Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2013;35(7):317-322
DOI 10.1590/S0100-72032013000700006
PURPOSE: To investigate relationship between placental thickness during the second and third trimesters and placental and birth weights. METHODS: From January 2011 to June 2012, a total of 250 singleton pregnant women presented at our antenatal clinic were enrolled in this prospective study. All recruited women were assessed at the 1st trimester screening for baseline demographic and obstetric data. The placental thickness was measured trans-abdominally by placing the ultrasound transducer perpendicularly to the plane of the placenta, in the area of the cord insertion at second and third trimester. Pearson's correlation analysis was used to establish the degree of relationship between placental thickness and birth and placental weights. RESULTS: Of 250 recruited participants, 205 women were able to complete the study. The mean age of cases was 26.4±5.1. Values of mean birth and placental weights were 305.56±657.0 and 551.7±104.8 grams respectively. Ultrasonographic measures of placental thickness in second and third trimester and changes between them were 21.68±4.52, 36.26±6.46 and 14.67±5.67 mm respectively. There was a significant positive correlation between placental thickness and birth weight in the second and third trimesters (r=0.15, p=0.03; r=0.14, p=0.04 correspondingly). CONCLUSION: According to our study, birth weight has a positive relation with both second and third trimester placental thickness; however, placental thickness change could not predict low birth weight.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2012;34(10):466-472
DOI 10.1590/S0100-72032012001000006
PURPOSES: To elaborate models for the estimation of fetal weight and longitudinal reference intervals of estimated fetal weight (EFW) using a sample of the Brazilian population. METHODS: Prospective observational study. Two groups of patients were evaluated: Group EFW (estimation of fetal weight): to elaborate (EFW-El) and validate (EFW-Val) a model for the prediction of fetal weight; Group LRI (longitudinal reference intervals): To elaborate (LRI-El) and validate (LRF-Val) conditional (longitudinal) percentiles of EFW. Polynomial regression analysis was applied to the data from subgroup EFW-El to elaborate a model for the estimation of fetal weight. The performance of this model was compared to those of previously published formulas. Linear mixed models were used for the elaboration of longitudinal reference intervals of EFW using data from subgroup LRI-El. Data obtained from subgroup LRI-Val were used to validate these intervals. RESULTS: Group EFW consisted of 458 patients (EFW-El: 367; EFW-Val: 91) and Group LRI consisted of 315 patients (LRI-El: 265; LRI-Val: 50). The model obtained for EFW was: EFW=-8.277+2.146xBPDxACxFL-2.449xFLxBPD². The performances of other models were significantly worse than those obtained with our formula. Equations for the prediction of conditional percentiles of EFW were derived from the longitudinal observation of patients of subgroup LRI-El and validated with data from subgroup LRI-Val. CONCLUSIONS: We described a method for customization of longitudinal reference intervals of EFW obtained using formulas generated from a sample of the Brazilian population.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2012;34(3):107-112
DOI 10.1590/S0100-72032012000300003
PURPOSE: To analyze the influence of maternal nutritional status, weight gain and energy consumption on fetal growth in high-risk pregnancies. METHODS: A prospective study from August 2009 to August 2010 with the following inclusion criteria: puerperae up to the 5th postpartum day; high-risk singleton pregnancies (characterized by medical or obstetrical complications during pregnancy); live fetus at labor onset; delivery at the institution; maternal weight measured on the day of delivery, and presence of medical and/or obstetrical complications characterizing pregnancy as high-risk. Nutritional status was assessed by pregestational body mass index and body mass index in late pregnancy, and the patients were classified as: underweight, adequate, overweight and obese. A food frequency questionnaire was applied to evaluate energy consumption. We investigated maternal weight gain, delivery data and perinatal outcomes, as well as fetal growth based on the occurrence of small for gestational age and large for gestational age neonates. RESULTS: We included 374 women who were divided into three study groups according to newborn birth weight: adequate for gestational age (270 cases, 72.2%), small for gestational age (91 cases, 24.3%), and large for gestational age (13 cases, 3.5%). Univaried analysis showed that women with small for gestational age neonates had a significantly lower mean pregestational body mass index (23.5 kg/m², p<0.001), mean index during late pregnancy (27.7 kg/m², p<0.001), and a higher proportion of maternal underweight at the end of pregnancy (25.3%, p<0.001). Women with large for gestational age neonates had a significantly higher mean pregestational body mass index (29.1 kg/m², p<0.001), mean index during late pregnancy (34.3 kg/m², p<0.001), and a higher proportion of overweight (30.8%, p=0.02) and obesity (38.5%, p=0.02) according to pregestational body mass index, and obesity at the end of pregnancy (53.8%, p<0.001). Multivariate analysis revealed the index value during late pregnancy (OR=0.9; CI95% 0.8-0.9, p<0.001) and the presence of hypertension (OR=2.6; 95%CI 1.5-4.5, p<0.001) as independent factors for small for gestational age. Independent predictors of large for gestational age infant were the presence of diabetes mellitus (OR=20.2; 95%CI 5.3-76.8, p<0.001) and obesity according to body mass index during late pregnancy (OR=3.6; 95%CI 1.1-11.7, p=0.04). CONCLUSION: The maternal nutritional status at the end of pregnancy in high-risk pregnancies is independently associated with fetal growth, the body mass index during late pregnancy is a protective factor against small for gestational age neonates, and maternal obesity is a risk factor for large for gestational age neonates.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2012;34(1):22-27
DOI 10.1590/S0100-72032012000100005
PURPOSE: Evaluate the effects of ipriflavone during fetogenesis, since no studies have been conducted to assess its effect during this period. METHODS: 60 pregnant rats were divided randomly into four groups (n=15). G-control (1 mL of distilled water) and three groups treated intragastrically with ipriflavone from the 16th to the 20th post coitus (PC) day: G-300 (300 mg/kg), G-1,500 (1,500 mg/kg) and G-3,000 (3,000 mg/kg). The animals were weighed, anaesthetized intraperitoneally with xylazine and ketamine at doses of 180 mg/kg and 10 mg/kg, respectively, and sacrificed by total exsanguination on the 21st day. A complete blood count was performed and serum cholesterol, triglycerides, AST, ALT, urea, creatinine, and glucose were determined in pregnant rats. After laparotomy, the liver, kidneys, adrenals, spleen and ovaries were removed and weighed; fetuses and placentas were also weighed to obtain the average weight of the litters. Four fetuses (two males and two females) were chosen at random for the determination of the length and weight of brain, liver, kidneys and lungs. Statistical analysis: ANOVA followed by Dunnett's test. For raw data without normal distribution and homoscedasticity, we used the Kruskal-Wallis test followed by the Mann-Whitney test. Proportions were analyzed by the χ² test (p<0.05). RESULTS: Triglyceride levels (mg/dL) were: Control-G (138.8±21.8), G-300 (211.2±63.9) G-1,500 (251.5±65.2) G-3,000 (217.7±49.6); p<0.05. The body weight of fetuses (g) was: G-Control (male 3.3±0.3; female 3.1±0.3), G-300 (male 3.4±0.2; female 3.1±0.4), G-1,500 (male 3.5±0.3; female 3.2±0.3), G-3,000 (male 3.4±0.5; female 3.1±0.4). CONCLUSION: Ipriflavone did not cause maternal toxicity, but increased triglyceride levels and reduced hematocrit at higher doses. The body and organ weights of the fetuses did not change with dam treatment. There were no external malformations or fetal deaths.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2011;33(4):164-169
DOI 10.1590/S0100-72032011000400003
PURPOSE: to assess the validity of several fetal weight charts, commonly used in Portugal, to classify its population. METHODS: observational retrospective study. Singleton birth data was analyzed, from a two- year period (May 2008 to April 2010), from pregnancies with an ultrasound in the same institution, between the 8th and 14th gestational week. Upon data validation, percentiles for each completed gestational week were created, smoothed by a quadratic function, analyzed and compared to the tables more commonly utilized, in the institution and country, by using Z-scores, percentile comparison, sample 10th percentile detection sensibility and birthweight means comparison. RESULTS: a total of 5,378 newborns (NB) were born in the period; 2,195 (42%) NB were included, born from the 24th to 42nd gestational week, allowing statistical analysis from the 34th to the 41st week. There were differences in the mean birthweight for each gestational age, between references and with the sample, as well as between sexes. The 10th percentile from some references has shown differences ranging from -288g at 37 weeks (-11% in Lubchenco et al. data), with and +133g at 34 weeks (+7,6% with Carrascosa et al. data) compared to the values found with the sample. Differences were also found concerning the sensitivity of the identification of a sample birthweight below the 10th percentile, which was between 14.1 and 100%, depending on the reference used. DISCUSSION: the limitation of these kinds of reference values must be remembered and minimized, with the adoption of regionally or nationally produced references, contemplating other variables, such as sex, with precisely known gestation duration and with validation of the utilized references in loco.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2010;32(9):420-425
DOI 10.1590/S0100-72032010000900002
PURPOSE: to compare the patterns of fetal heart rate (FHR) in the second and third trimesters of pregnancy. METHODS: a prospective and comparative study performed between January 2008 and July 2009. The inclusion criteria were: singleton pregnancy, live fetus, pregnant women without clinical or obstetrical complications, no fetal malformation, gestational age between 24 and 27 weeks (2nd trimester - 2T) or between 36 and 40 weeks (3rd trimester - 3T). Computerized cardiotocography (System 8002 - Sonicaid) was performed for 30 minutes and the fetal biophysical profile was obtained. System 8002 analyzes the FHR tracings for periods of 3.75 seconds (1/16 minutes). During each period, the mean duration of the time intervals between successive fetal heart beats is determined in milliseconds (ms); the mean FHR and also the differences between adjacent periods are calculated for each period. The parameters included: basal FHR, FHR accelerations, duration of high variation episodes, duration of low variation episodes and short-term variation. The dataset was analyzed by the Student t test, chi-square test and Fisher's exact test. Statistical significance was set at p<0.05. RESULTS: eighteen pregnancies on the second trimester were compared to 25 pregnancies on the third trimester. There was a significant difference in the FHR parameters evaluated by computerized cardiotocography between the 2T and 3T groups, regarding the following results: mean basal FHR (mean, 143.8 bpm versus 134.0 bpm, p=0.009), mean number of transitory FHR accelerations > 10 bpm (3.7 bpm versus 8.4 bpm, p <0.001) and >15 bpm (mean, 0.9 bpm versus 5.4 bpm, p <0.001), mean duration of high variation episodes (8.4 min versus 15.4 min, p=0.008) and mean short - term variation (8.0 ms versus 10.9 ms, p=0.01). The fetal biophysical profile showed normal results in all pregnancies. CONCLUSION: the present study shows significant differences in the FHR characteristics when the 2nd and 3rd trimesters of pregnancy are compared and confirms the influence of autonomic nervous system maturation on FHR regulation.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2010;32(1):4-10
DOI 10.1590/S0100-72032010000100002
PURPOSE: to evaluate the correlation between the estimated fetal weight (EFW) by ultrasonography and the neonatal weight (NW), as well as the EFW's capacity to predict changes in NW among pregnant women in João Pessoa, Paraíba, Brazil. METHODS: a diagnostic validation study, including 122 pregnant women who have had the EFW calculated by ultrasonography up to seven days before delivery and the NW established immediately after birth, with a specific newborn's scale. The correlation between EFW and NW measurements was assessed by Pearson's correlation coefficient and by the mean difference between them. EFW and NW were classified as: low for the gestational age (LGA), adequate for the gestational age (AGA) and high for the gestational age (HGA), according to the percentiles 10 and 90 of the respective reference curves. The diagnosis of EFW deviation has been validated using the values of the Alexander's NW reference curve as gold-standard, by estimating the sensitivity, specificity, and positive and negative predictive values. RESULTS: there has been a high linear correlation between the EFW and NW (R=0.96), and the difference between them has varied from -474 g to +480 g, with an average of +3 g. Most of the highest percent weight estimate variations were between 10 and 15%. EFW has had 85.7% of sensitivity and 100% of specificity for the detection of LGA, and 100 and 77.2%, respectively, for the detection of HGA. CONCLUSIONS: EFW is able to predict NW adequately, and the reference EFW tested has had a good performance in the screening of fetal growth deviation, in the population studied.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2006;28(9):513-522
DOI 10.1590/S0100-72032006000900003
PURPOSE: to describe, in participants of the Brazilian Study of Gestational Diabetes (EBDG), the percentile distribution of uterine height by gestational age and to validate the use of percentiles of the chart derived by the "Centro Latino-Americano de Perinatologia" (CLAP), used as reference in predicting abnormal fetal growth. METHODS: the EBDG is a cohort study of 5564 pregnant women older than 19 years, followed through and after delivery. Interviews and standardized anthropometry were performed at baseline between 20-28 weeks. Medical records covering prenatal and delivery periods were then reviewed following a standardized approach. Analyses pertain to 3539 women with gestational age confirmed by ultrasound. Diagnostic properties of the 10th and the 90th percentiles of both charts (EBDG and CLAP) as predictors of abnormal neonatal weight were determined. RESULTS: uterine height was higher in EBDG than in the CLAP chart at every gestational week, being 1-4 and 2-6 cm greater, at the 10th and 90th percentiles respectively. The CLAP 10th percentile classified as small the uterine heights of only 0.3 to 1.7% of Brazilian women, while the 90th percentile classified as large the uterine heights of 42 to 57% of the sample. The sensitivity of CLAP percentile 10 in the prediction of small for gestational age varied from 0.8 to 6% and the specificity of CLAP percentile 90 in the prediction of large for gestational age, from 46 to 61%. CONCLUSIONS: the CLAP uterine height reference chart does not reflect the current uterine growth pattern of pregnant Brazilians, limiting its clinical applicability in the detection of abnormal fetal growth, especially intrauterine growth restriction.