Roberto Eduardo Bittar

Cervical length at 11–14 weeks' and 22–24 weeks' gestation evaluated by transvaginal sonography, and gestational age at delivery

To compare cervical length measurements obtained at 11 to 14 weeks and 22 to 24 weeks of gestation in an unselected group of pregnant women and to correlate the measurements with time of delivery.

Prediction of preterm delivery in the second trimester.

OBJECTIVE: The aim of this study was to estimate the probability of spontaneous delivery at 34 weeks or less according to cervical assessment by transvaginal scan associated with previous obstetric history. METHODS: Ultrasound transvaginal cervical length and presence of funneling were evaluated in 1,958 singleton pregnancies between 21 and 24 weeks of gestation. For the prediction of preterm delivery, the results of cervical assessment were analyzed in association with the previous obstetric history of preterm delivery, spontaneous miscarriage, and curettage. Sensitivity, specificity, and positive and negative predictive values for the various cutoff cervical lengths in the groups with or without previous history of preterm delivery were calculated. Multivariable regression analysis was used to identify the predictive factors for preterm delivery at 34 weeks or less. RESULTS: The incidence of spontaneous delivery at gestational age of 34 weeks or less was 3.4%. The mean cervical length was 30.1 mm (standard deviation 10.1 mm) in the group with previous history of prematurity (n = 180) and 35.8 mm (standard deviation 7.9 mm) in the group without previous history of prematurity (P < .001). The mean cervical length in the group of patients who delivered at or before 34 weeks was 23.8 mm, and for patients who delivered after 34 weeks it was 35.6 mm (P < .001). The mean gestational age at delivery was significantly lower in the group with funneling compared with the group without funneling (33.5 weeks versus 38.8 weeks, P < .001). Logistic regression analysis demonstrated that cervical length, funneling, and history of previous preterm delivery were independent contributors for preterm delivery. CONCLUSION: Ultrasound cervical assessment may be useful in the prediction of preterm delivery, but it should also be considered in association with the obstetric history of prematurity. LEVEL OF EVIDENCE: II-2

Cervical fetal fibronectin in patients at increased risk for preterm delivery

OBJECTIVE This study aimed to evaluate fetal fibronectin concentrations in cervical secretions measured by either a rapid immunoassay or an enzyme-linked immunosorbent assay as a tool for the screening of premature delivery in otherwise asymptomatic pregnant women at high risk for prematurity. STUDY DESIGN One hundred two pregnant women at high risk for premature delivery were followed up. Samples of the cervical secretion were taken every 2 weeks between the twenty-fourth and the thirty-fourth weeks of pregnancy. The samples were obtained from the ectocervix with two swabs. One cervical sample was used for the immediate-reading membrane test, and the other one for the immunoenzyme test. The correlation between the presence of fetal fibronectin in the cervical secretions and preterm birth was evaluated. In addition, a comparison between tests was made. RESULTS The rate of preterm birth was 37.25% (38/102). Membrane tests revealed a sensitivity of 73.68% and a specificity of 92.18%; its positive predictive value was 84.84% and the negative predictive value was 85.50%. The enzyme-linked immunosorbent assays revealed a sensitivity of 78.94% and a specificity of 85.93%; its positive predictive value was 76.92%, and the negative predictive value was 87.30%. When compared with each other, the tests were found essentially concordant (p < 0.05). The elapsed time between the last sampling and the occurrence of preterm birth was 2.9 +/- 1.8 weeks. CONCLUSION The rapid result membrane test is comparable to the standard fetal fibronectin enzyme-linked immunosorbent assays for the detection of fetal fibronectin in cervical secretions between the twenty-fourth and thirty-fourth weeks of gestation. Moreover, both assays were found to be good tools for the prediction of premature delivery in asymptomatic pregnant women at high risk for prematurity. The availability of a rapid search for the presence of cervical fetal fibronectin should improve our ability to efficiently identify patients at risk for preterm delivery to discriminate between such patients and those with benign Braxton Hicks contractions.

Predicting preterm delivery in asymptomatic patients with prior preterm delivery by measurement of cervical length and phosphorylated insulin-like growth factor-binding protein-1

To evaluate the efficacy of cervical length measurement in combination with a bedside assessment of phosphorylated insulin‐like growth factor‐binding protein‐1 (phIGFBP‐1) as a predictor of preterm delivery in asymptomatic pregnant women with a history of preterm birth.

Abruptio placentae following snake bite

A case in which, besides the clinical complications that commonly follow snake biting, abruptio placentae occurred is reported here. None of the factors that are frequently associated with abruptio placentae were present. The laboratory tests performed showed that renal function was impaired and that a dramatic hypercoagulability was present. The relationship of the latter to the abruptio placentae is discussed.

Risk predictors for preterm birth

Among the clinical factors for preterm birth, some confer substantial increased risk, including a history of preterm birth, multiple gestation and vaginal bleeding in the second trimester. However, these factors are present only in a minority of women who ultimately deliver preterm and thus have low sensitivity. Cervical dilatation, effacement and position as determined by manual examination have been related to an increased risk of preterm birth but also suffer from low sensitivity and positive predictive values. Cervical length measured with transvaginal ultrasound has also been related to an increased risk of preterm birth as cervical length decreases. The reported sensitivity is better than other tests, but positive predictive value is low. The principal utility of the fetal fibronectin assay lies in its negative predictive value in symptomatic women. Increased sensitivity has been reported when cervical length is used in combination with fetal fibronectin.

Neonatal Outcomes of Late-Preterm Birth Associated or Not with Intrauterine Growth Restriction

Objective. To compare neonatal morbidity and mortality between late-preterm intrauterine growth-restricted (IUGR) and appropriate-for-gestational-age (AGA) infants of the comparable gestational ages (GAs). Methods. We retrospectively analyzed neonatal morbidity and mortality of 50 singleton pregnancies involving fetuses with IUGR delivered between 34 and 36 6/7 weeks of GA due to maternal and/or fetal indication. The control group consisted of 36 singleton pregnancies with spontaneous preterm delivery at the same GA, in which the infant was AGA. Categorical data were compared between IUGR and AGA pregnancies by X 2 analysis and Fishers exact test. Ordinal measures were compared using the Kruskal-Wallis test. Results. The length of stay of newborns in the nursery, as well as the need for and duration of hospitalization in the neonatal intensive care unit, was longer in the group with IUGR. Transient tachypnea of the newborn or apnea rates did not differ significantly between the IUGR and AGA groups. IUGR infants were found to be at a higher risk of intraventricular hemorrhage. No respiratory distress syndrome, pulmonary hemorrhage or bronchopulmonary dysplasia was observed in either group. The frequency of sepsis, thrombocytopenia and hyperbilirubinemia was similar in the two groups. Hypoglycemia was more frequent in the IUGR group. No neonatal death was observed. Conclusion. Our study showed that late-preterm IUGR infants present a significantly higher risk of neonatal complications when compared to late-preterm AGA infants.

Determinantes diretos do parto prematuro eletivo e os resultados neonatais

OBJETIVO: caracterizar gestantes submetidas ao parto prematuro eletivo e relacionar diagnosticos clinicos e obstetricos com os resultados neonatais. METODO: foram coletados prospectivamente os dados de 100 gestantes internadas na enfermaria da Clinica Obstetrica e os seus recem-nascidos. Os criterios de inclusao foram: gestacao unica; idade gestacional confirmada por ultra-sonografia precoce; ausencia de trabalho de parto; presenca de condicao materna e/ou fetal que motivasse a indicacao do parto prematuro. Para relacionar a causa do parto prematuro eletivo com os resultados neonatais, classificamos as causas diretas do parto em grupos. Comparamos os grupos, considerando a idade gestacional. Para avaliar os resultados neonatais, considerou-se: acidose, Apgar no 1o e no 5o minuto (menor que 7), hemorragia intracraniana, mortalidade neonatal, sepse neonatal e sindrome do desconforto respiratorio. A analise estatistica utilizada para a correlacao entre as causas do parto e a idade gestacional aos resultados neonatais foi realizada por modelos log-lineares. RESULTADOS: uma das pacientes foi excluida do estudo por malformacao fetal. As causas diretas mais comuns do parto foram: sofrimento fetal anteparto (49,5%), sindromes hipertensivas (21,2%), restricao do crescimento fetal (13,1%) e outras causas (16,2%). Entre as complicacoes neonatais, destacaram-se: asfixia (33,3%), acidose (30,4%), sindrome do desconforto respiratorio (26,3%), sepse (22,2%), hemorragia intracraniana (21,2%) e morte neonatal (13,1%). A analise por modelos log-lineares evidenciou associacao entre as causas do parto e a incidencia de acidose e sindrome do desconforto respiratorio e a idade gestacional associou-se a sindrome do desconforto respiratorio, Apgar de 1o minuto <7, sepse, hemorragia intracraniana e morte neonatal. CONCLUSOES: a causa do parto influencia os resultados neonatais. Entretanto, as complicacoes mais graves dependeram diretamente da idade gestacional no parto. Desta maneira, o diagnostico anteparto deve ser criteriosamente avaliado pelo obstetra, para que a decisao de se interromper a gestacao possa ser feita em momento adequado, evitando-se assim as complicacoes neonatais.

Prematurity prevention: the role of progesterone.

Purpose of review This review summarizes the evidence of the effectiveness of progesterone on the rate of preterm birth and evaluates the most recent studies. Recent findings The incidence of preterm delivery is about 7–11% of all pregnant women and preterm birth is one of the most important causes of neonatal morbidity and mortality. Interventions to reduce such complications have been attempted for several years. Most efforts so far have been tertiary interventions, such as treatment with antenatal corticosteroids, tocolytic agents, and antibiotics. Some of these measures have reduced perinatal morbidity and mortality, but the incidence of preterm birth is increasing. Recently, researches have suggested prophylactic progesterone could reduce the preterm birth rate in a select group presenting previous preterm birth and a short cervical length by transvaginal scan at mid-trimester pregnancy. Summary This review intends to define the current indication for administration of progesterone for pregnant women. On the basis of current knowledge, progesterone should be offered to women with a documented history of a previous spontaneous birth at less than 37 weeks and for those found to have a short cervical length of 15 mm or less. Studies are needed to evaluate progesterone efficacy on other risk factors.

Proposta de Nova Curva de Altura Uterina para Gestações entre a 20ª e a 42ª Semana

Purpose: to create a uterine height growth curve, according to gestational age, to verify differences among the existing curves and to evaluate the influence of color, parity and maternal weight on the variation of uterine height. Methods: during the period from July 1997 to July 1999, 100 normal pregnant women were submitted to uterine height measurements between the 20th and 42nd week of gestation. All the pregnant women had ultrasonically confirmed gestational age. A total of 726 measurements of uterine height were carried out by the same examiner, using a metric tape from the upper border of the symphysis pubis to the fundus uteri. Results: curves and tables of uterine height according to gestational age were obtained. The average uterine height growth was 0.7 cm/week. The study revealed different average uterine height values in relation to other uterine height growth curves. No statistically significant variations were found between the distributions of uterine heights according to color, parity and weight. Conclusion: the construction of a methodologically accepted uterine height growth curve aimed to detect, as a clinical method, the fetal growth disturbances. This should be analyzed in a posterior study.