Using restorations borne totally by anterior implants to preserve the edentulous mandible.

BACKGROUND: This study quantifies the changes in bone height of the posterior area of the edentulous mandible when the load of complete dentures is borne entirely by anteriorly placed osseointegrated implants. METHODS: Thirty-three patients, of whom there were radiographs from the beginning of implant loading and from a follow-up visit at least three years later (a mean of 6.6 years later), were included in the study. Working with panoramic radiographs, the authors took height measurements in the premolar area (15 millimeters distal to the most distal implants). A valid correction factor was available because implants of known length were proximal to the area being evaluated. RESULTS: The authors calculated descriptive statistics using means, standard deviations, medians and proportions as appropriate. A P-value of less than .05 was considered significant. Of the 33 subjects, most showed increases in bone height--29 (87.9 percent) on the right side and 28 (84.9 percent) on the left side. The mean change in all subjects was +1.0 mm (range -0.8 to +3.3 mm). A comparison of mandibular height at implant placement vs. follow-up showed a statistically significant increase bilaterally (P < .001). CONCLUSIONS: This study demonstrates that dentures for edentulous mandibles that are borne totally by implants in the anterior area conserve or enhance the bone of the posterior portion of the mandible. An important future study should test the effect of implant-assisted restorations for the edentulous mandible that load the posterior ridge (a bar clasp, for example). CLINICAL IMPLICATIONS: One of the considerations in planning treatment for the edentulous mandible should be the preserving effect of totally implant-borne restorations vs. the continued resorption of the body of the mandible with conventional dentures.

Evaluation of the nonreactive positive contraction stress test prior to 32 weeks: the role of the biophysical profile.

A nonreactive positive contraction stress test in a pregnancy near term is an indication for delivery. Such nonreassuring antepartum testing combined with severe prematurity presents a management dilemma. Ideally, prolongation of selected pregnancies would allow time for corticosteroid therapy and fetal maturation. Prior to 32 weeks' gestation, we utilized the biophysical profile to select patients for continued intrauterine management as an alternative to immediate delivery. Continued surveillance was undertaken if the fetus had a reassuring biophysical profile score; immediate delivery by cesarean section was undertaken if the biophysical profile score was nonreassuring. This approach allowed a mean gain of 13 days in utero for the continued surveillance group. There was no evidence of further fetal compromise in this group based on umbilical cord pH or 5-minute Apgar scores. These data suggest that the biophysical profile can be safely used to prolong selected preterm pregnancies with nonreactive positive contraction stress tests without adversely affecting the initial neonatal metabolic status.

The value of a negative antepartum test: contraction stress test and modified biophysical profile.

OBJECTIVE: To examine the outcome of pregnancies in high-risk patients whose last antepartum fetal assessment was a negative contraction stress test (CST) or a negative modified biophysical profile. METHODS: Twenty-nine hundred ninety-four women who received modified biophysical profiles were compared with 2450 who had CSTs during the preceding 3 years. Pregnancy outcomes were evaluated in patients whose last test was negative. RESULTS: Seventeen hundred fifty-three patients had negative modified biophysical profiles as the last test before delivery, and 1337 had negative CSTs as the last test before delivery. Adverse perinatal outcomes included perinatal death or death before nursery discharge, cesarean delivery for fetal distress within the first 2 hours of labor, 5-minute Apgar score less than 7, neonatal seizures, or grade III or grade IV central nervous system hemorrhage. Adverse outcomes occurred in 90 patients (5.1%) whose last test before delivery was a negative modified biophysical profile and in 93 patients (7.0%) whose last test was a negative CST (P = .04, odds ratio 1.38, 95% confidence interval 1.01-1.88). Overall, there were 11 perinatal deaths, nine of which resulted from lethal congenital abnormalities. CONCLUSIONS: In this population, the frequency of adverse perinatal outcome following a negative modified biophysical profile was no greater than that following a negative CST. Further, the incidence of potentially preventable perinatal death following a negative modified biophysical profile or CST was less than one per 1000 tested high-risk pregnancies.

Antepartum fetal surveillance in patients with diabetes: when to start?

OBJECTIVE: Although antepartum fetal well-being testing is an accepted practice in the management of diabetic patients, there are few data suggesting when to start. Our goal was to examine when testing should be started in the pregnant diabetic woman. STUDY DESIGN: Antepartum test results and patient histories were prospectively collected on all diabetic pregnancies from January 1981 through December 1991. The data were retrospectively analyzed for when fetal compromise became evident. Fetal compromise was defined as stillbirth, first positive contraction stress test, or intervention because of an abnormal antepartum fetal test result. RESULTS: Six hundred fourteen patients were enrolled in the study. There were three stillbirths, 45 (7.4%) patients had at least one positive contraction stress test, and 71 (11.6%) patients were delivered because of an abnormal fetal test result. Those with early compromise (< or = 34 weeks' gestation) could not be identified solely by diabetic class. The majority of patients (73%) requiring early intervention because of an abnormal test were class R or F diabetic patients with a growth-retarded fetus or were patients who had a concomitant diagnosis of hypertension. CONCLUSIONS: Class R or F diabetic patients or diabetic patients with a growth-retarded fetus or a concomitant diagnosis of hypertension may require testing to be started as early as 26 weeks' gestation. Otherwise, testing may be safely delayed until 32 weeks' gestation.

Measured resting energy expenditure in children.

The majority of equations used to predict values for basal metabolic rates (BMRs) are the result of indirect calorimetry measurements performed in the 1930s and 1950s. To assess the reliability of these equations in predicting the resting energy expenditure (REE) of the children in our community, indirect calorimetry was performed on 92 male and 107 female healthy children 2-3 h postprandial. Each individual was measured for a duration of 15-20 min. The data for analysis were obtained from 5-15 min steady-state periods. Subjects ranged in age from 5 to 16 years. The results were compared with BMRs calculated from the Harris-Benedict equation (Harris J, Benedict F. A biometric study of basal metabolism in man. Washington, DC: Carnegie Institute of Washington, publication no. 279, 1919.), the Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU) equations, and the equations proposed by Schofield for use by the 1985 FAO/WHO/UNU Nutrition Committee. The values predicted by the FAO/WHO/UNU and Schofield equations were consistent with the measured resting values for all the children in the study population. Ninety-two children weighed between 90-110% of their ideal body weight. When the measured REE and estimated BMR were compared by gender and age in these children, the Schofield equations provided the best estimates. Ninety-four of the study subjects weighed > 110% of their ideal body weight. The predicted estimates by all equations were consistent with the measured values in this subgroup of the population. We conclude that the FAO/WHO/UNU and Schofield equations are reliable estimates of metabolic rate in healthy children when measurement of REE is not possible.

How frequently should the amniotic fluid index be repeated?

OBJECTIVE: Our objective was to determine the most appropriate interval for assessing amniotic fluid volume with amniotic fluid index. STUDY DESIGN: In a retrospective analysis amniotic fluid indexes performed every 3 to 4 days in antepartum testing patients were compared with their follow-up values. Of 10,742 amniotic fluid indexes there were 7393 with follow-up values within 4 days. The results were stratified by current amniotic fluid index, gestational age, and concurrent nonstress test results. The groups were compared with chi 2 analysis. RESULTS: Patients with normal amniotic fluid index (> or = 8 cm) had a 0.54% chance of oligohydramnios developing in the next 4 days. Those patients with low normal amniotic fluid indexes (5 to 8 cm) had a 5% chance of oligohydramnios developing within the next 4 days, and patients with low amniotic fluid indexes (< or = 5 cm) had a 59% chance of persistent oligohydramnios 4 days after the index examination. Subdividing by gestational age demonstrated that patients > or = 41 weeks' gestation had a 2.6% chance of oligohydramnios developing within 4 days if current amniotic fluid index was between 8 and 15 cm. Results of concurrent fetal heart rate findings did not appear to change the risk for development of oligohydramnios. CONCLUSION: In patients < 41 weeks' gestation with normal amniotic fluid indexes, a repeat amniotic fluid index is not necessary for 7 days.

Rate of recurrence of preterm premature rupture of membranes in consecutive pregnancies.

The reported incidence of preterm premature rupture of membranes ranges between 1% and 2% of all pregnancies. The rate of recurrence is poorly defined. The goal of this study was to establish the frequency of recurrence in a high-risk referral practice. Over a 5-year period we identified 121 patients with preterm premature rupture of membranes who had a minimum of two consecutive pregnancies under our care, resulting in a total of 255 pregnancies for analysis. Recurrent preterm premature rupture of membranes occurred in 39 of 121 patients, for a rate of 32.2% (95% confidence interval, 23.9 +/- 40.5). We were unable to demonstrate an association between the estimated gestational age at the time of rupture in the index pregnancy, latency period, interval between pregnancies, and the probability of repeat preterm premature rupture of membranes in the next pregnancy. We conclude that patients with preterm premature rupture of membranes should be counseled regarding the significant risk of recurrence and need to have close follow-up in their subsequent pregnancies.

Antepartum testing in the hypertensive patient: when to begin.

Antepartum testing has been recommended for patients whose pregnancies are complicated by hypertension. Although this is considered accepted practice, there are little data available to help the clinician know when to start testing. To help answer this question in patients with chronic hypertension and nonproteinuric pregnancy-induced hypertension, we reviewed the results of all antepartum tests between 1976 and 1987 in patients with these diagnoses. The primary mode of surveillance in the majority of our patients was the contraction stress test. We determined when patients first had positive contraction stress test results and when intervention occurred because of an abnormal antepartum test result. There were a total of 917 patients tested with these diagnoses. Fifty-three (5.8%) of these patients had at least one positive contraction stress test result. Twenty-two patients were delivered of infants before 35 weeks' gestation because of abnormal antepartum test results. Those with early intervention (less than 35 weeks' gestation) could not be differentiated from those with later intervention (greater than or equal to 35 weeks' gestation) by maternal age, diastolic blood pressure, or systolic blood pressure at the time of testing. The majority of patients who were delivered of infants before 35 weeks' gestation had a concomitant diagnosis of systemic lupus erythematosus, intrauterine growth retardation, diabetes mellitus, or superimposed preeclampsia. On the basis of when compromise was evident, patients with these diagnoses may require testing to be started as early as the fetus is considered viable. However, in those without these diagnoses, the clinician may delay the beginning of testing until 33 weeks' gestation without significant risk of pregnancy loss before testing.

Pulmonary injury associated with antepartum pyelonephritis: can patients at risk be identified?

The development of pulmonary injury in cases of antepartum pyelonephritis is rare but serious. To date, factors that might identify patients at risk have not been determined. We compared 11 patients with pyelonephritis and pulmonary injury with 119 patients with pyelonephritis only. Pulmonary injury was more likely to occur in the more severe cases; however, the presence of a maternal heart rate greater than 110 beats/min and a fever to 103 degrees F 12 to 24 hours before the occurrence of respiratory symptoms in a gestation greater than 20 weeks was highly predictive of pulmonary injury. The most significant predictive factors associated with pulmonary injury were elements of treatment such as fluid overload, use of tocolytic agents, and, to a lesser extent, choice of antibiotic. Therefore, if tocolytic agents are considered at all in the management of acute pyelonephritis in pregnancy, they should be used only in patients with documented cervical change. In addition, urinary output should be monitored very closely. These data also may suggest a cause of the pulmonary edema that is occasionally seen in the management of premature labor with the use of tocolytic agents and fluids in the presence of a possible occult infection.

Reliability of ultrasonographic formulary in the prediction of fetal weight and survival of very-low-birth-weight infants.

Antenatal management of very-low-birth-weight infants often requires difficult obstetric decisions. This study was designed to evaluate the predictive value for neonatal outcome of antenatally acquired estimation of gestational age and ultrasonographically estimated fetal weight or a combination of both in very-low-birth-weight infants. Sixty-seven fetuses with estimated gestational ages between 22 0/7 and 28 6/7 weeks were studied ultrasonographically to estimate fetal weight. A comparison of accuracy of estimated fetal weight with actual birth weight showed good correlation (r = 0.93). Neonatal outcome of these infants was analyzed by estimated gestational age and estimated fetal weight. Estimated gestational age and estimated fetal weight greater than 25 weeks and greater than 750 gm were associated with 50% survival, respectively. However, when both of these conditions were met survival reached 85%. This information may be useful to guide antepartum management decisions in this very-low-birth-weight group.

Gram stain results from amniocentesis in patients with preterm premature rupture of membranes--comparison of maternal and fetal characteristics.

A total of 108 patients with preterm premature rupture of membranes who had undergone amniocentesis were retrospectively analyzed. Seventy-seven patients had negative amniotic fluid Gram stains and were managed expectantly. Thirty-one patients had positive amniotic fluid Gram stains confirmed by subsequent cultures and were delivered of infants on that basis. A univariate comparison of various parameters revealed significant differences in maternal temperature, pulse, and white blood cell count. Patients with positive Gram stains had lower mean gestational age, higher baseline fetal heart rate, and nonreactive fetal heart rate tracings. On the basis of a multivariate stepwise discriminate analysis, fetal heart rate greater than 150 beats/min or nonreactive nonstress test were the best predictors of the Gram stain findings, with a sensitivity of 71%, specificity of 76%, and negative predictive value of 87%. These data suggest that in patients with preterm premature rupture of membranes and fetal tachycardia or nonreactive nonstress test, amniocentesis should be performed in the initial evaluation.

Quantitation of uterine activity preceding preterm, term, and postterm labor.

To assess uterine activity before labor in patients delivering preterm, at term, and postterm, the maximum spontaneous contraction frequency per 10-minute window during the initial portion of antepartum fetal heart rate monitoring was analyzed. Patients with multiple gestation, third trimester bleeding, polyhydramnios, or premature rupture of membranes and those already diagnosed with preterm labor were eliminated from the study. Of the 2446 remaining patients (7247 antepartum fetal heart rate tests) who went into spontaneous labor, 237 did so before 37 completed weeks of gestation, 1077 entered labor at term (38 to 42 completed weeks), and 1132 did so after 42 weeks. There was a significant increase in maximum uterine activity per 10-minute window from 30 to 44 weeks of gestation (average 4.7% per week; r = 0.97, p less than 0.0001). When compared with patients delivering spontaneously at term, average maximum uterine activity per 10-minute window was greatest in the preterm labor group (p less than 0.05) and least in the postterm labor group (p less than 0.05). These differences were present for several weeks preceding the onset of spontaneous labor. All three groups showed a surge of uterine activity during the 3 days before the onset of spontaneous labor.

The breast-stimulated contraction stress test.

A method was developed for using breast stimulation to induce uterine contractions for a contraction stress test (BSCST). Six hundred fifty-seven patients made 1,484 attempts with the BSCST and were successful in 1,072 trials (72.2%). A lower success rate was observed only in gestations less than or equal to 34 weeks. The distribution of test results (positive, negative, equivocal) by BSCST was unchanged from that of contraction stress tests performed with exogenous oxytocin (oxytocin challenge test [OCT]). The incidence of false-positive tests was similar to that in previous reports. The corrected perinatal mortality rate for the study population was 1.5 per 1,000 births. The time required for an adequate uterine response was 23.8 +/- 15.2 minutes, with 87.5% of patients responding in less than 30 minutes. The BSCST appears to be a reasonable alternative to the OCT, with elimination of the intravenous line and oxytocin administration and with a shorter testing time.

Prophylactic intrapartum amnioinfusion in patients with preterm premature rupture of membranes.

Patients with preterm premature rupture of the membranes are at increased risk to develop intrapartum variable decelerations and fetal distress. Short-term saline solution amnioinfusion may be of benefit in the treatment of variable or prolonged decelerations once they appear. In an effort to assess the benefit of prophylactic amnioinfusion, patients with preterm premature rupture of the membranes were studied during a 1-year period in a prospective randomized manner. Patients receiving prophylactic amnioinfusion had significantly decreased incidence and severity of variable decelerations in the first stage of labor (p less than 0.005). In the second stage of labor, the incidence of severe (p less than 0.005) and total (p less than 0.001) decelerations was also decreased in the treatment group. The umbilical arterial pH at delivery was significantly lower (p less than 0.001) as was the umbilical venous pH (p less than 0.005) in the newborn infants of control patients compared with those of patients receiving amnioinfusion. This suggests that prophylactic intrapartum amnioinfusion is of significant benefit in reducing the incidence of variable decelerations and improving the metabolic state in newborn infants born to women with preterm premature rupture of the membranes.

Advanced maternal age: the mature gravida.

A 3-year study of women ages 35 years and older who were delivered at Women's Hospital of Long Beach from January 1, 1981, to December 31, 1983, was performed to study the risks involved with advanced maternal age. The study group included 1023 women who were 35 years and older, and they were divided into parous and nulliparous groups. A control group consisting of 5343 women aged 20 to 25 years was used for comparison. Each group was analyzed for the following parameters: pregnancy complications, labor complications, delivery factors, and neonatal outcome. The results show very few statistical differences in the factors analyzed. On the basis of this 3-year study it appears that pregnancies in women of advanced maternal age in the 1980s who are delivered in a modern tertiary care center may be of no higher risk for adverse outcome than pregnancies in younger parturients.

The significance of a previous stillbirth.

Among 7052 patients studied between 1976 and 1982 in a collaborative project on antepartum fetal heart rate monitoring, 337 patients had a previous stillbirth as a reason for testing. Overall a previous stillbirth history significantly increased the risk of having a positive result on a contraction stress test, primarily among hypertensive patients. Patients with a previous stillbirth also had a significantly higher incidence of respiratory distress syndrome in their neonates attributable to premature intervention for maternal indications (primarily among hypertensive women and patients with clinical intrauterine growth retardation). Low Apgar scores were found to be significantly increased in diabetics with previous stillbirths primarily due to neonates with congenital malformations. Premature intervention by labor induction or cesarean section was more common among patients with a previous stillbirth for both maternal indications and abnormal antepartum fetal heart rate studies. Previous stillbirth would appear therefore to be a significant risk factor primarily when associated with a diagnosis of hypertension or clinical intrauterine growth retardation.

Nonreactive contraction stress test: clinical significance.

Between September 1, 1976, and December 31, 1980, there were 4629 contraction stress tests performed at Women's Hospital, Memorial Hospital Medical Center of Long Beach, California. Forty-four (1.0%) of these tests were completely nonreactive. Eight of 3367 negative contraction stress tests (0.2%), 19 of 1124 equivocal contraction stress tests (1.7%), and 17 of 63 positive contraction stress tests (27.0%) were nonreactive. When compared with patients who had reactive tests, only those patients with a nonreactive, positive contraction stress test had significantly increased perinatal mortality and infants with low Apgar scores. Twelve percent of patients with nonreactive contraction stress tests had fetuses with congenital anomalies. Eighteen percent of patients with nonreactive tests were taking phenobarbital or other sedative drugs, and 45% of patients with nonreactive tests were hypertensive. Excluding anomalous fetuses, there were no perinatal deaths and no Apgar scores below 7 at five minutes in patients with nonreactive negative, or nonreactive equivocal, contraction stress tests as the worst test result. The hypothesis that the completely nonreactive negative contraction stress test as the worst test result is associated with increased perinatal mortality and morbidity could not be substantiated. Standardization of criteria for reactivity and interpretation of the contraction stress test using the entire testing period is desirable.

The risks of amniocentesis in the management of premature rupture of the membranes.

Amniocentesis has proved to be a useful tool in the management of preterm gestation with premature rupture of the membranes. Concern has been expressed, however, regarding possible risks of amniocentesis to mother or fetus. A retrospective review was made of 137 patients referred to us because of premature rupture of the membranes between 28 and 34 weeks of gestation. Amniocentesis was successfully performed in 91 patients. A statistical analysis of the time interval from amniocentesis to labor failed to show any evidence that amniocentesis might induce labor. In addition, no maternal or neonatal morbidity could be attributed to amniocentesis.

Short-term variability assessment from abdominal electrocardiogram during the antepartum period.

One hundred eighty-eight patients undergoing antepartum fetal heart rate (FHR) monitoring with abdominal fetal electrocardiogram (ECG) technique were studied with respect to FHR variability derived from fetal R-R intervals. Statistically significant positive correlation existed between various measures of FHR variability and accelerations per minute (p less than 0.01). Insufficient numbers of positive contraction stress tests (CST) were available to establish a relationship with variability, although a trend existed between positive CST and low variability. Postdate pregnancies had significantly higher variability than nonpostdate pregnancies (p less than .05). This mathematical analysis establishes statistical significance between short-term variability and accelerations per minute and application of this technique for assessment of true variability in antepartum testing is possible.