 22-24 gestational weeks. Logistic regression was used to evaluate the relationship between preconception BMI and cervical length, after adjusting for potential confounders.Results: Of all the participants in the analysis, 580 (12.0%) women had a short cervical length (CL less than 30 mm). After adjusting for the age and parity status, the adjusted odds ratios of short CL for underweight: adjusted OR = 1.28 (95% CI: 1.02, 1.60); overweight: adjusted OR = 0.74 (95% CI: 0.55, 0.99); obesity: adjusted OR = 0.38 (95% CI: 0.17, 0.88) compared with normal weight. The mean CL in underweight, normal weight, overweight and obesity group demonstrated a significant linear increased trend (33.47, 34.16 and 34.96 mm, respectively) (p < .05), dependent of age and parity.Conclusions: This research revealed that low preconception BMI women were more likely to have a short CL.

Maternal age and the risk of adverse pregnancy outcomes: a retrospective cohort study

Background

The increased potential for negative pregnancy outcomes in both extremes of reproductive age is a well-debated argument. The aim of this study was to analyze the prevalence and the outcome of pregnancies conceived at extreme maternal ages.

Methods

This retrospective study considered all single consecutive pregnancies delivered in a tertiary referral center between 2001 and 2014. Patients were categorized into 4 groups according to maternal age at delivery (< 17 years; 18–28 years; 29–39 years; > 40 years). The following outcomes were considered (amongst others): pregnancy-related hypertensive disorders (PRHDs), neonatal resuscitation (NR), neonatal intensive care unit (NICU) admission, periventricular leucomalacia (PVL), and grade 3 and 4 intraventicular hemorrhage (IVH).

Results

During the considered period 22,933 single pregnancies gave birth in our unit. We observed 71 women aged < 17 years, and 1552 aged > 40 years. In each year throughout the study period, there was a significant increment in maternal age of 0.041 years (95% CI 0.024–0.058) every new year. Multivariate analysis concluded out that maternal age over 40 years was an independent risk factor for preterm delivery (OR 1.36 95% CI 1.16–1.61, p < 0.05, PRHDs (OR 2.36 95% CI 1.86–3.00, p < 0.05), GDM (OR 1.71 95% CI 1.37–2.12, p < 0.05) cesarean section (OR 1.99 95% CI 1.78–2.23, p < 0.05), abnormal fetal presentation (OR 1.29 95% CI 1.03–1.61, p < 0.05), and fetal PVL (OR 3.32 95% CI 1.17–9.44, p < 0.05). We also observed that maternal age under 17 years or over 40 years was an independent risk factor for grade 3 or 4 neonatal IVH (OR 2.97 95% CI 1.24–7.14, p < 0.05).

Conclusions

These findings confirm a negative impact of extreme maternal ages on pregnancy. These results should be carefully taken into account by maternal care providers in order to inform women adequately, supporting them in understanding potential risks associated with their procreation choices, and to improve clinical surveillance.

Electronic supplementary material

The online version of this article (10.1186/s12884-019-2400-x) contains supplementary material, which is available to authorized users.

Maternal body mass index and cervical length among women with a history of spontaneous preterm birth†

Objectives: To evaluate whether women with a prior spontaneous preterm birth (SPTB) with a higher body mass index (BMI) have a lower risk of a shortened cervix in a subsequent pregnancy.Study Design: A secondary analysis of the Maternal-Fetal Medicine Units Network RCT of omega-3 fatty acid supplementation for recurrent SPTB prevention. All women had ≥1 prior SPTB <37 weeks, a singleton pregnancy, and initiated 17-alpha hydroxyprogesterone caproate(17-OHPC). The primary exposure was pre-pregnancy BMI. The primary outcome was the shortest transvaginal cervical length <30 mm.Results: Of the 356 women with a prior SPTB receiving 17-OHPC and a cervical length available, 108 (30%) were overweight and 103 (29%) obese; 12% had a cervical length <30 mm. Fewer overweight/obese women had a shortened cervix compared to normal-weight women (43 versus 57%; odds ratio: 0.47 [95%CI: 0.25-0.89]). After adjusting for maternal age, number of prior SPTBs, and tobacco use, overweight/obese women were less than half as likely to have a shortened cervix compared to normal-weight women (adjusted odds ratio: 0.46, 95%CI: 0.24-0.89).Conclusions: Overweight and obese women with a prior SPTB receiving 17-OHPC have longer cervical lengths compared to normal weight women, and this finding could explain a possible mechanism between the decreased rate of SPTB and larger BMI.

Pelvic Ultrasound Findings in Women with Obstetric Fistula: A Cross-Sectional Study of Cases and Controls

Objective

Obstetric fistula (OF) is a morbid condition caused by prolonged obstructed labor. Women with OF experience profound injury and have high rates of infertility and poor obstetric outcomes. We examined endovaginal ultrasound parameters in women with and without OF.

Design/Setting/Sample/Methods

This cross-sectional study enrolled women evaluated at the Fistula Care Centre in Lilongwe, Malawi. Eligibility criteria included age 18–45, prior pregnancy, and a uterus on ultrasound. Participants underwent endovaginal ultrasound with measurement of cervical dimensions. Comparisons were done using t-tests and Fisher's exact test. Among women with OF, linear regression was used to assess whether fistula stage was associated with cervical length.

Results

We enrolled 98 cases and 12 controls. Women with OF had shorter cervical lengths (18.8 mm versus 27.3 mm, p < 0.01), as well as shorter anterior (7.0 mm versus 9.3 mm, p < 0.01) and posterior (9.5 mm versus 11.0 mm, p < 0.04) cervical stroma, compared to controls.

Conclusion

Women with OF have shorter cervical lengths and anterior and posterior cervical stroma, when compared to women without OF. This may offer a partial explanation for subfertility and poor obstetric outcomes in OF patients. Additional studies to clarify the role of ultrasound in OF patients and prediction of future fertility are warranted.

Elastography in predicting preterm delivery in asymptomatic, low-risk women: a prospective observational study

Background

Despite the efforts to decrease the rate of preterm birth, preterm delivery is still the main cause of neonatal morbidity and mortality. Identifying patients threatened with preterm delivery remains one of the main obstetric challenges. The aim of this study was to estimate the potential value of elastographic evaluation of internal cervical os stiffness at 18-22 weeks of pregnancy in low risk, asymptomatic women in the prediction of spontaneous preterm delivery.

Methods

This prospective observational study included 333 low-risk, asymptomatic women presenting for the routine second trimester ultrasound scan according to the Polish Gynecological Society recommendation between 18-22 weeks of pregnancy. Ultrasound examinations of the cervix were performed transvaginally. The following data were recorded: elastographic color assessment of the internal os and ultrasound cervical length at 18-22 and 30 weeks of pregnancy; maternal age; obstetrical history; presence of cervical funneling at 30 weeks of pregnancy; gestational age at birth. Elastographic assessment of the internal os was performed using a color map: red (soft), yellow (medium soft), blue (medium hard) and purple (hard). If two colors were visible in the region of the internal os, the softer option was noted. Statistical analysis was performed using Statistica software (version 10, Statsoft Poland) using the following tests: chi square test to compare frequency of preterm deliveries in various categories of internal os assessment and Spearman correlation test to determine the correlation between elastographic assessment and cervical shortening. To determine the cut off category of internal os elastography assessment in selecting high preterm delivery risk patients we have calculated the sensivity, specifity, negative predictive value and positive predictive value.

Results

The number of preterm deliveries (<37 weeks of pregnancy) was significantly higher in the red and yellow groups, than in the blue and purple groups. The sensivity, specifity, NPV and PPV for both red and yellow internal os assessment in predicting preterm delivery were 85.7%, 97.6%, 98.3% and 81.1% respectively.

Conclusions

Elastographic assessment of the internal cervical os at 18-22 weeks of pregnancy may identify patients with high risk of preterm delivery in low-risk, asymptomatic women.

Transabdominal evaluation of uterine cervical length during pregnancy fails to identify a substantial number of women with a short cervix

OBJECTIVE

To assess the diagnostic performance of transabdominal sonographic measurement of cervical length in identifying patients with a short cervix.

METHODS

Cervical length was measured in 220 pregnant women using transabdominal and transvaginal ultrasound (US). Reproducibility and agreement between and within both methods were assessed. The diagnostic accuracy of transabdominal US for identifying cases with a cervical length <25 mm was evaluated.

RESULTS

Twenty-one out of 220 cases (9.5%) had a cervical length <25 mm by transvaginal US. Only 43% (n = 9) of patients with a short cervix were correctly identified by transabdominal US. In patients with a cervical length of <25 mm by transvaginal US, transabdominal measurement of the cervix overestimated this parameter by an average of 8 mm (95% LOAs, -26.4 to 10.5 mm). Among women without a short cervix, transabdominal US underestimated cervical length on average (LOA) by 1.1 mm (95% LOAs, -11.0 to 13.2 mm). Transvaginal US was also more reproducible (intraclass correlation coefficient: (ICC) (0.96; 95% CI, 0.94 to 0.97) based on comparisons between 2D images and immediately acquired 3D volume datasets relative to transabdominal US (ICC: 0.71; 95% CI, 0.57 to 0.84). Transvaginal US detected 13 cases with funneling and six cases with sludge whereas only three cases of funneling and one of sludge were detected by transabdominal US.

CONCLUSION

Transabdominal measurement overestimated cervical LOA by 8 mm among women with a short cervix and resulted in the underdiagnosis of 57% of cases.

Is cervical elongation associated with pelvic organ prolapse?

INTRODUCTION AND HYPOTHESIS

It is commonly believed that pelvic organ prolapse (POP) is associated with cervical elongation. However, cervical lengths have not been formally compared between women with prolapse and those with normal support.

METHODS

Cervix and uterine corpus lengths were measured on magnetic resonance images in a case-control study of 51 women with prolapse and 46 women with normal support determined by the Pelvic Organ Prolapse Quantification (POP-Q) examination. Group matching ensured similar demographics in both groups. Ranges for normal cervical lengths were determined from the values in the control group in order to evaluate for cervical elongation amongst women with prolapse.

RESULTS

The cervix is 36.4 % (8.6 mm) longer in women with prolapse than in women with normal pelvic support (p < 0.001). Linear regression modeling suggests the feature most highly associated with cervical length is the degree of uterine descent (POP-Q point C). Approximately 40 % of women with prolapse have cervical elongation; 57 % of cervical elongation in prolapse can be explained by a logistic regression-based model including POP-Q point C, body mass index, and menopausal status.

CONCLUSIONS

Cervical elongation is found in one third of women with POP, with the extent of elongation increasing with greater degrees of uterine descent.