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Biomedical subjects

S P Chauhan

Publications and source records attributed to S P Chauhan.

At least 19 recordsLinked to original sources
PubMed2002

Ultrasound estimation of amniotic fluid volume using the largest vertical pocket containing umbilical cord: measure to or through the cord?

OBJECTIVES: The purpose of this investigation was to determine the preferable method, either measuring to the umbilical cord or through the umbilical cord to the base of the pocket, of ultrasonically estimating amniotic fluid volume. SUBJECT AND METHODS: This was a prospective study carried out in singleton pregnancies undergoing a third-trimester amniocentesis. The amniotic fluid index (AFI) and single deepest pocket (SDP) were measured prior to amniocentesis. If measured spaces contained umbilical cord, measurements were made to and through the cord. Actual amniotic fluid volume was determined by the dye-dilution technique. RESULTS: One-hundred pregnancies were evaluated. Low dye-determined volume was identified in a significantly greater number of pregnancies using the AFI to the cord (7/28, 25%) compared to through the cord (2/28, 7%) (P = 0.025). The SDP technique to the cord was superior in low volumes (2/28, 7%) vs. (0/28, 0%) through the cord (although statistical significance could not be determined because there were no low through-the-cord measurements). CONCLUSIONS: For the detection of low amniotic fluid volumes, the AFI to the cord is better than through the cord. Measurement to the cord and through the cord had similar accuracy for both the AFI and SDP techniques in normal and high dye-determined amniotic fluid volumes.

Adolescent↗
PubMed2002

Sonographic estimate of birth weight: relative accuracy of sonographers versus maternal-fetal medicine specialists.

OBJECTIVE: To compare the relative accuracy of predicting birth weight among registered diagnostic medical sonographers versus maternal-fetal medicine specialists. STUDY DESIGN: Over 7 months all patients who delivered within 2 weeks and had sonographic measurements of femur length and head and abdominal circumferences by sonographers and physicians were included in the analysis. The exclusion criteria were multiple gestation and anomalous fetuses. Receiver operating-characteristic curves (ROC) were constructed to determine the ability to detect intrauterine growth restriction (IUGR; birth weight < 2,500 g) and macrosomia (birth weight > or = 4,000 g) among term (gestational age > or = 37 weeks) parturients. A level of p < 0.05 was considered significant. RESULTS: Among 365 patients recruited, the mean gestational age was 37.3 +/- 2.4 weeks with a mean birth weight of 3,083 +/- 72.5 g. Among term patients the prevalence of IUGR was 7.5% (18/238) and of macrosomia 12% (29/238). A significantly higher percentage of predictions were within 10% of the birth weight when obtained by sonographers (70%) than physicians (54%; p < 0.0001). Registered sonographers were significantly more likely to detect IUGR than the specialists (area under the ROC curves 0.97 +/- 0.02 vs. 0.92 +/- 0.02, respectively; p = 0.02). Both groups had similar accuracy in detecting macrosomic fetuses (area under the ROC curves 0.92 +/- 0.02 for sonographers and 0.90 +/- 0.02 for physicians; p = 0.40). CONCLUSIONS: Prediction of birth weight is significantly more accurate when sonographers rather than maternal-fetal medicine specialists perform the ultrasonographic examination.

Abdomen↗
PubMed2002

Dye-dilution techniques using aminohippurate sodium: do they accurately reflect amniotic fluid volume?

OBJECTIVE: To determine whether the dye-dilution technique using aminohippurate sodium accurately measures amniotic fluid volume. METHODS: Singleton pregnancies with intact membranes undergoing a Cesarean delivery had their amniotic fluid volume assessed by the dye-dilution technique and direct measurement. RESULTS: Fifteen women were prospectively assessed. Six patients had their amniocentesis on the delivery table and nine patients at 4-24 h prior to the Cesarean delivery. The six women undergoing an amniocentesis just before delivery had good concordance between the dye-determined and direct measurement of amniotic fluid volume (r = 0.99, p = < 0.001). Among the nine women with varying times from amniocentesis to direct measurement, the correlation was not significant (r = 0.36, p = 0.08). The percentage difference between the dye-determined and directly measured amniotic fluid volume was significantly smaller in the women undergoing amniocentesis just prior to delivery (7%) than in the women with varying times from amniocentesis to delivery (37%, P < 0.001). CONCLUSION: Dye-determined amniotic fluid volume accurately reflects actual amniotic fluid volume but the dye-determined concentrations, in vivo, may undergo rapid changes.

Adolescent↗
PubMed2001

Ultrasound estimate of amniotic fluid volume: color Doppler overdiagnosis of oligohydramnios.

OBJECTIVE: To determine if concurrent use of color Doppler affects ultrasound estimates of amniotic fluid (AF) volume. METHODS: Study gravidas underwent ultrasound estimations of AF volume subjectively (visualization without measurements) and objectively (using amniotic fluid index [AFI]) and single-deepest pocket techniques, without and with concurrent color Doppler. Amniocentesis with the dye-dilution technique to measure actual AF volume was utilized for comparison. RESULTS: Sixty-seven women at a mean gestational age of 37.1 +/- 2.5 weeks were entered into this investigation between June 1999 and March 2000. Dye-determined AF volume was classified as low in 18 patients and as high in seven, with the remaining 42 within normal range. Using either ultrasound technique with color Doppler produced significantly lower estimates of AF volume (9.3 +/- 4.9) compared to those without color ([11.6 +/- 5], P <.001) for the AFI and (3.7 +/- 1.5) with color compared to those without color ([4.5 +/- 1.5], P <.003) for the single-deepest pocket. Using AFI without color identified two of 67 (3%) of the pregnancies as having low fluid compared to 14 of 67 ([21%] P =.002) using color. The increased classification of oligohydramnios with color did not accurately identify a greater number of dye-determined low volumes; instead, the AFI with color mislabeled nine pregnancies with normal fluid as low. The diagnosis of dye-determined low and high fluid volumes was not significantly different with or without color. CONCLUSION: Concurrent use of color Doppler with AFI measurements leads to the overdiagnosis of oligohydramnios.

Adolescent↗
PubMed2001

Mode of delivery for the morbidly obese with prior cesarean delivery: vaginal versus repeat cesarean section.

OBJECTIVE: We sought to describe the peripartum outcome of women weighing >300 pounds (135 kg) who were candidates for trial of labor after a prior cesarean delivery. STUDY DESIGN: All pregnant women who weighed in excess of 300 pounds and had a prior cesarean delivery were included in this prospective investigation. Student t test, chi(2) analysis, or Fisher exact tests were used. Odds ratios and 95% confidence intervals were calculated. P <.05 was considered significant. RESULTS: During a 2-year period, 69 patients met the inclusion criteria; 39 (57%) underwent an elective repeat cesarean delivery, and 30 (43%) women attempted a vaginal delivery after prior cesarean delivery. The demographics of age, race, gravidity, maternal weight, and preexisting medical conditions were similar for the two groups. Vaginal birth after prior cesarean delivery occurred in 13% (4/30). Reasons for failure included a labor arrest disorder in 46%, fetal distress in 38%, and failed induction in 15%. The rates of endometritis and wound breakdown were higher in the women undergoing trial of labor (30% and 23%, respectively) than in those undergoing repeat elective cesarean delivery (20% and 8%). The combined infectious morbidity rate was significantly higher for women attempting trial of labor (53%) than those undergoing elective repeat cesarean delivery (28%; odds ratio 1.78, 95% confidence intervals 1.05, 3.02). CONCLUSION: The success rate for a vaginal delivery in the morbidly obese woman with a prior cesarean delivery is less than 15%, and more than half of the patients undergoing a trial of labor have infectious morbidity.

Adult↗
PubMed2001

Does uterine wiping influence the rate of post-Cesarean endometritis?

OBJECTIVE: To compare two methods of uterine cleansing to remove residual amnion-chorion at the time of Cesarean delivery. METHODS: All consenting uninfected parturients undergoing a non-emergency Cesarean delivery at the university were enrolled. All patients received antibiotic prophylaxis of a 1-g intravenous bolus of a first-generation cephalosporin immediately after cord clamping. Postpartum endometritis was defined as a temperature of > or = 100.4 degrees F (38 degrees C) on two occasions 6 h apart after the first 24 h with uterine tenderness and/or foul-smelling lochia. RESULTS: Between January 1998 and February 2000 there were 1400 patients enrolled in this investigation. A total of 153 women were determined to have chorioamnionitis present at surgery and 17 women refused participation, leaving 614 women in the uterine wipe group and 616 in the no wipe group. Maternal demographics were similar between patient groups (NS). Intrapartum factors including gestational age at time of Cesarean section, type of anesthesia used for the operative delivery, hours of amnion rupture prior to delivery, use of internal monitoring devices, type of skin incision, method of placental removal, total operative time and estimated blood loss were similar between patient groups (NS). An almost identical number of patients in each arm of the study developed post-Cesarean endometritis (65 out of 614, 10.5%, in the uterine wipe group vs. 66 out of 616, 10.7%, in the no wipe group; p = 1). CONCLUSIONS: Both methods of removing residual amnion-chorion membrane tissue and associated debris at surgery were comparably effective, but neither produced a dramatic reduction in the incidence of postoperative endometritis.

Adult↗
PubMed2001

Subjective versus objective evaluation of amniotic fluid volume of pregnancies of less than 24 weeks' gestation: how can we be accurate?

This study was undertaken to compare subjective versus objective ultrasonic evaluation of amniotic fluid volume in pregnancies of less than 24 weeks' gestation. Amniotic fluid volume was subjectively (visualization without ultrasonic measurements) and objectively (visual interpretation with ultrasonic measurements) evaluated in 42 singleton pregnancies undergoing termination. The actual amniotic fluid volume was then determined using a dye-dilution technique. The women evaluated were in their mid-20s, primarily African American, and between 15 and 23 weeks' gestation. There was no significant difference in the total number of correct estimates of amniotic fluid volume when the data were stratified by level of operator experience (P = .34), ultrasonic technique (P = .33), or the combined correct subjective versus combined correct objective estimates (P = .68). We have concluded that the accuracy of amniotic fluid volume assessment in pregnancies of less than 24 weeks is not influenced by the level of operator experience or the type of ultrasonic measurement.

Amniotic Fluid↗
PubMed2001

Maternal morbidity and mortality associated with intrauterine fetal demise: five-year experience in a tertiary referral hospital.

BACKGROUND: Risk factors for and management of intrauterine fetal demise (IUFD) have been investigated, but the maternal morbidity has not been evaluated. METHODS: Over a 60-month interval, all cases of IUFD after 20 weeks' gestation were reviewed for maternal trauma and maternal postpartum complications. RESULTS: In this retrospective analysis, 498 singleton and 24 twin pregnancies with an IUFD were identified. A cervical or perineal laceration requiring surgical repair complicated 9.4% of pregnancies. One uterine dehiscence and one uterine rupture occurred. Endometritis, the most common postpartum complication, occurred in 63 of 522 patients (12%). One maternal death occurred. Total mean hospital stay was 4.9 +/- 5.7 days. CONCLUSION: Maternal morbidity and rarely mortality can follow IUFD, but this morbidity is similar to that observed without IUFD.

Adult↗
PubMed2000

Amniotic fluid index and single deepest pocket: weak indicators of abnormal amniotic volumes.

OBJECTIVE: To compare amniotic fluid index (AFI) with the single deepest pocket in the identification of actual abnormal amniotic fluid (AF) volumes. METHODS: One hundred seventy-nine women with singleton pregnancies at the University of Mississippi between March 1994 and June 1999 had ultrasound estimations of AF volume sequentially using the AFI and single deepest pocket techniques. Each woman subsequently had ultrasound-directed amniocentesis with dye-dilution and spectrophotometric calculation of actual AF volume. RESULTS: Actual AF volumes were low (under 5% by volume for gestational age) in 62 women, normal (5-95%) in 100 women, and high (more than 95%) in 17 women. An AFI up to 5 cm (sensitivity 10%, specificity 96%) and a single deepest pocket up to 2 cm (sensitivity 5%, specificity 98%) were similarly inadequate in identifying dye-determined low AF volumes. Likewise, AFI above 20 (sensitivity 29%, specificity 97%) and a single-deepest pocket above 8 cm (sensitivity 29%, specificity 94%) were poor in identifying dye-determined abnormally high volumes. CONCLUSION: There was no difference between AFI and single deepest pocket techniques for identifying truly abnormal AF volumes. Both techniques were unreliable for identifying true AF volumes.

Adult↗
PubMed2000

Antepartum detection of macrosomic fetus: clinical versus sonographic, including soft-tissue measurements.

OBJECTIVE: To compare clinical and sonographic estimates of birth weights with five new estimation techniques that involve measurements of soft tissue, for identifying newborns with birth weights of at least 4000 g. METHODS: Over 1 year, each woman at or after 36 weeks' gestation and suspected of having a macrosomic fetus had clinical and sonographic estimates of fetal weight (EFW) based on femur length (FL) and head and abdominal circumference, followed by five additional ways to identify excessive growth: cheek-to-cheek diameter, thigh soft tissue, ratio of thigh soft tissue to FL, upper arm subcutaneous tissue, and EFW derived from it. Areas (+/- standard error) of receiver operating characteristic (ROC) curves were calculated and compared with the area under the nondiagnostic line. P <.05 was considered statistically significant. RESULTS: Among 100 women recruited, 28 newborns weighed 4000 g or more. The areas under the ROC curves with clinical (0.72 +/- 0.06) and sonographic predictions using biometric characteristics (0.73 +/- 0.06) had the highest but similar accuracies (P.05). Three of the five newer methods (upper arm or thigh subcutaneous tissue and ratio of thigh subcutaneous tissue to FL) were poor diagnostic tests (range of areas under ROC 0.52 +/- 0.06 to 0.58 +/- 0.07). Estimated fetal weight based on upper arm soft tissue thickness and cheek-to-cheek diameter (areas 0.70 +/- 0.06 and 0.67 +/- 0.06, respectively) were not significantly better than clinical predictions (P.05) for detecting macrosomic fetuses. About 110 macrosomic and nonmacrosomic infants combined would be needed to have 80% power to detect a difference between ROC curves with areas of 0.58 (thigh subcutaneous tissue) and 0.72 (clinical estimate). CONCLUSION: ROC curves indicated that measurements of soft tissue are not superior to clinical or sonographic predictions in identifying fetuses with weights of at least 4000 g.

Adult↗
PubMed2000

Amniotic fluid volume estimation and the biophysical profile: a confusion of criteria.

The biophysical profile (BPP) can be used as an initial test of fetal health and as a secondary back-up assessment of fetuses at risk of adverse outcomes when preliminary evaluations are not reassuring. The BPP evaluates five characteristics: fetal movement, tone, breathing, heart reactivity, and amniotic fluid (AF) volume estimation. Three of the most frequently used obstetric textbooks define adequate AF volume differently. In two of the three, the stated method of evaluating AF volume differs from that actually used by the referenced authors. We reviewed articles by Manning and found that his methodology changed from a 1-cm pocket in one plane to a 1-cm pocket in two perpendicular planes, and finally to a 2-cm vertical pocket with a 1-cm horizontal measurement. The 2 x 2-cm pocket is a fourth methodology that has been introduced recently. It is not known how often and in which groups each of the four methods has been used to evaluate abnormal AF volumes. The relevance and importance of determining precisely the ultrasound measurement actually used for investigations are emphasized by looking at women with AF indices < or = 5. Fifty-three percent of those women had a 2 x 2 pocket, 72% had a 2 x 1 pocket, and 95% had a 1 x 1 pocket. The diagnosis of low fluid can lead to additional testing, hydration, and intervention, so the importance of a universal definition linked with pregnancy outcomes cannot be overemphasized.

Amniotic Fluid↗
PubMed2000

The effects of physical abuse on pregnancy outcomes in a low-risk obstetric population.

OBJECTIVE: This study was undertaken to evaluate the impact of physical abuse on pregnancy outcomes. STUDY DESIGN: This prospective investigation identified all women seen in the outpatient obstetric clinic with a history of physical abuse and matched each with the next 2 women seen without a history of physical abuse (case/control ratio, 1:2). RESULTS: Twenty-eight abused women were matched with 56 control subjects. The frequencies of preterm birth, mode of delivery, Apgar scores <7 at 5 minutes, umbilical artery pH <7.10 at birth, and unhappy or ambivalent feelings about the pregnancy were not statistically different between the 2 groups. Admission to the neonatal intensive care unit was more common among infants of the abused women (n = 4 [14.2%] vs n = 2 [3.6%]), despite heavier birth weights in the abused group (3501 +/- 581 g vs 3200 +/- 549 g; P =. 023), but this trend did not reach significance. CONCLUSION: A history of physical abuse did not result in adverse pregnancy outcomes, although neonatal intensive care unit admission was more likely.

Adult↗
PubMed2000

Determination of amniotic fluid volume in twin pregnancies: ultrasonographic evaluation versus operator estimation.

OBJECTIVE: We sought to determine the accuracy of amniotic fluid volume estimation (visually) in diamniotic twin pregnancy versus ultrasonography techniques. STUDY DESIGN: In this prospective study the volume of each sac in 23 sets of diamniotic twin pregnancies was subjectively and objectively estimated by a second-year obstetric resident, nurse sonographer, maternal-fetal medicine fellow, and maternal-fetal medicine staff. The actual volume was confirmed by amniocentesis and a dye-dilution technique. RESULTS: There was no difference in the total number of correct estimates of volume by level of operator experience (P =.98), ultrasonography technique (P =.87), or combined subjective versus objective correct estimates (P =.87). Identification of low volume was not different among the four evaluators (P =.48), but the percentage of correct estimates was poor (7%-29%). The 2-diameter pocket was a better predictor of oligohydramnios (57%) than the amniotic fluid index or the largest vertical pocket (12.5%; P =.002). CONCLUSION: The extremes of volume (low or high) are poorly identified by the subjective or objective assessment of volume.

Adult↗
PubMed2000

Validation of bioimpedance estimates of cardiac output in preeclampsia.

OBJECTIVE: We sought to evaluate the capacity of a new thoracic electric bioimpedance system to estimate cardiac output in patients with preeclampsia. STUDY DESIGN: We performed a prospective comparison of thoracic electric bioimpedance and echocardiographic M-mode volumetric estimates of cardiac output (in liters per minute) in preeclampsia. Subjects with preeclampsia who were chosen by means of strict criteria (either a systolic blood pressure >/=140 mm Hg or a diastolic blood pressure 90 mm Hg, or both, and proteinuria >/=300 mg in 24 hours or >/=+1 on repeat dipstick measurement 6 hours apart) were asked to participate in an institutional review board-approved study. Thoracic electric bioimpedance and echocardiography were performed with the patients in the left lateral recumbent position. Thoracic electric bioimpedance estimates were recorded at bedside; investigators were blinded to 3 simultaneously obtained echocardiographic M-mode estimates of cardiac output. Means were entered as the estimate for each patient. To satisfy the assumption of independent samples, only 1 estimate from each technique was used for each patient. Data were analyzed by Bland-Altman comparison. Hemodynamic and demographic variables are presented as mean +/- SD. RESULTS: Fifteen patients were enrolled. Mean maternal age was 25.9 +/- 4.8 years, and mean gestational age was 34.0 +/- 3.5 weeks. Mean arterial pressure was 112 +/- 14 mm Hg. There was good agreement of thoracic electric bioimpedance-derived and M-mode-derived cardiac output estimates. CONCLUSIONS: In patients with preeclampsia, thoracic electric bioimpedance estimates of cardiac output compare well with echocardiographic M-mode estimates.

Adult↗
PubMed2000

Sonographic measurements of fetal parts to predict pulmonary maturity among twins and singletons.

To determine if sonographic examination of fetus can be readily utilized to predict a mature lecithin/sphingomyelin (L/S) ratio among twins and singletons. Twins (n = 36) undergoing amniocentesis for assessment of pulmonary maturity were matched with singleton (1:2) for maternal demographics, gestational age (GA), and indications for procedure. At the time of amniocentesis, twins and singletons with mature L/S ratios differed significantly in mean GA (33.2 +/- 2.7 vs 34.5 +/- 4.6 wks, p = 0.01), biparietal diameter (BPD), abdominal circumference (AC), femur length (FL) and estimate of birth weight (EFW). Based on ten receiver operating characteristics curves constructed, the following diagnostic thresholds predicted a mature L/S ratio with a true positive rate of 100% among twins and singletons, respectively: 1) BPD $84 and $92 mm; 2) head circumference $315 and $320 mm; 3) AC $295 and $350 mm; or 4) FL $64 and $72 mm; or 5) EFW $2400 and $3200 g. Using any one of these five criteria correctly identified pulmonary maturity among 59% of twins and 28% of singletons (p = 0.001). Sonographic measurement of fetal parts or EFW may be a noninvasive method to predict a mature L/S ration among twins as well as singletons.

Adult↗
PubMed2000

Clinical vs. sonographic estimate of birth weight in term parturients. A randomized clinical trial.

OBJECTIVE: To determine the relative accuracy of clinical and sonographic birth weight estimation among term parturients (> or = 37 weeks) and to assess the performance of the two techniques in identifying newborns with weights of < 2,500 g vs. > or = 2,500 g or < 2,500 g vs. at least 4,000 g. STUDY DESIGN: The sample size for this randomized clinical trial was based on the assumption that 50% of clinical predictions are within 10% of birth weight. Thus, 700 parturients were necessary to show a difference of 10% with sonographic estimates (alpha = .05, beta = .02). Inclusion criteria were singletons with a reliable gestational age of > or = 37 weeks, admitted for delivery and with no known fetal anomalies. Physicians who were unaware of previous sonographic estimates obtained the estimates. Student t and chi 2 tests were used; relative risk (RR) and 95% confidence intervals (CIs) were calculated. Receiver-operating characteristic (ROC) curves were constructed to compare the two techniques' ability to differentiate between abnormal (birth weight < 2,500 g and > 4,000 g) and normal (2,500-3,999 g). P < .05 was considered significant. RESULTS: Over 30 months, 758 term parturients were recruited; of them, 391 had clinical estimates and 367, sonographic. The two groups were similar in gestational age, prepregnancy and intrapartum body mass index, station of the presenting part, actual birth weight and frequency of newborns with weights < 2,500 g or > or = 4,000 g. Predictions based on clinical examination were significantly more likely to be within 10% of actual weight (58%) than those derived from ultrasound examination (32%; P < .0001; RR, 1.65; 95% CI, 1.43, 1.69). The areas under the ROC curves indicated that both techniques had a similar ability to differentiate normally and abnormally grown fetuses (P > .05). CONCLUSION: Among term parturients, clinical estimates had significantly higher accuracy than ones derived sonographically.

Adult↗