The prediction of morbidity related to vaginal delivery in nulliparous women - A secondary analysis from the genesis multicenter trial.

OBJECTIVE: In the prospective multicenter Genesis study, we developed a prediction model for Cesarean delivery (CD) in term nulliparous women. The objective of this secondary analysis was to determine whether the Genesis model has the potential to predict maternal and neonatal morbidity associated with vaginal delivery. STUDY DESIGN: The national prospective Genesis trial recruited 2,336 nulliparous women with a vertex presentation between 39 + 0- and 40 + 6-weeks' gestation from seven tertiary centers. The prediction model used five parameters to assess the risk of CD: maternal age, maternal height, body mass index, fetal head circumference and fetal abdominal circumference. Simple and multiple logistic regression analyses were used to develop the Genesis model. The risk score calculated using this model were correlated with maternal and neonatal morbidity in women who delivered vaginally: postpartum hemorrhage (PPH), obstetric anal sphincter injury (OASI), shoulder dystocia, one- and five-minute Apgar score ≤ 7, neonatal intensive care (NICU) admission, cephalohematoma, fetal laceration, nerve palsy and fractures. The morbidities associated with spontaneous vaginal delivery were compared with those associated with operative vaginal delivery (OVD). The likelihood ratios for composite morbidity and the morbidity associated with OVD based on the Genesis risk scores were also calculated. RESULTS: A total of 1,845 (79%) nulliparous women had a vaginal delivery. A trend of increasing intervention and morbidity was observed with increasing Genesis risk score, including OVD (p < 0.001), PPH (p < 0.008), NICU admission (p < 0.001), low Apgar score at one-minute (p < 0.001) and OASI (p = 0.009). The morbidity associated with OVD was significantly higher compared to spontaneous vaginal delivery, including NICU admission (p < 0.001), PPH (p = 0.022), birth injury (p < 0.001), shoulder dystocia (p = 0.002) and Apgar score of<7 at one-minute (p < 0.001). The positive likelihood ratios for composite outcomes (where the OVD was excluded) increases with increasing risk score from 1.005 at risk score of 5% to 2.507 for risk score of>50%. CONCLUSION: In women who ultimately achieved a vaginal birth, we have shown more maternal and neonatal morbidity in the setting of a Genesis nomogram-determined high-risk score for intrapartum CD. Therefore, the Genesis prediction tool also has the potential to predict a more morbid vaginal delivery.

Correlation of maternal body mass index with umbilical artery Doppler in pregnancies complicated by fetal growth restriction and associated outcomes.

OBJECTIVE: To evaluate the correlation between umbilical artery (UA) Doppler and its feasibility across categories of maternal body mass index (BMI; calculated as weight in kilograms divided by the square of height in meters) in the presence of fetal growth restriction (FGR). METHODS: A total of 1074 singleton pregnancies with suspected FGR on ultrasound examination between 24+0 and 36+0 weeks of pregnancy were reviewed. Evaluation of the UA Doppler was performed at 1- to 2-weekly intervals. Abnormal UA Doppler findings and delivery outcomes were compared between the different maternal BMI categories. RESULTS: Increased UA pulsatility index (PI >95th centile) was reported in 81% of obese class II patients (BMI 35-39.9) compared with a 46% incidence in the remaining categories, normal (BMI <24.9), overweight (BMI 25-29.9), and obese class I (BMI 30-34.9) (P = 0.001). In absent or reversed end diastolic flow (AEDF/REDF) we found an increasing incidence across the BMI categories (4%-25%) (P < 0.001). Higher maternal BMI was associated with lower birthweights and higher cesarean section rates. Increasing maternal BMI did not affect successful assessment of UA Doppler. CONCLUSION: There is a positive correlation between increasing maternal BMI and abnormal UA Doppler findings in FGR. Maternal BMI may be considered as an additional risk factor when evaluating UA Doppler for placental insufficiency.

Inter-hospital comparison of Cesarean delivery rates should not be considered to reflect quality of care without consideration of patient heterogeneity: An observational study.

OBJECTIVE: Contemporary approaches to monitoring quality of care in obstetrics often focus on comparing Cesarean Delivery rates. Varied rates can complicate interpretation of quality of care. We previously developed a risk prediction tool for nulliparous women who may require intrapartum Cesarean delivery which identified five key predictors. Our objective with this study was to ascertain if patient heterogeneity can account for much of the observed variation in Cesarean delivery rates, thereby enabling Cesarean delivery rates to be a better marker of quality of care. MATERIALS AND METHODS: This is a secondary analysis of the Genesis study. This was a large prospective study of 2336 nulliparous singleton pregnancies recruited at seven hospitals. A heterogeneity score was calculated for each hospital. An adjusted Cesarean delivery rate was also calculated incorporating the heterogeneous risk score. RESULTS: A cut-off at the 90th percentile was determined for each predictive factor. Above the 90th percentile was considered to represent 'high risk' (with the exception of maternal height which identified those below the 10th percentile). The patient heterogeneous risk score was defined as the number of risk factors > 90th percentile (<10th percentile for height). An unequal distribution of high-risk patients between centers was observed (p < 0.001). The correlation between the Cesarean delivery rate and the patient heterogeneous risk score was high (0.76, p < 0.05). When adjusted for patient heterogeneity, Cesarean delivery rates became closer aligned. CONCLUSION: Inter-institutional diversity is common. We suggest that crude comparison of Cesarean delivery rates between different hospitals as a marker of care quality is inappropriate. Allowing for marked differences in patient characteristics is essential for correct interpretation of such comparisons.

Defining the upper limit of the second stage of labor in nulliparous patients.

BACKGROUND: Increased duration of the second stage of labor provides clinical challenges in decision-making regarding the optimal mode of delivery that minimizes maternal and neonatal morbidity. OBJECTIVE: In a large cohort of uncomplicated nulliparous singleton cephalic labors, we sought to examine the effect of increasing duration of second stage on delivery and perinatal outcome. STUDY DESIGN: The GENESIS Study recruited 2336 nulliparous patients with vertex presentation in a prospective double-blinded study to examine prenatal and intrapartum predictors of delivery. Metrics included maternal demographics, duration of second stage, mode of delivery, and associated maternal and neonatal outcomes. Indicators of morbidity included third- or fourth-degree tear, postpartum hemorrhage, neonatal intensive care unit admission, low Apgar scores, cord pH <7.20 and a composite of birth injury that included cephalohematoma, fetal laceration, brachial plexus palsy, facial nerve palsy, and fetal fracture. RESULTS: Of 2336 recruited nulliparous participants, 1872 reached the second stage of labor and had complete data for analysis. Increased maternal age (P=.02) and birthweight (P<.001) were found to be associated with a longer second stage. Increasing second stage duration was found to impact on mode of delivery, such that at <1 hour duration the spontaneous vaginal delivery rate was 63% vs 24% at >3 hours (P<.001). Operative vaginal delivery increased from 35% at <1 hour to 65% at >3 hours (P<.001). The rate of cesarean delivery increased with duration of the second stage from 1.2% at <1 hour to 11% at >3 hours (P<.001). The rates of third- or fourth-degree tear increased with second stage duration (P=.003), as did postpartum hemorrhage (P<.001). The composite neonatal birth injury rate increased from 1.8% at <1 hour to 3.4% at >3 hours. The maximum rate of birth injury was 6.5% at 2-3 hours (P<.001). Multiple logistic regression analysis that controlled for maternal age and birthweight confirmed that operative vaginal delivery, perineal trauma, postpartum hemorrhage, and neonatal birth injury remained significantly more likely with increasing second stage duration. CONCLUSION: In a prospective cohort of nulliparous pregnancies, increasing duration of second stage of labor was associated with increased rates of operative vaginal and cesarean delivery. Although almost 90% of term nulliparous women with a second stage of labor >3 hours will succeed in achieving a vaginal birth, this success comes at a maternal morbidity cost, with a 10% risk of severe perineal injury and an increasing rate of significant neonatal injury.

Pregnancy-specific stress, fetoplacental haemodynamics, and neonatal outcomes in women with small for gestational age pregnancies: a secondary analysis of the multicentre Prospective Observational Trial to Optimise Paediatric Health in Intrauterine Growth Restriction.

OBJECTIVES: To examine associations between maternal pregnancy-specific stress and umbilical (UA PI) and middle cerebral artery pulsatility indices (MCA PI), cerebroplacental ratio, absent end diastolic flow (AEDF), birthweight, prematurity, neonatal intensive care unit admission and adverse obstetric outcomes in women with small for gestational age pregnancies. It was hypothesised that maternal pregnancy-specific stress would be associated with fetoplacental haemodynamics and neonatal outcomes. DESIGN: This is a secondary analysis of data collected for a large-scale prospective observational study. SETTING: This study was conducted in the seven major obstetric hospitals in Ireland and Northern Ireland. PARTICIPANTS: Participants included 331 women who participated in the Prospective Observational Trial to Optimise Paediatric Health in Intrauterine Growth Restriction. Women with singleton pregnancies between 24 and 36 weeks gestation, estimated fetal weight <10th percentile and no major structural or chromosomal abnormalities were included. PRIMARY AND SECONDARY OUTCOME MEASURES: Serial Doppler ultrasound examinations of the umbilical and middle cerebral arteries between 20 and 42 weeks gestation, Pregnancy Distress Questionnaire (PDQ) scores between 23 and 40 weeks gestation and neonatal outcomes. RESULTS: Concerns about physical symptoms and body image at 35-40 weeks were associated with lower odds of abnormal UAPI (OR 0.826, 95% CI 0.696 to 0.979, p=0.028). PDQ score (OR 1.073, 95% CI 1.012 to 1.137, p=0.017), concerns about birth and the baby (OR 1.143, 95% CI 1.037 to 1.260, p=0.007) and concerns about physical symptoms and body image (OR 1.283, 95% CI 1.070 to 1.538, p=0.007) at 29-34 weeks were associated with higher odds of abnormal MCA PI. Concerns about birth and the baby at 29-34 weeks (OR 1.202, 95% CI 1.018 to 1.421, p=0.030) were associated with higher odds of AEDF. Concerns about physical symptoms and body image at 35-40 weeks were associated with decreased odds of neonatal intensive care unit admission (OR 0.635, 95% CI 0.435 to 0.927, p=0.019). CONCLUSIONS: These findings suggest that fetoplacental haemodynamics may be a mechanistic link between maternal prenatal stress and fetal and neonatal well-being, but additional research is required.

Prediction of cesarean delivery in the term nulliparous woman: results from the prospective, multicenter Genesis study.

BACKGROUND: In contemporary practice many nulliparous women require intervention during childbirth such as operative vaginal delivery or cesarean delivery (CD). Despite the knowledge that the increasing rate of CD is associated with increasing maternal age, obesity and larger infant birthweight, we lack a reliable method to predict the requirement for such potentially hazardous obstetric procedures during labor and delivery. This issue is important, as there are greater rates of morbidity and mortality associated with unplanned CD performed in labor compared with scheduled CDs. A prediction algorithm to identify women at risk of an unplanned CD could help reduced labor associated morbidity. OBJECTIVE: In this primary analysis of the Genesis study, our objective was to prospectively assess the use of prenatally determined, maternal and fetal, anthropomorphic, clinical, and ultrasound features to develop a predictive tool for unplanned CD in the term nulliparous woman, before the onset of labor. MATERIALS AND METHODS: The Genesis study recruited 2336 nulliparous women with a vertex presentation between 39+0 and 40+6 weeks' gestation in a prospective multicenter national study to examine predictors of CD. At recruitment, a detailed clinical evaluation and ultrasound assessment were performed. To reduce bias from knowledge of these data potentially influencing mode of delivery, women, midwives, and obstetricians were blinded to the ultrasound data. All hypothetical prenatal risk factors for unplanned CD were assessed as a composite. Multiple logistic regression analysis and mathematical modeling was used to develop a risk evaluation tool for CD in nulliparous women. Continuous predictors were standardized using z scores. RESULTS: From a total enrolled cohort of 2336 nulliparous participants, 491 (21%) had an unplanned CD. Five parameters were determined to be the best combined predictors of CD. These were advancing maternal age (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.09 to 1.34), shorter maternal height (OR, 1.72; 95% CI, 1.52 to 1.93), increasing body mass index (OR, 1.29; 95% CI, 1.17 to 1.43), larger fetal abdominal circumference (OR, 1.23; 95% CI, 1.1 to 1.38), and larger fetal head circumference (OR, 1.27; 95% CI, 1.14 to 1.42). A nomogram was developed to provide an individualized risk assessment to predict CD in clinical practice, with excellent calibration and discriminative ability (Kolmogorov-Smirnov, D statistic, 0.29; 95% CI, 0.28 to 0.30) with a misclassification rate of 0.21 (95% CI, 0.19 to 0.25). CONCLUSION: Five parameters (maternal age, body mass index, height, fetal abdominal circumference, and fetal head circumference) can, in combination, be used to better determine the overall risk of CD in nulliparous women at term. A risk score can be used to inform women of their individualized probability of CD. This risk tool may be useful for reassuring most women regarding their likely success at achieving an uncomplicated vaginal delivery as well as selecting those patients with such a high risk for CD that they should avoid a trial of labor. Such a risk tool has the potential to greatly improve planning hospital service needs and minimizing patient risk.

Prenatal prediction of significant intertwin birthweight discordance using standard second and third trimester sonographic parameters.

INTRODUCTION: Our study aim was to evaluate standard ultrasound-derived fetal biometric parameters in the prediction of clinically significant intertwin birthweight discordance defined as ≥18%. MATERIAL AND METHODS: This was a secondary analysis of a prospective cohort study of 1028 unselected twin pairs recruited over a two-year period. Dichorionic twins underwent two-weekly ultrasonographic surveillance from 24 weeks' gestation, with surveillance of monochorionic twins two-weekly from 16 weeks. Ultrasonographic biometric data from 24 to 36 weeks were evaluated for the prediction of an intertwin birthweight discordance threshold ≥18%. Umbilical artery Doppler waveform data was also analyzed to evaluate whether it was predictive of birthweight discordance. RESULTS: Of the 956 twin pairs analyzed for discordance, 208 pairs were found to have a clinically significant birthweight discordance ≥18%. All biometric parameters were predictive of significant inter-twin birthweight discordance at low cut-offs, with low discriminatory powers when ROC curves were analyzed. Discordance in estimated fetal weight was predictive of a significant birthweight discordance at all gestational categories with cut-offs between 8 and 11%. A low-discriminatory power and poor sensitivity and specificity were also observed. An abnormal umbilical artery Doppler was predictive of birthweight discordance ≥18% between 28 and 32 weeks' gestation, although with poor sensitivity and specificity. CONCLUSIONS: Calculation of estimated fetal weight and birthweight discordance between twins allows minimal margin for error. These margins make it difficult to accurately predict those who are at or above the discordance threshold of 18%. These findings highlight that small intertwin discrepancies in weight and biometry should not be overlooked and merit further investigation.

Gestational hypertensive disease in twin pregnancy: Influence on outcomes in a large national prospective cohort.

OBJECTIVE: Gestational hypertensive disease (GHD) is associated with pregnancy-related complications and poor maternal and fetal outcomes in singleton pregnancies. We sought to examine the influence of GHD in a large prospective cohort of twin pregnancies. STUDY DESIGN: The ESPRIT study was a national multicenter observational cohort study of 1028 structurally normal twin pregnancies. Each pregnancy underwent sonographic surveillance with two-week ultrasound from 24 weeks for dichorionic and from 16 weeks for monochorionic gestations. Characteristics and demographics as well as labour and delivery outcome data were prospectively recorded. Perinatal mortality, admission to the neonatal intensive care unit (NICU) and a composite of morbidity of respiratory distress syndrome, hypoxic ischaemic encephalopathy, periventricular leukomalacia, necrotising enterocolitis and sepsis were documented for all cases. Outcomes for patients with documented GHD (pre-eclampsia and gestational hypertension) were compared with those without GHD. RESULTS: Perinatal outcome data were recorded for 977 patients. Women with GHD had a higher body mass index (27.1 ± 6.4 vs 25.2 ± 4.5, P < 0.0001) than those without and were more likely to be nulliparous (65% (59/92) vs 46% (407/885), P = 0.001). Both groups had similar mean birthweights, but those with GHD were more likely to have a birthweight discordance ≥18% (35% (32/92) vs 20% (179/885), P = 0.001). Rates of caesarean delivery were higher in those twin pregnancies affected by GHD, and while the rate of composite morbidity was similar in both groups, twins in the GHD group had higher rates of NICU admission. CONCLUSION: In twin gestations, gestational hypertension independently confers an increased risk for emergency caesarean delivery, birthweight discordance and NICU admission, such that intensive maternal-fetal monitoring is justified when hypertension develops in a twin pregnancy.

The effect of maternal obesity on sonographic fetal weight estimation and perinatal outcome in pregnancies complicated by fetal growth restriction.

PURPOSE: Maternal obesity represents a challenge in the sonographic (US) assessment of fetal weight, and is a recognized risk factor for adverse pregnancy outcome. The objective of this secondary analysis of data from the Prospective Observational Trial to Optimize Pediatric Health in fetal growth restriction (FGR) Study (PORTO) was to describe the effect of maternal obesity on the accuracy of US in determining the estimated fetal weight (EFW) and the perinatal outcome of pregnancies affected by FGR. METHODS: Between 2010 and 2012, 1,116 women with nonanomalous singleton pregnancies with an EFW in less than the tenth centile were recruited for the PORTO study. Maternal body mass index (BMI) was divided into five subcategories: normal (BMI < 24.9 kg/m(2) ), overweight (25-29.9), obese class 1 (30-34.9), obese class 2 (35-39.9), and obese class 3 (>40). The accuracy of the EFW was determined in women who delivered within 2 weeks of their last US scan. Perinatal outcomes were analyzed by BMI subcategory. RESULTS: Of the 1,074 patients with complete records, 691 (64%) were of normal weight, 258 (24%) were overweight, 93 (9%) were in obese class 1, 32 (3%) were in obese class 2, and none were in obese class 3. Overall, the EFW determined prior to delivery was within 6% of the actual birth weight in all BMI subcategories. Overweight and obese women delivered more commonly by cesarean section and at earlier gestational ages than did women with a normal BMI (p = 0.0008), resulting in lower birth weights (p = 0.0031) and significantly increased composite perinatal morbidity (p < 0.0001) and mortality (p = 0.0215) rates. CONCLUSIONS: US examination is reliable for assessing the weight of fetuses with FGR in overweight women. Maternal obesity, however, has a significant adverse effect on perinatal outcomes. Thus, health education should focus on awareness of this adverse effect, with optimization of prepregnancy weight as its main goal.

Dichorionic twin ultrasound surveillance: sonography every 4 weeks significantly underperforms sonography every 2 weeks: results of the Prospective Multicenter ESPRiT Study.

OBJECTIVE: A 2-week ultrasound scanning schedule for monochorionic twins is endorsed widely. There is a lack of robust data to inform a schedule for the surveillance of dichorionic gestations. We aimed to determine how ultrasound scanning that is performed at 2- or 4-week intervals (or every 4 weeks before 32 weeks' gestation and every 2 weeks thereafter) may impact the prenatal detection of fetal growth restriction (FGR) and ultimately influence timing of delivery. STUDY DESIGN: In a consecutive cohort of 789 dichorionic twin pregnancies that were recruited prospectively for the multicenter Evaluation of Sonographic Predictors of Restricted Growth in Twins study, ultrasound determination of fetal growth and interrogation of umbilical and middle cerebral artery Doppler scans were performed every 2 weeks from 24 weeks' gestation until delivery. Complete delivery and perinatal outcome data were recorded for all pregnancies. Where delivery was prompted by FGR, abnormal umbilical artery Doppler examination or poor biophysical profile and in the absence of ruptured membranes, onset of labor, preeclampsia, or antepartum hemorrhage, the delivery was considered "ultrasound-indicated." For ultrasound-indicated deliveries, detection probabilities for FGR/abnormal umbilical artery Doppler scans/poor biophysical were determined according to the interval between examinations, by the suppression if alternate examination data. RESULTS: Among 789 dichorionic twin pregnancies, 66 pairs (8%) had an "ultrasound indicated" delivery. Detection of FGR was reduced from 88-69%, and detection of abnormal umbilical artery Doppler was reduced from 82-62% when a 4-week ultrasound schedule was simulated. Both of these reductions reached statistical significance. There was a nonsignificant trend toward a reduction in the recording of oligohydramnios with a 4-week interval between examinations. CONCLUSION: This study suggests that the ultrasound surveillance program of every 2 weeks that is recommended currently for monochorionic twins should be extended to dichorionic gestations.

Ultrasound assessment of fetal head circumference at the onset of labor as a predictor of operative delivery.

OBJECTIVE: This study sought to determine whether ultrasound assessment of fetal head circumference (FHC) at the onset of labor can predict the likelihood of operative delivery. METHODS: We performed a prospective cohort study of 200 nulliparous women with singleton, cephalic, term pregnancies in an Irish Maternity Hospital. Transabdominal ultrasound assessment of FHC was performed when spontaneous labor was diagnosed or immediately prior to induction. Odds ratios for operative delivery (instrumental delivery or cesarean section) and maternal and neonatal morbidity were calculated using logistic regression with FHC categorized at a ≥350-mm cut-off (90th percentile). RESULTS: Ultrasound assessment of FHC at the onset of labor was highly correlated with post-delivery neonatal head circumference (NHC) (Pearson's correlation coefficient 0.74), suggesting that it can be measured reliably. FHC ≥350 mm was associated with more than twice the risk of any operative delivery (OR 2.5, 95% CI 1.0-6.2) and a two-fold increased risk of cesarean section for dystocia (OR 2.0, 95% CI 1.0-4.3). Differences in maternal and neonatal morbidity were not statistically significant. CONCLUSION: These preliminary data suggest that ultrasound assessment of FHC at the onset of labor may be useful in identifying women at greater risk of intrapartum intervention and warrant further research.

Defining the residual risk of adverse perinatal outcome in growth-restricted fetuses with normal umbilical artery blood flow.

OBJECTIVE: We sought to determine the cause of adverse perinatal outcome in fetal growth restriction (FGR) where umbilical artery (UA) Doppler was normal, as identified from the Prospective Observational Trial to Optimize Pediatric Health (PORTO). We compared cases of adverse outcome where UA Doppler was normal and abnormal. STUDY DESIGN: The PORTO study was a national multicenter study of >1100 ultrasound-dated singleton pregnancies with an estimated fetal weight <10th centile. Each pregnancy underwent intensive ultrasound, including multivessel Doppler. UA Doppler was considered abnormal when the pulsatility index was >95th centile or end-diastolic flow was absent/reversed. Adverse perinatal outcome was defined as a composite of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, or death. RESULTS: In all, 57 (5.0%) of the 1116 fetuses had an adverse perinatal outcome. Nine (1.3%) of 698 fetuses with normal UA Doppler had an adverse outcome, compared with 48 (11.5%) of 418 with abnormal UA Doppler (P < .0001). There were 2 perinatal deaths in the normal group and 6 in the abnormal group (P = .01). The perinatal deaths in the normal group were 1 case of pulmonary hypoplasia after prolonged preterm rupture of the membranes from 12 weeks' gestation and a case of placental abruption. Gestation at delivery was 33 ± 3 vs 31 ± 4 weeks (P = .05) and mean birthweight was 1830 ± 737 vs 1146 ± 508 g (P = .001) in the respective groups. Neonatal sepsis was the commonest adverse outcome in both groups: 0.1% and 0.4%, respectively (P = .01). CONCLUSION: Adverse perinatal outcome is uncommon in FGR with normal UA Doppler. The cases we identified were associated with heterogenous pathologies. FGR with normal UA blood flow is a largely benign condition.

The role of brain sparing in the prediction of adverse outcomes in intrauterine growth restriction: results of the multicenter PORTO Study.

OBJECTIVE: The aim of the Prospective Observational Trial to Optimize Pediatric Health in IUGR Study was to evaluate the optimal management of fetuses with an estimated fetal weight less than the 10th centile. The objective of this secondary analysis was to describe the role of the cerebroplacental ratio (CPR) in the prediction of adverse perinatal outcome. STUDY DESIGN: More than 1100 consecutive singleton pregnancies with intrauterine growth restriction (IUGR) were recruited over 2 years at 7 centers, undergoing serial sonographic evaluation including multivessel Doppler measurement. CPR was calculated using the pulsatility and resistance indices of the middle cerebral and umbilical artery. Adverse perinatal outcome was defined as a composite of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, and death. RESULTS: Data for CPR calculation was available in 881 cases, which was performed at a mean gestational age of 33 weeks (interquarile range, 28.7-35.9). Of the 146 cases with CPR less than 1, 18% (n = 27) had an adverse perinatal outcome. This conferred an 11-fold increased risk (odds ratio, 11.7; P < .0001) when compared with cases with normal CPR (2%; 14 of 735). An abnormal CPR was present in all 3 cases of mortality. Prediction of adverse outcomes was comparable when using all definitions of abnormal CPR. CONCLUSION: Irrespective of the CPR calculation used, brain sparing is significantly associated with an adverse perinatal outcome in IUGR. This adds further weight to integrating CPR evaluation into the clinical assessment of IUGR pregnancies. The impact of this finding on long-term neurodevelopmental outcomes in this patient cohort is underway.

Fetal growth restriction and the risk of perinatal mortality-case studies from the multicentre PORTO study.

BACKGROUND: Intrauterine growth restriction (IUGR) is the single largest contributing factor to perinatal mortality in non-anomalous fetuses. Advances in antenatal and neonatal critical care have resulted in a reduction in neonatal deaths over the past decades, while stillbirth rates have remained unchanged. Antenatal detection rates of fetal growth failure are low, and these pregnancies carry a high risk of perinatal death. METHODS: The Prospective Observational Trial to Optimize Paediatric Health in IUGR (PORTO) Study recruited 1,200 ultrasound-dated singleton IUGR pregnancies, defined as EFW <10th centile, between 24+0 and 36+6 weeks gestation. All recruited fetuses underwent serial sonographic assessment of fetal weight and multi-vessel Doppler studies until birth. Perinatal outcomes were recorded for all pregnancies. Case records of the perinatal deaths from this prospectively recruited IUGR cohort were reviewed, their pregnancy details and outcome were analysed descriptively and compared to the entire cohort. RESULTS: Of 1,116 non-anomalous singleton infants with EFW <10th centile, 6 resulted in perinatal deaths including 3 stillbirths and 3 early neonatal deaths. Perinatal deaths occurred between 24+6 and 35+0 weeks gestation corresponding to birthweights ranging from 460 to 2260 grams. Perinatal deaths occurred more commonly in pregnancies with severe growth restriction (EFW <3rd centile) and associated abnormal Doppler findings resulting in earlier gestational ages at delivery and lower birthweights. All of the described pregnancies were complicated by either significant maternal comorbidities, e.g. hypertension, systemic lupus erythematosus (SLE) or diabetes, or poor obstetric histories, e.g. prior perinatal death, mid-trimester or recurrent pregnancy loss. Five of the 6 mortalities occurred in women of non-Irish ethnic backgrounds. All perinatal deaths showed abnormalities on placental histopathological evaluation. CONCLUSIONS: The PNMR in this cohort of prenatally identified IUGR cases was 5.4/1,000 and compares favourably to the overall national rate of 4.1/1,000 births, which can be attributed to increased surveillance and timely delivery. Despite antenatal recognition of IUGR and associated maternal risk factors, not all perinatal deaths can be prevented.

The influence of maternal body mass index on fetal weight estimation in twin pregnancy.

OBJECTIVE: Sonographic estimated fetal weight (EFW) is important in the management of high-risk pregnancies. The possibility that increased maternal body mass index (BMI) adversely affects EFW assessments in twin pregnancies is controversial. The aim of this study was to investigate the effect of maternal BMI on the accuracy of EFW assessments in twin gestations prospectively recruited for the ESPRiT (Evaluation of Sonographic Predictors of Restricted growth in Twins) study. STUDY DESIGN: One thousand one twin pair pregnancies were recruited. After exclusion, BMI, birthweights, and ultrasound determination of EFW (within 2 weeks of delivery) were available for 943 twin pairs. The accuracy of EFW determination was defined as the difference between EFW and actual birthweight for either twin (absolute difference and percent difference). Cells with less than 5% of the population were combined for analysis resulting in the following 3 maternal categories: (1) normal/underweight, (2) overweight, and (3) obese/extremely obese. RESULTS: Analysis of the 3 categories revealed mean absolute variation values of 184 g (8.0%) in the normal/underweight group (n = 531), 196 g (8.5%) in the overweight group (n = 278), and 206 g (8.6%) in the obese/extremely obese group (n = 134) (P = .028, which was nonsignificant after adjustment for multiple testing). Regression analysis showed no linear or log-linear relationship between BMI and the accuracy of EFW (P value for absolute difference = .11, P value for percentage difference = .27). CONCLUSION: Contrary to a commonly held clinical impression, increasing maternal BMI has no significant impact on the accuracy of EFW in twin pregnancy.

Comparison of outcomes of twins conceived spontaneously and by artificial reproductive therapy.

OBJECTIVE: To compare the outcomes of twin pregnancies conceived by artificial reproductive techniques (ART) with those of spontaneous conception. STUDY DESIGN: In this multicenter prospective trial, comparisons were made between methods of conception in twin pregnancies, for maternal and perinatal outcomes. RESULTS: Of 1001 twin pairs, 763/1001 (72.7%) were spontaneously conceived and 238/1001(27.3%) were conceived by ART. There were no significant differences between the two groups with respect to obstetric complications. There were 13 per 1000 (20/1504; 1%) perinatal deaths in the spontaneously conceived group and 6 per 1000 (3/466; 0.6%) in the ART group (p = 0.8141). We found no differences in gestational age at delivery (median 36.9 versus 37.0 weeks), birth weight (median 2520 g versus 2538 g), or in a composite measure of adverse perinatal outcome (17% versus 15%) between the groups. CONCLUSION: There were no differences in the rate of adverse obstetric or perinatal outcomes between twins conceived naturally compared with twins conceived by assisted conception.

Definition and management of fetal growth restriction: a survey of contemporary attitudes.

OBJECTIVE: To evaluate opinions among Irish obstetricians and obstetric trainees regarding the optimal definition, assessment and management of pregnancies affected by intrauterine growth restriction (IUGR). STUDY DESIGN: An anonymous, structured, web-based survey that comprised 14 questions was sent to 200 obstetricians and obstetric trainees in Ireland. RESULTS: Of the 113 participants (57% response rate), the majority (50%) were consultants, with over 10 years' clinical experience (46%), who worked in large maternity units (58%) with neonatal units providing care for preterm IUGR fetuses (94%). Eighty-three clinicians (74%) agreed that an estimated fetal weight (EFW) below the 10th centile constitutes small-for-gestational age (SGA). The majority (n=93; 82%) would deliver the SGA fetus between 37(+0) and 39(+6) weeks gestation. In total, the survey yielded 30 different IUGR definitions; the top three definitions were (i) an EFW below the 5th centile (n=18; 16%), (ii) an EFW below the 10th centile with oligohydramnios and abnormal umbilical artery (UA) Doppler (n=16; 14%), and (iii) an EFW below the 10th centile (n=12; 11%). In the evaluation of the preterm IUGR fetus with abnormal UA Doppler, the assessment of amniotic fluid volume, middle cerebral artery, ductus venosus, cardiotocograph (CTG) and biophysical profiling was performed in 74%, 60%, 60%, 54% and 52% respectively. The majority of clinicians applied three or more assessment modalities and 60% referred to a maternal-fetal medicine (MFM) subspecialist. Interestingly, even among MFM subspecialists there was no common consistent management approach. Most doctors (81%) would deliver the IUGR fetus for CTG abnormalities but MFM subspecialists more commonly deliver on the basis of absent end-diastolic flow in the UA alone (37% vs. 10%; p=0.006). Two-thirds of doctors (n=74) would implement customised growth charts if they became available for their population and over 80% thought that a national guideline on IUGR would be beneficial. CONCLUSION: The results of this survey confirm the inconsistencies surrounding the clinical management of IUGR pregnancies and highlight the need for standardisation of terminology and antenatal surveillance, implementation of fetal weight customisation and national guidance for Ireland.

Predictable progressive Doppler deterioration in IUGR: does it really exist?

OBJECTIVE: An objective of the Prospective Observational Trial to Optimize Pediatric Health in IUGR (PORTO) study was to evaluate multivessel Doppler changes in a large cohort of intrauterine growth restriction (IUGR) fetuses to establish whether a predictable progressive sequence of Doppler deterioration exists and to correlate these Doppler findings with respective perinatal outcomes. STUDY DESIGN: More than 1100 unselected consecutive ultrasound-dated singleton pregnancies with estimated fetal weight (EFW) less than the 10th centile were recruited between January 2010 and June 2012. Eligible pregnancies were assessed by serial Doppler interrogation of umbilical (UA) and middle cerebral (MCA) arteries, ductus venosus (DV), aortic isthmus, and myocardial performance index (MPI). Intervals between Doppler changes and patterns of deterioration were recorded and correlated with respective perinatal outcomes. RESULTS: Our study of 1116 nonanomalous fetuses comprised 7769 individual Doppler data points. Five hundred eleven patients (46%) had an abnormal UA, 300 (27%) had an abnormal MCA, and 129 (11%) had an abnormal DV Doppler. The classic pattern from abnormal UA to MCA to DV existed but no more frequently than any of the other potential pattern. Doppler interrogation of the UA and MCA remains the most useful and practical tool in identifying fetuses at risk of adverse perinatal outcome, capturing 88% of all adverse outcomes. CONCLUSION: In contrast to previous reports, we have demonstrated multiple potential patterns of Doppler deterioration in this large prospective cohort of IUGR pregnancies, which calls into question the usefulness of multivessel Doppler assessment to inform frequency of surveillance and timing of delivery of IUGR fetuses. These data will be critically important for planning any future intervention trials.

The role of growth trajectories in classifying fetal growth restriction.

OBJECTIVE: To examine the validity of a growth trajectory method to discriminate between pathologically and constitutionally undergrown fetuses using repeated measures of estimated fetal weight. METHODS: In a prospective, observational, multicenter study in Ireland, 1,116 women with a growth-restricted fetus diagnosed participated with the objective of evaluating ultrasound findings as predictors of pediatric morbidity and mortality. Fetal growth trajectories were based on estimated fetal weight. RESULTS: Between 22 weeks of gestation and term, two fetal growth trajectories were identified: normal (96.7%) and pathologic (3.3%). Compared with the normal trajectory, the pathologic trajectory was associated with an increased risk for preeclampsia (odds ratio [OR] 8.1, 95% confidence interval [CI] 2.6-23.4), increased umbilical artery resistance at 30 weeks of gestation (OR 12.6, 95% CI 4.6-34.1) or 34 weeks of gestation (OR 28.0, 95% CI 8.9-87.7), reduced middle cerebral artery resistance at 30 weeks of gestation (OR 0.33, 95% CI 0.12-0.96) or 34 weeks of gestation (OR 0.14, 95% CI 0.03-0.74), lower gestational age at delivery (mean 32.02 weeks of gestation compared with 38.02 weeks of gestation; P<.001), and higher perinatal complications (OR 21.5, 95% CI 10.5-44.2). In addition, 89.2% of newborns with pathologic fetal growth were admitted to neonatal intensive care units compared with 25.9% of those with normal growth. CONCLUSIONS: Fetal growth trajectory analysis reliably differentiated fetuses with a pathologic growth pattern among a group of women with growth-restricted fetuses. With further development, this approach could provide clarity to how we define, identify, and ultimately manage pathologic fetal growth. LEVEL OF EVIDENCE: II.

Optimizing the definition of intrauterine growth restriction: the multicenter prospective PORTO Study.

OBJECTIVE: The objective of the Prospective Observational Trial to Optimize Pediatric Health in Intrauterine Growth Restriction (IUGR) (PORTO Study), a national prospective observational multicenter study, was to evaluate which sonographic findings were associated with perinatal morbidity and mortality in pregnancies affected by growth restriction, originally defined as estimated fetal weight (EFW) <10th centile. STUDY DESIGN: Over 1100 consecutive ultrasound-dated singleton pregnancies with EFW <10th centile were recruited from January 2010 through June 2012. A range of IUGR definitions were used, including EFW or abdominal circumference <10th, <5th, or <3rd centiles, with or without oligohydramnios and with or without abnormal umbilical arterial Doppler (pulsatility index >95th centile, absent or reversed end-diastolic flow). Adverse perinatal outcome, defined as a composite outcome of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, and death was documented for all cases. RESULTS: Of 1116 fetuses, 312 (28%) were admitted to neonatal intensive care unit and 58 (5.2%) were affected by adverse perinatal outcome including 8 mortalities (0.7%). The presence of abnormal umbilical Doppler was significantly associated with adverse outcome, irrespective of EFW or abdominal circumference measurement. The only sonographic weight-related definition consistently associated with adverse outcome was EFW <3rd centile (P = .0131); all mortalities had EFW <3rd centile. Presence of oligohydramnios was clinically important when combined with EFW <3rd centile (P = .0066). CONCLUSION: Abnormal umbilical artery Doppler and EFW <3rd centile were strongly and most consistently associated with adverse perinatal outcome. Our data call into question the current definitions of IUGR used. Future studies may address whether using stricter IUGR cutoffs comparing various definitions and management strategies has implications on resource allocation and pregnancy outcome.