PubMed Health⌕ Search

Biomedical subjects

E R Norwitz

Publications and source records attributed to E R Norwitz.

At least 19 recordsLinked to original sources
PubMed2005

Placental growth factor in the cerebrospinal fluid of women with preeclampsia.

OBJECTIVE: Recent data suggest that excess circulating soluble fms-like tyrosine kinase-1 (sFlt-1) may causally relate to preeclampsia. This study investigates the levels of sFlt-1, VEGF, and PlGF in cerebrospinal fluid (CSF) of patients with preeclampsia and normotensive controls. METHODS: CSF was collected from preeclamptic patients (n=15) and controls (n=7) at the time of spinal anesthesia and assayed for PlGF, sFlt-1, and VEGF (total and free) by specific immunoassays. RESULTS: All sought angiogenic factors were measurable. Levels of free PlGF but not sFlt-1 or VEGF (total or free) were increased in CSF of preeclamptic women. There was no significant difference in the ratios of angiogenic factors in the CSF of women with preeclampsia. There was no correlation between levels of angiogenic factors and CSF cell counts or severity of symptoms. CONCLUSION: Elevated levels of PlGF in CSF preeclamptic women may promote vascular permeability and contribute to the hypertensive encephalopathy seen in such patients.

Adult↗
PubMed2005

Role of cytokines in preterm labor and birth.

Preterm birth (defined as delivery prior to 37 weeks' gestation) complicates 5-10% of all births. It is a major cause of perinatal mortality and morbidity. Approximately 20% of all preterm births are iatrogenic resulting from obstetric intervention for maternal and/or fetal indications. Of the remainder, 2/3 are spontaneous preterm labor with or without preterm premature rupture of the membranes (pPROM). Preterm labor is a syndrome rather than a diagnosis since the etiologies are varied. Risk factors include, among others, pPROM, cervical insufficiency, pathologic uterine distention (polyhydramnios, multiple gestation), uterine anomalies, intrauterine infection/inflammation, and social factors (stress, smoking, heavy work). The final common pathway appears to be activation of the inflammatory cascade. Bacterial colonization and/or inflammation of the choriodecidual interface induces production of pro-inflammatory cytokines that, in turn, lead to neutrophil activation and the synthesis and release of uterotonins such as prostaglandins (which cause uterine contractions) and metalloproteinases (that weaken fetal membranes and remodel cervical collagen). This monograph reviews the role of cytokines in the pathophysiology of preterm labor and delivery.

Adolescent↗
PubMed2001

Prenatal diagnosis of pyruvate dehydrogenase deficiency using magnetic resonance imaging.

INTRODUCTION: Pyruvate dehydrogenase deficiency is an inherited inborn error of metabolism associated with early neonatal death and long-term neurologic sequelae in survivors. Prenatal diagnosis currently relies on isolation of fetal cells for subsequent genetic and/or biochemical studies. Magnetic resonance imaging and magnetic resonance spectroscopy have been used on occasion for both postnatal diagnosis and management of pyruvate dehydrogenase deficiency. We illustrate a case in which these non-invasive modalities also prove useful for prenatal diagnosis of this condition. CASE: A 31-year-old multipara with a history of two prior infants affected with pyruvate dehydrogenase deficiency presented with a spontaneous dichorionic, diamniotic twin pregnancy. Magnetic resonance imaging and magnetic resonance spectroscopy were performed on both fetuses. Magnetic resonance imaging of the presenting (male) fetus demonstrated mild ventriculomegaly, increased extracerebrospinal fluid, and decreased cortical sulcation and gyration. The non-presenting (female) fetus was structurally normal. Magnetic resonance spectroscopy spectra were obtained for both fetuses, and were normal. The diagnosis of pyruvate dehydrogenase deficiency was made in the presenting fetus after delivery on the basis of subsequent mortality from severe lactic acidosis. CONCLUSION: Prenatal MR imaging of the fetal brain can be used for prenatal diagnosis in fetuses at risk for pyruvate dehydrogenase deficiency. Prenatal MR spectroscopy, although technically feasible, does not appear to have a role in the prenatal diagnosis of this condition.

Acidosis, Lactic↗
PubMed2001

Neonatal outcome of infants born at 23 weeks' gestation.

OBJECTIVE: To determine the neonatal outcome in accurately dated 23-week deliveries. METHODS: We reviewed the records of consecutive births between 23 0/7 and 23 6/7 weeks at Brigham & Women's Hospital, Boston, Massachusetts, from January 1995 to December 1999. Women were excluded if they presented for elective termination or had known fetal death or poor dating criteria. Neonatal records were abstracted for mortality and short-term morbidity, including the respiratory distress syndrome (RDS), intraventricular hemorrhage, chronic lung disease, necrotizing enterocolitis, periventricular leukomalacia, and retinopathy of prematurity. Survival was defined as discharge from neonatal intensive care. RESULTS: Thirty-three singleton pregnancies met criteria for inclusion, 11 of whom survived to discharge (survival rate 0.33; 95% CI 0.18, 0.52). More advanced gestational age was associated with increased likelihood of survival: 0 of 12 at 23 0/7 to 23 2/7 weeks, 4 of 10 at 23 3/7 to 23 4/7 weeks, and 7 of 11 at 23 5/7 to 23 6/7 weeks (P =.02). All 11 survivors developed RDS and chronic lung disease. One of 11 survivors had necrotizing enterocolitis, and 2 of 11 had severe retinopathy of prematurity. One survivor had periventricular leukomalacia on head ultrasonography, compared with 7 of the nonsurvivors who had head ultrasonography (P =.03). One survivor developed severe intraventricular hemorrhage (grade 3 or 4) compared with 8 of the 12 at-risk nonsurvivors who had head ultrasonography (P =.01). CONCLUSION: About one third of infants delivered at 23 weeks' gestation survived to be discharged from neonatal intensive care. More advanced gestational age was associated with increased likelihood of survival. No neonates survived free of substantial morbidity.

Enterocolitis, Necrotizing↗
PubMed2001

Placenta percreta and uterine rupture associated with prior whole body radiation therapy.

BACKGROUND: Injury to reproductive organs including the uterus is a known complication of ionizing radiation, but the risks to the mother and fetus during subsequent pregnancies are not well defined. CASE: A young woman with a remote history of whole body irradiation for childhood leukemia had uterine rupture at 17 weeks' gestation. Pathologic examination of the supracervical hysterectomy specimen revealed a posterior-fundal placenta percreta with a diffusely thinned myometrium (1-6 mm). The clinicopathologic findings were consistent with prior radiation injury. CONCLUSION: Uterine irradiation may predispose to abnormal placentation and uterine rupture in a subsequent pregnancy.

Adult↗
PubMed2001

A systematic approach to the management of preterm labor.

Preterm birth occurs in 7% to 12% of all deliveries, but accounts for over 85% of all perinatal morbidity and mortality. Although the ability of obstetric care providers to identify women at risk for preterm delivery has improved, the overall incidence of preterm birth has remained unchanged for the past 30 years. Preterm birth remains the single greatest challenge for physician-researchers in the field of maternal-fetal medicine in the 21st century. This article reviews in detail the current state of the literature as regards the etiology, pathophysiology, prevention, and treatment of premature labor and preterm birth. A better understanding of the molecular mechanisms responsible for the process of labor, both at term and preterm, will improve our ability to identify and manage women at risk of premature delivery.

Animals↗
PubMed2001

The epidemiology of preterm labor.

There are many factors that are associated with preterm labor and delivery. These include maternal conditions such as medical illness, anemia and uterine malformation. They may be related to past events such as prior obstetric complication, previous preterm labor, cervical surgery or induced abortion. They may be intrinsic to the current pregnancy, such as reproductive tract infection, multifetal gestation, maternal age, short interpregnancy interval or prolonged menstrual conception interval. Maternal behaviors such as smoking and substance abuse can be risk factors for a short gestation. Demographic variables such as race, employment and socioeconomic status can also be associated with preterm labor. This article briefly reviews these subjects.

Anemia↗
PubMed2001

Prenatal ultrasonography and the diagnosis of fetal cleft lip.

OBJECTIVE: To determine the efficacy of obstetric ultrasonography in the detection of fetal cleft lip. METHODS: The study population included all women who had a fetal anatomic survey with adequate visualization of the face and who gave birth at Brigham and Women's Hospital between January 1, 1990, and January 31, 2000. All neonates born with cleft lip were identified from the Brigham and Women's Active Malformation Surveillance Program. Confirmation of the anatomic defect was obtained from the pediatric record or from the pathologic report if the pregnancy was terminated or ended in miscarriage. Cases of isolated cleft palate were excluded. An ultrasonography database was used to identify all cases of cleft lip diagnosed before delivery. Maternal information regarding the pregnancy was abstracted from the medical record. Statistical significance was determined using the chi2 statistic for categorical variables and the t test for continuous variables. RESULTS: A total of 56 confirmed cases of cleft lip were identified in the study population. Overall, 73% of the cases (41 of 56) were identified antenatally. Additional fetal anomalies were present in 54% of the cases (30 of 56). A comparison between those cases that were detected and those in which the diagnosis was missed showed that there was a significantly lower detection rate if the ultrasonography was performed before 20 weeks (12 [57%] of 21 versus 29 [83%] of 35; P = .035). There was no difference between the 2 groups in terms of maternal age or weight. Maternal parity, prior maternal abdominal surgery, the presence of a multiple gestation, or coexisting fetal anomalies did not significantly affect the detection rate. There was no difference in detection rate in the first half of the study period (1990-1995; 23 [72%] of 32) compared with the second half (1996-2000; 18 [76%] of 24; P = .79). CONCLUSIONS: In this cohort of women, the rate of detection of fetal cleft lip was significantly lower when the anatomic survey was performed before 20 weeks' gestation. This difference could not be accounted for by such variables as prior maternal abdominal surgery, coexisting fetal anomalies, or improvements in ultrasonographic detection with time. We recommend that the anatomic survey for fetuses at high risk for this condition be performed after 20 weeks' gestation.

Cleft Lip↗
PubMed2000

A syringe adapter to facilitate aspiration at amniocentesis.

BACKGROUND: Syringes were developed for injection, not aspiration. We describe an adapter that attaches to a standard syringe and aspirates by advancement rather than withdrawal. TECHNIQUE: The adapter consists of a syringe barrel extension and an attachable finger grip. The adapter attached to a standard syringe allows aspiration by advancement rather than withdrawal, with the same hand motion used as with injection. EXPERIENCE: In a comparison of timed in vitro fluid aspiration by 10 practitioners, mean times for aspiration of 15 mL were 32.4 seconds (range 24-45) with standard technique and 25.3 seconds (range 24-30) with the adapted syringe (P < .003, paired t test). Thirteen of 14 physicians who used the adapted syringe in vivo reported that much less effort was required, and one physician reported that a little less effort was required. Overall, eight practitioners reported that the adapted syringe made amniocentesis much easier and six found no difference between the two devices. CONCLUSION: This adapter converts a standard syringe to one permitting aspiration by advancement rather than withdrawal. Practitioner feedback was positive with regard to ease of use, degree of effort, and overall satisfaction.

Amniocentesis↗
PubMed2000

Predictors of episiotomy use at first spontaneous vaginal delivery.

OBJECTIVE: To identify factors associated with the use of episiotomy at spontaneous vaginal delivery. METHODS: We studied 1576 consecutive term, singleton, spontaneous vaginal deliveries in nulliparas at Brigham & Women's Hospital between December 1, 1994 and July 31, 1995. The association of demographic variables and obstetric factors with the rate of episiotomy use were examined. Adjusted odds ratios (OR) and confidence intervals (CI) were estimated from multiple logistic regression analysis. RESULTS: The overall rate of episiotomy was 40.6% (640 of 1576). Midwives performed episiotomies at a lower rate (21.4%) than faculty (33.3%) and private providers (55.6%) (P =. 001). After controlling for confounding factors with logistic regression, private practice provider was the strongest predictor of episiotomy use (OR, 4.1; 95% CI, 3.1, 5.4) followed by faculty provider (OR, 1.7; 95% CI, 1.1, 2.5), prolonged second stage of labor (OR, 1.8; 95% CI, 1.2, 2.7), fetal macrosomia (OR, 1.6; 95% CI, 1.1, 2.5), and epidural analgesia (OR 1.4, 95% CI, 1.1, 1.8). CONCLUSION: The strongest factor associated with episiotomy at delivery was the category of obstetric provider. Obstetric and demographic factors evaluated did not readily explain this association.

Adult↗
PubMed2000

Cortical blindness in severe preeclampsia: computed tomography, magnetic resonance imaging, and single-photon-emission computed tomography findings.

BACKGROUND: Cortical blindness is a complication of severe preeclampsia, but it is unclear whether it results from cerebral vasospasm and ischemic injury or vasogenic (hydrostatic) edema due to increased capillary permeability. CASE: Reversible cortical blindness in a 33-year-old gravida 2, para 1, with severe postpartum preeclampsia after evacuation of a partial molar pregnancy at 19 weeks' gestation is presented. Initial neuroimaging studies showed hyperperfusion on head single-photon-emission computed tomography scan, which corresponded with lesions found on head computed tomography and magnetic resonance imaging scans. Follow-up neuroimaging studies 2 weeks later, by which time the patient's visual acuity had returned to normal, showed complete resolution of radiologic abnormalities. CONCLUSION: Neuroimaging studies in a woman with severe postpartum preeclampsia complicated by reversible cortical blindness showed that blindness resulted from vasogenic (hydrostatic) cerebral edema and not cerebral vasospasm.

Adult↗
PubMed2000

Post-term induction of labor revisited.

Post-term pregnancy (longer than 42 weeks or 294 days) occurs in approximately 10% of all singleton gestations. The adverse outcomes of post-term pregnancy include a substantial increase in perinatal mortality and morbidity. ACOG currently recommends induction of labor for low-risk pregnancy during the 43rd week of gestation. However, that recommendation dates from 1989. Recent reports mandate reconsideration of the management of post-term pregnancy, including reinterpretation of the statistical risk of stillbirth in post-term pregnancies using ongoing (undelivered) rather than delivered pregnancies as the denominator, which shows a far higher risk to post-term fetuses than believed. Recent data also suggest that the risk of cesarean delivery after induction of labor at term is lower than reported, possibly because of improvements in methods for cervical ripening. Those findings provide rationale for earlier labor induction in low-risk pregnancies.

Female↗
PubMed2000

Cervical hydrosonography in pregnancy to assess cervical length by transabdominal ultrasound.

BACKGROUND: Some women's cervices cannot be evaluated because they are obscured by obesity or vertex-presenting fetuses. Measuring cervical length in these cases is difficult or impossible. TECHNIQUE: We hypothesized that the problem of obscured cervices on transabdominal ultrasound could be resolved by introducing sterile water into the vagina, creating a hydroacoustic window between the vaginal lumen and the cervix. Women with unmeasurable cervices on transabdominal ultrasound had repeat studies after introduction of 60 mL of sterile water into their vaginas, and cervical length measurements taken were compared with those made on transvaginal scans. EXPERIENCE: Six pregnant women were studied (four singleton, one twin, and one triplet pregnancy). In all cases, previously unidentifiable cervices were seen adequately. No complications were noted. Statistical analysis (kappa 0.66) suggested good correlation between transabdominal cervical hydrosonography and transvaginal measurements of cervical length. CONCLUSION: Introducing water into the vagina at transabdominal ultrasound can make an obscured cervix visible and measurable.

Administration, Intravaginal↗
PubMed2000

Differences in TDx fetal lung maturity assay values between twin and singleton gestations.

OBJECTIVE: The purpose of this study was to quantify differences in indexes of pulmonary maturity between singleton and twin gestations by means of the TDx fetal lung maturity assay. STUDY DESIGN: We identified records of a total of 830 singleton and twin pregnancies not complicated by diabetes and delivered between 28 and 37 weeks' gestation from December 1994 through August 1995. Among these, 170 (20%) had TDx fetal lung maturity measurements performed within 72 hours of delivery. Linear regression was used to assess differences in TDx fetal lung maturity assay values between singleton gestations (n = 143 gestations) and twin gestations (n = 27 gestations) while controlling for potential confounding factors. RESULTS: Twin gestations were no more likely than singleton gestations to undergo TDx fetal lung maturity screening (odds ratio, 1.3; 95% confidence interval, 0.8-2.2). Pregnancy complications and corticosteroid treatment were similar in the two groups. After 31 weeks' gestation the twin gestations had significantly higher TDx fetal lung maturity values. Linear regression with controls for gestational age indicated that twin gestations on average had a TDx fetal lung maturity value that was 22.0 mg/g (95% confidence interval, 9.8-34.6 mg/g) higher than that of gestational age-matched singleton gestations. CONCLUSION: Beyond 31 weeks' gestation twin pregnancies appeared to have a TDx fetal lung maturity value that was 22 mg/g higher than that of singleton pregnancies. If the underlying incidences of respiratory distress syndrome are similar between twin and singleton gestations, then the potential exists for false-positive prediction of adequate lung maturity values among twin gestations.

Adrenal Cortex Hormones↗
PubMed2000

Secretory component: a potential regulator of endometrial-decidual prostaglandin production in early human pregnancy.

OBJECTIVE: We sought to investigate the production of secretory component, an inhibitor of phospholipase A(2), and prostaglandins by human endometrium-decidua. STUDY DESIGN: The production of secretory component and prostaglandins by explants and dispersed glandular and stromal cells of secretory endometrium and first-trimester and term decidua were measured by enzyme-linked immunosorbent assay and radioimmunoassay, respectively. RESULTS: Explants of first-trimester decidua produced significantly more secretory component and less prostaglandins than secretory endometrium. Immunohistochemical studies localized secretory component to epithelial glandular cells. At term, when fewer glandular cells are present, both secretory component and prostaglandin production were low. Exposure of first-trimester decidua to progesterone significantly increased secretory component production. CONCLUSION: Secretory component and prostaglandins localize primarily to epithelial glandular cells in endometrium-decidua, and their production appears to be inversely correlated. The increase in secretory component by first-trimester decidua after progesterone stimulation may account for the down-regulation of endometrial prostaglandin synthesis after implantation, a process thought to be necessary for pregnancy success.

Adolescent↗
PubMed2000

Management of cervical cerclage and preterm premature rupture of the membranes: should the stitch be removed?

OBJECTIVE: Our aim was to determine whether retention of cerclage after preterm premature rupture of the membranes occurring before 34 completed weeks' gestation influences pregnancy outcome. STUDY DESIGN: Singleton pregnancies with cerclage and premature rupture of the membranes between 24.0 and 34.9 weeks were reviewed. Women were excluded if they were first seen in labor, had chorioamnionitis, or were delivered within 48 hours. Control subjects consisted of women with premature rupture of the membranes without cerclage. RESULTS: Eighty-one cases of cerclage with premature rupture of the membranes met criteria for inclusion: 30 women (37%) had their cerclage removed at presentation, and 51 (63%) retained the cerclage until delivery. Cases were similar in terms of gestational age at placement and gestational age at premature rupture of the membranes. There was no significant difference between the retained, removed, or control groups in terms of latency, gestational age at delivery, chorioamnionitis, or neonatal morbidity and mortality. CONCLUSIONS: Retention of cervical cerclage after premature rupture of the membranes occurring before 34 completed weeks' gestation is associated with comparable clinical outcomes with respect to latency and perinatal outcome, when compared with removal of the cerclage.

Adult↗