Gestational age-based reference ranges for cervical length and preterm birth prediction in triplet pregnancies: an observational retrospective study

Cervical length; Preterm delivery; Triplet pregnancyLongitud cervical; Parto prematuro; Embarazo de trillizosLongitud cervical; Part prematur; Embaràs de trillissosObjectives To develop gestational age-based reference ranges for cervical length in triplet pregnancies. The secondary objective was to assess the performance of cervical length measured between 18 and 20 + 6 days for the prediction of preterm delivery before 28 and 32 weeks, respectively. Methods Observational retrospective study of triplet pregnancies in three Spanish tertiary-care hospitals between 2001 and 2019. Cervical length measurements were consecutively obtained between 15 and 34 weeks of gestation. Pregnancies undergoing multifetal reduction or fetal surgery were excluded. Results Two hundred and six triplet pregnancies were included in the final analysis. There was a quadratic decrease in cervical length with gestational age. The median and fifth centiles for cervical length at 20 weeks were 35 and 13 mm. In the prediction of preterm birth < 28 weeks, for a false positive rate of 5%, and 10%, the detection rates were 40.9%, and 40.9%, respectively, and the prediction of preterm birth < 32 weeks, 22.0% and 26.0%, respectively. Conclusions In triplet pregnancies, cervical length decreases with gestational age. The performance of cervical length at 18–20 + 6 in screening for preterm birth before 28 and 32 weeks is poor

Abnormal Maternal Body Mass Index and Customized Fetal Weight Charts: Improving the Identification of Small for Gestational Age Fetuses and Newborns

Maternal body mass index; Newborn weight; ObesityÍndice de masa corporal materno; Peso del neonato; ObesidadÍndex de massa corporal matern; Pes del nounat; ObesitatBackground: Obesity and thinness are serious diseases, but cases with abnormal maternal weight have not been excluded from the calculations in the construction of customized fetal growth curves (CCs). Method: To determine if the new CCs, built excluding mothers with an abnormal weight, are better than standard CCs at identifying SGA. A total of 16,122 neonates were identified as SGA, LGA, or AGA, using the two models. Logistic regression and analysis of covariance were used to calculate the OR and CI for adverse outcomes by group. Gestational age was considered as a covariable. Results: The SGA rates by the new CCs and by the standard CCs were 11.8% and 9.7%, respectively. The SGA rate only by the new CCs was 18% and the SGA rate only by the standard CCs was 0.01%. Compared to AGA by both models, SGA by the new CCs had increased rates of cesarean section, (OR 1.53 (95% CI 1.19, 1.96)), prematurity (OR 2.84 (95% CI 2.09, 3.85)), NICU admission (OR 5.41 (95% CI 3.47, 8.43), and adverse outcomes (OR 1.76 (95% CI 1.06, 2.60). The strength of these associations decreased with gestational age. Conclusion: The use of the new CCs allowed for a more accurate identification of SGA at risk of adverse perinatal outcomes as compared to the standard CCs

First-trimester screening for pre-eclampsia and small for gestational age: A comparison of the gaussian and Fetal Medicine Foundation algorithms

Preeclampsia d'inici precoç; Primer trimestreEarly-onset pre-eclampsia; First trimesterPreeclampsia de inicio precoz; Primer trimestreObjective Pre-eclampsia (PE) and small for gestational age (SGA) can be predicted from the first trimester. The most widely used algorithm worldwide is the Fetal Medicine Foundation (FMF) algorithm. The recently described Gaussian algorithm has reported excellent results although it is unlikely to be externally validated. Therefore, as an alternative approach, we compared the predictive accuracy for PE and SGA of the Gaussian and FMF algorithms. Methods Secondary analysis of a prospective cohort study was conducted at Vall d'Hebron University Hospital (Barcelona) with 2641 singleton pregnancies. The areas under the curve for the predictive performance for early-onset and preterm PE and early-onset and preterm SGA were calculated with the Gaussian and FMF algorithms and subsequently compared. Results The FMF and Gaussian algorithms showed a similar predictive performance for most outcomes and marker combinations. Nevertheless, significant differences for early-onset PE prediction favored the Gaussian algorithm in the following combinations: mean arterial blood pressure (MAP) with pregnancy-associated plasma protein A, MAP with placental growth factor, and MAP alone. Conclusions The first-trimester Gaussian and FMF algorithms have similar performances for PE and SGA prediction when applied with all markers within a routine care setting in a Spanish population, adding evidence to the external validity of the FMF algorithm

Confirmation of preeclampsia-like syndrome induced by severe COVID-19: an observational study

COVID-19; Preeclampsia; PregnancyCOVID-19; Preeclampsia; EmbarazoCOVID-19; Preeclampsia; EmbaràsBACKGROUND Since the outbreak of the COVID-19 pandemic, some studies have reported an increased preeclampsia incidence in pregnant women with SARS-CoV-2 infection. Several explanations for this association have been proposed, including a preeclampsia-like syndrome induced by severe COVID-19. This syndrome was described in a small case series and has not been confirmed in larger studies, and its effect on perinatal outcomes has not been studied. OBJECTIVE This study aimed to confirm the preeclampsia-like syndrome because of COVID-19 and to investigate its implications on pregnancy outcomes and prognosis. STUDY DESIGN This was a prospective, observational study conducted in a tertiary referral hospital. The inclusion criteria were pregnant women admitted to the intensive care unit for severe pneumonia because of COVID-19. They were classified into 3 groups based on clinical and laboratory findings: preeclampsia, preeclampsia-like syndrome, and women without preeclampsia features. The 3 cohorts were analyzed and compared at 3 different times: before, during, and after severe pneumonia. The main outcomes were incidence of adverse perinatal outcomes and signs and symptoms of PE, such as hypertension, proteinuria, thrombocytopenia, elevated liver enzymes, and increased angiogenic factors (soluble fms-like tyrosine kinase 1–to–placental growth factor ratio). RESULTS A total of 106 women were admitted to the intensive care unit because of severe pneumonia, and 68 women were included in the study. Of those, 53 (50.0%) did not meet the diagnostic criteria for preeclampsia and remained pregnant after pneumonia (non-preeclampsia); 7 (6.6%) met the diagnostic criteria for preeclampsia, had abnormal (>38) soluble fms-like tyrosine kinase 1–to–placental growth factor ratio (preeclampsia), and delivered during severe pneumonia, and 8 (7.5%) met the diagnostic criteria for preeclampsia, had normal (≤38) soluble fms-like tyrosine kinase 1–to–placental growth factor ratio (preeclampsia like), and did not deliver during pneumonia. Despite not having delivered, most preeclampsia-related features improved after severe pneumonia in women with preeclampsia-like syndrome. Women with preeclampsia had significantly poorer outcomes than women with preeclampsia-like syndrome or without preeclampsia. CONCLUSION More than 50% of women with severe COVID-19 and diagnostic criteria for preeclampsia may not be preeclampsia but a preeclampsia-like syndrome, which may affect up to 7.5% of women with severe COVID-19. Preeclampsia-like syndrome might have similar perinatal outcomes to those of normotensive women with severe pneumonia because of COVID-19. For these reasons, preeclampsia-like syndrome should be excluded by using soluble fms-like tyrosine kinase 1–to–placental growth factor ratio in future research and before making clinical decisions

Reference values for interleukin-6 in the amniotic fluid of asymptomatic pregnant women

Amniocentesis; Interleukin-6; Intra-amniotic inflammationAmniocentesi; Interleucina-6; Inflamació intraamniòticaAmniocentesis; Interleucina-6; Inflamación intraamnióticaIntroduction Nowadays, proinflammatory factors are considered to play an important role in the pathophysiology of threatened preterm labor or chorioamnionitis. The aim of this study was to establish the normal reference range for interleukin-6 (IL-6) levels in the amniotic fluid and to identify factors which may alter this value. Material and methods Prospective study in a tertiary-level center including asymptomatic pregnant women undergoing amniocentesis for genetic studies from October 2016 to September 2019. IL-6 measurements in amniotic fluid were performed using a fluorescence immunoassay with microfluidic technology (ELLA Proteinsimple, Bio Techne). Maternal history and pregnancy data were also recorded. Results This study included 140 pregnant women. Of those, women who underwent termination of pregnancy were excluded. Therefore, a total of 98 pregnancies were included in the final statistical analysis. The mean gestational age was 21.86 weeks (range: 15–38.7) at the time of amniocentesis, and 38.6 weeks (range: 30.9–41.4) at delivery. No cases of chorioamnionitis were reported. The log10 IL-6 values follow a normal distribution (W = 0.990, p = 0.692). The median, and the 5th, 10th, 90th, and 95th percentiles for IL-6 levels were 573, 105, 130, 1645, and 2260 pg/mL, respectively. The log10 IL-6 values were not affected by gestational age (p = 0.395), maternal age (p = 0.376), body mass index (p = 0.551), ethnicity (p = 0.467), smoking status (p = 0.933), parity (p = 0.557), method of conception (p = 0.322), or diabetes mellitus (p = 0.381). Conclusions The log10 IL-6 values follow a normal distribution. IL-6 values are independent of gestational age, maternal age, body mass index, ethnicity, smoking status, parity and method of conception. Our study provides a normal reference range for IL-6 levels in the amniotic fluid that can be used in future studies. We also observed that normal IL-6 values were higher in the amniotic fluid than in serum.Some of the authors are members of the European Reference Network on Rare Congenital Malformations and Rare Intellectual Disability ERN-ITHACA (EU Framework Partnership Agreement ID: 3HP-HP-FPA ERN-01-2016/739516)

Seguiment de gestants portadores de pesari cervical mitjançant ecografia 2D i 3D

Hipòtesi L’ecografia transvaginal pot identificar els canvis que el pesari exerceix sobre el cèrvix uterí i aquests canvis es podrien correlacionar amb el risc de part prematur (PP) <34 setmanes d’amenorrea (SA) i d’esdeveniments perinatals adversos severs. Objectius Avaluar múltiples variables cervicals, obtingudes mitjançant ecografia transvaginal en dues (2D) i tres dimensions (3D), abans i després de la inserció del pesari cervical, amb l’objectiu de comprendre els mecanismes d’acció del pesari i obtenir millors eines predictores de PP i esdeveniments adversos perinatals. Mètodes Estudi de cohorts prospectiu, a l’Hospital Universitari Vall d’Hebron, on es van mesurar diversos paràmetres cervicals en gestants amb longitud cervical (LC) curta comparant-los amb un grup control amb LC normal. Els paràmetres avaluats eren: LC, angles cervicouterins (UCA), índexs de consistència cervical (CCI i CLCI), volum cervical (V) i els índexs vasculars. Tots ells van ser revaluats immediatament després de la inserció del pesari i 4-6 setmanes després. Una nova variable va ser descrita, anomenada angle intersegmentari (ISA), amb l’objectiu de millorar la detecció de canvis en almenys un dels dos UCA i a la vegada, per comprendre la relació entre els eixos cervical i uterí. Els resultats gestacionals van ser registrats per determinar la capacitat de predicció de PP<34SA i esdeveniments perinatals adversos, de les variables estudiades. Resultats Trenta-tres pacients amb LC curta i 24 controls van ser inclosos. En el moment d’inclusió, es van trobar diferències significatives: en el grup pesari, la LC era més curta, els UCA més obtusos, l’ISA més agut, el V inferior i la consistència cervical inferior que en els controls. Immediatament després del pesari, no es van observar efectes significatius en els índexs vasculars o en l’escala de grisos; no obstant, la LC va augmentar, els UCA es van tornar més aguts, l’ISA més obtús i el CLCI va millorar. Tots aquests paràmetres modificats pel pesari van esdevenir predictors de PP<34SA i esdeveniments perinatals adversos. La LC i l’A-UCA eren els millors paràmetres predictors amb una àrea sota la corba ROC de 0.88 i 0.87, respectivament. Després de 4-6 setmanes, l’ISA i el CLCI, en les pacients amb pesari, eren les úniques variables que seguien significativament modificades respecte al seu estat basal. Cap de les variables mostrava canvis significatius en les pacients control. Quan es va comparar l’evolució entre grups, es va veure com amb el pas del temps, la LC havia disminuït en les gestants control (-2.56 mm) mentre que en les gestants pesari, la LC havia augmentat (1.47 mm). Amés, l’ISA havia augmentat en les pacients amb pesari (11.25°) mentre que havia disminuït en els controls (-4.31°). Aquestes tendències inverses en la LC i en l’ISA van resultar estadísticament significatives (p=0.006 i p=0.044, respectivament). L’ecografia transvaginal va detectar 4 participants en les quals el pesari no es trobava correctament inserit (12.9%). Conclusions El pesari cervical redueix ambdós UCA i incrementa l’ISA; en conseqüència, corregeix l’angulació cervical per mitjà de la subjecció i elevació de l’OCI i el segment uterí. Addicionalment, el pesari ofereix suport estructural al cèrvix i per tant incrementa la consistència cervical i estabilitza la LC. Aquests canvis permeten predir i reduir el risc de PP<34SA i esdeveniments perinatals adversos. L’ecografia transvaginal s’hauria de realitzar de forma rutinària, després de la inserció d’un pesari cervical, per verificar el seu correcte emplaçament. Els nostres resultats informen de quin pesari té més possibilitats de ser efectiu o si pel contrari, caldria utilitzar tractaments alternatius o complementaris. Calen més estudis per poder avaluar la utilitat d’aplicar tractaments alternatius o addicionals. Els nostres resultats podrien ser considerats a l’hora de dissenyar aquest tipus d’estudis.Hypothesis Transvaginal ultrasound can identify the changes exerted on the cervix by the cervical pessary and these changes may correlate to the risk of spontaneous preterm birth (sPTB) at <34 weeks of gestation (WG) and severe adverse perinatals outcomes (APO). Objective To evaluate multiple cervical characteristics assessed by two-dimensional (2D) and three-dimensional (3D) ultrasound before and after placement of a cervical pessary to ascertain its mechanism of action and provide better predictive and follow-up tools. Methods In this prospective cohort study conducted at Vall d’Hebron Universitary Hospital, we assessed the cervical characteristics in patients with short cervical length (CL) and compared them with matched controls with normal CL. The variables evaluated were: CL, uterocervical angles (UCA), cervical consistency indices (CCI and CLCI), cervical volume (V) and vascular indices. All variables were re-assessed immediately after pessary placement in pessary carriers and 4 to 6 weeks later in all participants. A novel variable termed intersegmentary angle (ISA) was described to estimate relative uterocervical orientation and improve the detection of minor changes in at least one UCA. Pregnancy outcomes were recorded in order to determine the predicitive capacity of these variables for sPTB at <34 WG and severe adverse perinatals outcomes. Results Thirty-three study patients with short CL and 24 controls were enroled. At the time of enrolment, gestational age (GA) and maternal baseline characteristics did not differ between groups; however, significant differences were found in some cervical baseline variables: in the study group, CL was shorter, UCA wider, ISA more acute, V smaller and cervical consistency softer. Immediately after pessary placement, no significant effect was observed in vascular indices or mean grey scale (MG); however, CL increased, UCA were more acute, ISA was greater and cervical length consistency index (CLCI) improved; being all of them predicitive for sPTB at <34WG and severe APO. CL and A-UCA after pessary placement were the best predictive parameters with an area under de ROC curve of 0.88 and 0.87, respectively. After 4-6 weeks, P-UCA, ISA and CCI were the only variables that had persisted significantly modified since the baseline examination in the study group. No significant changes in any of the cervical characteristics were observed in controls. When the magnitude of change in cervical variables was compared over time between controls and the study group, median CL had increased in the study group (1.47 mm) while it had shortened in the control group (-2.56 mm). Additionally, ISA had widened in the study group (11.25°) while it had decreased in controls (-4.31°). These inverse trends in CL and ISA were statistically significant (p=0.006 and p=0.044, respectively). Cervical ultrasound assessment after pessary insertion allowed to detect 4 participants where the pessary was not correctly placed around the cervix (12.9%). Conclusions Cervical pessary reduces both UCA and increases ISA; consequently, the pessary corrects cervical angulation by pushing the cervix up towards the uterus and maintaining the cervix aligned to the uterine axis, which leads to reduced cervical tissue stretch. Additionally, pessary stabilises the cervical structure by increasing cervical consistency and avoiding cervical shortening. All these changes led to a lower risk of sPTB and severe APO. Transvaginal ultrasound after pessary insertion should be always performed in order to ascertain its correct placement around the cervix. Our results help to better understand in which patients the pessary is more likely to be successful or if contrarily, alternative or additional treatments should be considered. Further research is needed to assess the effectivity of applying alternative, sequential or additional treatments to reduce prematurity and our results should be considered when designing such studies

Seguiment de gestants portadores de pesari cervical mitjançant ecografia 2D i 3D

Hipòtesi L’ecografia transvaginal pot identificar els canvis que el pesari exerceix sobre el cèrvix uterí i aquests canvis es podrien correlacionar amb el risc de part prematur (PP) <34 setmanes d’amenorrea (SA) i d’esdeveniments perinatals adversos severs. Objectius Avaluar múltiples variables cervicals, obtingudes mitjançant ecografia transvaginal en dues (2D) i tres dimensions (3D), abans i després de la inserció del pesari cervical, amb l’objectiu de comprendre els mecanismes d’acció del pesari i obtenir millors eines predictores de PP i esdeveniments adversos perinatals. Mètodes Estudi de cohorts prospectiu, a l’Hospital Universitari Vall d’Hebron, on es van mesurar diversos paràmetres cervicals en gestants amb longitud cervical (LC) curta comparant-los amb un grup control amb LC normal. Els paràmetres avaluats eren: LC, angles cervicouterins (UCA), índexs de consistència cervical (CCI i CLCI), volum cervical (V) i els índexs vasculars. Tots ells van ser revaluats immediatament després de la inserció del pesari i 4-6 setmanes després. Una nova variable va ser descrita, anomenada angle intersegmentari (ISA), amb l’objectiu de millorar la detecció de canvis en almenys un dels dos UCA i a la vegada, per comprendre la relació entre els eixos cervical i uterí. Els resultats gestacionals van ser registrats per determinar la capacitat de predicció de PP<34SA i esdeveniments perinatals adversos, de les variables estudiades. Resultats Trenta-tres pacients amb LC curta i 24 controls van ser inclosos. En el moment d’inclusió, es van trobar diferències significatives: en el grup pesari, la LC era més curta, els UCA més obtusos, l’ISA més agut, el V inferior i la consistència cervical inferior que en els controls. Immediatament després del pesari, no es van observar efectes significatius en els índexs vasculars o en l’escala de grisos; no obstant, la LC va augmentar, els UCA es van tornar més aguts, l’ISA més obtús i el CLCI va millorar. Tots aquests paràmetres modificats pel pesari van esdevenir predictors de PP<34SA i esdeveniments perinatals adversos. La LC i l’A-UCA eren els millors paràmetres predictors amb una àrea sota la corba ROC de 0.88 i 0.87, respectivament. Després de 4-6 setmanes, l’ISA i el CLCI, en les pacients amb pesari, eren les úniques variables que seguien significativament modificades respecte al seu estat basal. Cap de les variables mostrava canvis significatius en les pacients control. Quan es va comparar l’evolució entre grups, es va veure com amb el pas del temps, la LC havia disminuït en les gestants control (-2.56 mm) mentre que en les gestants pesari, la LC havia augmentat (1.47 mm). Amés, l’ISA havia augmentat en les pacients amb pesari (11.25°) mentre que havia disminuït en els controls (-4.31°). Aquestes tendències inverses en la LC i en l’ISA van resultar estadísticament significatives (p=0.006 i p=0.044, respectivament). L’ecografia transvaginal va detectar 4 participants en les quals el pesari no es trobava correctament inserit (12.9%). Conclusions El pesari cervical redueix ambdós UCA i incrementa l’ISA; en conseqüència, corregeix l’angulació cervical per mitjà de la subjecció i elevació de l’OCI i el segment uterí. Addicionalment, el pesari ofereix suport estructural al cèrvix i per tant incrementa la consistència cervical i estabilitza la LC. Aquests canvis permeten predir i reduir el risc de PP<34SA i esdeveniments perinatals adversos. L’ecografia transvaginal s’hauria de realitzar de forma rutinària, després de la inserció d’un pesari cervical, per verificar el seu correcte emplaçament. Els nostres resultats informen de quin pesari té més possibilitats de ser efectiu o si pel contrari, caldria utilitzar tractaments alternatius o complementaris. Calen més estudis per poder avaluar la utilitat d’aplicar tractaments alternatius o addicionals. Els nostres resultats podrien ser considerats a l’hora de dissenyar aquest tipus d’estudis.Hypothesis Transvaginal ultrasound can identify the changes exerted on the cervix by the cervical pessary and these changes may correlate to the risk of spontaneous preterm birth (sPTB) at <34 weeks of gestation (WG) and severe adverse perinatals outcomes (APO). Objective To evaluate multiple cervical characteristics assessed by two-dimensional (2D) and three-dimensional (3D) ultrasound before and after placement of a cervical pessary to ascertain its mechanism of action and provide better predictive and follow-up tools. Methods In this prospective cohort study conducted at Vall d’Hebron Universitary Hospital, we assessed the cervical characteristics in patients with short cervical length (CL) and compared them with matched controls with normal CL. The variables evaluated were: CL, uterocervical angles (UCA), cervical consistency indices (CCI and CLCI), cervical volume (V) and vascular indices. All variables were re-assessed immediately after pessary placement in pessary carriers and 4 to 6 weeks later in all participants. A novel variable termed intersegmentary angle (ISA) was described to estimate relative uterocervical orientation and improve the detection of minor changes in at least one UCA. Pregnancy outcomes were recorded in order to determine the predicitive capacity of these variables for sPTB at <34 WG and severe adverse perinatals outcomes. Results Thirty-three study patients with short CL and 24 controls were enroled. At the time of enrolment, gestational age (GA) and maternal baseline characteristics did not differ between groups; however, significant differences were found in some cervical baseline variables: in the study group, CL was shorter, UCA wider, ISA more acute, V smaller and cervical consistency softer. Immediately after pessary placement, no significant effect was observed in vascular indices or mean grey scale (MG); however, CL increased, UCA were more acute, ISA was greater and cervical length consistency index (CLCI) improved; being all of them predicitive for sPTB at <34WG and severe APO. CL and A-UCA after pessary placement were the best predictive parameters with an area under de ROC curve of 0.88 and 0.87, respectively. After 4-6 weeks, P-UCA, ISA and CCI were the only variables that had persisted significantly modified since the baseline examination in the study group. No significant changes in any of the cervical characteristics were observed in controls. When the magnitude of change in cervical variables was compared over time between controls and the study group, median CL had increased in the study group (1.47 mm) while it had shortened in the control group (-2.56 mm). Additionally, ISA had widened in the study group (11.25°) while it had decreased in controls (-4.31°). These inverse trends in CL and ISA were statistically significant (p=0.006 and p=0.044, respectively). Cervical ultrasound assessment after pessary insertion allowed to detect 4 participants where the pessary was not correctly placed around the cervix (12.9%). Conclusions Cervical pessary reduces both UCA and increases ISA; consequently, the pessary corrects cervical angulation by pushing the cervix up towards the uterus and maintaining the cervix aligned to the uterine axis, which leads to reduced cervical tissue stretch. Additionally, pessary stabilises the cervical structure by increasing cervical consistency and avoiding cervical shortening. All these changes led to a lower risk of sPTB and severe APO. Transvaginal ultrasound after pessary insertion should be always performed in order to ascertain its correct placement around the cervix. Our results help to better understand in which patients the pessary is more likely to be successful or if contrarily, alternative or additional treatments should be considered. Further research is needed to assess the effectivity of applying alternative, sequential or additional treatments to reduce prematurity and our results should be considered when designing such studies

Seguiment de gestants portadores de pesari cervical mitjançant ecografia 2D i 3D

Hipòtesi L'ecografia transvaginal pot identificar els canvis que el pesari exerceix sobre el cèrvix uterí i aquests canvis es podrien correlacionar amb el risc de part prematur (PP) <34 setmanes d'amenorrea (SA) i d'esdeveniments perinatals adversos severs. Objectius Avaluar múltiples variables cervicals, obtingudes mitjançant ecografia transvaginal en dues (2D) i tres dimensions (3D), abans i després de la inserció del pesari cervical, amb l'objectiu de comprendre els mecanismes d'acció del pesari i obtenir millors eines predictores de PP i esdeveniments adversos perinatals. Mètodes Estudi de cohorts prospectiu, a l'Hospital Universitari Vall d'Hebron, on es van mesurar diversos paràmetres cervicals en gestants amb longitud cervical (LC) curta comparant-los amb un grup control amb LC normal. Els paràmetres avaluats eren: LC, angles cervicouterins (UCA), índexs de consistència cervical (CCI i CLCI), volum cervical (V) i els índexs vasculars. Tots ells van ser revaluats immediatament després de la inserció del pesari i 4-6 setmanes després. Una nova variable va ser descrita, anomenada angle intersegmentari (ISA), amb l'objectiu de millorar la detecció de canvis en almenys un dels dos UCA i a la vegada, per comprendre la relació entre els eixos cervical i uterí. Els resultats gestacionals van ser registrats per determinar la capacitat de predicció de PP<34SA i esdeveniments perinatals adversos, de les variables estudiades. Resultats Trenta-tres pacients amb LC curta i 24 controls van ser inclosos. En el moment d'inclusió, es van trobar diferències significatives: en el grup pesari, la LC era més curta, els UCA més obtusos, l'ISA més agut, el V inferior i la consistència cervical inferior que en els controls. Immediatament després del pesari, no es van observar efectes significatius en els índexs vasculars o en l'escala de grisos; no obstant, la LC va augmentar, els UCA es van tornar més aguts, l'ISA més obtús i el CLCI va millorar. Tots aquests paràmetres modificats pel pesari van esdevenir predictors de PP<34SA i esdeveniments perinatals adversos. La LC i l'A-UCA eren els millors paràmetres predictors amb una àrea sota la corba ROC de 0.88 i 0.87, respectivament. Després de 4-6 setmanes, l'ISA i el CLCI, en les pacients amb pesari, eren les úniques variables que seguien significativament modificades respecte al seu estat basal. Cap de les variables mostrava canvis significatius en les pacients control. Quan es va comparar l'evolució entre grups, es va veure com amb el pas del temps, la LC havia disminuït en les gestants control (-2.56 mm) mentre que en les gestants pesari, la LC havia augmentat (1.47 mm). Amés, l'ISA havia augmentat en les pacients amb pesari (11.25°) mentre que havia disminuït en els controls (-4.31°). Aquestes tendències inverses en la LC i en l'ISA van resultar estadísticament significatives (p=0.006 i p=0.044, respectivament). L'ecografia transvaginal va detectar 4 participants en les quals el pesari no es trobava correctament inserit (12.9%). Conclusions El pesari cervical redueix ambdós UCA i incrementa l'ISA; en conseqüència, corregeix l'angulació cervical per mitjà de la subjecció i elevació de l'OCI i el segment uterí. Addicionalment, el pesari ofereix suport estructural al cèrvix i per tant incrementa la consistència cervical i estabilitza la LC. Aquests canvis permeten predir i reduir el risc de PP<34SA i esdeveniments perinatals adversos. L'ecografia transvaginal s'hauria de realitzar de forma rutinària, després de la inserció d'un pesari cervical, per verificar el seu correcte emplaçament. Els nostres resultats informen de quin pesari té més possibilitats de ser efectiu o si pel contrari, caldria utilitzar tractaments alternatius o complementaris. Calen més estudis per poder avaluar la utilitat d'aplicar tractaments alternatius o addicionals. Els nostres resultats podrien ser considerats a l'hora de dissenyar aquest tipus d'estudis.Hypothesis Transvaginal ultrasound can identify the changes exerted on the cervix by the cervical pessary and these changes may correlate to the risk of spontaneous preterm birth (sPTB) at <34 weeks of gestation (WG) and severe adverse perinatals outcomes (APO). Objective To evaluate multiple cervical characteristics assessed by two-dimensional (2D) and three-dimensional (3D) ultrasound before and after placement of a cervical pessary to ascertain its mechanism of action and provide better predictive and follow-up tools. Methods In this prospective cohort study conducted at Vall d'Hebron Universitary Hospital, we assessed the cervical characteristics in patients with short cervical length (CL) and compared them with matched controls with normal CL. The variables evaluated were: CL, uterocervical angles (UCA), cervical consistency indices (CCI and CLCI), cervical volume (V) and vascular indices. All variables were re-assessed immediately after pessary placement in pessary carriers and 4 to 6 weeks later in all participants. A novel variable termed intersegmentary angle (ISA) was described to estimate relative uterocervical orientation and improve the detection of minor changes in at least one UCA. Pregnancy outcomes were recorded in order to determine the predicitive capacity of these variables for sPTB at <34 WG and severe adverse perinatals outcomes. Results Thirty-three study patients with short CL and 24 controls were enroled. At the time of enrolment, gestational age (GA) and maternal baseline characteristics did not differ between groups; however, significant differences were found in some cervical baseline variables: in the study group, CL was shorter, UCA wider, ISA more acute, V smaller and cervical consistency softer. Immediately after pessary placement, no significant effect was observed in vascular indices or mean grey scale (MG); however, CL increased, UCA were more acute, ISA was greater and cervical length consistency index (CLCI) improved; being all of them predicitive for sPTB at <34WG and severe APO. CL and A-UCA after pessary placement were the best predictive parameters with an area under de ROC curve of 0.88 and 0.87, respectively. After 4-6 weeks, P-UCA, ISA and CCI were the only variables that had persisted significantly modified since the baseline examination in the study group. No significant changes in any of the cervical characteristics were observed in controls. When the magnitude of change in cervical variables was compared over time between controls and the study group, median CL had increased in the study group (1.47 mm) while it had shortened in the control group (-2.56 mm). Additionally, ISA had widened in the study group (11.25°) while it had decreased in controls (-4.31°). These inverse trends in CL and ISA were statistically significant (p=0.006 and p=0.044, respectively). Cervical ultrasound assessment after pessary insertion allowed to detect 4 participants where the pessary was not correctly placed around the cervix (12.9%). Conclusions Cervical pessary reduces both UCA and increases ISA; consequently, the pessary corrects cervical angulation by pushing the cervix up towards the uterus and maintaining the cervix aligned to the uterine axis, which leads to reduced cervical tissue stretch. Additionally, pessary stabilises the cervical structure by increasing cervical consistency and avoiding cervical shortening. All these changes led to a lower risk of sPTB and severe APO. Transvaginal ultrasound after pessary insertion should be always performed in order to ascertain its correct placement around the cervix. Our results help to better understand in which patients the pessary is more likely to be successful or if contrarily, alternative or additional treatments should be considered. Further research is needed to assess the effectivity of applying alternative, sequential or additional treatments to reduce prematurity and our results should be considered when designing such studies