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Biomedical subjects

D M Sherer

Publications and source records attributed to D M Sherer.

At least 19 recordsLinked to original sources
PubMed2007

Nomograms of the axial fetal cerebellar hemisphere circumference and area throughout gestation.

OBJECTIVE: The widely applied transcerebellar diameter (TCD) obtained at axial cranial imaging, measures the distance between the lateral aspects of the cerebellum and incorporates the width of the cerebellar vermis. Our objective was to create reference ranges of axial fetal cerebellar hemisphere circumference (CHC) and area (CHA), independent of the cerebellar vermis, throughout gestation. METHODS: This cross-sectional study involved pregnant patients between 14 and 41 weeks of gestation. Inclusion criteria consisted of well-established dates (confirmed by early ultrasound), non-anomalous singleton fetuses and intact amniotic membranes. Sonographic measurements included biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), humerus length (HL), TCD, and estimated fetal weight (EFW). Values of axial fetal CHC and CHA were each calculated as the mean of three separate measurements. The 5th, 50th and 95th centiles were estimated at each week of gestational age (GA) by least-squares regression for the mean and standard deviation (SD) of the CHC and CHA as functions of GA. r2 and associated P-values for the relationships of CHC and CHA with other sonographic biometric measurements were calculated. RESULTS: The study included 651 consecutive patients. All attempts at obtaining axial fetal CHC and CHA were successful. Mean maternal age was 27.3+/-6.7 years, median gravidity was 1 (range 1-16), and median parity was 1 (range 0-6). Mean CHC (cm) throughout gestation was modeled as -2.091+0.2563xGA (weeks) (SD=-0.075+0.0164xGA), and mean CHA (cm2) was modeled as 0.245-0.0765xGA+0.00506xGA2 (SD=1.167-0.1565xGA+0.006785xGA(2)-0.00008028xGA3). Fetal axial CHC and CHA correlated significantly and strongly with BPD, HC, AC, HL, FL, TCD and EFW (all R2 values were >or=0.95, and all P-values were <0.001). CONCLUSION: Nomograms of axial fetal cerebellar hemisphere circumference and area throughout gestation, independent of the cerebellar vermis, have been provided.

Abdomen↗
PubMed2006

Fetal clavicle length throughout gestation: a nomogram.

OBJECTIVE: To create a nomogram of fetal clavicle length (CL) throughout gestation. METHODS: Cross-sectional study of patients between 14 and 42 weeks' gestation. Inclusion criteria consisted of well-established dates (consistent with early ultrasound), singleton, non-anomalous fetuses, and intact amniotic membranes. Sonographic measurements included biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), humerus length (HL) and sonographically estimated fetal weight (SEFW). For every case, the average of three separate measurements of the CL was used. The 5th, 50th and 95th centiles were obtained by least squares regression. Pearson's correlation coefficient and associated P-values for the relationships between CL and other biometric measurements were calculated. The data were compared to a nomogram of the CL generated in 1985 from the measurement of 85 fetuses. RESULTS: A total of 623 consecutive patients were studied. In all but three cases, CL was successfully measured. Mean maternal age was 27.7 +/- 6.2 years, median gravidity 3 (range, 1-14) and median parity 1 (range, 0-9). Mean CL (mm) = -75.30 + 32.70*ln(GA) and SD = -0.41 + 0.08328*GA, where ln represents the natural logarithm and GA the gestational age in weeks. Fetal CL correlated significantly and strongly with BPD, HC, AC, HL, FL and the logarithm of SEFW, with Pearson correlation values of 0.973, 0.977, 0.976, 0.979, 0.977 and 0.979, respectively (all P < 0.001). Measurements according to comparable 1985 data were consistently substantially below the present data (smaller CL for any given GA except below 17 weeks' gestation). CONCLUSIONS: We propose a new nomogram of CL, which differs significantly from the previously published nomogram. We suggest that the present data reflect the use of high-resolution ultrasound technology and propose that these data, based on a large number of fetuses, replace the previous nomogram. We also suggest that the '1 mm = 1 week' rule of thumb should no longer be used, since it can be erroneous by as much as 6 weeks.

Adult↗
PubMed2005

Is fetal cerebral vascular resistance affected by the presence of nuchal cord(s) in the third trimester of pregnancy?

OBJECTIVE: To assess whether fetal cerebral vascular resistance is affected by the presence of nuchal cord(s) in the third trimester. METHODS: A set of 115 patients with well-established dates and singleton, appropriate for gestational age (GA), non-anomalous fetuses with nuchal cord(s) diagnosed with prenatal color Doppler imaging, between 28 and 41 weeks and 115 controls matched for GA, were studied. Patients with hypertension, diabetes and autoimmune conditions were excluded. Doppler indices were obtained from the umbilical artery (UA) and the fetal middle cerebral artery (MCA) upon initial diagnosis of the nuchal cord. RESULTS: Of 115 GA-matched pairs of pregnancies, 103 fetuses had a single nuchal cord and 12 a double nuchal cord. No significant differences were noted in patient age, gravidity, parity, sonographically estimated fetal weight (SEFW), and growth centile at ultrasonographic diagnosis. Mean UA systolic/diastolic ratio (S/D) was 2.28 +/- 0.32 and 2.36 +/- 0.33 (P = 0.03) and UA resistance index (RI) 0.55 +/- 0.06 and 0.57 +/- 0.06 (P = 0.02) among study and controls, respectively. Mean fetal MCA S/D and RI did not differ significantly between the two groups (fetal MCA S/D 5.01 +/- 1.28 and 5.04 +/- 1.71 (P = 0.86), and mean fetal MCA RI 0.78 +/- 0.06 and 0.78 +/- 0.05 (P = 0.88)). No significant differences were noted in GA at delivery, incidence of meconium-stained amniotic fluid, birth weight, mode of delivery, neonatal gender, 1 and 5 minute Apgar scores, or UA pH and base excess, between study and control patients. CONCLUSION: Fetal cerebral vascular resistance is not affected by the presence of nuchal cord(s) in the third trimester of pregnancy.

Adult↗
PubMed2005

Cord entanglement of monochorionic diamniotic twins following spontaneous antepartum septostomy sonographically simulating a true knot of the umbilical cord.

Spontaneous antepartum septostomy occurring in monochorionic diamniotic twins is extremely rare. We present a case in which prenatal sonography at 26 weeks' gestation depicted a monochorionic diamniotic twin gestation with concordant fetal growth and findings suggestive of a true knot of the umbilical cord. At Cesarean delivery at 34 weeks' gestation, spontaneous antepartum septostomy with entanglement of the two separate umbilical cords was noted. This case suggests that the differential diagnosis of findings considered consistent with a true knot of the umbilical cord in monochorionic diamniotic twin gestations, should include spontaneous antepartum septostomy and umbilical cord entanglement.

Adolescent↗
PubMed2004

Nomograms of sonographic measurements throughout gestation of the fetal hard palate width, length and area.

OBJECTIVE: To assess the feasibility of sonographic depiction of the fetal hard palate and secondarily to create nomograms throughout gestation of its sonographic width, length and area. METHODS: This was a cross-sectional study of pregnant patients between 15 and 41 weeks' gestation. Inclusion criteria consisted of well-established dates (confirmed by early ultrasound), and singleton, non-anomalous fetuses. Sonographic measurements obtained included biparietal diameter, head circumference, abdominal circumference and femur length. Fetal hard palate measurements included maximum width, maximum length and the calculated area. Tables were prepared depicting the estimated mean +/- SD and 5(th), 50(th) and 95(th) centiles at each gestational week between 15 and 41 weeks. Pearson's correlation coefficient and associated P-values for the relationships between fetal hard palate measurements and other sonographic measurements and coefficients of variation for each of the fetal hard palate measurements were calculated. RESULTS: The study included 602 consecutive patients. The mean maternal age was 28.7 +/- 6.3 years, with median gravidity of 2 (range, 1-12) and parity 1 (range, 0-8). All attempts at obtaining fetal hard palate ultrasound measurements were successful. Mean fetal hard palate width (cm) = -0.73579345 + 0.11370432 x GA - 0.00083919 x GA(2) and SD = -0.017842055 + 0.005142475 x GA, where GA is gestational age in weeks. Mean fetal hard palate length (cm) = -0.82020463 + 0.11767777 x GA - 0.00092801 x GA(2) and SD = -0.043064317 + 0.006378869 x GA. Mean fetal hard palate area (cm(2)) = -2.40090641 + 0.17136556 x GA + 0.00097308 x GA(2) and SD = -0.603647741 + 0.040740282 x GA. Sonographic measurements of the fetal hard palate width, length and area correlated significantly and strongly with gestational age (all P < 0.001) and significantly but less strongly with femur length (P = 0.004). CONCLUSION: The fetal hard palate may be depicted sonographically with relative ease between 15 and 41 weeks' gestation and measurements of the fetal hard palate width, length and area correlate well with gestational age, biparietal diameter, abdominal circumference, sonographic estimated fetal weight, and femur length.

Adult↗
PubMed2003

Intrapartum assessment of fetal head engagement: comparison between transvaginal digital and transabdominal ultrasound determinations.

OBJECTIVE: To test the null hypothesis that no correlation exists between transvaginal digital examination and the gold standard technique of intrapartum transabdominal ultrasound determination of fetal head engagement, and secondarily to compare the performance of attending physicians and senior residents in depicting fetal head engagement by transvaginal digital examination. METHODS: Two hundred and twenty-two consecutive patients in labor > 37 weeks' gestation with normal singleton cephalic-presenting fetuses and with either ruptured or intact membranes were included. Of these, 119 were nulliparous and 103 were multiparous. Transvaginal digital examinations were performed by either attending physicians or senior residents and were followed immediately by transverse suprapubic sonographic assessments by a single sonographer. The fetal head was considered engaged on transvaginal digital examination if the leading part of the fetal head was positioned at least at maternal ischial spine station 0, and on transverse suprapubic ultrasound if the fetal biparietal diameter was below the maternal pelvic inlet. Examiners were blinded to each other's findings and the effect of examiner experience on the rate of agreement between the two techniques was assessed. The effect of several other independent variables upon the rate of agreement between the two modalities was also assessed. RESULTS: Overall, transvaginal digital examinations were consistent with ultrasound determinations with a raw percent agreement rate of 85.6% (95% confidence interval (CI), 80.8-90.3); kappa = 69.5% (95% CI, 59.4-73.9; P < 0.001). When stratified according to parity, the raw percent agreement rate for nulliparous patients was 81.5% (95% CI, 73.4-88.0); kappa = 60.7% (95% CI, 45.9-64.1; P < 0.001), and for multiparous patients it was 90.3% (95% CI, 84.1-95.9); kappa = 80.4% (95% CI, 63.0-87.5; P < 0.001). Maternal age, gravidity, maternal body mass index, gestational age, cervical dilatation, effacement, membrane status, ischial spine station of the fetal head, fetal head position at ultrasound assessment, birth weight and mode of delivery did not significantly affect rate of agreement. Parity did not affect examination consistency in multiparous patients, but in the whole group increasing parity increased the rate of agreement between modalities. Presence of combined spinal epidural anesthesia significantly increased the rate of agreement in the complete group and among multiparous but not among nulliparous patients. CONCLUSION: These data demonstrate a high rate of agreement (85.6%) between ultrasound determination and transvaginal digital assessment of fetal head engagement. Examiner experience had no effect. These data support the use of intrapartum transabdominal assessment of fetal head engagement.

Adult↗
PubMed2002

Intrapartum fetal head position I: comparison between transvaginal digital examination and transabdominal ultrasound assessment during the active stage of labor.

OBJECTIVE: To test the null hypothesis that no correlation exists between transvaginal digital and the gold standard technique of transabdominal suprapubic ultrasound assessments of fetal head position during labor. A secondary objective was to compare the performance of attending physicians vs. senior residents in depicting fetal head position by transvaginal digital examination in comparison with ultrasound, respectively. METHODS: Consecutive patients in active labor at term with normal singleton cephalic-presenting fetuses were included. All participants had ruptured membranes, cervical dilation > or = 4 cm and fetal head at ischial spine station -2 or lower. Transvaginal sterile digital examinations were performed by either senior residents or attending physicians and followed immediately by transverse suprapubic transabdominal ultrasound assessments. Examiners were blinded to each other's findings. Power-analyses dictated number of subjects required. Statistical analyses included Chi-square, Cohen's Kappa test and logistic regression analysis. P < 0.05 was considered statistically significant. RESULTS: One hundred and two patients were studied (n = 102). In only 24% of patients (n = 24), transvaginal digital examinations were consistent with ultrasound assessments (P = 0.002, 95% confidence interval, 16-33). Logistic regression revealed that cervical effacement (P = 0.03) and ischial spine station (P = 0.01) significantly affected the accuracy of transvaginal digital examination. Parity, gestational age, combined spinal epidural anesthesia, cervical dilation, birth weight and examiner experience did not significantly affect accuracy of the examination. The accuracy of the transvaginal digital exams was increased to 47% (n = 48) (95% confidence interval, 37-57) when fetal head position at transvaginal digital examination was recorded as correct if reported within +/- 45 degrees of the ultrasound assessment. The rate of agreement between the two assessment methods for attending physicians vs. residents was 58% vs. 33%, respectively (P = 0.02) with the +/- 45 degrees analysis. CONCLUSIONS: Using ultrasound assessment as the gold standard, our data demonstrate an overall high rate of error (76%) in transvaginal digital determination of fetal head position during active labor, consistent with the null hypothesis. Attending physicians exhibited an almost two-fold higher success rate in depicting correct fetal head position by physical examination vs. residents in the +/- 45 degrees analysis. Intrapartum ultrasound increases the accuracy of fetal head position assessment during active labor and may serve as an educational tool for physicians in training.

Adolescent↗
PubMed2002

Intrapartum fetal head position II: comparison between transvaginal digital examination and transabdominal ultrasound assessment during the second stage of labor.

OBJECTIVE: To test the null hypothesis that no correlation exists between transvaginal digital examination compared with the gold standard technique of transabdominal suprapubic ultrasound assessment of fetal head position during the second stage of labor. A secondary objective was to compare the performance of attending physicians vs. senior residents in depicting fetal head position by transvaginal digital examination in comparison with ultrasound assessment. METHODS: Consecutive patients in the second-stage of labor at term with normal singleton cephalic-presenting fetuses and ruptured membranes were included. Transvaginal digital examinations were performed by either attending physicians or senior residents and were followed immediately by transverse suprapubic transabdominal sonographic assessments performed by a single sonographer. Examiners were blinded to each other's findings. Power analysis dictated sample size. Exact binomial confidence intervals around observed rates were compared with chi 2 and Cohen's kappa-tests. Logistic regression was applied. P < 0.05 was considered significant throughout. RESULTS: One hundred and twelve patients were studied. The absolute error of transvaginal digital examinations was recorded in 65% of patients (95% confidence interval, 56-74%). Parity, pelvic station, combined spinal epidural anesthesia, length of first or second stages of labor, use of oxytocin augmentation, gestational age, mode of delivery, birth weight, and examiner experience did not significantly affect examination accuracy. Stratification, when the transvaginal digital examination was recorded as correct if occurring within +/- 45 degrees of the ultrasound assessment, reduced the error of the transvaginal digital examinations to 39% (95% confidence interval, 30-49%). Independent variables again did not affect examination accuracy in this assessment modality. Rates of agreement between the two methods for attending physicians compared with residents were not significantly different. The overall degrees of agreement were 40% (95% confidence interval, 26-55%) and 68% (95% confidence interval, 53-80%) (kappa = 0.25 and 0.30) for the absolute agreement and +/- 45 degrees assessment modalities, respectively, for attending physicians, and 31% (95% confidence interval, 20-44%) and 55% (95% confidence interval, 42-68%) (kappa = 0.14 and 0.12) for senior residents. CONCLUSION: Using ultrasound assessment as the gold standard, our data demonstrate a high rate of error (65%) in transvaginal digital determination of fetal head position during the second stage of labor. The performance of senior residents in transvaginal digital examinations did not differ significantly from that of attending physicians. Intrapartum ultrasound increases the accuracy of fetal head position assessment during the second stage of labor.

Adolescent↗
PubMed2001

Angiogenesis during implantation, and placental and early embryonic development.

Angiogenesis, the development of new capillaries from pre-existing vessels, is induced by inflammation, wound healing, immune reactions and neoplasia, and is required for tumour growth and progression. Angiogenesis participates in a wide range of ovulatory-related and non-ovulatory-related reproductive processes. We present a review of current data pertaining to angiogenesis of pregnancy, with specific emphasis on implantation and placental and embryonic development in both normal physiology processes and various pathological conditions. To this goal, MEDLINE, Current Contents and Index Medicus were searched for studies published between 1966 and August 1999. Pertinent studies (including human and animal models) pertaining to angiogenesis of implantation and placental and embryonic development were reviewed. Current literature supports that angiogenesis is an essential physiological component of implantation, and placental and embryonic development. Angiogenesis also actively participates in abnormal implantation, and various pathological processes of the placenta including those observed in association with pre-eclampsia, growth restriction, maternal anaemia in the first-trimester and other hypoxia-related conditions during pregnancy. Finally, administration of an angiogenesis inhibitor (AGM-1470) in mice has been shown to result in complete failure of embryonic growth due to interference with decidualization, placental and yolk sac formation, and embryonic vascular development.

Adult↗
PubMed2001

Adverse perinatal outcome of twin pregnancies according to chorionicity: review of the literature.

Twin gestations are at significant increased risk for adverse perinatal outcome. As a result, although prospective randomized data is lacking, increased fetal surveillance has been advocated for twins. Growth concordance is considered a reassuring sign in twins and conversely, discordancy to possibly reflect a hostile intrauterine environment at least to the smaller twin. Consequently, increased surveillance of discordant twins is commonly practiced. Monochorionic twins are at further risk for type-specific perinatal complications, for example, twin-twin transfusion syndrome. Recently, precise first-trimester depiction of chorionicity has enabled early antepartum stratification of twin gestations according to chorionicity, in comparison with previous later (mid- and third-trimester) ultrasonographic diagnosis of chorionicity. This immediately leads to the question whether antenatal testing of twins should differ according to chorionicity? Review of the literature supports that despite the existence of complications unique to monochorionic twin gestations, dichorionic twins sustain an increased risk of adverse perinatal outcome (such as fetal growth restriction) in comparison with singletons, and that close antenatal fetal surveillance of twins should be performed, irrespective of chorionicity.

Diseases in Twins↗
PubMed2001

An unusual case of diverticulitis complicating pregnancy at 33 weeks' gestation.

A 38-year-old para 2 presented with the gradual onset of nausea vomiting and increasing left lower quadrant pain, at 33 weeks' gestation. She was known to have uterine leiomyomas, with ultrasonography depicting an 8-cm intramural fundal leiomyoma. In addition a left lateral nondiscrete 10 x 8-cm mass was depicted at the point of maximum tenderness. Magnetic resonance imaging (MRI) demonstrated diverticulosis of the descending and sigmoid colon. The patient remained afebrile and received repeated doses of intramuscular analgesics and was cleared by the surgical consultant, only to be readmitted with similar symptomatology 24 hours later. Subsequently, following repeat discharge she delivered at 34 weeks' gestation, and developed a small bowel obstruction during the immediate postpartum course. With the continued finding of a left lower abdominal mass and computed tomography findings suggestive of perforated sigmoid diverticulitis and resulting small bowel obstruction, laparotomy was performed. Multiple adhesions and phlegmon sequelae of chronic perforation of the sigmoid were confirmed, and a diverting descending colostomy and Hartman's procedure were performed. We present unusual MRI findings of diverticulitis in the third-trimester and review the literature pertaining to this unusual complication of pregnancy.

Adult↗
PubMed2001

First-trimester transvaginal ultrasonographic diagnosis of Dandy-Walker malformation.

We present transvaginal ultrasonographic findings of a fetus with Dandy-Walker malformation and associated massive obstructive hydrocephalus at 13 weeks' gestation. First-trimester ultrasonographic diagnosis of Dandy-Walker malformation is uncommon with only two such occurrences having been reported previously. These cases and recent reports of single gene transmission of this condition in some families emphasize the importance of first-trimester transvaginal ultrasound assessment especially in women with previously affected fetuses.

Adult↗
PubMed2001

Celiac disease: fertility and pregnancy.

Celiac disease (gluten-sensitive enteropathy) may manifest clinically with an array of nongastrointestinal symptoms among which are: dermatitis herpetiformis; dementia; depression; various neurological symptoms; osteoporosis; osteomalacia; dental enamel defects, and anemia of various types. Important data have accumulated in recent years regarding the association between celiac disease, fertility and pregnancy. Many primary care obstetricians and gynecologists and perinatologists are not aware of these important relationships. The aim of this review, utilizing a MEDLINE search from 1966 through March 2000 of the English language, is to describe the possible effects of celiac disease and its treatment upon the reproductive cycle, fertility, pregnancy, and menopause. Review of the literature reveals that patients with untreated celiac disease sustain a significantly delayed menarche, earlier menopause, and an increased prevalence of secondary amenorrhea. Patients with untreated celiac disease incur higher miscarriage rates, increased fetal growth restriction, and lower birth weights. It appears that improvement of celiac disease, as reflected by restoration of small bowel mucosa associated with implementation of a gluten-free diet, may decrease miscarriage rates, improve fetal nutritional support and overall perinatal outcome.

Celiac Disease↗
PubMed2001

Prenatal ultrasonographic diagnosis of congenital umbilical hernia and associated patent omphalomesenteric duct.

We present an unusual case in whom a small congenital hernia of the umbilical cord and associated patent omphalomesenteric duct were diagnosed at midtrimester ultrasonography. The diagnosis was confirmed following delivery, and neonatal corrective surgery was performed. We compare prenatal ultrasound findings of umbilical hernia and associated persistent omphalomesenteric duct with those of omphalocele.

Adult↗
PubMed2001

Postcesarean small bowel volvulus. Case report and review of the literature.

Volvulus is an uncommon cause of bowel obstruction during pregnancy. We present an unusual case in which cesarean delivery at 26 weeks of gestation was complicated by volvulus of the small bowel 1 week following delivery. At laparotomy, detorsion of the loop of the terminal ileum sufficed, and bowel resection was not required. We review the literature pertaining to volvulus of the bowel during pregnancy and discuss recent new diagnostic imaging modalities for midgut volvulus, which may assist early noninvasive diagnosis of this condition.

Adult↗
PubMed2001

Pseudomyxoma peritonei: a review of current literature.

Pseudomyxoma peritonei is an unusual condition more common in females, in which massive amounts of mucinous ascites in conjunction with mucinous peritoneal and omental implants occur. We performed a MEDLINE search of the English-language literature from 1966 to June 2000, utilizing the key words pseudomyxoma peritonei. All case reports, series and studies regarding this condition were reviewed. Cross-referencing was also performed. The etiology and treatment of this condition are currently controversial. Most investigators agree that surgical debulking and appendectomy are adequate initial therapeutic measures. The role of intraperitoneal chemotherapy, radiotherapy or application of mucolytic therapy remains uncertain. Recent molecular genetic studies suggest the appendix as the organ of primary origin of this disease.

Female↗
PubMed2001

Neonatal vaginal prolapse.

We present an unusual case of neonatal vaginal prolapse in a term newborn and review the literature pertaining to this rare condition.

Female↗