Biomedical subjects

N B Isada

Publications and source records attributed to N B Isada.

At least 55 records · Page 3Linked to original sources

PubMed1988

Nongenetic implications of childbearing after age thirty-five.

A comprehensive review of the effects of advanced maternal age on nongenetic aspects of delayed childbearing is presented. Implications for fertility are assessed. Antepartum complications including hypertension, diabetes, placental abnormalities, and maternal mortality are reviewed. Labor patterns and neonatal outcome are evaluated with respect to age and parity. Recent well-controlled studies using multivariate regression analysis show that prenatal diagnosis, recognition, and management of high-risk pregnancy, antenatal and intrapartum fetal monitoring, and advances in perinatal medicine have dramatically reduced the problems associated with age. A management plan is presented.

Adult↗

PubMed1987

Genetic implications of idiopathic hydramnios.

The antenatal diagnosis of hydramnios requires a careful search for associated underlying maternal or fetal conditions. Even in pregnancies associated with idiopathic hydramnios in which no underlying condition can be identified, a high perinatal mortality rate exists. Although trisomy 18 has been seen in pregnancies with hydramnios and growth retardation, the association with specific chromosomal disorders and idiopathic hydramnios has not been well defined. A review of pregnancies complicated by hydramnios was undertaken; 99 cases with complete pregnancy and delivery information were identified. Fifty-nine pregnancies were complicated by idiopathic hydramnios, and except for the hydramnios, sonographic evaluation was normal. Delivery information revealed one infant with trisomy 18 and eight infants with structural anomalies not appreciated antenatally. Of the undiagnosed malformations, 25% are frequently associated with trisomy 21. We recommend fetal chromosomal analysis as an adjunct to the evaluation of pregnancies complicated by idiopathic hydramnios.

Chromosomes, Human, Pair 18↗

PubMed1987

A simple method for gross examination of the brain in abortuses and macerated fetuses.

The use of maternal serum alpha-fetoprotein screening and sonography has led to an increase in the prenatal diagnosis of major central nervous system (CNS) malformations. Therefore, it is important to correctly identify the type of malformation for proper counseling. We describe an autopsy method--freezing and sectioning of the fetal head--that should increase the accuracy of diagnosis after second-trimester abortion.

Brain↗

PubMed1987

A rapid screening test for the diagnosis of endocervical group B streptococci in pregnancy: microbiologic results and clinical outcome.

Four hundred thirty-one parturient women were tested for cervical infection with group B streptococcus using standard bacterial culture and a commercially available latex particle agglutination test. The total time required to perform each latex test was 30 minutes or less. The prevalence of endocervical group B streptococcus by culture was 4.4%, half of whom developed clinically significant group B streptococcus infection; all such cases were identified correctly by the latex test. The predictive value of a negative latex test for a negative group B streptococcus culture was 98%. This method seems promising as a rapid intrapartum diagnostic test for ruling out group B streptococcus infection and thus avoiding unnecessary antibiotic treatment.

Female↗

PubMed1987

Postabortal septic pelvic thrombophlebitis diagnosed with computed tomography. A case report.

Septic pelvic thrombophlebitis is an uncommon complication in obstetrics and gynecology that may be difficult to diagnose clinically. Computed tomography (CT), an accurate and noninvasive modality, has greatly aided in the diagnosis of this disorder. In a case of septic pelvic thrombophlebitis complicating second-trimester pregnancy termination, CT enabled the correct diagnosis to be made and treatment to be initiated.

Abortion, Induced↗

PubMedDate not supplied

Maternal thyroid function does not alter maternal serum alpha-fetoprotein interpretation.

OBJECTIVE: Endocrine alterations of metabolism such as diabetes and obesity are known to affect maternal serum alpha-fetoprotein interpretation. Thyroid function has been questioned, e.g., because of binding globulins, but not adequately studied as to its impact upon maternal serum alpha-fetoprotein. The purpose of this study was to assess the possible effects of T4 and thyroid-stimulating hormone (TSH) on alpha-fetoprotein production, and to determine if thyroid function (hypothyroidism) alters maternal serum alpha-fetoprotein. METHODS: We evaluated maternal serum alpha-fetoprotein, T4, and TSH records of 25,551 patients, between 14 and 20 weeks' gestation, on whom both studies had been ordered by the patient's primary obstetrician to rule out maternal thyroid disease in pregnancy. Statistical analyses were performed by chi 2 and regression analysis. RESULTS: Patients were stratified according to thyroid function tests into two groups: hypothyroidism (T4 < 6.5 micrograms/dL and/or TSH > 5.0 micrograms/mL), and normal or hyperthyroidism (T4 > or = 6.5 micrograms/dL and/or TSH > or = 5.0 microU/mL). Maternal serum alpha-fetoprotein values were compared among groups for each gestational age. No significant variation or correlation of maternal serum alpha-fetoprotein and thyroid function was observed. CONCLUSIONS: Although other endocrine abnormalities are known to impact maternal serum alpha-fetoprotein values either through decreased production, decreased placental permeability, or plasma volume distribution alterations, maternal thyroid status does not interfere with proper interpretation of maternal serum alpha-fetoprotein.

Female↗

PubMedDate not supplied

Abnormal second-trimester ultrasounds: an indication for karyotype.

There are limited data on the risks of aneuploidy for normal-appearing fetuses with amniotic fluid volume (AFV) abnormalities. The purpose of this study was to determine the relative risks of aneuploidy associated with second-trimester abnormal AFVs and fetal structural anomalies in a cohort of 2,823 singleton, viable fetuses. Compared to gravidas younger than 35 with normal ultrasounds, normal fetuses had an increased incidence of aneuploidy with polyhydramnios, increased AFV, i.e. subjectively increased but normal by maximum vertical pocket (MVP) and/or amniotic fluid index (AFI), oligohydramnios, and decreased AFV, i.e. subjectively decreased but normal by MVP and/or AFI. These included: increased AFV [odds ratio = 12.9, 95% confidence interval (CI) = 4.1-39.4], polyhydramnios (odds ratio = 4.6, CI = 0.6-36.8), and decreased AFV (odds ratio = 3.8, CI = 1.1-13.1). There were no aneuploidies among the 28 normal fetuses with oligohydramnios. Anomalous fetuses had a markedly increased incidence of aneuploidy (odds ratio = 13.4, CI = 7.2-24.9). We conclude that fetal structural anomalies as well as isolated AFV abnormalities were associated with an increased risk for aneuploidy.

Adult↗

PubMedDate not supplied

Viable pregnancies after diagnosis of trisomy 16 by CVS: lethal aneuploidy compartmentalized to the trophoblast.

Increasing utilization of chorionic villus sampling (CVS) has lead to the discovery that the placenta can karyotypically be a very heterogeneous organ, and chromosomal mosaicism within the placental can confuse cytogenetic interpretation. Recently, confined placental mosaicism (confined regions of aneuploidy in the otherwise normal diploid placental and fetus) has been described involving a number of chromosomal abnormalities. Fetal trisomy 16 is considered uniformly lethal early in gestation. However, we present 3 cases of nonmosaic trisomy 16 confined regionally to the placenta. We discuss the possible etiology, impact on the developing fetus, and suggest an approach to the workup and evaluation of cases where the karyotype obtained on CVS is not compatible with the findings on ultrasound.

Adult↗

PubMedDate not supplied

Amniotic fluid platelet factor 4 and beta-thromboglobulin.

Platelet activating factor (PAF), a powerful platelet activator, has been identified in human embryos and fetuses, and may induce fetal lung maturation. The potential effect of PAF on fetal platelets as indicated by release of beta-thromboglobulin (BTG) and platelet factor 4 (PF4) has not been investigated. We measured BTG and PF4 in amniotic fluid from 78 genetic and 35 pulmonary maturity amniocenteses. BTG and PF4 were higher in the genetic amniocentesis samples (p < 0.001 in each case) than in the lung maturity samples. BTG and PF4 did not correlate with the pulmonary maturity parameters as measured by the lecithin to sphingomyelin ratio and phosphatidylglycerol concentration. Our findings suggest a fetal origin of BTG and PF4 in amniotic fluid.

Amniocentesis↗

PubMedDate not supplied

Amniotic fluid acetylcholinesterase is found in gastroschisis but not omphalocele.

Amniotic fluid acetylcholinesterase (ACHE) has been used to evaluate neutral tube defects. It has also been detected in ventral wall defects. However, the role of ACHE to differentiate between omphalocele and gastroschisis has not been established. We examined amniotic fluid ACHE in 16 pregnancies complicated by gastroschisis and 8 by omphalocele. One ruptured omphalocele was excluded. ACHE was negative in all 7 omphaloceles and either positive or suspicious in all gastroschises (chi 2 = 17.3, p < 0.0001). Amniotic fluid ACHE may be useful to differentiate between omphalocele and gastroschisis.

Abdominal Muscles↗

PubMedDate not supplied

Amniotic fluid platelet factor 4 and beta-thromboglobulin as markers of structural abnormalities.

Platelet factor 4 (PF4) and beta-thromboglobulin (BTG) are unique markers of irreversible platelet activation. We measured PF4 and BTG in amniotic fluid from 102 genetic amniocenteses, in which 78 had normal amniotic fluid alpha-fetoprotein (AFP) levels with normal pregnancies, and 24 had high amniotic fluid AFP levels with abnormal pregnancies. PF4 and BTG were significantly higher in the abnormal pregnancy/elevated amniotic fluid AFP group (p < 0.002 in each case) and correlated with AFP expressed as multiples of the median (p < 0.05 and p < 0.0001, respectively). Our results are compatible with passage of PF4 and BTG across fetal membranes and/or enhanced fetal platelet activation in fetuses with structural anomalies and elevated AFP.

Amniocentesis↗

PubMedDate not supplied

Age of gestation (size) at embryonic demise: tailoring counseling for lethal versus potentially viable aneuploidy.

The incidence of chromosomal abnormalities in spontaneous abortions is much higher than commonly appreciated. Using postmortem chorionic villus sampling (as we have previously described), our much increased yield of results allows us to divide embryos into two groups based upon potential viability. Embryonic size at the time of demise correlated with viability, i.e., the more 'viable' the embryo for term survival. Even in the absence of chromosomal results, the size of the embryonic pole can be used to infer, to a degree, the type of abnormality.

Adult↗

PubMedDate not supplied

Maternal serum alpha-fetoprotein screening: the need to use race/ethnic specific medians in Asians.

OBJECTIVES: We questioned whether race-specific databases for maternal serum alpha-fetoprotein (MSAFP) screening should be added to those already available for African-American and white patients. STUDY DESIGN: We analyzed 138,272 MSAFP samples. The geographic origin of the samples was New York metropolitan area. Patients were classified as white, African-American, Hispanic or Asian. The usual adjustments were made and groups compared. Statistical analysis included ANOVA and multiple comparison test. RESULTS: MSAFP values are highest (p < 0.05) for Asians, followed by African-Americans, Hispanics, and whites, although the difference between Hispanic and white was not significant. CONCLUSIONS: Four separate databases are definable if specimen quantity is sufficient. Race/ethnic specific databases are more likely to yield the most accurate detection of abnormal MSAFP values, and therefore, fetal anomalies.

Asian↗

PubMedDate not supplied

Meroanencephaly: pathology and prenatal diagnosis.

Meroanencephaly is a rare form of anencephaly characterized by malformed cranial bones and a median cranial defect, through which protrudes abnormal tissue, called the area cerebrovasculosa. Area cerebrovasculosa denotes abnormal spongy, vascular tissue admixed with glial tissue ranging from a thin membrane to a large pseudoencephalic mass simulating cerebral tissue, that is composed of connective tissue, hemorrhagic vascular channels, glial nodules, and disorganized choroid plexuses. There are three types of anencephaly: (1) meroanencephaly, where there is rudimentary brain tissue and partial formation of the cranium; (2) holoanencephaly, the most common type, in which the brain is completely absent, and (3) craniorachischisis, the most severe, where area cerebrovasculosa and area medullovasculosa fill both cranial defects and the spinal column. In meroanencephaly, there is a median defect present, through which protrudes the area cerebrovasculosa. We present 3 cases of meroanencephaly diagnosed prenatally, along with histopathologic analysis. One case showed ectopic glial tissue in the lung and adrenal medullary hyperplasia. Two cases were diagnosed in the early second trimester by ultrasound scanning. Meroanencephaly may be mistaken for encephalocele both at the bedside exam and sonographically, and should be included in the differential for protruding anterior cranial masses.

Adult↗

PubMedDate not supplied

Technical aspects of transcervical chorionic villus sampling.

Following the 1990 FDA approval of the Trophocan catheter for use in transcervical chorionic villus sampling (CVS), an increasing number of US physicians have begun offering the procedure. To obtain privileges to perform CVS, some states such as California have enacted legislation requiring the performance of a certain number of CVS procedures in pregnancies in which the patient has already chosen first-trimester abortion. This practice is not universally feasible for legal, logistic, or financial reasons. We describe our approach to training in a busy reproductive genetics service. The physician initially trains by performing amniocentesis to optimize skills in ultrasound-directed needle guidance and placement. During this initial period, he or she also assists in performing transabdominal CVS procedures. The initial transcervical CVS cases should be performed in those situations requiring minimal catheter manipulation, or in those individuals undergoing CVS in the setting of spontaneous abortion. Cases of increasing difficulty should only be performed as skill and familiarity increase. For a physician already skilled and experienced in ultrasound-guided invasive procedures, sequential periods of observation at a busy center allows him or her to become familiar with the common pitfalls in performing transcervical CVS, and thus avoid them. Using this approach, we have performed over 5,000 CVS procedures and trained 6 reproductive genetics fellows in transcervical CVS.

Cervix Uteri↗

PubMedDate not supplied

Sonographic screening for trisomy 21: fetal humerus:foot length ratio, a useful new marker.

We have analyzed morphometric measurements from midgestational fetal necropsies and shown that arm and foot lengths are linear relationships versus gestational age (GA). Using foot length as the GA determinant, we found that the ratio of arm:foot length was also a linear relationship and was decreased in trisomy 21 fetuses when compared to age-matched normals. Based on these laboratory findings, we prospectively evaluated the use of the humerus:foot length ratio as a sonographic screening tool for identification of fetuses at risk for trisomy 21. Humerus length, foot length and the humerus:foot length ratio were found to be linear relationships vs. gestational age in both the normal and trisomy 21 populations. However, the regressions for the humerus:foot length ratio were significantly different between normals and Down's fetuses (p < 0.001). We found that a humerus:foot length ratio < or = 0.85 correctly identified 47% of our trisomy 21 fetuses (spec = 0.92, PPV = 0.25, NPV = 0.97). When compared to women > or = 35 years old in our high risk population, a humerus:foot length ratio < or = 0.85 carried an odds ratio of 52.7 (99% CL = 9.72-285.23) for trisomy 21.

Adult↗

PubMedDate not supplied

Fluorescent in situ hybridization and second-trimester sonographic anomalies: uses and limitations.

The critical need for rapid and reliable karyotype analysis can be no greater than in the setting of sonographic fetal anomalies. Fluorescent in situ hybridization (FISH) directly applied to interphase chromosomes can decrease the time required to identify the common aneuploidies. Our retrospective study reviewed 50 consecutive patients with sonographic fetal anomalies who underwent FISH. Within this high risk group, nonmosaic chromosomal aneuploidies were present in 16% of the fetuses (8 of 50), and 2 additional fetuses had cytogenetic abnormalities: 1 case, 46,XY,-12,+der(12)t(12;13)(p13; q14.1), and 1 case a 10% mosaic for trisomy 21. Of the 10 cytogenetically abnormal fetuses, FISH was able to identify correctly all 8 of the nonmosaic aneuploidies within 2 days of receipt of the specimen in the laboratory. Clinical decisions can be made on the basis of concordant FISH and ultrasound abnormalities, shortening the decision-making process for most of the aneuploid cases. However, our experience demonstrates some of the limitations of current FISH protocols and the continued necessity for formal karyotype analysis.

Amniocentesis↗

PubMedDate not supplied

Role of ultrasonography in pregnancies with marker chromosome aneuploidy.

The objective of this report was to evaluate the effect of ultrasonographic (US) findings on pregnancy management in patients with marker chromosome (MC) aneuploidy ascertained through prenatal diagnosis. From 1989 through June 1993, 15,522 prenatal diagnostic procedures were performed for accepted indications. Charts of patients with MC on amniocentesis or chorionic villus sampling (CVS) karyotype were evaluated with respect to US anomalies, pregnancy complications, and outcome. Nineteen cases of MC were identified. The prevalence of MC in our study was 0.12% (1:816 procedures). No significant difference between CVS and amniocentesis was found: 5/19 (26%) were CVS specimens, which is comparable to our CVS (3,259/15,522) case distribution. Three cases with incomplete records were excluded from the analysis. Four inherited MC cases were identified: 1 case had anencephaly. Of the 12 de novo MC cases 4 (33%) had abnormal US findings, and an additional 4 were found to have cytogenetic evidence for partial trisomy. Seven of these 8 abnormal de novo MC cases were terminated. MC aneuploidy is more common in pregnancies sampled for usual genetic indications than previously reported in pediatric series. High-resolution US may identify a major malformation not etiologically related to a MC inherited from a normal phenotypic parent. The association of the novo MC with US anomalies confers a poor prognosis, suggesting the expression of genetic imbalance from the accessory chromatin (partial trisomy). However, when US appears normal on initial and follow-up examinations, the chances for a normal-phenotypic newborn are high.

Amniocentesis↗