Bridging the notch: quantification of the end diastolic notch to better predict fetal growth restriction.

PURPOSE: We aimed to evaluate several quantitative methods to describe the diastolic notch (DN) and compare their performance in the prediction of fetal growth restriction. MATERIALS AND METHODS: Patients who underwent a placental scan at 16-26 weeks of gestation and delivered between Jan 2016 and Dec 2020 were included. The uterine artery pulsatility index was measured for all of the patients. In patients with a DN, it was quantified using the notch index and notch depth index. Odds ratios for small for gestational age neonates (defined as birth weight <10th and <5th percentile) were calculated. Predictive values of uterine artery pulsatility, notch, and notch depth index for fetal growth restriction were calculated. RESULTS: Overall, 514 patients were included, with 69 (13.4%) of them delivering a small for gestational age neonate (birth weight<10th percentile). Of these, 20 (20.9%) had a mean uterine artery pulsatility index >95th percentile, 13 (18.8%) had a unilateral notch, and 11 (15.9%) had a bilateral notch. 16 patients (23.2%) had both a high uterine artery pulsatility index (>95th percentile) and a diastolic notch. Comparison of the performance between uterine artery pulsatility, notch, and notch depth index using receiver operating characteristic curves to predict fetal growth restriction <10th percentile found area under the curve values of 0.659, 0.679, and 0.704, respectively, with overlapping confidence intervals. CONCLUSION: Quantifying the diastolic notch at 16-26 weeks of gestation did not provide any added benefit in terms of prediction of neonatal birth weight below the 10th or 5th percentile for gestational age, compared with uterine artery pulsatility index.

A prediction tool for mode of delivery in twin pregnancies-a secondary analysis of the Twin Birth Study.

BACKGROUND: One of the controversies regarding the management of twin gestations relates to the mode of delivery. Currently, counseling regarding the mode of delivery and the chance of successful vaginal twin delivery is based on the average risk for intrapartum cesarean delivery in the general population of twin pregnancies. Decision support tools that provide an individualized risk for intrapartum cesarean delivery based on the unique characteristics of each patient can improve counseling and decision-making regarding the choice of mode of delivery in twin pregnancies. OBJECTIVE: This study aimed to develop and validate a prediction model to determine the risk for intrapartum cesarean delivery in twin pregnancies. STUDY DESIGN: In this secondary analysis of the Twin Birth Study, a multicenter randomized controlled trial, we considered the subgroup of individuals who underwent a trial of vaginal delivery. Candidate predictors included maternal age, parity, previous cesarean delivery, conception method, chorionicity, diabetes and hypertension in pregnancy, gestational age at birth, the onset of labor, presentation of the second twin, sonographic fetal weight estimation, and fetal sex. The co-primary outcomes were overall intrapartum cesarean delivery and cesarean delivery of the second twin. Multivariable logistic regression models were used to estimate the probability of the study outcomes. Model performance was evaluated using measures of discrimination (the area under the receiver operating characteristic curve), calibration, and predictive accuracy. Internal validation was performed using the bootstrap resampling technique. RESULTS: A total of 1221 individuals met the study criteria. The rate of overall intrapartum cesarean delivery and cesarean delivery for the second twin was 25.4% and 5.7%, respectively. The most contributory predictor variables were nulliparity, term birth (≥37 weeks), a noncephalic presentation of the second twin, previous cesarean delivery, and labor induction. The models for overall intrapartum cesarean delivery and cesarean delivery of the second twin had good overall discriminatory accuracy (area under the receiver operating characteristic curve, 0.720; 95% confidence interval, 0.688-0.752 and 0.736; 95% confidence interval, 0.669-0.803, respectively) and calibration (as illustrated by the calibration plot and Brier scores of 0.168; 95% confidence interval, 0.156-0.180 and 0.051; 95% confidence interval, 0.040-0.061, respectively). The models achieved good specificity (66.7% and 81.6%, respectively), high negative predictive value (86.0% and 96.9%, respectively), and moderate sensitivity (68.1% and 57.1%, respectively). CONCLUSION: The prediction models developed in this study may assist care providers in counseling individuals regarding the optimal timing and mode of delivery in twin pregnancies by providing individualized estimates of the risk for intrapartum cesarean delivery.

National and international guidelines on the management of twin pregnancies: a comparative review.

Twin gestations are associated with increased risk of pregnancy complications. However, high-quality evidence regarding the management of twin pregnancies is limited, often resulting in inconsistencies in the recommendations of various national and international professional societies. In addition, some recommendations related to the management of twin gestations are often missing from the clinical guidelines dedicated to twin pregnancies and are instead included in the practice guidelines on specific pregnancy complications (eg, preterm birth) of the same professional society. This can make it challenging for care providers to easily identify and compare recommendations for the management of twin pregnancies. This study aimed to identify, summarize, and compare the recommendations of selected professional societies from high-income countries on the management of twin pregnancies, highlighting areas of both consensus and controversy. We reviewed clinical practice guidelines of selected major professional societies that were either specific to twin pregnancies or were focused on pregnancy complications or aspects of antenatal care that may be relevant for twin pregnancies. We decided a priori to include clinical guidelines from 7 high-income countries (United States, Canada, United Kingdom, France, Germany, and Australia and New Zealand grouped together) and from 2 international societies (International Society of Ultrasound in Obstetrics and Gynecology and the International Federation of Gynecology and Obstetrics). We identified recommendations regarding the following care areas: first-trimester care, antenatal surveillance, preterm birth and other pregnancy complications (preeclampsia, fetal growth restriction, and gestational diabetes mellitus), and timing and mode of delivery. We identified 28 guidelines published by 11 professional societies from the 7 countries and 2 international societies. Thirteen of these guidelines focus on twin pregnancies, whereas the other 16 focus on specific pregnancy complications predominantly in singletons but also include some recommendations for twin pregnancies. Most of the guidelines are recent, with 15 of the 29 guidelines published over the past 3 years. We identified considerable disagreement among guidelines, primarily in 4 key areas: screening and prevention of preterm birth, using aspirin to prevent preeclampsia, defining fetal growth restriction, and the timing of delivery. In addition, there is limited guidance on several important areas, including the implications of the "vanishing twin" phenomenon, technical aspects and risks of invasive procedures, nutrition and weight gain, physical and sexual activity, the optimal growth chart to be used in twin pregnancies, the diagnosis and management of gestational diabetes mellitus, and intrapartum care.This consolidation of key recommendations across several clinical practice guidelines can assist healthcare providers in accessing and comparing recommendations on the management of twin pregnancies and identifies high-priority areas for future research based on either continued disagreement among societies or limited current evidence to guide care.

The smaller firstborn: exploring the association of parity and fetal growth.

PURPOSE: To investigate the association of parity with a range of neonatal anthropometric measurements in a cohort of uncomplicated term singleton pregnancies. METHODS: Retrospective cohort study of patients with a singleton term birth at a single tertiary center (2014-2020) was carried out. The primary exposure was parity. The following neonatal anthropometric measures were considered: birthweight, head circumference, length, ponderal index, and neonatal body mass index (BMI). RESULTS: A total of 8134 patients met the study criteria, 1949 (24.0%) of whom were nulliparous. Compared with multiparous patients, infants of nulliparous patients had a lower mean percentile for birthweight (43.1 ± 26.4 vs. 48.3 ± 26.8 percentile, p < 0.001), head circumference (44.3 ± 26.4 vs. 48.1 ± 25.5 percentile, p < 0.001), length (52.6 ± 25.1 vs. 55.5 ± 24.6 percentile, p < 0.001), ponderal index (34.4 ± 24.0 vs. 37.6 ± 24.2 percentile, p < 0.001), and BMI (39.1 ± 27.1 vs. 43.9 ± 27.3 percentile, p < 0.001). In addition, infants of nulliparous patients had higher odds of having a small (< 10th percentile for gestational age) birthweight (aOR 1.32 [95% CI 1.12-1.56]), head circumference (aOR 1.54 [95% CI 1.29-1.84]), length (aOR 1.50 [95% CI 1.16-1.94]), ponderal index (aOR 1.30 [95% CI 1.12-1.51]), and body mass index (aOR 1.42 [95% CI 1.22-1.65]). Most neonatal anthropometric measures increased with parity until a parity of 2, where it seemed to reach a plateau. CONCLUSION: Parity has an independent impact on a wide range of neonatal anthropometric measures, suggesting that parity is associated with both fetal skeletal growth and body composition. In addition, the association of parity with fetal growth does not follow a continuous relationship but instead reaches a plateau after the second pregnancy.

Guideline No. 428: Management of Dichorionic Twin Pregnancies.

OBJECTIVE: To review evidence-based recommendations for the management of dichorionic twin pregnancies. TARGET POPULATION: Pregnant women with a dichorionic twin pregnancy. BENEFITS, HARMS, AND COSTS: Implementation of the recommendations in this guideline may improve the management of twin pregnancies and reduce neonatal and maternal morbidity and mortality. EVIDENCE: Published literature was retrieved through searches of PubMed and the Cochrane Library using appropriate controlled vocabulary (e.g., twin, preterm birth). Results were restricted to systematic reviews, randomized controlled trials, controlled clinical trials, and observational studies. There were no date limits, but results were limited to English- or French-language materials. VALIDATION METHODS: The content and recommendations were drafted and agreed upon by the principal authors. The Board of the SOGC approved the final draft for publication. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations). INTENDED AUDIENCE: Obstetricians, family physicians, nurses, midwives, maternal-fetal medicine specialists, radiologists, and other health care providers who care for women with twin pregnancies. SUMMARY STATEMENTS: RECOMMENDATIONS.

Directive clinique no 428 : Prise en charge de la grossesse gémellaire bichoriale.

OBJECTIF: Examiner les recommandations fondées sur des données probantes pour la prise en charge de la grossesse gémellaire bichoriale. POPULATION CIBLE: Femmes enceintes qui mènent une grossesse gémellaire bichoriale. BéNéFICES, RISQUES ET COûTS: La mise en œuvre des recommandations de la présente directive pourrait améliorer la prise en charge de la grossesse gémellaire et réduire les risques de morbidité et mortalité néonatales et maternelles. DONNéES PROBANTES: La littérature publiée a été rassemblée par des recherches dans les bases de données PubMed et Cochrane Library au moyen d'un vocabulaire contrôlé approprié (p. ex., twin, preterm birth). Seuls les résultats de revues systématiques, d'essais cliniques randomisés ou comparatifs et d'études observationnelles ont été retenus. Aucune contrainte n'a été appliquée quant à la date de publication, mais les résultats ont été limités aux contenus en anglais ou en français. MéTHODES DE VALIDATION: Le contenu et les recommandations ont été rédigés et acceptés par les auteurs principaux. Le conseil d'administration de la SOGC a approuvé la version définitive aux fins de publication. Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique d'évaluation, de développement et d'évaluation (GRADE). Consulter l'annexe A en ligne (le tableau A1 pour les définitions et le tableau A2 pour les interprétations des recommandations fortes et faibles). PROFESSIONNELS CONCERNéS: Obstétriciens, médecins de famille, infirmières, sages-femmes, spécialistes en médecine fœto-maternelle, radiologistes et autres professionnels de la santé qui prodiguent des soins aux femmes enceintes de jumeaux. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Glucose tolerance test with a single abnormal value in pregnancy and the risk of type-2 diabetes mellitus.

PURPOSE: To evaluate the association between a single abnormal value on a 3-h 100 g oral glucose tolerance test (OGTT) results and future type-2 diabetes mellitus (Type-2 DM). METHODS: Retrospective cohort study of women between 18 and 45 years of age who underwent a 3-h OGTT during pregnancy and delivered in a tertiary medical center between 2007 and 2014. The women  were followed for a median period of 64 months postpartum. According to OGTT values, women were divided into three groups: normoglycemic (normal OGTT), single abnormal OGTT value (SAV) and gestational diabetes mellitus (two or more abnormal OGTT values, GDM). General pre-pregnancy characteristics, cardiovascular risk factors and future diagnosis of Type-2 DM, as the primary outcome, were recorded. RESULTS: During the study period, 5295 women underwent an OGTT and were followed for a median period of 64 months (interquartile range of 32). The cohort was divided as following: 3639 (68.73%) were normoglycemic, 854 (16.13%) had a SAV in the OGTT and 802 (15.15%) were diagnosed with GDM. Compared with normoglycemic controls, women with SAV and GDM tended to be older (32.20, 33.10 and 31.35 years for SAV, GDM and controls, respectively, p < 0.001); with higher rates of pre-pregnancy obesity (18.62%, 20.77% and 13.22% for SAV, GDM and controls, respectively, p < 0.001), pre-pregnancy hyperlipidemia (13.35%, 15.30% and 10.52% for SAV, GDM and controls, respectively, p = 0.021) and pre-pregnancy chronic hypertension (5.50%, 4.43% and 3.18% for SAV, GDM and controls, respectively, p = 0.01). Post-pregnancy Type-2 DM was diagnosed at a higher rate among women with SAV or GDM (2.69% for SAV, 7.39% for GDM and 0.66% for normoglycemic controls, p < 0.001). Using a cox proportional hazard regression, SAV and GDM were significantly and independently associated with a higher rate of future overt type-2 diabetes (adjusted aOR 3.59 for SAV and 11.38 for GDM, p < 0.001). In a sub-analysis of the OGTT values, overall, abnormal fasting glucose had the highest correlation with developing future Type-2 DM (8.95% compared with 6.02% for OGTT_60, 6.03% for OGTT_120 and 7.35% for OGTT_180, p < 0.001). A predictive model, combining multiple risk factors, as pre-pregnancy obesity and hypertension with SAV complicating the index pregnancy showed a risk as high as 3.40% for developing future Type-2 DM. CONCLUSION: SAV is independently associated with a significant higher rate of future Type-2 DM, as early as 5 years following the index pregnancy.

Timing of antenatal corticosteroids in relation to clinical indication.

PURPOSE: This study aimed at determining the proportion of women who receive antenatal corticosteroids (ACS) within the optimal time window before birth based on the indication for ACS, and to explore in more detail indications that are associated with suboptimal timing. METHODS: A retrospective cohort study of all women who received ACS in a single tertiary center between 2014 and 2017. The primary outcome was an ACS-to-birth interval ≤ 7 days. Secondary outcomes were ACS-to-birth interval of ≤ 14 days, and the proportion women who received ACS but ultimately gave birth at term (≥ 370/7 weeks). The study outcomes were stratified by the clinical indication for ACS. RESULTS: A total of 1261 women met the study criteria, of whom 401 (31.8%) and 569 (45.1%) received ACS within ≤ 7 days and ≤ 14 days before birth, respectively, and 203 (16.1%) ultimately gave birth at term. The proportion of women who received ACS within 7 days before birth was highest for women with preeclampsia (50.4%), and was lowest for women with an incidental finding of a short cervix (8.4%). In the subgroup of women with an incidental finding of a short cervix, the likelihood of optimal timing was not related to the magnitude of cervical shortening, history of preterm birth, multifetal gestation, presence of cervical funneling, or the presence of cervical cerclage. CONCLUSION: Over two-thirds of infants who are exposed to ACS do not get the maximal benefit from this intervention. The current study identified clinical indications for ACS that are associated with suboptimal timing of ACS where more research is needed to develop quantitative, indication-specific prediction models to guide the timing of ACS.

Patterns of discordant growth and adverse neonatal outcomes in twins.

BACKGROUND: Intertwin size discordance is an independent risk factor for adverse neonatal outcomes in twin pregnancies. However, size discordance at a given point in gestation fails to take into consideration information, such as the timing of onset and the rate of progression of discordance, that may be of prognostic value. OBJECTIVE: In this study, we aimed to identify distinct patterns of discordant fetal growth in twin pregnancies and to determine whether these patterns are predictive of adverse pregnancy outcomes. STUDY DESIGN: This was a retrospective cohort study of women with twin pregnancies in a single tertiary referral center between January 2011 and April 2020, who had at least 3 ultrasound examinations during pregnancy that included assessment of fetal biometry. Size discordance was calculated at each ultrasound examination, and pregnancies were classified into 1 of 4 predetermined patterns based on the timing of onset and the progression of discordance: pattern 1, no significant discordance group (referent); pattern 2, early (<24 weeks' gestation) progressive discordance group; pattern 3, early discordance with plateau group; or pattern 4, late (≥24 weeks' gestation) discordance group. The associations of discordance pattern (using pattern 1 as referent) with preterm birth, preeclampsia, size discordance at birth, and birthweight<10th percentile were expressed as adjusted relative risk with 95% confidence intervals and were compared with those observed for a single measurement of size discordance at 32 weeks' gestation. RESULTS: Of 2075 women with a twin gestation who were identified during the study period, 1059 met the study criteria. Of the 1059 women, 599 (57%) were classified as no significant discordance (pattern 1), 23 (2%) as early progressive discordance (pattern 2), 160 (15%) as early discordance with plateau (pattern 3), and 277 (26%) as late discordance (pattern 4). The associations of discordance pattern with preterm birth at <34 weeks' gestation and preeclampsia were strongest for pattern 2 (rates of 43% [adjusted relative risk, 3.43; 95% confidence interval, 2.10-5.62] and 17% [adjusted relative risk, 5.81; 95% confidence interval, 2.31-14.60], respectively), intermediate for pattern 3 (rates of 23% [adjusted relative risk, 1.82; 95% confidence interval, 1.28-2.59] and 6% [adjusted relative risk, 2.08; 95% confidence interval, 1.01-4.43], respectively), and weakest for pattern 4 (rates of 12% [adjusted relative risk, 0.96; 95% confidence interval, 0.65-1.42] and 4% [adjusted relative risk, 1.41; 0.68-2.92], respectively). In contrast, a single measurement of size discordance at 32 weeks' gestation showed no association with preeclampsia and only a weak association with preterm birth at <34 weeks' gestation. CONCLUSION: We identified 4 distinct discordance growth patterns among twins that demonstrated a dose-response relationship with adverse outcomes and seemed to be more informative than a single measurement of size discordance.

The association between fetal head station at the first diagnosis of the second stage of labor and delivery outcomes.

BACKGROUND: Controversy surrounds the impact of the fetal head station on labor duration and mode of delivery. Although an extensive body of evidence has been published evaluating fetal head station in early labor, there is a paucity of data on the impact of fetal head descent during the second stage. OBJECTIVE: This study aimed to explore the association between fetal head station at the diagnosis of the second stage of labor and the second stage duration and the risk of operative delivery. STUDY DESIGN: This is a retrospective cohort study of all singleton vertex deliveries in a single tertiary center (2011-2016). Women were grouped according to fetal head station upon the diagnosis of the second stage of labor as follows: above (S<0), at the level (S=0), and below (S>0) the level of the ischial spine. The duration of the second stage and the risk of operative delivery were compared between the groups and stratified by parity. RESULTS: Overall, 34,334 women met the inclusion criteria. Of these, 18,743 (54.6%) were nulliparous and 15,591 (45.4%) were multiparous. Of the nulliparous women, 8.1%, 35.8%, and 56.1% were diagnosed as having fetal head above, at the level, and below the ischial spine upon second stage diagnosis. Of the multiparous women, 19.7%, 35.6%, and 44.7% were diagnosed as having fetal head above, at the level, and below the ischial spine. Fetal head station upon second stage diagnosis was independently and significantly associated with second stage duration (P<.001); however, its contribution was 4.5-fold among nulliparous women compared with multiparous women. In multivariable analysis, after controlling for maternal age, gestational age at delivery, prepregnancy body mass index, epidural anesthesia, and birthweight, the risk of operative delivery was substantially increased in a dose-dependent pattern for both nulliparous and multiparous women. CONCLUSION: The fetal head station at the first diagnosis of the second stage is significantly and independently associated with the duration of the second stage and correlated with the risk of operative delivery in both nulliparous and multiparous women (P<.001).

Comparison of sonographic fetal weight estimation formulas in patients with preterm premature rupture of membranes.

BACKGROUND: Estimation of fetal weight (EFW) by ultrasound is useful in clinical decision-making. Numerous formulas for EFW have been published but have not been validated in pregnancies complicated by preterm premature rupture of membranes (PPROM). The purpose of this study is to compare the accuracy of EFW formulas in patients with PPROM, and to further evaluate the performance of the most commonly used formula - Hadlock IV. METHODS: A retrospective cohort study of women with singleton gestations and PPROM, admitted to a single tertiary center between 2005 and 2017 from 220/7-330/7 (n = 565). All women had an EFW within 14 days of delivery by standard biometry (biparietal diameter, head circumference, abdominal circumference and femur length). The accuracy of previously published 21 estimated EFW formulas was assessed by comparing the Pearson correlation with actual birth weight, and calculating the random error, systematic error, proportion of estimates within 10% of birth weight, and Euclidean distance. RESULTS: The mean gestational was 26.8 ± 2.4 weeks at admission, and 28.2 ± 2.6 weeks at delivery. Most formulas were strongly correlated with actual birth weight (r > 0.9 for 19/21 formulas). Mean systematic error was - 4.30% and mean random error was 14.5%. The highest performing formula, by the highest proportion of estimates and lowest Euclidean distance was Ott (1986), which uses abdominal and head circumferences, and femur length. However, there were minimal difference with all of the first 10 ranking formulas. The Pearson correlation coefficient for the Hadlock IV formula was strong at r = 0.935 (p < 0.001), with 319 (56.5%) of measurements falling within 10%, 408 (72.2%) within 15% and 455 (80.5%) within 20% of actual birth weight. This correlation was unaffected by gender (r = 0.936 for males, r = 0.932 for females, p < 0.001 for both) or by amniotic fluid level (r = 0.935 for mean vertical pocket < 2 cm, r = 0.943 for mean vertical pocket ≥2 cm, p < 0.001 for both). CONCLUSIONS: In women with singleton gestation and PPROM, the Ott (1986) formula for EFW was the most accurate, yet all of the top ten ranking formulas performed quite well. The commonly used Hadlock IV performed quite similarly to Ott's formula, and is acceptable to use in this specific setting.

Questionnaire-based vs universal PCR testing for SARS-CoV-2 in women admitted for delivery.

BACKGROUND: It has been suggested that women admitted for delivery should have universal PCR testing for SARS-CoV-2. Yet, the considerable difference in the incidence of COVID-19 between different geographic regions may affect screening strategies. Therefore, we aimed to compare questionnaire-based testing versus universal PCR testing for SARS-CoV-2 in women admitted for delivery. METHODS: A prospective cohort study of women admitted for delivery at a single center during a four-week period (April 22-May 25, 2020). All women completed a questionnaire about COVID-19 signs, symptoms, or risk factors, and a nasopharyngeal swab for PCR for SARS-CoV-2. Women who were flagged as suspected COVID-19 by the questionnaire (questionnaire-positive) were compared with women who were not flagged by the questionnaire (questionnaire-negative). RESULTS: Overall, 446 women were eligible for analysis, of which 54 (12.1%) were questionnaire-positive. PCR swab detected SARS-CoV-2 in four (0.9%) women: 3 of 392 (0.8%) in the questionnaire-negative group, and 1 of 54 (1.9%) in the questionnaire-positive group (P = .43), yielding a number needed to screen of 92 (95% CI 62-177). In 96% of the cases, the PCR results were obtained only in the postpartum period. No positive PCR results were obtained from neonatal testing for SARS-CoV-2. The sensitivity of the questionnaire was 75.0%, and the negative predictive value was 99.7%. CONCLUSIONS: Although the rate of positive PCR results was not significantly different between the groups, the number needed to screen is considerably high. The use of questionnaire-based PCR testing in areas with low incidence of COVID-19 allows for a reasonable allocation of resources and is easy to implement.

Maternal Ethnicity and the Risk of Obstetrical Anal Sphincter Injury: A Retrospective Cohort Study.

OBJECTIVE: To explore the role of maternal ethnicity as a risk factor for obstetrical anal sphincter injury (OASI). METHODS: A retrospective cohort study of all women with singleton gestations who had a vaginal delivery at term, between January 2014 and October 2017, at a single center. OASI was defined as a third-degree perineal tear (anal sphincter complex) or a fourth-degree perineal tear (anorectal mucosa). The characteristics of women with and without OASIs were compared. Multiple logistic regression was performed to account for potential confounders, including ethnicity. RESULTS: During the study period, 11 012 women were eligible for inclusion, of whom 336 (3.1%) had an OASI; 313 (93.1%) had a third-degree tear, and 23 (6.9%) had a fourth-degree tear. Women with OASIs were characterized by younger maternal age (<35 years), Asian ethnicity, nulliparity, neonatal birth weight ≥3500 grams, midline and mediolateral episiotomy, second stage of labour lasting ≥60 minutes, and assisted vaginal delivery. After adjusting for potential confounders, Asian ethnicity remained independently associated with increased risk of OASI (adjusted odds ratio 2.07; 95% CI 1.6-2.7) whereas mediolateral episiotomy was independently associated with decreased risk of OASI (adjusted odds ratio 0.64; 95% CI 0.5-0.9). CONCLUSION: Asian ethnicity is independently associated with increased risk of OASI. Although midline episiotomy increases the risk of OASI, mediolateral episiotomy may protect against OASI, and should be considered in high-risk patients.

Trial of labor after previous single cesarean delivery in grand-multiparous women: a retrospective cohort study.

PURPOSE: To compare pregnancy outcomes in grand-multiparous (GMP) women with and without one previous cesarean delivery (CD), and to evaluate the number of previous successful vaginal deliveries after a CD needed to reduce the complication rate of trials of labor after a previous CD. METHODS: This is a retrospective cohort study of women with singleton pregnancy at term who had a trial of vaginal delivery between 2007 and 2014 at a tertiary medical center. We compared pregnancy outcomes in GMP women with and without one previous cesarean delivery. The primary outcome was mode of delivery and secondary outcomes were uterine rupture and composite maternal and neonatal morbidity. For the secondary objective, we compared pregnancy outcomes in women in TOLAC, stratified by the number of previous vaginal deliveries. RESULTS: Overall, 2815 GMP women met the study criteria, of which 310 (11%) had a previous cesarean delivery. The rate of a successful vaginal deliveries (VBAC) was similar, regardless of the presence of a previous cesarean delivery. No other differences in outcomes were found between the groups. In a secondary analysis, it was found that the presence of a single previous VBAC (compared to no previous VBACs) increased the odds of achieving a vaginal delivery in the next trial of labor after cesarean delivery (TOLAC) (aOR 5.66; 95% CI 3.73-8.60), and decreased the risk of maternal or neonatal adverse outcomes (aOR 0.62; 95% CI 0.39-0.97, and aOR 0.49; 95% CI 0.25-0.97, respectively). Multiple prior VBACs (as compared to a single prior VBAC) did not increase the odds of achieving another VBAC. CONCLUSION: Grand-multiparous women with and without previous uterine scar have comparable pregnancy outcomes. Additionally, after the first VBAC, additional successful VBACs do not improve the success rate in the next TOLAC.

Pathologic Basis for the Definition of Discordant Growth in Dichorionic Twins.

OBJECTIVE: The aim of the current study was to identify the optimal cutoff that should define discordance in dichorionic twin gestations through correlation with abnormal placental pathology as a specific measure of fetal growth restriction of the smaller twin. METHODS: We performed a retrospective cohort study of all women with dichorionic twin pregnancies who gave birth in a single center between 2002 and 2015. We investigated the association between the level of growth discordance and maternal vascular malperfusion (MVM) pathology in the placenta of the smaller twin, with and without adjustment for whether the smaller twin is small for gestational age (SGA). RESULTS: A total of 1,198 women with dichorionic twin gestation met the study criteria. The rate of MVM pathology in the placenta of the smaller twin increased with the level of discordance and was most obvious for discordance ≥25% (rate of MVM 12.0% compared with 2.8% in cases with discordance <10%, adjusted relative risk [aRR] 3.71, 95% confidence interval [CI] 1.97-6.99). When the analysis was adjusted for SGA of the smaller twin, discordance was independently associated with MVM pathology only when growth discordance was ≥25% (aRR 2.18, 95%-CI 1.01-4.93), while SGA was strongly associated with MVM pathology irrespective of the level of discordance. CONCLUSION: Our findings suggest that discordant growth in dichorionic twins should raise the concern of fetal growth restriction of the smaller twin, irrespective of whether the smaller twin is SGA, only when the discordance s ≥25%. The association of lower levels of discordance with abnormal placental pathology is mainly driven by the confounding effect of SGA of the smaller twin.

Abnormal glucose challenge test in absence of oral glucose tolerance test - are there consequences?

This is a retrospective analysis of mothers with abnormal 1-hour, 50-grams glucose challenge test (GCT) who did not take a 3-hour, 100-gram oral glucose tolerance test (OGTT). This study group of women was compared to three control groups, based on an OGTT diagnostic test- normal OGTT, single pathological value and gestational diabetes mellitus. Overall- 4,185 women were included and sub-divided accordingly into four groups: Group A-340 (8.12%)- no OGTT; Group B-2,585 (61.77%)- Norm OGTT (All values normal); Group C- 564 (13.48%)- SinOGTT (single pathological value) and Group D- 696 (16.63%)- Gestational Diabetes Mellitus (GDM, ≥ 2 pathological values). Groups A, C and D had higher rates of intrapartum Caesarean Delivery (10.29%, 11.52% and 10.19% vs. 8.43%, p < .0001). Group A had highest rates of neonatal adverse outcomes, as neonatal intensive care unit (NICU) admission (12.4% vs. 8.4%, 11.0% and 10.0%, p = .039), small for gestational age (SGA) neonates (7.0% vs. 5.3%, 3.7% and 6.0%, p = .0092) and neonatal hypoglycaemia (3.5% vs. 1.3%, 3.2% and 2.9%, p = .007). A multivariable regression revealed that having an abnormal GCT without an OGTT was an independent risk factor for neonatal intensive care unit admission, neonatal hypoglycaemia and intrapartum caesarean delivery. We concluded that women with pathological GCT who did not complete OGTT have higher rates of obstetric adverse outcomes. They should be closely monitored during delivery and should not be overlooked.IMPACT STATEMENTWhat is already known on this subject? Adverse outcomes of gestational diabetes mellitus are well established. But, the group of women who fail to complete a confirmatory OGTT following a pathological GCT is not well described.What the results of this study add? Our results point out that women who fail to complete an OGTT, suffer from higher rates of obstetric complications, presumably attributed to disrupted glucose values, but also to poor prenatal care.What the implications are of these findings for clinical practice and/or further research? These women should not be overlooked. They should be closely monitored during labour and delivery.

Contemporary patterns of labor in nulliparous and multiparous women.

BACKGROUND: Controversy surrounds the definition of "normal" and "abnormal" labor. OBJECTIVE: In this study, we used contemporary labor charts to explore labor patterns in large obstetric population (2011-2016). STUDY DESIGN: Detailed information from electronic medical records of live singleton deliveries at term (≥37 weeks of gestation) was extracted. Cases of elective cesarean deliveries, nonvertex presentation, and cesarean deliveries during the first stage of labor were excluded. RESULTS: Overall, 35,146 deliveries were included, of whom 15,948 deliveries (45.3%) were of nulliparous women. Median cervical dilation at admission was not significantly different between nulliparous (median, 4 cm; interquartile range, 3-5 cm) and multiparous women (median, 4 cm; interquartile range, 3-6 cm). In all, 99.3% of the women delivered vaginally. For nulliparous women, the median duration of the first stage of labor was 274 minutes (interquartile range, 145-441 minutes; 95th percentile, 747.5 minutes). Likewise, for multiparous women, the corresponding duration was 133 minutes (interquartile range, 56-244 minutes; 95th percentile, 494 minutes). During the latent phase (cervical dilation at admission, ≤4 cm), the time elapsed to the second stage of labor was 120-140 minutes longer in nulliparous women, whereas the gap between the groups decreased dramatically with advanced cervical dilation on admission. Nulliparous and multiparous women appeared to progress at a similar pace during the latent phase; however, after 5 cm, labor accelerated faster in multiparous women. Epidural anesthesia lengthens duration first and second stages of labor in all parities. Partograms according to cervical dilation at presentation are proposed. CONCLUSION: Cervical dilation rate is relatively constant between nulliparous and multiparous pregnant women during the latent phase. Time interval of the first stage was far slower than previously described, which allowed labor to continue for a longer period during this stage. These findings may reduce the rate of intrapartum iatrogenic interventions.

Delivery of monochorionic twins: lessons learned from the Twin Birth Study.

BACKGROUND: The current literature regarding the recommended mode of delivery of monochorionic-diamniotic twins is limited to small numbers, retrospective studies, and comparisons of outcomes of monochorionic-diamniotic twin pregnancies with those of dichorionic-diamniotic twin pregnancies instead of outcomes of trial of labor vs elective cesarean delivery of monochorionic-diamniotic twins. OBJECTIVE: This study aimed to compare perinatal and maternal outcomes of planned cesarean delivery and planned vaginal delivery of monochorionic-diamniotic twins using the Twin Birth Study data. STUDY DESIGN: This study is a secondary analysis of the Twin Birth Study. Women were randomized from 32 weeks and 0 days gestation to 38 weeks and 6 days gestation to planned cesarean delivery or planned vaginal delivery. Twin A in the cephalic presentation and estimated weight of each twin between 1500 and 4000 grams were the inclusion criteria. Pregnancies complicated by fetal reduction after 13 weeks of gestation, lethal fetal anomaly, or contraindication to vaginal delivery were excluded. Elective delivery was planned between 37 weeks and 5 to 7 days of gestation and 38 weeks and 6 to 7 days of gestation. Perinatal and maternal outcomes of monochorionic-diamniotic twin pregnancies were compared between those randomized for planned cesarean delivery and those randomized for planned vaginal delivery. In addition, outcomes of monochorionic-diamniotic twin pregnancies were compared with those of dichorionic-diamniotic twin pregnancies. RESULTS: Out of the 1393 women in each arm, 346 (24.9%) women in the planned cesarean delivery arm and 324 (23.3%) women in the planned vaginal delivery arm had monochorionic-diamniotic twin pregnancies and were eligible for the first analysis. The rate of cesarean delivery was 39.2% in the planned vaginal delivery arm and was 91.3% in the planned cesarean delivery arm. There was no significant difference in gestational age at delivery between the groups (34.4±1.8 weeks vs 34.5±1.8 weeks; P=.78). No difference was found in maternal outcomes. As for perinatal outcomes, the rate of the primary adverse neonatal composite outcomes in twins A or twins B was similar in both the planned vaginal delivery and the planned cesarean delivery arms (twins A, 1.2% vs 1.2% [P=.92]; twins B, 1.2% vs 3.2% [P=.09]). Within the planned cesarean delivery arm, the rate of primary adverse neonatal composite outcome was higher in twins B than twins A (3.2% vs 1.2%; P=.03). There was no difference in the primary adverse neonatal composite outcome between twins A in the monochorionic-diamniotic group and the dichorionic-diamniotic group (1.2% vs 1.3%; P=.89) or between twins B in similar groups (2.3% vs 2.7%; P=.47). CONCLUSION: In monochorionic-diamniotic twin pregnancy between 32 weeks and 0 to 7 days of gestation and 38 weeks and 6 to 7 days of gestation, with twin A in a cephalic presentation, planned cesarean delivery did not decrease or increase the risk of fetal or neonatal death or serious neonatal morbidity, as compared with planned vaginal delivery.

Interpregnancy interval and the risk for recurrence of placental mediated pregnancy complications.

Objective The aim of this study was to investigate the effect of short or long interpregnancy interval (IPI) with placental mediated pregnancy complications after already complicated first delivery. Methods We performed a retrospective cohort analysis of all women with singleton pregnancies who delivered their first three consecutive deliveries in one university-affiliated medical center (1994-2013). Placental mediated complications included placental abruption, small for gestational age, preeclampsia, gestational hypertension, or preterm delivery. Following first complicated delivery, IPI was compared stratified by second delivery outcome. Following two complicated deliveries, IPI was compared stratified by third delivery outcome. IPI was evaluated as continuous or categorical variable (>18, 18-60, >60 months). Related samples Cochrans' Q test and Mann-Whitney analysis were used as appropriate. Results Overall, 4310 women entered analysis. Of them, 18.3%, 10.5%, and 9.3% had complicated first, second, and third delivery, consecutively. Evaluated continuously, longer IPI, but not short IPI, was associated with higher rates of complicated second delivery. Stratified to categories, IPI had no effect on recurrent complications evaluated separately or as composite. Conclusion Our results suggest that long IPI may increase risk for placental mediated pregnancy complications. Further studies are needed to evaluate this effect.

Association between hypertensive disorders and fetal growth restriction in twin compared with singleton gestations.

BACKGROUND: Hypertensive disorders of pregnancy (including preeclampsia or gestational hypertension) are associated with fetal growth restriction in singleton pregnancies, an association that may be attributed to abnormal placentation as the shared etiology between these conditions. Given that the pathogenesis of these conditions in twin pregnancies may involve mechanisms other than abnormal placentation, it is unclear whether a similar association between hypertensive disorders of pregnancy and fetal growth restriction is present in twins. Data on the relationship between hypertensive disorders of pregnancy and fetal growth restriction in twins are limited and conflicting. This controversy may be attributed to limitations of existing studies including the use of a singleton-based birthweight reference to define fetal growth restriction in twins and the lack of a positive control group of singleton gestations. OBJECTIVE: The objective of the study was to determine the association between hypertensive disorders of pregnancy and fetal growth restriction in dichorionic twin gestations, using both a singleton- and a twin-based birthweight reference, and to compare this association with that observed in singleton gestations. STUDY DESIGN: We performed a retrospective cohort study of all women with dichorionic twin or singleton gestations giving birth in a single tertiary center during 2003-2015. Fetal growth restriction was defined in separate analyses as birthweight <10th percentile for gestational age using either a singleton- or a twin-based birthweight reference. The association between hypertensive disorders of pregnancy and fetal growth restriction was determined separately for twin and singleton gestations and was expressed as adjusted relative risk with 95% confidence interval. RESULTS: A total of 1520 twin and 48,943 singleton gestations were included. In singleton gestations, hypertensive disorders of pregnancy were associated with an increased risk of fetal growth restriction (16.6% vs 7.4%, adjusted relative risk, 2.07, 95% confidence interval, 1.87-2.30). In twins, there was no association between hypertensive disorders of pregnancy and fetal growth restriction when a singleton-based reference was used to define fetal growth restriction. However, when using a twin-based reference to define fetal growth restriction, hypertensive disorders of pregnancy in twin gestations were associated with a similar increase in the risk of fetal growth restriction to that seen in singletons (11.8% vs 4.7%, adjusted relative risk, 2.37, 95% confidence interval, 1.69-3.34). Findings were similar with regard to the reverse association between fetal growth restriction and hypertensive disorders of pregnancy: in women with twin gestations, the increase in the risk of hypertensive disorders of pregnancy in pregnancies complicated by fetal growth restriction of 1 twin was similar to that observed in singletons only when a twin-based reference was used to define fetal growth restriction (twins: 21.3% vs 9.8%, adjusted relative risk, 2.15, 95% confidence interval, 1.63-3.06; singletons: 8.8% vs 3.7%, adjusted relative risk, 2.19, 95% confidence interval, 1.95-2.44). CONCLUSION: The association between hypertensive disorders of pregnancy and fetal growth restriction in dichorionic twins is similar in magnitude to that observed in singletons so long as appropriate birthweight references are applied. Therefore, women with a twin gestation complicated by one of these conditions should be closely monitored for the other. Our findings suggest that the use of a twin-based reference to diagnose fetal growth restriction in twin gestations may be more informative and clinically relevant than using a singleton-based reference.