Biomedical subjects

J C Morrison

Publications and source records attributed to J C Morrison.

At least 55 records · Page 3Linked to original sources

PubMed1999

The impact of leiomyomas on pregnancy.

In this retrospective case control investigation, 51 pregnant patients who were diagnosed by ultrasound with uterine myomas were compared to 102 randomly selected control patients to determine if the ultrasound diagnosis of one or more leiomyoma is associated with increased untoward pregnancy outcomes compared to controls. Women with uterine myomas were older (p = 0.001), more likely to be African American (p = 0.001), and undergo Caesarean delivery (p = 0.03) than controls. However, when women who underwent abdominal delivery for previous myomectomy (n = 5) were excluded from analysis, there was no significant difference in the incidence of Caesarean delivery. Overall, there was no difference in the incidence of obstetric complications between groups even when the data was stratified for large and/or multiple leiomyomas. The discovery of uterine leiomyomas by gestational ultrasound does not appear to place the patient at increased risk for preterm labour, early delivery, or other untoward pregnancy outcomes.

Adult↗

PubMed1999

Amniotic fluid index in normal pregnancy: a longitudinal study.

OBJECTIVE: This longitudinal study was undertaken to characterize the change in the amniotic fluid volume in normal pregnancy. METHODS: Prospectively, patients with uncomplicated gestations underwent serial amniotic fluid index by a single sonographer. RESULTS: Fifty-six patients underwent a total of 378 determinations of amniotic fluid volume (6.8 +/- 2.5 examinations per patient). The variation in mean amniotic fluid index between 24 and 40(+6) weeks was not significantly different (p = 0.381). Among the 42 patients who delivered at term there was no significant decrease in the amniotic fluid index between their first and last measurement (p = 0.86). However, in the 14 patients who delivered after 41 weeks, there was a significant decrease in the index over time (p = 0.04). CONCLUSION: The longitudinal study on amniotic fluid volume in normal pregnancy reveals that amniotic fluid index does not change significantly with gestational age.

Adult↗

PubMed1999

Microvasculature of the rat optic nerve head.

PURPOSE: To describe the arterial blood supply, capillary bed, and venous drainage of the rat optic nerve head. METHODS: Ocular microvascular castings from 6 Wistar rats were prepared by injection of epoxy resin through the common carotid arteries. After polymerization, tissues were digested with 6 M KOH, and the castings washed, dried, and coated for scanning electron microscopy. RESULTS: Immediately posterior to the globe, the ophthalmic artery trifurcates into the central retinal artery and two posterior ciliary arteries. The central retinal artery directly provides capillaries to the nerve fiber layer and only contributes to capillary beds in the neck of the nerve head. The remainder is supplied by branches of the posterior ciliary arteries that are analogous to the primate circle of Zinn-Haller. Arterioles arising from these branches supply the capillaries of the transitional, or laminar, region of the optic nerve head. These capillaries are continuous with those of the neck and retrobulbar optic nerve head. All optic nerve head capillaries drain into the central retinal vein and veins of the optic nerve sheath. A flat choroidal sinus communicates with the central retinal vein, the choriocapillaris, and with large veins of the optic nerve sheath. CONCLUSIONS: The microvasculature of the rat optic nerve head bears several similarities to that of the primate, with a centripetal blood supply from posterior ciliary arteries and drainage into the central retinal and optic nerve sheath veins. Association of nerve sheath veins with the choroid represents an important difference from the primate.

Animals↗

PubMed1999

May-Hegglin anomaly in a pregnancy complicated by intrauterine growth restriction and ambiguous genitalia.

OBJECTIVE: Thrombocytopenia as a hematologic disorder complicates up to 4% of all pregnancies. May-Hegglin anomaly is a rare cause of low platelets in pregnancy. METHODS: A case of May-Hegglin anomaly complicating pregnancy and intrauterine growth restriction in a fetus with ambiguous genitalia is described. RESULTS: The antepartum and intrapartum diagnosis and management of a patient diagnosed with May-Hegglin anomaly is discussed. The involvement and consultation of a perinatologist, neonatologist, internist, and anesthesiologist is reviewed, with emphasis on the mode of delivery. CONCLUSION: The potential maternal and fetal complications associated with May-Hegglin anomaly warrant early pregnancy diagnosis and access to a tertiary care facility.

Disorders of Sex Development↗

PubMed1999

Accuracy of sonographically estimated fetal weight with and without oligohydramnios. A case-control study.

OBJECTIVE: To determine the accuracy of sonographically estimated fetal weight among women with and without oligohydramnios (amniotic fluid index [AFI] < or = 5.0 cm) and to ascertain the ability to detect fetal growth restriction (FGR) (estimated birth weight < 10th percentile for gestational age [GA]) among patients in two groups. STUDY DESIGN: Assuming that 50% of sonographic predictions are within 10% of the birth weight in the study group, 300 parturients are necessary to show a difference of 15% among controls (alpha = .05, beta = .02). The study group consisted of parturients with a reliable GA of > or = 24, no known anomalies and known AFI of < or = 5.0 cm. The control (1:1) was the next patient with the same GA but AFI between 5.1 and 23.9 cm. The paired t test was used, and the odds ratio (OR) and 95% confidence interval (CI) were calculated. P < .05 was considered significant. RESULTS: Among the study and control groups (N = 162 each), maternal demographics, mean estimate (P = .078) and actual birth weight (P = .091) were similar. Sonographic estimates within 10% of weight were not significantly different among those with (57%) and without oligohydramnios (59%; OR 0.92; 95% CI 0.59, 1.44). The frequency of FGR was higher among those with inadequate fluid (18%) than controls (9%; OR 2.13; 95% CI 1.10, 4.16). Sensitivity, positive predictive value and likelihood ratio were higher among those with oligohydramnios (76%, 78% and 16) than controls (53%, 42% and 7). CONCLUSION: The accuracy of sonographic estimates of fetal weight is not influenced by whether the parturient has oligohydramnios. Moreover, the accuracy of identifying FGR is not diminished among those with AFI < or = 5.0 versus > 5.0 cm.

Adult↗

PubMed1998

Can we decrease postdatism in women with an unfavorable cervix and a negative fetal fibronectin test result at term by serial membrane sweeping?

OBJECTIVE: Our purpose was to determine whether the risk for postdatism can be reduced by serial membrane sweeping in women with an unfavorable cervix at 39 weeks' gestation and a negative fetal fibronectin test result. STUDY DESIGN: Women with uncomplicated pregnancies, who were candidates for a vaginal delivery with an unfavorable cervix at 39 weeks' gestation and a negative fetal fibronectin test result were asked to participate in this investigation. Patients were chosen at random and assigned to a group for membrane sweeping every 3 days or to a control group who received gentle examinations every 3 days. RESULTS: Sixty-five women were selected at random for serial membrane sweeping (n = 33) or for the control group (n = 32). Although gestational age and Bishop score at study entry were similar, the gestational age on admission for delivery was earlier in the membrane sweeping group (39.9 +/- 0.3) versus the control group (41.5 +/- 0.6, P < .0001). The Bishop score on admission to labor and delivery was greater (8.8 +/- 2.1) in the membrane sweeping group than in the control group (6.2 +/- 2.7, P < .0001). The number of women admitted for labor inductions at 42 weeks' gestation was 18 of 32 (56%) in the control group versus none (0 of 24) in the membrane-sweeping group (P < .0001). CONCLUSIONS: Women with an unfavorable cervix at 39 weeks' gestation and a negative fetal fibronectin test result are at risk for not being delivered by 41 completed weeks and thus may require postdates induction or antenatal testing. Serial membrane sweeping significantly reduces the risk of postdatism and induction of labor.

Cervical Ripening↗

PubMed1998

Ultrasonographic estimate of birth weight at 24 to 34 weeks: a multicenter study.

OBJECTIVE: The study was intended to compare the accuracies of ultrasonographic estimates of birth weights among infants born between 24 and 34 weeks' gestation at 3 tertiary centers. STUDY DESIGN: In this retrospective study subjects were matched for gestational age (1:1); all underwent ultrasonographic examination within 2 weeks of delivery. The estimates of birth weight were obtained according to 26 published regression equations and their accuracies were assessed with the mean standardized absolute error. For each center the equation with the lowest error was selected to generate (1) receiver-operating characteristic curves for an estimate to identify actual weight < 1500 g and (2) prediction limit calculations to determine the estimate that ensures at 70% confidence a birth weight > 1500 g. RESULTS: One hundred seventy-one cases were analyzed at each center. Comparison of the 26 mean standardized errors at each center indicated that (1) the range was rather wide (eg, 89 +/- 87 to 365 +/- 313 g/kg) and (2) 73% (19/26) of the equations had significantly (P < .05) different accuracies. Receiver-operator characteristic curves show that fetal weight estimates of > or = 1600 g at 2 centers and > or = 1700 g at the third center are required to predict actual birth weight < 1500 g. Prediction limit calculation suggests that different fetal weight estimates (> 1600 g at center 1, > 1900 g for the center II, and > 1800 g at center III) are needed to predict actual weight > 1500 g with a 70% accuracy. CONCLUSIONS: Ultrasonographic estimates of weight for preterm infants, as obtained from 26 equations, are characterized by a rather wide range of accuracy; for most of the equations the accuracies of estimates differ markedly among centers.

Birth Weight↗

PubMed1998

Management of pregnancies beyond forty-one weeks' gestation with an unfavorable cervix.

OBJECTIVE: Our purpose was to determine the optimal management of pregnancies beyond 41 weeks' gestation with a cervix unfavorable for induction. STUDY DESIGN: All uncomplicated pregnancies that reached 41 weeks' gestation with a Bishop score of < or = 4 were randomly assigned to one of three groups: (1) daily cervical examinations, (2) daily membrane stripping, or (3) daily placement of prostaglandin gel until 42 weeks. RESULTS: In 105 pregnancies the Bishop score on admission to labor and delivery was significantly greater in the groups receiving prostaglandin or stripping of the membranes versus the control group, whereas the converse was time of gestational age at delivery (p = 0.0001). Fewer patients required induction in the two treatment groups (20%, 17%) versus the control (69%) patients (p < 0.0001). CONCLUSIONS: Daily membrane stripping or daily placement of prostaglandin gel is successful in reducing the number of inductions at 42 weeks for postdatism.

Administration, Intravaginal↗

PubMed1998

Premature rupture of membranes at 34 to 37 weeks' gestation: aggressive versus conservative management.

OBJECTIVE: Our purpose was to compare induction of labor with preterm rupture of membranes between 34 and 37 weeks' gestation with expectant management. STUDY DESIGN: In this prospective investigation 120 gravid women at > or = 34 weeks 0 days and < 36 weeks 6 days of gestation were randomized to receive oxytocin induction (n = 57) or observation (n = 63). RESULTS: Estimated gestational age at rupture of membranes (34.3 +/- 1.4 weeks vs 34.5 +/- 1.4 weeks) and ultrasonographically estimated fetal weight (2230 +/- 321 gm vs 2297 +/- 365 gm) were equivalent between groups (not significant). Chorioamnionitis occurred more often (16% vs 2%, p = 0.007), and maternal hospital stay (5.2 +/- 6.8 days vs 2.6 +/- 1.6 days, p = 0.006) was significantly longer in the control group. Neonatal sepsis was also more common in the observation group (n = 3) than among induction patients (n = 0), but the difference was not statistically significant. CONCLUSION: Aggressive management of preterm premature rupture of the membranes at > or = 34 weeks 0 days of gestation by induction of labor is safe for the infant in our population and avoids maternal-neonatal infectious complications.

Adolescent↗

PubMed1998

Limitations of clinical and sonographic estimates of birth weight: experience with 1034 parturients.

OBJECTIVE: To compare the accuracy of clinical and sonographic estimates of fetal weight made throughout the third trimester of pregnancy. METHODS: Patients in early labor had fetal weight estimated by two approaches: 1) clinical evaluation and palpation followed by 2) sonographic mensuration of fetal biparietal diameter, abdominal circumference, and femur length applied to Hadlock's formula. The accuracy of these two methods of estimating fetal weight was compared using Student t test, Wilcoxon test, and chi2 tests. P < .05 was considered significant. Prediction limits (50th, 90th, and 95th percentiles) were calculated for both techniques by obtaining the range of actual weights associated for a particular estimated fetal weight (EFW). RESULTS: We enrolled 1034 parturients whose clinical EFWs yielded significantly higher mean (+/- standard deviation) simple error (48.2 +/- 411 g) and standardized absolute error (130 +/- 122 g/kg) than were obtained by use of sonographic formulas for EFW (-6.6 +/- 381 g and 104 +/- 89 g/kg, respectively). When the population was partitioned by gestational age, we found that sonographic EFW was more accurate than clinical EFW in preterm (n = 373) but not in term (n = 460) or post-term (n = 201) pregnancies. Prediction limits indicate that for a given EFW, for example, 800 g, the 90% ranges of actual weight based on clinical and sonographic EFW are 566-1829 g and 469-1667 g, respectively. CONCLUSION: The apparent superiority of sonographic EFW over clinical EFW applies principally to preterm pregnancies. The prediction limitation calculation suggests that either method, for any particular estimate between 500 and 4500 g, has limited value in the estimation of actual birth weight, because this outcome is highly variable and frequently lies outside of the useful bandwidth (+/- 10%) for prospective management.

Adult↗

PubMed1998

Intrapartum amniotic fluid index: a poor predictor of abnormal fetal size.

OBJECTIVE: Using receiver-operating characteristic (ROC) curves, we tried to determine the diagnostic threshold of amniotic fluid index (AFI) that will identify abnormal fetal size (birth weights under 2500 g or at least 4000 g) at 37 weeks or beyond. METHODS: We analyzed prospectively over 2 years all parturients with intact membranes and known AFI in early labor. Patients with the following conditions were excluded: pregestational or gestational diabetes, known anomalies, and preterm labor. Two ROC curves were constructed, and the areas (+/- standard error of the mean [SE]) under the curves were calculated. P < .05 was considered significant. RESULTS: Of the 1038 subjects meeting study criteria, 3.6% and 11.5% gave birth to infants who were small for gestational age (SGA) or macrosomic, respectively. Overall, 28.7% had oligohydramnios (AFI at most 5.0 cm) and 3.6% had hydramnios (AFI at least 24.0 cm). Small for gestational age was more common in patients with AFI at most 5.0 cm (6.4%) than in those with adequate fluid (AFI 5.1-23.9; 2.5%), or hydramnios (2.7%; P = .012). Macrosomic newborns were less likely to be born to women with oligohydramnios (7.7%) than to those with adequate amniotic fluid (13.1%) or hydramnios (13.5%). Areas under ROC curves are not significantly different from the area under the nondiagnostic line, indicating that AFI (0-34 cm) cannot differentiate between newborns under 2500 g and at or over 2500 g or under 4000 and at or more 4000 g. CONCLUSION: Intraparterium AFI appears to be a poor screening test to identify risk for delivery of SGA or macrosomic fetus.

Adult↗

PubMed1998

Has the use of home monitors, fetal fibronectin, and measurement of cervical length helped predict labor and/or prevent preterm delivery in twins?

Home monitoring accurately detects contractions, and thus is useful in predicting preterm labor. Appropriate physician action is necessary to significantly prolong pregnancy even in the presence of evidence of excessive contractions. Despite conflicting studies, the majority of evidence heavily favors the use of monitoring as part of a comprehensive preterm birth prevention program. Indeed, monitoring has greater clinical utility in twin gestations because of the recognized propensity for preterm labor. Fetal fibronectin is one of the most sensitive and specific markers for preterm labor and subsequent early delivery presently available. It appears to be equally effective in multifetal gestations compared with singleton gestations, but intervention trials are needed to substantiate its clinical effectiveness. Cervical status monitoring by ultrasound correlates inversely with preterm labor, but studies in twin gestation are currently lacking. Other markers, such as salivary estriol for preterm labor, have yet to be assessed as predictors of preterm labor among multifetal gestations.

Cervix Uteri↗

PubMed1998

Cesarean delivery for the second twin in the vertex-vertex presentation: operative indications and predictability.

BACKGROUND: The incidence of second twin delivery by cesarean section and whether obstetric parameters are predictive should be studied. METHODS: In this retrospective study, all vertex-vertex twin deliveries during a 48-month period were reviewed. RESULTS: During the study period, 106 sets of vertex-vertex twins were identified. In 68 pairs, both were delivered vaginally (group 1), and 21 pairs were born via cesarean section. In the 17 pairs in group 2, the first infant was delivered vaginally and the second by cesarean section because of fetal distress in 6 cases (35%), cord prolapse in 6 (35%), abnormal/unstable lie in 4 (23%), and abruptio placenta in 1 case (6%). The only maternal factor associated with abdominal delivery for twin B was greater maternal age. When cesarean delivery was required for twin B, a longer interval between deliveries and a lower Apgar score were noted. CONCLUSION: Cesarean birth of twin B is a more common clinical event than previously reported but is not easily predicted by obstetric parameters.

Apgar Score↗

PubMed1998

Medical practices of past graduates from one obstetric/gynecologic training program.

BACKGROUND: We sought to assess the practice patterns of former obstetric-gynecologic residents and to solicit their opinions regarding their educational experience and its clinical relevance to primary care. METHOD: In response to a Residency Review Committee mandate regarding past residents, a questionnaire was sent to all graduates from our residency program over a 17-year period (1979 to 1995). RESULTS: Of the 90 subjects who received the survey, 86 responded. Their ages ranged from 29 years to 49 years; 79 were married and 7 were single. Of the 75 in clinical practice, 71 practiced both obstetrics and gynecology and 13 had subspecialized. Most of the respondents (77/80) practiced in the mid-South. Of all graduates, 93% routinely provided primary care. In rating 20 major resident education categories, respondents gave high grades to training in surgically related areas. Only 4% rated their experience as fair or poor in the operative categories. CONCLUSION: Our graduates indicate satisfaction with their training, and their practices include primary care.

Adult↗

PubMed1998

Formal pathology rotation during obstetrics and gynecology residency: is it beneficial?

BACKGROUND: Our objective was to assess the educational benefits of a formal pathology rotation during an obstetrics and gynecology residency program and to determine the utility of this information in clinical practice. METHODS: In this descriptive study, the benefits of a 2-month rotation in pathology for obstetrics and gynecology residents were analyzed. A computerized listing of surgical cases processed by each resident was sent to the obstetrics and gynecology program director. RESULTS: Our resident accessioned 5.4% of the total pathology cases processed each month. Reports from previous residents (over a 17-year period) and from program directors at the annual educational retreat indicate that such information was not relevant to our graduates in their clinical practice. CONCLUSIONS: A formal pathology rotation for obstetric residents can improve knowledge base, but the usefulness of this knowledge in clinical practice is dubious.

Curriculum↗

PubMed1998

Bishop score: a poor diagnostic test to predict failed induction versus vaginal delivery.

BACKGROUND: We evaluated the accuracy of the Bishop score in predicting the likelihood of successful labor induction (entry into active phase) in nulliparous and multiparous women. METHODS: During an index year, all patients having induction of labor and a preinduction Bishop score were included in a standard protocol for cervical ripening and use of oxytocin. Receiver-operating characteristic (ROC) curves were constructed for Bishop scores (0 to 11) to predict abdominal delivery for failed induction (final cervical dilation <4 cm) versus vaginal delivery. RESULTS: Parturients who had vaginal delivery (n = 253) and those in whom attempted induction failed (n = 38) did not differ significantly with respect to maternal demographics, length of gestation, Bishop score and its distribution, and infant birth weight. The area under the ROC curve did not differ significantly from the area under the nondiagnostic line. CONCLUSION: The Bishop score appears to be a poor predictor of the outcome of labor induction.

Adult↗

PubMed1998

Absence of seasonal variation on the frequency of HELLP syndrome.

BACKGROUND: We wanted to determine the relationship between weather/seasonal conditions and the incidence/severity of HELLP syndrome. METHODS: We retrospectively reviewed medical records of all patients with class 1 (platelet nadir < or = 50,000/microL), class 2 (platelet nadir > 50,000/microL but < or = 100,000/microL), and class 3 (platelet nadir > 100,000/microL but < or = 150,000/microL) HELLP syndrome, who had been treated at the University of Mississippi Medical Center between January 1, 1980, and December 31, 1992. RESULTS: No seasonal differences were observed in the incidence or severity of pregnancies complicated by HELLP syndrome. CONCLUSION: HELLP syndrome appears to occur throughout the year without any seasonal variation.

Female↗

PubMed1998

Effect of amniotic fluid volume on neonatal outcome in diamniotic twin pregnancies.

PROBLEM: We assessed neonatal outcome of normal diamniotic twin pregnancies with known amniotic fluid (AF) volume. METHOD: The AF volume was empirically determined in 39 diamniotic twin gestations. The neonates were stratified by AF volume and evaluated for clinical outcome, gestational age, lecithin-sphingomyelin (L/S) ratio, and birth weight. RESULTS: Neonatal complications did not significantly differ among infants delivered from pregnancies with low (155 to 404 mL), moderate (405 to 807 mL), or high (808 to 5,430 mL) volumes of AF. Relatively constant volumes of AF were maintained throughout the 27 to 38 week range of gestational age, with no apparent correlation between AF volume and gestational age. Variations in the L/S ratio and newborn birth weights were also independent of AF volume. Gestational age was the only significant determinant of the frequency of neonatal complications. CONCLUSION: Amniotic fluid volume does not greatly affect neonatal outcome in normal diamniotic twin pregnancies.

Adult↗