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M C Treadwell

Publications and source records attributed to M C Treadwell.

At least 37 records · Page 2Linked to original sources
PubMed1995

Prenatal cytogenetic abnormalities: correlations of structural rearrangements and ultrasonographically detected fetal anomalies.

OBJECTIVE: Our purpose was to determine the distribution of karyotypic abnormalities detected at prenatal diagnosis, fetal anomalies, and ability for fluorescent in situ hybridization detection. STUDY DESIGN: Our cytogenetic database from January 1988 to April 1994 was categorized according to type and potential detection by current standard fluorescent in situ hybridization probes. Fetal anomalies and cytogenetic aberrations were compared. RESULTS: A total of 664 cases of abnormal fetal karyotypes were identified from 12,454 prenatal cytogenetic cases (7529 amniocenteses and 4925 chorionic villus sampling) and were classified as autosomal aneuploidy (331), sex aneuploidy (103), polyploidy (38), marker aneuploidy (19) and structural rearrangements (173). Standard fluorescent in situ hybridization probes would have missed 31% of the abnormal cases: 90 aneuploidy, 14 de novo marker aneuploidy, and 65 de novo structural aberrant cases. The 134 cases of structural chromosomal rearrangements with complete ultrasonographic records were further classified as polymorphism (42), familial (43), or de novo (49). Frequency of fetal anomaly detection by ultrasonography in de novo cases (22/49) was higher than other rearrangements (chi 2 7.4, p = 0.006). CONCLUSION: The contribution of unusual aneuploidies (16%) and structural chromosomal rearrangements (26%) in prenatal diagnostic practice is significant. Fetal anomalies were detected by ultrasonography in 45% of the de novo rearrangement cases. Fluorescent in situ hybridization would miss 31% of the abnormal cases.

Aneuploidy↗
PubMed1995

Combining humerus and femur length for improved ultrasonographic identification of pregnancies at increased risk for trisomy 21.

OBJECTIVE: Our purpose was to evaluate the value of the combination of femur and humerus length measurements in ultrasonographic screening for trisomy 21. STUDY DESIGN: Direct necropsy measurements were analyzed on 703 midgestational fetuses (641 normal, 62 with trisomy 21). The (leg+arm length)/foot length ratio was found to be significantly shortened for fetuses with trisomy 21. On the basis of necropsy data 576 midgestational pregnancies were evaluated ultrasonographically for (femur+humerus length)/foot length ratio to identify fetuses at increased risk for trisomy 21. RESULTS: An ultrasonographic (femur+humerus length)/foot length ratio < or = 1.75 gave a 15.3 odds ratio risk for trisomy 21 in our high-risk population and correctly identified 53% of fetuses with trisomy 21, with a false-positive rate of 7%. In addition, the use of this ratio eliminates the need for gestational age-corrected nomograms and complicated calculations in ultrasonographic screening. CONCLUSION: The (femur+humerus length)/foot length ratio may be an additional effective ultrasonographic marker for identification of fetuses at increased risk for trisomy 21.

Anthropometry↗
PubMed1995

Prenatal detection of preaxial upper limb reduction in trisomy 18.

BACKGROUND: Abnormalities of the upper and lower extremities, such as club feet, rocker-bottom feet, and abnormal hand posturing, are frequently detected prenatally in trisomy 18 fetuses. Aplasia of the radius, usually associated with the absence or hypoplasia of the first metacarpal and thumb, is the most prevalent reduction malformation in trisomy 18 infants. Because this anomaly is easily missed during prenatal ultrasonography, the role of prenatal detection of this particular preaxial upper limb reduction has not been emphasized. CASES: Three cases of trisomy 18 in which preaxial upper limb reduction (radial aplasia) was identified prenatally by ultrasound are reported. Although in all cases there were additional ultrasonographic findings suggestive of trisomy 18, the prenatal detection of preaxial upper limb reduction facilitated the diagnosis. CONCLUSION: Ultrasonographic examination of fetal forearms for the detection of preaxial upper limb reduction should be a routine part of the prenatal evaluation of fetuses in whom trisomy 18 is suspected.

Abnormalities, Multiple↗
PubMed1995

Prenatal ultrasonographic diagnosis of ductus arteriosus aneurysm with spontaneous neonatal closure.

Aneurysm of the ductus arteriosus may be either spontaneous or acquired as a complication of surgical closure of a patent duct. Patients may be asymptomatic or present with a wide spectrum of symptoms, including hoarseness, respiratory symptoms, aortic or pulmonary thrombosis or embolism, or rupture of the aneurysm. We present the first report of prenatal ultrasonographic diagnosis of isolated ductus arteriosus aneurysm. The aneurysm presented at 39 weeks as an enlarged, dilated, vascular structure 15 mm in diameter, which began at the bifurcation of the main pulmonary artery and ended in the descending aorta. Doppler imaging demonstrated turbulent flow in this lesion. Following spontaneous delivery, a bidirectional shunt in the ductus arteriosus was found on the 1st day, but the caliber of the vessel was normal. An almost completely functionally closed ductus was found on the 2nd day. Spontaneous resolution of the lesion was confirmed by magnetic resonance imaging at 4 weeks of age.

Adult↗
PubMed1995

Doppler velocimetry of the fetal middle cerebral artery in patients with preterm labor and intact membranes.

A prospective cohort study was conducted to determine whether preterm labor is associated with changes in the impedance to blood flow of the fetal middle cerebral artery. Doppler velocimetry studies were performed in 194 consecutive patients with preterm labor and intact membranes. Pulsatility indices of the middle cerebral artery and umbilical artery were determined on admission. Results were expressed as ratio of the observed pulsatility index to mean value for gestational age expressed as delta MCA PI and delta UA PI, respectively. The prevalence of preterm delivery (< 37 weeks) and delivery within 24 hours of admission was 55.2% (107/194) and 15.5% (30/194), respectively. Patients with an examination-to-delivery interval within 24 hours had significantly lower mean delta MCA PI than that of patients delivered at > or = 37 weeks and > or = 4 weeks after the examination (P < 0.01). Fetuses with a delta MCA PI at or below 0.88 had a relative risk of 2 (95% confidence interval, 1.32 to 2.9) who were delivered within 24 hours compared to controls (sensitivity 76.7%, specificity 62.8%, positive predictive value 26.7%, negative predictive value 93.5%). Stepwise logistic regression analysis indicated that the relationship between delta MCA PI and examination-to-delivery interval remained statistically significant after correcting for cervical dilatation (P < 0.001). Our data indicate that preterm parturition is associated with a decrease in the impedance to flow in the fetal cerebral circulation.

Adult↗
PubMed1994

Gastroschisis: can antenatal ultrasound predict infant outcomes?

OBJECTIVE: To test previously proposed but unproven antenatal ultrasound prognostic criteria in fetal gastroschisis. METHODS: Thirty consecutive gastroschisis-affected pregnancies and their outcomes were reviewed retrospectively. Data were tabulated by review of antenatal ultrasound videotapes, with blinded comparison to indicators of short- and long-term infant outcomes obtained from the medical records. Criteria of previous reports were applied to these data, focusing on their ability to prognosticate effectively. RESULTS: Applying a criterion of 10 mm bowel dilatation proved minimally useful in prognosticating infant outcomes. However, a stricter 17-mm criterion for clinically important bowel dilatation provided prognostic information, with remarkable improvement in specificity (75 versus 37%) and positive predictive value (55 versus 37%) for infant morbidity, with comparatively little loss of sensitivity (71 versus 85%). CONCLUSIONS: Bowel dilated more than 17 mm on antenatal ultrasound appears to be associated with increased short- and long-term infant morbidity. Whether this finding warrants obstetric intervention in the preterm gastroschisis-affected pregnancy with substantial bowel dilatation remains to be determined.

Congenital Abnormalities↗
PubMed1993

Prenatal diagnosis of nonrhizomelic chondrodysplasia punctata (Conradi-Hünermann syndrome).

Chondrodysplasia punctata has been classified into two major types including the rare autosomal recessive "rhizomelic type" and a more common but genetically heterogenous nonrhizomelic type (referred to by some authors as "Conradi-Hünermann (CH) type"). The former is typically lethal, manifesting serious anomalies, and allowing several instances of confident prenatal diagnosis. The latter being milder has more subtle anomalies and prenatal diagnosis has been uncommonly reported (confined to cases diagnosed incidentally by flat-plate X-ray examination of the mother in late third trimester, and a case found by directed ultrasound performed in a Mendelian affected mother). Cases included 1) a young primigravida thought to be affected with Conradi-Hünermann syndrome presented at 16 weeks gestation for prenatal diagnosis and counseling. Ultrasound examination of the fetus detected assymetric limb shortness allowing the presumptive diagnosis of an affected fetus which was confirmed after delivery near term. 2) A normal 38-year-old multipara with unremarkable family history underwent routine fetal ultrasound evaluation at 18 weeks gestation. Disorganization of the spine, premature echogenicity of femoral epipheses, and frontal bossing with depressed nasal bridge were described. Neonatal examination confirmed suspicion of CH. Case 1 demonstrates the importance of solid clinical diagnosis in Mendelian malformation-affected parents for directing prenatal diagnostic efforts. Case 2 represents the first index case of CH diagnosed antenatally by ultrasound. Diagnostic clues which must be considered in establishing these diagnoses are discussed, as are some of the difficulties and limitations in antenatal counseling such cases.

Adult↗
PubMed1993

Trends in sonographic fetal organ visualization.

In order to assess changes in sonographic visualization over the last 6 years, 7092 second- and third-trimester ultrasound examinations from separate pregnancies in three individual years (1451 in 1985, 3016 in 1988, and 2625 in 1991) were compared. Overall, visualization across all gestational ages improved from 63.9% (1985) to 85.8% (1988) to 87.3% (1991), with the year in which the scan was performed explaining 19.6% of the variance in visualization. Maternal size (as determined by body mass index) remained the major determinant of ultrasound visualization in 1991 (r(2) = 11.2%), with gestational age explaining only 5.2% additional variance. Overall organ visualization was maximal at 21-23 weeks' gestation, with the decline in later gestation primarily accounted for by worsened visualization of fetal extremities and spine. Improved fetal visualization earlier in the second trimester and the advent of embryonic visualization in the first trimester may allow a continuum of prenatal sonographic diagnosis.

Journal Article↗
PubMed1993

Fetal leg and femur/foot length ratio: a marker for trisomy 21.

OBJECTIVE: Our purpose was to determine whether the femur/foot length ratio is useful in the prenatal detection of trisomy 21. STUDY DESIGN: Direct necropsy measurements were analyzed on 436 midgestational fetuses (391 normal, 45 with trisomy 21). Necropsy leg/foot length ratio versus gestational age was found to be significantly different between normal fetuses and those with trisomy 21. On the basis of the necropsy data, 345 midgestational pregnancies were evaluated ultrasonographically for femur/foot length ratio versus gestation age to identify fetuses at risk for trisomy 21. RESULTS: A leg/foot length ratio versus gestation age < or = 2.3 correctly identified 84% of fetuses with trisomy 21 between 110 to 155 days gestation age at necropsy. An ultrasonographic femur/foot length ratio versus gestational age < or = 0.9 had an 18.3 odds ratio risk for trisomy 21 in our high-risk population and correctly identified 71% of fetuses with trisomy 21 (positive predictive value 0.24, negative predictive value 0.98). CONCLUSION: The femur/foot length ratio is an additional ultrasonographic marker for identification of fetuses at increased risk for trisomy 21.

Adult↗
PubMed1993

First-trimester simple hygroma: cause and outcome.

OBJECTIVE: First-trimester fetuses with simple nuchal hygromas represent a population that is different from midgestation nuchal cystic hygroma in terms of karyotype abnormalities and long-term prognosis. STUDY DESIGN: Sixty-eight consecutive fetuses diagnosed with simple nuchal hygromas between 10 and 14 weeks' gestation were evaluated ultrasonographically and karyotyped. Those with normal chromosome complements were ultrasonographically monitored throughout the remainder of the pregnancy for resolution of their hygromas. RESULTS: Twenty-three of 27 fetuses with normal karyotypes resolved their hygromas within 4 weeks of diagnosis and were phenotypically normal at birth. Forty-one fetuses were karyotypically abnormal, with trisomy 21 being the most common abnormality. CONCLUSIONS: Fetuses with first-trimester simple nuchal hygromas are at high risk for aneuploidy and should be offered prenatal testing. Such fetuses with normal karyotypes will likely resolve their hygromas by 18 weeks' gestation, and most will be phenotypically normal at birth.

Chromosomes, Human, Pair 21↗
PubMed1992

Infection and labor. VIII. Microbial invasion of the amniotic cavity in patients with suspected cervical incompetence: prevalence and clinical significance.

OBJECTIVE: The purpose of this study was to determine the prevalence and clinical significance of microbial invasion of the amniotic cavity in patients presenting with cervical dilatation in the midtrimester of pregnancy. STUDY DESIGN: Amniocentesis for microbial studies was performed in women admitted with cervical dilatation > or = 2 cm, intact membranes, and without active labor between 14 and 24 weeks of gestation. Amniotic fluid was cultured for aerobic and anaerobic bacteria, as well as for mycoplasmas. Gram stain was performed on all samples. RESULTS: The prevalence of microbial invasion of the amniotic cavity was 51.5% (17/33). The most common microbial isolates were Ureaplasma urealyticum, Gardnerella vaginalis, Candida albicans, and Fusobacterium sp. All patients with microbial invasion of the amniotic cavity had complications. Patients who underwent cervical cerclage in the presence of a positive amniotic fluid culture had rupture of membranes, clinical chorioamnionitis, or pregnancy loss. On the other hand, the prognosis of patients with a negative amniotic fluid culture was better than that of patients with a positive culture. Of 16 patients with a negative amniotic culture, nine were delivered at > 34 weeks. CONCLUSIONS: (1) Microbial invasion of the amniotic cavity occurs frequently in women presenting with cervical dilatation in the midtrimester; (2) the microbiologic state of the amniotic cavity is an important prognostic factor for pregnancy outcome; (3) amniocentesis to determine the microbiologic characteristics of the amniotic cavity should be considered before a cerclage is placed in women presenting with cervical dilatation in the midtrimester.

Abortion, Spontaneous↗
PubMed1991

Prognostic factors and complication rates for cervical cerclage: a review of 482 cases.

Charts from 482 singleton pregnancies undergoing cerclage placement in patients over a 6-year period were reviewed. Cervical dilatation at time of surgery, number of previous spontaneous losses, and gestational age at placement were key determinants of outcome. The most frequent complication, premature rupture of the membranes, ultimately occurred in 38% of patients. The 6.6% infection rate was increased in patients undergoing emergent versus elective surgery (12.7% vs 4.7%, p less than 0.005) and in patients at increased dilatation at time of surgery (5.7% for less than or equal to 2 cm vs 41.7% for greater than 2 cm, p less than 0.005). McDonald and Shirodkar procedures had similar obstetric outcomes in patients undergoing their first cerclage. The subgroup of patients with prior cerclage surgery showed improved birth weight when the Shirodkar procedure was performed instead of the McDonald cerclage (mean birth weight 3020 vs 2470 gm, p less than 0.005). An increased rate of primary cesarean section was found in the Shirodkar group (31% vs 17%, p less than 0.005). Complication rates and pregnancy outcome appear to reflect cervical dilatation more than gestational age at time of surgery.

Adolescent↗
PubMed1990

Perinatal characteristics of the phenotypically and chromosomally abnormal live-born.

Perinatal characteristics of 105 singleton live infants born during the last 5 years and suspected phenotypically of having karyotypic abnormalities were studied; 33 abnormal karyotypes were found. These pregnancies were compared with all pregnancies delivering at our hospital during the same time period. A retrospective analysis using our perinatal data base examined maternal age, gravidity, parity, race, mode of delivery, birth weight, gestational age at delivery, Apgar scores, and size for gestational age. Within the phenotypically abnormal group, karyotypically normal and abnormal infants showed no significant differences in primary cesarean rates, low Apgar scores, mean birth weight, or appropriateness of size for gestational age. Karyotypically abnormal infants were smaller than the general population (P less than .001) and had lower Apgar scores (P less than .05) but were just as likely to be full-term (66.7 versus 70.3%). These chromosomally abnormal pregnancies had a higher primary cesarean rate than the general population (30.3 versus 15.4%; P less than .001). Black infants undergoing genetic studies had a 37% rate of karyotypic abnormalities, which was significantly higher than the 12.5% rate in the white infants tested (P less than .05). The term black infant with phenotypic abnormalities suggestive of karyotypic abnormalities may be less likely to be recognized and appropriately tested. Increased awareness of phenotypic abnormalities with subsequent genetic testing seems warranted.

Cesarean Section↗
PubMed1989

The physician factor in cesarean birth rates.

To investigate the influence of physicians' practice styles on the rate of deliveries by cesarean section, we studied 1533 affluent women at low risk of obstetrical complications who were cared for by 11 obstetricians in a single community hospital. The mean rate of delivery by cesarean section was 26.9 percent, but the rate ranged from 19.1 to 42.3 percent, according to the physician. The mean rate of primary cesarean section (i.e., the rate for women without previous cesarean deliveries) was 17.2, with a range of 9.6 to 31.8 percent. A stepwise logistic-regression model of the determinants of primary cesarean section, including the individual physician, parity, birth weight, and maternal age and excluding specific medical indications, showed that only nulliparity (P less than 0.0001) was more important than the identity of the physician (P less than 0.001) in its influence on the rate of cesarean section. Variation in cesarean-section rates among physicians was not attributable to the practice setting, the patient population, the degree of obstetrical risk, or the physician's recent medicolegal experience, and it was not accompanied by corresponding differences in neonatal outcome. We conclude that individual practice style may be an important determinant of the wide variations in the rates of cesarean delivery among obstetricians. Our data do not permit us to say with certainty whether the procedure is overused by some obstetricians or underused by others, but we found no obvious differences in neonatal outcome associated with differences in the cesarean-section rate.

Apgar Score↗
PubMedDate not supplied

Isolated mild ventriculomegaly: associated karyotypic abnormalities and in utero observations.

OBJECTIVE: The incidence of abnormal chromosomes in fetuses with mild lateral ventriculomegaly as an isolated prenatal ultrasound finding is not well established, and the rate of progression to more severe ventriculomegaly is uncertain. We wished to better define both the incidence of karyotypic abnormalities and the in utero course of fetuses with isolated mild ventriculomegaly. SUBJECTS AND METHODS: From July 1992 to September 1994, all cases of mild ventriculomegaly at our institution were reviewed (N = 94). Forty-six were isolated. Of these, 25 had genetic evaluation, and 37 had serial ultrasound examination. We evaluated the frequencies of karyotype abnormality and in utero progression for atrial measurements of 11-15 mm. RESULTS: In fetuses with atria 11-15 mm, three of the 25 karyotypes were abnormal (47 XXY and two 47 + 21, giving an incidence of 12% (95% CI 4.2-30.1%). Of the 37 with serial scans, five resolved in utero, 11 remained unchanged, and 20 progressed (one beyond 15 mm). CONCLUSION: Isolated mild ventriculomegaly is associated with a significantly increased incidence of chromosomal abnormalities. Therefore, these patients should be offered genetic testing. When mild and isolated, some fetuses will show in utero resolution of the ventriculomegaly. Progression to more severe degrees of hydrocephalus is uncommon.

Cerebral Ventricles↗
PubMedDate not supplied

Effects of intrapartum zidovudine therapy on fetal heart rate parameters in women with human immunodeficiency virus infection.

OBJECTIVE: To determine the effects of intrapartum maternal administration of zidovudine on fetal heart rate (FHR) parameters in women infected with the human immunodeficiency virus (HIV). METHODS: Term HIV-infected women who delivered at our institution (1995-1998) were identified by medical records coding. Sixty minutes of FHR tracing prior to zidovudine administration and 60 min of FHR tracing 2 h after initiation of therapy were reviewed by 3 perinatologists blinded to patient status. Data were compared with paired t tests; p < 0.05 was considered significant. Inter- and intra-observer FHR interpretation variation were calculated. RESULTS: Ten patients met study criteria. Their demographic data included: Maternal age 26.5 +/- 6.5 years, gestational age 38.9 +/- 1.3 weeks, median parity 2 (range 0-3). Eighty percent were African American. There were no significant differences in FHR parameters after intravenous zidovudine therapy (pretreatment versus 2 h after treatment) with respect to FHR baseline (p = 0.2), FHR variability (p = 0.3), or the number of accelerations (p = 0.1). There was also no difference in the number of variable (moderate or severe), early, or prolonged decelerations following zidovudine infusion. CONCLUSION: Two hours of continuous intrapartum intravenous infusion of zidovudine does not alter any parameter of the FHR in the laboring HIV-infected gravida.

Adult↗