Browsing by Author "Akolekar, Ranjit"
Now showing 1 - 5 of 5
- Results Per Page
- Sort Options
Item Efficiency of the Cerebroplacental Ratio in Identifying High-Risk Late-Term Pregnancies.(Medicina, 2023) Martin-Alonso, Raquel; Rolle, Valeria; Akolekar, Ranjit; De Paco Matallana, Catalina; Fernández Buhigas, Irene; Sánchez-Camps, Maria Isabel; Giacchino, TaraBackground and Objectives: Over the last few years, great interest has arisen in the role of the cerebroplacental ratio (CPR) to identify low-risk pregnancies at higher risk of adverse pregnancy outcomes. This study aimed to assess the predictive capacity of the CPR for adverse perinatal outcomes in all uncomplicated singleton pregnancies attending an appointment at 40–42 weeks. Materials and Methods: This is a retrospective cohort study including all consecutive singleton pregnancies undergoing a routine prenatal care appointment after 40 weeks in three maternity units in Spain and the United Kingdom from January 2017 to December 2019. The primary outcome was adverse perinatal outcomes defined as stillbirth or neonatal death, cesarean section or instrumental delivery due to fetal distress during labor, umbilical arterial cord blood pH < 7.0, umbilical venous cord blood pH < 7.1, Apgar score at 5 min < 7, and admission to the neonatal unit. Logistic mixed models and ROC curve analyses were used to analyze the data. Results: A total of 3143 pregnancies were analyzed, including 537 (17.1%) with an adverse perinatal outcome. Maternal age (odds ratio (OR) 1.03, 95% confidence interval (CI) 1.01 to 1.04), body mass index (OR 1.04, 95% CI 1.03 to 1.06), racial origin (OR 2.80, 95% CI 1.90 to 4.12), parity (OR 0.36, 95% CI 0.29 to 0.45), and labor induction (OR 1.79, 95% CI 1.36 to 2.35) were significant predictors of adverse perinatal outcomes with an area under the ROC curve of 0.743 (95% CI 0.720 to 0.766). The addition of the CPR to the previous model did not improve performance. Additionally, the CPR alone achieved a detection rate of only 11.9% (95% CI 9.3 to 15) when using the 10th centile as the screen-positive cutoff. Conclusions: Our data on late-term unselected pregnancies suggest that the CPR is a poor predictor of adverse perinatal outcomes.Item First-trimester screening for trisomies by cfDNA testing of maternal blood in singleton and twin pregnancies: factors affecting test failure.(Ultrasound in Obstetrics and Gynecology, 2019) Galeva, Slavyana; Gil Mira, María del Mar; Konstantinidou, Liountmila; Akolekar, Ranjit; Nicolaides, Kypros H.Objectives: To examine factors affecting the failure rate to obtain a result from (cf) DNA testing of maternal blood for fetal trisomies 21, 18 and 13 in singleton and twin pregnancies in the first trimester of pregnancy. Methods: This was a prospective study in 23,495 singleton and 928 twin pregnancies undergoing screening for fetal trisomies by targeted cfDNA testing at 10+0-14+1 weeks’ gestation. Multivariate regression analysis was used to determine significant predictors of failure to obtain a result after first sampling. Results: There was no result from cfDNA testing after first sampling in 3.4% (798/23,495) of singletons, 11.3% (91/806) of DC twins and in 4.9% (6/122) of MC twins. Multivariate logistic regression analysis demonstrated that the risk of test failure first, increased with increasing maternal age (odds ratio (OR) 1.02; 95% confidence interval (CI) 1.01, 1.04) and weight (OR 1.05; 95% CI 1.04, 1.05), decreasing gestational age (OR 0.85; 95% CI 0.79, 0.91) and serum PAPP-A (OR 0.56; 95% CI 0.49, 0.64) and free ß-hCG (OR 0.67; 95% CI 0.60, 0.74), second, was higher in women of Black (OR 1.72; 95% CI 1.33, 2.20) and South Asian (OR 1.99; 95% CI 1.56, 2.52) than White racial origin, in dichorionic twin (OR 1.75; 95% CI 1.34, 2.25) than singleton pregnancy and in in vitro fertilization (OR 3.82; 95% CI 3.19, 4.55) than natural conception and third, was lower in parous (OR 0.63; 95% CI 0.55, 0.74) than nulliparous women. Conclusions: Maternal age, weight, racial origin and parity, gestational age, dichorionicity, method of conception and serum levels of free ß-hCG and PAPP-A are independent predictors of cfDNA test failure. The risk of test failure is higher in dichorionic twin than in singleton pregnancies, mainly because a higher proportion of twins are conceived by in vitro fertilization and more of the women are nulliparous.Item Pravastatin versus Placebo in Pregnancies at High Risk of Term Preeclampsia.(Circulation, 2021) Döbert, Moritz; Nektaria Varouxaki, Anna; Chi Mu, An; Syngelaki, Argyro; Ciobanu, Anca; Akolekar, Ranjit; De Paco Matallana, Catalina; Cicero, Simona; Greco, Elena; Singh, Mandeep; Janga, Deepa; Gil Mira, María del Mar; C. Jani, Jacques; Bartha, José Luis; Maclagan, Kate; Wright, David; H. Nicolaides, KyprosBACKGROUND: Effective screening for term preeclampsia is provided by a combination of maternal factors with measurements of mean arterial pressure, serum placental growth factor and serum soluble fms-like tyrosine kinase-1 at 35 to 37 weeks of gestation, with detection rate of about 75%, at screen positive rate of 10%. However, there is no known intervention to reduce the incidence of the disease. METHODS: In this multicenter, double-blind, placebo-controlled trial, we randomly assigned 1,120 women with singleton pregnancies at high-risk of term preeclampsia to receive pravastatin, at a dose of 20 mg per day, or placebo from 35 to 37 weeks of gestation until delivery or 41 weeks. The primary outcome was delivery with preeclampsia at any time after randomization. The analysis was performed according to intention-to-treat. RESULTS: A total of 29 women withdrew consent during the trial. Preeclampsia occurred in 14.6% (80/548) participants in the pravastatin group and in 13.6% (74/543) in the placebo group. Allowing for the effect of risk at the time of screening and participating centre, the mixed effects Cox regression showed no evidence of an effect of pravastatin; hazard ratio (statin/placebo) 1.08 (95% confidence interval: 0.78, 1.49; p=0.65). There was no evidence of interaction between the effect of pravastatin, estimated risk of preeclampsia, previous pregnancy history, adherence and aspirin treatment. There was no significant between-group difference in the incidence of any secondary outcomes, including gestational hypertension, stillbirth, abruption, delivery of small for gestational age neonates, neonatal death or neonatal morbidity. There was no significant between-group difference in the treatment effects on serum placental growth factor and soluble fms-like tyrosine kinase-1 concentrations 1 and 3 weeks after randomization Adherence was good, with reported intake of 80% or more of the required number of tablets in 89% of participants. There were no significant between-group differences in neonatal adverse outcomes or other adverse events.Item Routine first-trimester screening for fetal trisomies in twin pregnancies: cell-free DNA test contingent on results from the combined test.(Ultrasound in Obstetrics and Gynecology, 2018) Galeva, Slavyana; Konstantinidou, Liountmila; Gil Mira, María del Mar; Akolekar, Ranjit; Nicolaides, Kypros H.Objective: To report on the routine clinical implementation of cell-free (cf)DNA analysis of maternal blood for trisomies 21, 18 and 13 contingent on the results of the first-trimester combined test in twin pregnancies. Methods: Screening for trisomies 21, 18 and 13 was carried out by a combination of maternal age, fetal nuchal translucency (NT) thickness, and serum free ß-hCG and PAPP-A at 11-13 weeks’ gestation in 959 twin pregnancies in two UK NHS hospitals. Women in the high-risk group (risk >1 in 100) were offered options of invasive testing, cfDNA testing or no further testing and those in the intermediate-risk group (risk 1 in 101 to 1 in 2500 in the first phase of the study and 1 in 101 to 1 in 500 in the second phase) were offered cfDNA or no further testing. The trisomic status of the pregnancies was determined by prenatal or postnatal karyotyping or examination of the neonates. Results: In 42 (4.4%) of the 959 pregnancies there was termination, miscarriage or stillbirth with no known karyotype or there was loss to follow up. The 917 pregnancies with known trisomic status of both twins, included 6 that were discordant for trisomy 21, 4 discordant for trisomy 18 and 896 with no trisomies 21, 18 or 13. Following combined screening, 47 (5.1%), 203 (22.2%) and 667 (72.7%) of the pregnancies were classified as high-risk, intermediate-risk and low-risk, respectively. The high-risk group included 5 (83.3%) cases of trisomy 21 and 3 (75.0%) of trisomy 18. The cfDNA test was carried out in 224 pregnancies and results were provided in 214 (95.5%); this group included 6 with trisomy 21, 3 with trisomy 18 and 206 with no trisomies 21, 18 or 13. The cfDNA test correctly classified as screen positive all 6 cases of trisomy 21 and 2 of the 3 with trisomy 18 and as screen negative for each of the trisomies all 206 unaffected pregnancies. Contingent screening, led to prenatal detection of all cases of trisomy 21 and 3 of 4 with trisomy 18. Conclusions: The study has demonstrated the feasibility of introducing cfDNA testing, contingent on the results of the first-trimester combined test for major trisomies, in a routine population of twin pregnancies.Item Screening for trisomies by cfDNA testing of maternal blood in twin pregnancy: update of the Fetal Medicine Foundation results and meta-analysis.(Ultrasound in Obstetrics and Gynecology, 2019) Gil Mira, María del Mar; Galeva, Slavyana; Jani, Jacques; Konstantinidou, Liountmila; Akolekar, Ranjit; Plana, María Nieves; Nicolaides, Kypros H.Objective: To report on the routine clinical implementation of cell-free (cf)DNA analysis of maternal blood for trisomies 21, 18 and 13 in twin pregnancies and to define the performance of the test by combining our results with those arising from systematic review of the literature. Methods: The data for the study were derived from prospective screening for trisomies 21, 18 and 13 in twin pregnancies at 10+0-14+1 weeks’ gestation. Two populations were included; first self-referred women to the Fetal Medicine Centre in London or Brugmann University Hospital in Brussels and second, women selected for the cfDNA test after routine first-trimester combined testing in one of two National Health Service hospitals in England. This dataset was used to determine the performance of screening for the three trisomies. Search of Medline, Embase, CENTRAL (The Cochrane Library), ClinicalTrials.gov and ICTRP (World Health Organization) was carried out to identify all peer-reviewed publications on clinical validation or implementation of maternal cfDNA testing for trisomies 21, 18 and 13 in twin pregnancies. Meta-analysis was then performed using our data and data from the studies identified by the literature search. Results: In our dataset of 997 twin pregnancies with a cfDNA result and known outcome, the test classified correctly 16 (94.1%) of the 17 cases of trisomy 21, 9 (90.0%) of 10 of trisomy 18, 1 (50.0%) of 2 of trisomy 13 and 963 (99.5%) of 968 cases without any of the three trisomies. The literature search identified 7 relevant studies, excluding our papers because their data are included in the current study. In the combined total of our study and the 7 studies identified by the literature search there were 56 trisomy 21 and 3,718 non-trisomy 21 twin pregnancies; the pooled weighted detection rate (DR) and false positive rate (FPR) were 98.2% (95% CI 83.2, 99.8%) and 0.05% (95% CI 0.01, 0.26%), respectively. In the combined total of 18 cases of trisomy 18 and 3,143 non-trisomy 18 pregnancies the pooled weighted DR and FPR were 88.9% (95% CI 64.8, 97.2%) and 0.03% (95% CI 0.00, 0.33%), respectively. For trisomy 13, there were only 3 affected cases and 2 (66.7%) of these were detected by the cfDNA test at FPR of 0.19% (5/2,569). Conclusions: Performance of cfDNA testing for trisomies 21 in twin pregnancies is similar to that reported for singleton pregnancies. The number of cases of trisomies 18 and 13 is too small for accurate assessment of predictive performance of the cfDNA test.