Transient Elastography to Assess the Cervical Ripening during Pregnancy: A Preliminary Study.

Purpose To explore the feasibility of transient elastography (TE) to quantify cervical stiffness changes during normal pregnancy and its spatial variability. Materials and Methods TE was used to quantify the cervical stiffness in four anatomical regions. 42 women between 17 and 43 years of age and at 6 - 41 weeks of gestation were studied. The stiffness was related to gestational age at the time of examination, interval from ultrasound examination to delivery and cervical length to evaluate the potential of TE to assess cervical ripening. In addition, a sensitivity analysis based on Cronbach's alpha coefficient was carried out to assess the concordance between inter/intra-operator measurements. Results There were significant correlations between cervical stiffness measured in the four regions with gestational age and the remaining time for delivery. Results confirm stiffness variability within the cervix. No significant association was found between cervical length and stiffness in the four ROIs. Associations between gestational age and remaining time for delivery with cervical length present weaker correlations than with cervical stiffness. The external part of the cervix was significantly softer than the internal one, and these stiffness values vary significantly in the anterior compared to the posterior cervix. The measurements taken by the same and by two different observers for different regions in the cervix were reliable and reproducible. Conclusion It is feasible to objectively quantify the decrease of cervical stiffness correlated to gestational age. Transient elastography is a valuable promising tool to provide additional information on the process of cervical effacement to that obtained from digital examination and conventional ultrasound. Further studies are needed to assess the feasibility of the technique in obstetric clinical applications, such as prediction of preterm birth or success in labor induction.

Reproducibility and usability assessment of the novel Fine Birth device for threatened preterm labor diagnosis.

BACKGROUND: Preterm delivery is considered the leading cause of mortality worldwide in children under 5 years old. Approximately 45 million pregnant women are hospitalized yearly for threatened preterm labor. However, only 50% of pregnancies complicated by threatened preterm labor end in delivery before the estimated date, classifying the rest as false threatened preterm labor. The ability of current diagnostic methods to predict threatened preterm labor is low (low positive predictive value), ranging between 8% and 30%. This highlights the need for a solution that accurately detects and differentiates between false and real threatened preterm labors in women who attend obstetrical clinics and hospital emergency departments with delivery symptoms. OBJECTIVE: Primarily, this aimed to assess the reproducibility and usability of a novel medical device, the Fine Birth, aimed at accurately diagnosing threatened preterm labor through the objective quantification of pregnant women's cervical consistency. Secondarily, this study aimed to evaluate the effect of training and the incorporation of a lateral microcamera on the device's reliability and usability outcomes. STUDY DESIGN: A total of 77 singleton pregnant women were recruited during their follow-up visits to the obstetrical and gynecologic departments at 5 Spanish hospitals. The eligibility criteria included pregnant women aged ≥18 years; women with a normal fetus and uncomplicated pregnancy; women without prolapse of membranes, uterine anomalies, previous cervical surgery, or latex allergy; and women signing the informed written consent. Cervical tissue stiffness was assessed using the Fine Birth device, whose technology is based on the propagation of torsional waves through the studied tissue. Cervical consistency measurements were taken for each woman until obtaining 2 valid measurements by 2 different operators. The intraobserver and interobserver reproducibilities of the Fine Birth measurements were assessed using the intraclass correlation coefficients with a 95% confidence interval and the Fisher test P value. The usability was evaluated on the basis of the clinicians' and participants' feedback. RESULTS: There was good intraobserver reproducibility (intraclass correlation coefficient, 0.88; 95% confidence interval, 0.84-0.95; Fisher test P value<.05). As the results obtained for the interobserver reproducibility did not reach the desired acceptable values (intraclass correlation coefficient of <0.75), a lateral microcamera was added to the Fine Birth intravaginal probe, and the operators involved in the clinical investigation received the corresponding training with the modified device. The analysis of 16 additional subjects demonstrated excellent interobserver reproducibility (intraclass correlation coefficient, 0.93; 95% confidence interval, 0.78-0.97) and an improvement after the intervention (P<.0001). CONCLUSION: The robust reproducibility and usability results obtained after the insertion of a lateral microcamera and the corresponding training make the Fine Birth a promising novel device to objectively quantify the patient's cervical consistency, diagnose threatened preterm labor, and, thus, predict the risk of spontaneous preterm birth. Further research is needed to demonstrate the clinical utility of the device.

A Preliminary Study on the Safety of Elastography during Pregnancy: Hypoacusia, Anthropometry, and Apgar Score in Newborns.

Transient or acoustic radiation force elastography (ARFE) is becoming the most extended technology to assess cervical effacement, additionally to the Bishop test and conventional ultrasound. However, a debate on the fetal safety has been opened due to the high intensity focused beam emitted to produce shear waves. This work is aimed at providing preliminary data to assess clinical effects of fetal exposure. A follow-up study in newborns of 42 women exposed to ARFE during pregnancy was carried out to explore neonatal hypoacusia, Apgar test, and anthropometry. No hypoacusia cases attributable to ARFE were observed. The Apgar test at five minutes scored normally in all the newborns. Comparisons between anthropometric measurements showed no significant statistically differences. The results preclude to state the harmfulness nor the safety of ARFE. However, given the concern on the high level of energy and the potential risk of harmful bioeffects, larger studies are recommended.

Monochorionic diamniotic in vitro fertilization twins have a decreased incidence of twin-to-twin transfusion syndrome.

OBJECTIVE: To compare the incidence of twin-to-twin transfusion syndrome (TTTS) in spontaneous versus IVF-conceived twin pregnancies. DESIGN: Retrospective multicenter study. SETTING: University-affiliated tertiary medical centers. PATIENT(S): Women admitted for 11-14 week's scan between January 1997 and July 2013 who were diagnosed with monochorionic (MC) diamniotic twin pregnancies. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Mode of conception, TTTS. RESULT(S): The study cohort included 327 pregnant women with live MC diamniotic twins. Of them, 284 (86.9%) and 43 (13.1%) were spontaneous and IVF conceived, respectively. The mean maternal age was significantly higher in IVF compared with in spontaneously conceived pregnancies (33.8 ± 5.5 vs. 31.6 ± 5.4, respectively). Thirty-seven twins (11.3%) had TTTS, of whom 36/284 (12.7%) versus 1/43 (2.3%) were spontaneously and IVF conceived, respectively. The mean week of delivery was significantly lower in MC twins diagnosed with TTTS compared with those without TTTS (32.7 ± 3.3 vs. 35.5 ± 2.5, respectively). Furthermore, there was a significantly higher birthweight discordancy in twins diagnosed with TTTS compared with those without (20.6% vs. 11%, respectively). CONCLUSION(S): The significantly lower proportion of TTTS found in IVF-conceived twins may suggest a different embryological process that lies at the core of IVF conception of monozygotic twinning.