Biomedical subjects

T H Strong

Publications and source records attributed to T H Strong.

At least 19 recordsLinked to original sources

PubMed1997

The umbilical pump: a contributor to twin-twin transfusion.

BACKGROUND: Umbilical vascular coiling may function as a rudimentary pump that facilitates venous return from the placenta. CASES: Three consecutive twin gestations with twin-twin transfusion syndrome were evaluated prospectively at delivery. The birth weights and umbilical coiling indices of donor and recipient twins were compared. The umbilical coiling index was determined by dividing the number of complete vascular coils in a given umbilical cord by the cord's length in centimeters. In each case, the recipient twin was larger at birth and had an umbilical coiling index value that was at least twice that of the corresponding donor twin. CONCLUSION: Differential umbilical vascular coiling densities among monochorionic twins may play a role in the pathogenesis of twin-twin transfusion syndrome.

Adult↗

PubMed1997

The effect of amnioinfusion on the duration of labor.

OBJECTIVE: To test the hypothesis that women receiving intrapartum amnioinfusion have more rapid labors than do controls. DATA SOURCES: Prospective clinical trials of amnioinfusion published in major American obstetric and gynecologic journals between 1985 and 1995, identified through a literature search using MEDLINE and manual index review, were examined. METHOD OF STUDY SELECTION: Eleven studies that presented data regarding the length of labor were identified. Each study was reviewed for the design, number of subjects enrolled, volume of amnioinfusate, birth weight, maternal parity, interval from amniorrhexis to delivery, and total length of labor. TABULATION, INTEGRATION AND RESULTS: Meta-analysis revealed no differences between amnioinfusion groups and controls with regard to length of labor or the interval between membrane rupture and delivery. CONCLUSION: Amnioinfusion has no effect on the duration of labor.

Amnion↗

PubMed1995

Amnioinfusion.

Amnioinfusion is a relatively new technique with a variety of uses. Its most common application is the treatment of variable decelerations in the fetal heart rate during labor. By artificially increasing the amniotic fluid volume, the umbilical cord is better protected from compression. Amnioinfusion can represent the difference between operative intervention and spontaneous vaginal delivery. This simple, inexpensive technique appears to pose little risk and warrants consideration for the properly selected patient.

Amnion↗

PubMed1995

Fetal acoustic stimulation as an adjunct to external cephalic version.

OBJECTIVE: To evaluate fetal acoustic stimulation (FAS) as an adjunct to external cephalic version in a midline fetal spine presentation. STUDY DESIGN: Breech presentation in a woman presenting for attempted version at 37 weeks' gestation with a fetus in a midline position and the spine anterior is difficult to convert to a vertex. An evaluation of FAS to assist in repositioning the fetus in a more spine lateral position was carried out. Patients with a failed version attempt and a midline breech presentation were enrolled in the study. The patient served as her own control. If that attempt failed, an electrolarynx device was used to produce a one- to three-second stimulus, and then another version attempt was made. RESULTS: Sixteen patients were enrolled. Prior to FAS, 0/16 fetuses were successfully turned. FAS altered the position in 100% of patients from spine midline to lateral. After FAS, 15/16 (94%) were successfully converted to vertex presentation. The one patient whose fetus failed to convert also failed her second version attempt (P < .0005). CONCLUSION: FAS may improve the opportunity for successful external cephalic version in the properly selected candidate with a fetus in a midline position with the spine anterior.

Acoustic Stimulation↗

PubMed1995

Trisomy among fetuses with noncoiled umbilical blood vessels.

OBJECTIVE: To examine the relationship between trisomy and neonates with noncoiled umbilical blood vessels. STUDY DESIGN: The incidence of and risk factors for trisomy were evaluated among 48 consecutive, live-born neonates with noncoiled umbilical vessels. RESULTS: Four cases (8.3%) of trisomy were identified. One case of mosaicism was also noted (2.1%). In no case was noncoiling of the umbilical vessels the only identifiable risk factor. The remaining 43 infants (89.6%) were phenotypically normal, although not all underwent karyotype analysis. CONCLUSION: Noncoiled umbilical blood vessels alone do not appear to represent an independent risk factor for trisomy. Rather, identification of noncoiled blood vessels should prompt a thorough search for other abnormalities.

Chromosomes, Human, 13-15↗

PubMed1994

Antepartum diagnosis of noncoiled umbilical cords.

OBJECTIVE: The null hypothesis is that fetuses with noncoiled umbilical cords diagnosed in the antepartum period will have outcomes no different from those with normally coiled cords. STUDY DESIGN: We prospectively gathered data from Jan. 1 through May 18, 1992, from all fetuses undergoing routine ultrasonographic evaluation. The outcomes of fetuses noted to have noncoiled umbilical cords were compared with those of a control group of fetuses with normally coiled cords. The control group consisted of those subjects undergoing ultrasonography during the study period who were ultimately transferred to our perinatal practice for the remainder of the pregnancy (i.e., the highest-risk patients). Two outcome parameters were selected for comparison: fetal anomalies and fetal death. RESULTS: Six hundred eighty-seven consecutive ultrasonographic examinations were performed. Twenty-five subjects (3.7%) had noncoiled umbilical cords identified ultrasonographically (mean gestational age at diagnosis 20.3 +/- 3.5 [SD] weeks). The control group had 197 subjects. The combined incidence of fetal anomalies or death in the noncoiled group (16%) was significantly greater (p < or = 0.05, relative risk 4.6 [95% confidence interval 1.41 to 14.15]) than that of the control group (3.5%). The noncoiled group had two fetal deaths (8%), whereas two deaths (1%) occurred among controls (p < or = 0.05, relative risk 8 [95% confidence interval 1.16 to 50]). Two (8%) fetal anomalies (anencephaly, prune-belly syndrome) occurred in the noncoiled group, whereas the controls (n = 197) had five fetuses (2.5%) with anomalies (not significant). CONCLUSION: The antepartum identification of noncoiled umbilical cords appears to be a risk factor for suboptimal pregnancy outcome.

Case-Control Studies↗

PubMed1994

The umbilical coiling index.

OBJECTIVE: Our purpose was to objectively quantitate umbilical vascular coiling. STUDY DESIGN: In this prospective study the umbilical cords and delivery records of 100 consecutive liveborn neonates were studied. The umbilical coiling index of each cord was determined by dividing the total number of complete umbilical vascular coils by the umbilical cord length (in centimeters). The obstetric history, intrapartum fetal heart rate tracing, and pregnancy outcome of each fetus were evaluated without knowledge of the umbilical coiling index. RESULTS: The mean umbilical coiling index was 0.21 +/- 0.07 (SD) coils per centimeter. The 100 values were normally distributed. Among those whose umbilical coiling index values fell < or = 10th percentile, there was a significantly greater incidence of karyotypic abnormalities (p = 0.04), meconium staining (p = 0.03), and operative intervention for fetal distress (p = 0.03). There was a significantly greater incidence of moderate or severe variable fetal heart rate decelerations for those whose umbilical coiling index value was either < or = 10th percentile (0.1 coils per centimeter) or > 90th percentile (0.3 coils per centimeter) (p = 0.03). CONCLUSION: The umbilical coiling index may have utility for objectively describing the degree of umbilical vascular coiling.

Chi-Square Distribution↗

PubMed1993

Experience with early postcesarean hospital dismissal.

OBJECTIVE: Our purpose was to assess early postcesarean hospital dismissal. STUDY DESIGN: A retrospective review was performed of all women receiving cesarean delivery over the most recent 6-month period in a busy private obstetrics practice that routinely dismisses its cesarean patients on postoperative day 2. Women who meet certain criteria (uncomplicated pregnancy, Pfannenstiel incision, uncomplicated surgery, no febrile morbidity, stable vital signs, ability to ambulate without assistance, ability to urinate without assistance, and auscultation of active bowel sounds) on postoperative day 2 are dismissed from the hospital. Outcomes were compared against women undergoing cesarean delivery during the 6 months immediately before the institution of the early dismissal program. RESULTS: Among 147 women undergoing cesarean deliveries, 117 (80%) met the criteria for early dismissal. When compared with controls (n = 93), there was no difference in outcomes. No one in the early dismissal group required readmission to the hospital. CONCLUSION: Among properly selected candidates, early postcesarean hospital admission is a reasonable option.

Adult↗

PubMed1993

Reversal of oligohydramnios with subtotal immersion: a report of five cases.

OBJECTIVE: The purpose was to summarize five cases where subtotal immersion was associated with an increase in the amniotic fluid index. STUDY DESIGN: Five women with oligohydramnios, as defined by an amniotic fluid index < 8 cm, who underwent subtotal (shoulder-deep) immersion therapy are described. RESULTS: The mean pretreatment amniotic fluid index was 4.9 +/- 3 cm. After immersion therapy was instituted, the amniotic fluid index increased an average of 6 +/- 2.2 cm. In three subjects whose immersion therapy was discontinued, the amniotic fluid index fell an average of 4.7 cm. CONCLUSION: Subtotal immersion may help reverse oligohydramnios stemming from uteroplacental insufficiency.

Adult↗

PubMed1993

Intrapartum auscultation of the fetal heart rate.

A fetal heart rate recording containing a variable deceleration was played for 120 physicians and nurses. Although mean estimates for baseline and nadir of the fetal heart rate and duration of the deceleration were not significantly different from the actual values, individual estimates of the three parameters were widely distributed. Adjunctive techniques for intrapartum fetal heart rate auscultation are recommended.

Auscultation↗

PubMed1993

Intrapartum amnioinfusion in twin gestation. A preliminary report of three cases.

Amnioinfusion is an intrapartum technique that is not usually attempted in twin gestations. This report describes infusion of normal saline into the amniotic sacs of three twin gestations with oligohydramnios. All the twins were safely delivered vaginally. No untoward effects were noted. Ultrasound is advised following amnioinfusion to assess the increase in the amniotic fluid volume.

Adult↗

PubMed1993

Non-coiled umbilical blood vessels: a new marker for the fetus at risk.

OBJECTIVE: To evaluate the perinatal outcomes of fetuses born with non-coiled umbilical blood vessels. METHODS: We performed a prospective study of umbilical cords that lacked umbilical vascular coiling. The perinatal outcomes were compared with those of neonates born with coiled umbilical blood vessels. RESULTS: Thirty-eight (4.3%) of 894 fetuses were born with non-coiled umbilical vessels. The non-coiled group had a significantly increased incidence of intrauterine death (P = .009), preterm delivery (P = .006), repetitive intrapartum fetal heart rate decelerations (P < .00005), operative delivery for fetal distress (P < .00005), meconium staining (P = .007), and anatomical-karyotypic abnormalities (P = .03). CONCLUSIONS: Our findings suggest that the fetus with non-coiled (ie, straight) umbilical blood vessels is at increased risk for perinatal morbidity and mortality. Non-coiled umbilical vessels may represent a pathologic developmental process that places the fetus at risk. Moreover, absence of the normal coiled umbilical configuration may result in a cord that is structurally less able to resist external compressive forces.

Female↗

PubMed1992

Amniotic fluid turbidity: a useful adjunct for assessing fetal pulmonary maturity status.

A rapid, very simple technique for establishing fetal pulmonary maturity status is presented. Among 100 receiving amniocenteses, aspiration of turbid amniotic fluid that would not permit the reading of newsprint through it was associated with a lecithin/sphingomyelin (LS) ratio of greater than or equal to 2.0, or the presence of phosphatidyl glycerol (PG) in 97% (specificity 98%, positive predictive value 97%). The authors conclude that when turbid fluid is aspirated, delay until LS and PG results are known may not be necessary.

Amniocentesis↗

PubMed1992

The fetal recoil test.

A reassuring fetal recoil test has positive and negative predictive values of 98% and 8%, respectively, for a reactive nonstress test (sensitivity 89%, specificity 33%). Among 21 of 30 subjects in whom recoil was present immediately before delivery, none had umbilical arterial pH values < or = 7.20 versus 5 of 9 (56%) with nonreassuring recoil (p = 0.005). We concluded that a reassuring fetal recoil test is a reliable marker for fetal well-being.

Acoustic Stimulation↗

PubMed1992

Amnioinfusion does not affect the length of labor.

OBJECTIVE: Our objective was to determine whether amnioinfusion prolongs or shortens the length of labor in patients who have an accepted indication for amnioinfusion. STUDY DESIGN: We performed a retrospective post hoc analysis of the length of labor of 437 patients who were enrolled in three prospective, randomized, controlled studies of amnioinfusion. RESULTS: The length of labor was not significantly different for patients who received amnioinfusion compared with those who did not receive amnioinfusion (control group). Among the subgroup with vaginal delivery, the duration of labor after amnioinfusion did not differ from the duration of labor among the controls. The length of labor (mean +/- SD, in hours) for the amnioinfusion group was 9.3 +/- 6.3 versus 10.6 +/- 6.9 for the control groups (p not significant). Among the subgroup that required cesarean delivery, the duration of labor after amnioinfusion did not differ from the duration of labor among the controls. The length of labor (mean +/- SD, in hours) in patients requiring cesarean delivery in the amnioinfusion group was 11.1 +/- 6.3 versus 13.0 +/- 7.5 for the control group (p not significant). CONCLUSION: Amnioinfusion does not prolong or shorten the length of labor among patients who have an accepted indication for the treatment.

Adult↗

PubMed1992

Significance of intrapartum amniotic fluid volume in the presence of nuchal cords.

Among 70 women delivering infants with nuchal cords, there was a significantly higher incidence of meconium passage and severe variable fetal heart rate decelerations/fetal bradycardia in those who had intrapartum oligohydramnios, as defined by an amniotic fluid index less than or equal to 5.0 cm. Oligohydramnios in the presence of nuchal cord entanglement might represent an increased risk of ominous intrapartum fetal heart rate patterns.

Amniotic Fluid↗

PubMed1992

Amnioinfusion among women attempting vaginal birth after cesarean delivery.

Eighteen of 901 women (2%) attempting vaginal birth after cesarean delivery (VBAC) received amnioinfusion. No untoward effects occurred in the subjects or their fetuses. We conclude that, though amnioinfusion in the setting of a VBAC attempt is needed only infrequently, it appears to be a reasonable intrapartum management option. The usual safeguards for a VBAC attempt should be followed.

Amnion↗

PubMed1992

Amnioinfusion with preterm, premature rupture of membranes.

Excluding labor, the greatest risks to the fetus from preterm PROM are umbilical cord accidents and infection. Heretofore, the clinical options for the PROM patient have been limited. With the advent and refinement of amnioinfusion, the utility of expectant management may be greatly increased. Through the use of amnioinfusion or its permutations, a number of diagnostic and therapeutic procedures previously unavailable to the PROM patient may become routine, including amniotic fluid volume expansion and direct in utero prophylaxis/treatment of amnionitis.

Amnion↗