Performance of the first-trimester Fetal Medicine Foundation competing risks model for preeclampsia prediction: an external validation study in Brazil.

BACKGROUND: The current version of the Fetal Medicine Foundation competing risks model for preeclampsia prediction has not been previously validated in Brazil. OBJECTIVE: This study aimed (1) to validate the Fetal Medicine Foundation combined algorithm for the prediction of preterm preeclampsia in the Brazilian population and (2) to describe the accuracy and calibration of the Fetal Medicine Foundation algorithm when considering the prophylactic use of aspirin by clinical criteria. STUDY DESIGN: This was a cohort study, including consecutive singleton pregnancies undergoing preeclampsia screening at 11 to 14 weeks of gestation, examining maternal characteristics, medical history, and biophysical markers between October 2010 and December 2018 in a university hospital in Brazil. Risks were calculated using the 2018 version of the algorithm available on the Fetal Medicine Foundation website, and cases were classified as low or high risk using a cutoff of 1/100 to evaluate predictive performance. Expected and observed cases with preeclampsia according to the Fetal Medicine Foundation-estimated risk range (≥1 in 10; 1 in 11 to 1 in 50; 1 in 51 to 1 in 100; 1 in 101 to 1 in 150; and <1 in 150) were compared. After identifying high-risk pregnant women who used aspirin, the treatment effect of 62% reduction in preterm preeclampsia identified in the Combined Multimarker Screening and Randomized Patient Treatment with Aspirin for Evidence-Based Preeclampsia Prevention trial was used to evaluate the predictive performance adjusted for the effect of aspirin. The number of potentially unpreventable cases in the group without aspirin use was estimated. RESULTS: Among 2749 pregnancies, preterm preeclampsia occurred in 84 (3.1%). With a risk cutoff of 1/100, the screen-positive rate was 25.8%. The detection rate was 71.4%, with a false positive rate of 24.4%. The area under the curve was 0.818 (95% confidence interval, 0.773-0.863). In the risk range ≥1/10, there is an agreement between the number of expected cases and the number of observed cases, and in the other ranges, the predicted risk was lower than the observed rates. Accounting for the effect of aspirin resulted in an increase in detection rate and positive predictive values and a slight decrease in the false positive rate. With 27 cases of preterm preeclampsia in the high-risk group without aspirin use, we estimated that 16 of these cases of preterm preeclampsia would have been avoided if this group had received prophylaxis. CONCLUSION: In a high-prevalence setting, the Fetal Medicine Foundation algorithm can identify women who are more likely to develop preterm preeclampsia. Not accounting for the effect of aspirin underestimates the screening performance.

Application of 4 birthweight curves and local reference range at a University Hospital of Rio de Janeiro, Brazil.

BACKGROUND: Numerous fetal growth curves have been developed from various subpopulations and geographic locations worldwide. OBJECTIVE: To determine the birthweight standard at the Maternity School and compare it to currently used standards in the clinical practice services. STUDY DESIGN: Cross-sectional, observational, and descriptive study. Data from infants born between 2011 and 2016 were collected from the Maternity School Hospital of the Federal University of Rio de Janeiro to define the 10th, 25th, 50th, 75th, and 90th percentiles of the birthweight by gestational age. It was determined the performance of the INTERGROWTH-21st, Fenton, Alexander, and Lubchenco for the Maternity School standards. RESULTS: After the 33rd week of pregnancy, the INTERGROWTH standard was similar to the local standard for small-for-gestational-age infants and Fenton for large-for-gestational-age infants at Maternity School Hospital. The INTERGROWTH standard was found to be inadequate to classify small-for-gestational-age infants, which are babies at major risk for morbidity and mortality at the onset of the 33rd week of pregnancy. CONCLUSION: It was possible to define reference values for birthweight for the maternal school hospital considering at least 33 weeks of pregnancy with a 95% confidence interval. The comparison of the INTERGROWTH, Fenton, Alexander, and Lubchenko standards to the maternal school hospital curve showed that the Fenton curve was the most suitable for the diagnosis of small for gestational age.

Use of antenatal corticosteroids in Brazil: data analysis from the National Survey Nascer no Brasil.

OBJECTIVE: To estimate the rate of the use of antenatal corticosteroids (ANC) among pregnant women and to identify the conditions associated with their non-use in Brazil. METHODS: Secondary data analysis from "Birth in Brazil", a national hospital-based survey carried out in 2011-2012 on childbirth and birth. The sample was characterized regarding maternal age, marital status and maternal education, parity, mode of delivery and place of residence. The association of ANC use with gestational age and type of delivery was analyzed. The studied maternal complications were the presence of hypertension, pre-eclampsia/eclampsia, and pyelonephritis, infection by the HIV virus or acquired immune deficiency syndrome. RESULTS: 2,623 pregnant women with less than 37 weeks of gestational age were identified, and, of these, 835 (31.8%) received ANC. The frequency of ANC use was higher among women with gestational ages between 26-34 weeks (481 cases; 48.73%). In pregnancies with less than 37 weeks, the use of ANC was 23.9% in spontaneous deliveries, 20.6% in induced deliveries and 43.8% among those who did not go into labor. The variables vaginal delivery (OR 2.5; 95%CI 1.8-3.4) and living in the countryside were associated with not using ANC, and the occurrence of pre-eclampsia/eclampsia (OR 1.8; 95%CI 1.2-2.9) was associated with the use of ANC. CONCLUSIONS: The use of ANC among Brazilian pregnant women was low. Interventions to increase its use are necessary and can contribute to reduce neonatal mortality and morbidity. ANC should be promoted in pregnancies of less than 37 weeks, especially in cases of vaginal delivery and for those living in the countryside.

Performance of Fetal Medicine Foundation Software for Pre-Eclampsia Prediction Upon Marker Customization: Cross-Sectional Study.

BACKGROUND: FMF2012 is an algorithm developed by the Fetal Medicine Foundation (FMF) to predict pre-eclampsia on the basis of maternal characteristics combined with biophysical and biochemical markers. Afro-Caribbean ethnicity is the second risk factor, in magnitude, found in populations tested by FMF, which was not confirmed in a Brazilian setting. OBJECTIVE: This study aimed to analyze the performance of pre-eclampsia prediction software by customization of maternal ethnicity. METHODS: This was a cross-sectional observational study, with secondary evaluation of data from FMF first trimester screening tests of singleton pregnancies. Risk scores were calculated from maternal characteristics and biophysical markers, and they were presented as the risk for early pre-eclampsia (PE34) and preterm pre-eclampsia (PE37). The following steps were followed: (1) identification of women characterized as black ethnicity; (2) calculation of early and preterm pre-eclampsia risk, reclassifying them as white, which generated a new score; (3) comparison of the proportions of women categorized as high risk between the original and new scores; (4) construction of the receiver operator characteristic curve; (5) calculation of the area under the curve, sensitivity, and false positive rate; and (6) comparison of the area under the curve, sensitivity, and false positive rate of the original with the new risk by chi-square test. RESULTS: A total of 1531 cases were included in the final sample, with 219 out of 1531 cases (14.30; 95% CI 12.5-16.0) and 182 out of 1531 cases (11.88%; 95% CI 10.3-13.5) classified as high risk for pre-eclampsia development, originally and after recalculating the new risk, respectively. The comparison of FMF2012 predictive model performance between the originally estimated risks and the estimated new risks showed that the difference was not significant for sensitivity and area under the curve, but it was significant for false positive rate. CONCLUSIONS: We conclude that black ethnicity classification of Brazilian pregnant women by the FMF2012 algorithm increases the false positive rate. Suppressing ethnicity effect did not improve the test sensitivity. By modifying demographic characteristics, it is possible to improve some performance aspects of clinical prediction tests.

How do maternal factors impact preeclampsia prediction in Brazilian population?

Objective: To evaluate the impacts of maternal risk factors described by the Fetal Medicine Foundation's 2012 algorithm (FMF2012) in a Brazilian population. Methods: All singleton pregnancies submitted to first-trimester preeclampsia (PE) screening using the FMF2012 algorithm were considered for study inclusion. Maternal factors, recorded via a patient questionnaire, were described and compared between PE outcome groups. A Gaussian regression model was derived to measure the effects of maternal factors, and to identify factors that contributed significantly (p < .05) to the alteration of gestational age at delivery, in pregnancies with PE. Results: Of the 1934 cases considered for study inclusion, the final sample consisted of 1531 cases. The sample included 120 (7.8%) cases of PE, of which 26 (1.7%) were preterm PE (PE < 37 weeks) and 11 (0.72%) were early PE (PE < 34 weeks). The PE rate did not differ according to ethnicity, smoking, family history of PE, or use of assisted reproductive technology. Significant differences (p < .05) between the normal and PE groups in maternal age, maternal weight, previous history of PE, chronic hypertension, and types 1 and 2 diabetes were detected. Conclusions: The significance and magnitude of associations of maternal factors in our sample differed from those incorporated in the FMF2012 model, implying the need to derive a fitted model for our population.

Preeclampsia: Prevalence and perinatal repercussions in a University Hospital in Rio de Janeiro, Brazil.

Preeclampsia (PE) prevalence studies in Brazil are both scarce and not divided in accordance with gestational age at delivery. We accessed PE prevalence according to delivery before 34, 37 and 42weeks in a cross-sectional study including 4464 single deliveries. PE was diagnosed in 301 cases (6.74%); Prevalence of PE was 0.78%; 1.92% and 6.74% according to deliveries before 34, 37 and 42weeks. PE was associated with fetal death, prematurity and small for gestational age newborns.