Outcomes of extremely low-birth-weight infants between 500 and 750 g.

OBJECTIVE: The purpose of this study was to describe morbidity, mortality, and developmental outcomes among extremely low-birth-weight infants (500-750 g). STUDY DESIGN: This retrospective cohort study included 167 live-born infants born at Long Beach Memorial Medical Center between January 1990 and December 1995. RESULTS: Mortality rates were 86% among infants <600 g and 44% among those > or =600 g, and the rate decreased with increasing gestational age. The absence of chorioamnionitis (P =.01) and the use of antepartum corticosteroids (P <.0001) or neonatal surfactant (P =.0001) were associated with survival. Sixty-four percent of studied infants had respiratory distress syndrome, and 17% had grade III or IV intraventricular hemorrhage. Among the 63 survivors 57% were tested at 30 months of corrected age with the Bayley Scales of Infant Development. Mild or significant delays were seen on the mental development index in 68% of these cases and on the psychomotor development index in 58% of cases. CONCLUSION: Morbidity and mortality rates and the rate of developmental delay among infants with birth weights between 500 and 750 g were significant.

Neonatal outcome when delivery follows a borderline immature lecithin to sphingomyelin ratio.

OBJECTIVE: Occasionally, clinicians are presented with a complicated preterm pregnancy where fetal pulmonary maturity testing might be used to help guide management decisions. However, should delivery be allowed if the lecithin to sphingomyelin ratio (L/S ratio) is not quite mature? The incidence of newborn complications after delivery with L/S ratio values of 1.8 and 1.9 is unknown. The purpose of this study was to evaluate the neonatal morbidity and mortality in patients that delivered with these borderline immature results. STUDY DESIGN: All patients who underwent fetal pulmonary maturity testing were prospectively recorded in log books. An L/S ratio of > or = 2.0 was considered mature. Patients with an L/S ratio of 1.8 or 1.9 were considered "borderline immature." These borderline immature cases were evaluated for the gestational age at amniocentesis, the gestational age at delivery, and neonatal outcome. RESULTS: During the 9-year study period, L/S ratio testing was performed on 2038 patients. Of these, 162 preterm patients (7.9%) had an L/S ratio of 1.8 or 1.9 A total of 63 of these 162 patients delivered < 72 hours after the amniocentesis and met study criteria. The pregnancies ranged from 27 to 36 weeks' gestation. There was a 13% incidence (95% confidence interval (CI) of 4% to 30%) of major neonatal morbidity and a 3% incidence (95% CI of 0% to 17%) of neonatal mortality in the 30 pregnancies with an L/S ratio of 1.8. The incidence of major neonatal morbidity was only 3% (95% CI of 0% to 15%) in the 33 patients with an L/S ratio of 1.9, with no cases of mortality (95% CI of 0% to 9%). CONCLUSION: Based on 95% CIs, the data of this study reveal that the maximum risk for major morbidity is < or = 15%, with a mortality risk of < 10% in a preterm newborn delivered with a 1.9 L/S ratio value. The maximum risk is 30% for major morbidity and 17% for mortality in preterm newborns delivered with a 1.8 L/S ratio. This information may help in the decision-making process of whether to deliver or to observe when faced with a borderline immature L/S ratio result in a complicated preterm pregnancy.

Incidence of intrapartum maternal risk factors for identifying neonates at risk for early-onset group B streptococcal sepsis: A prospective study.

OBJECTIVE: In mid-1996 and early 1997, the Centers for Disease Control and Prevention, The American College of Obstetricians and Gynecologists, and the American Academy of Pediatrics all published guidelines outlining 2 potential strategies for the purpose of preventing neonatal sepsis caused by group B Streptococcus. One of these approaches involves treating pregnant women intrapartum with antibiotics if any of the following risk factors develop: delivery at <37 weeks' gestation, membrane rupture for >/=18 hours' duration, or temperature during labor of >/=38 degrees C. However, to date there have been no population-based studies that have ascertained the percentage of pregnant women eligible to receive intrapartum antibiotic chemoprophylaxis if these risk factors were used. Our objective was to perform a large patient-based study at >1 institution evaluating all deliveries for the presence of maternal risk factors by using the definitions of the current guidelines. STUDY DESIGN: A prospective cohort study was initiated in 1995 at 3 private community hospitals and 1 private referral center. The study population was composed of 5410 consecutively delivered patients from the 4 different hospitals. Every pregnancy was analyzed for gestational age at delivery, duration of membrane rupture, temperature during labor, and use of intrapartum antibiotic chemoprophylaxis. RESULTS: Of the 5410 patients, a total of 455 (8. 4%) were delivered of their neonates before 37 weeks' gestation, 421 (7.8%) had rupture of membranes for at least 18 hours' duration, and 378 (7.0%) had an intrapartum temperature of >/=38 degrees C. Overall, 1071 pregnant women (19.8% of the population studied) had >/=1 of the defined risk factors. CONCLUSIONS: These data suggest that, if the current risk factor strategy is used, 19.8% of the delivering population would potentially be candidates for intrapartum antibiotic chemoprophylaxis.

Epidural analgesia compared with combined spinal-epidural analgesia during labor in nulliparous women.

BACKGROUND: Among nulliparous women, there appears to be an association between the use of epidural analgesia during labor and an increased risk of dystocia. We tested the hypothesis that combined spinal-epidural analgesia, which permits ambulation during labor, is associated with a lower incidence of dystocia than continuous lumbar epidural analgesia. METHODS: Between July 1995 and September 1996, we randomly assigned 761 nulliparous women in spontaneous labor at term who requested epidural analgesia to receive either continuous lumbar epidural analgesia or a combination of spinal and epidural analgesia. Among the women who received combined spinal-epidural analgesia, some were discouraged from walking and others were encouraged to walk. Maternal and neonatal outcomes, the incidence of dystocia necessitating cesarean section, and measures of patients' satisfaction were compared in the two groups. RESULTS: There were no significant differences in the overall rate of cesarean section, the incidence of dystocia, the frequency of maternal or fetal complications, the patients' or nursing staff's assessment of the adequacy of analgesia, or the degree of overall satisfaction between the two groups. Significantly more women receiving combined spinal-epidural analgesia had pruritus (P<0.001) and requested additional epidural bolus doses of local anesthetic (P=0.01). For all the women, dystocia necessitating cesarean section was significantly more likely when analgesia was administered with the fetal vertex at a negative station (odds ratio, 2.5; P<0.001) or at less than 4 cm of cervical dilatation (odds ratio, 2.2; P<0.001). CONCLUSIONS: As compared with continuous lumbar epidural analgesia, the combination of spinal and epidural analgesia is not associated with an overall decrease in the incidence of cesarean delivery.

Is fluorescence polarization reliable and cost efficient in a fetal lung maturity cascade?

OBJECTIVE: The objective of the study was to compare the accuracy of the TDxFLM test (Abbott Laboratories) with the fetal lung maturity cascade (shake, foam stability index, lecithin/sphingomyelin tests) and to determine whether the TDxFLM test could increase the efficiency and reduce the cost without decreasing the reliability of a cascade. STUDY DESIGN: A prospective, single-blinded study was conducted. Uncontaminated amniotic fluid obtained by transabdominal amniocentesis for fetal lung maturity assessment was evaluated with use of the fetal lung maturity cascade and the TDxFLM test. At study completion the results of the TDxFLM test were compared with those of the maturity cascade with regard to hyaline membrane disease, which was defined by strict clinical and radiographic parameters. A power analysis was performed requiring a sample size of 100 infants delivered within 72 hours of amniocentesis with use of the 95% confidence interval. RESULTS: A total of 115 cases had a full maturity cascade performed, of which 40 (35%) had a positive shake or foam stability index and 75 cases required progression to a lecithin/sphingomyelin ratio because of negative results. The TDxFLM test result was > or = 70 mg/gm in 42 (37%) of these 115. One hundred eight newborns were delivered within 72 hours of the amniocentesis; 65% (71) of these were between 30 and 37 weeks of estimated gestational age. There were 7 cases of hyaline membrane disease in the 108 newborns. Of these 108, 87 had a mature original cascade versus 85 mature tests with use of a proposed TDxFLM test-lecithin/sphingomyelin ratio cascade with one case of respiratory distress syndrome and hyaline membrane disease. The sensitivity, specificity, and positive and negative predictive values for the original cascade were 86%, 84%, 27%, and 99%, respectively; for the proposed TDxFLM test-lecithin/sphingomyelin ratio cascade the values were 86%, 83%, 26%, and 99%, respectively. The TDxFLM test-lecithin/sphingomyelin ratio cascade would have resulted in a cost reduction of 24% with no significant delay in turnaround time. CONCLUSION: The TDxFLM test appears to be a reliable and accurate assessment of fetal lung maturity. Furthermore, by replacing the shake and foam stability index portion of the cascade with the TDxFLM test, a cost savings of 24% would occur without a decrease in safety. These results also reveal that it could enhance patient care and be cost efficient for institutions not currently doing fetal pulmonary maturity testing to undertake use of the TDxFLM test and to only send out specimens for a lecithin/sphingomyelin ratio that have an initial immature TDxFLM test result (< 70 mg/gm). Likewise, institutions currently only performing a lecithin/sphingomyelin ratio may consider a TDxFLM test-lecithin sphingomyelin ratio cascade. Although direct costs would increase, they would be counterbalanced by a significant reduction in laboratory technician time.

Cervical assessment: visual or digital?

Our hypothesis for this study was that visual cervical assessment is not equivalent to digital assessment in patients with uterine contractions. We compared visual with digital cervical examinations done on 133 gravid women evaluated in the labor and delivery department because of uterine contractions. Patients at 27 weeks' gestation or more, subjectively in early labor, were prospectively entered into the study. Cervical dilatation and effacement were determined by two separate examiners blinded to each other's assessment, one by digital examination and the other by visual examination, in random order no more than 5 minutes apart. Eight of 133 patients were excluded from data analysis because of inability to visualize the cervix during speculum examination. Data analysis was done with correlation coefficient and the Bland and Altman test for agreement of two clinical measurements. Visual examination only underestimated actual cervical dilation by 0.60 cm (95% confidence interval [CI] 0.58 to 0.62 cm) and the limits of agreement were -2.06 cm (95% CI -2.02 to -2.09 cm) to 3.25 cm (95% CI 3.21 to 3.29 cm). Similarly, visual assessment underestimated effacement by 14.2% (95% CI 13.7% to 14.6%) and the limits of agreement were -41.3% (95% CI -40.5% to 42.0%) to 69.9% (95% CI 68.8% to 70.4%). In conclusion, cervical assessment in patients with uterine contractions who are thought to be in labor by visual speculum examination is not equivalent to that by digital examination. This difference seems to only be clinically significant if the cervix is more than 3 cm dilated.

The influence of elective amniotomy on fetal heart rate patterns and the course of labor in term patients: a randomized study.

OBJECTIVES: Our study was designed to evaluate the effects of routine elective amniotomy on the frequency and severity of abnormal fetal heart rate patterns and on the course of labor and the need for oxytocin augmentation. STUDY DESIGN: A randomized, controlled trial was conducted at term in patients in active labor who were randomly selected to undergo elective amniotomy (amniotomy group) or left intact with amniotomy reserved for specific indications (intact group). RESULTS: Four hundred fifty-nine patients were studied (235 in the amniotomy group vs 224 in the intact group). Average cervical dilatation at rupture was 5.5 cm in the amniotomy group and 8.1 cm in the intact group. Analysis of fetal heart rate revealed more mild and moderate variable decelerations in the active phase of labor in the amniotomy group but no difference in the frequency of more severe decelerations or operative deliveries. In the intact group the need for oxytocin was twice as common (76 in the intact group vs 36 in the amniotomy group, p = 0.000005), and the active phase of labor was considerably longer (5 hours 56 minutes in the intact group vs 4 hours 35 minutes in the amniotomy group). Neonatal outcome was similar in the two groups. CONCLUSIONS: Elective amniotomy appears to increase the likelihood of umbilical cord compression in the active phase of labor and results in more mild and moderate variable decelerations, but it does not result in more severe abnormal fetal heart rate patterns or more operative intervention. Elective amniotomy does, however, shorten the active phase of labor and decreases the need for oxytocin augmentation.

A randomized, placebo-controlled trial of betamethasone for the prevention of respiratory distress syndrome at 24 to 28 weeks' gestation.

Previous randomized controlled studies of corticosteroids for the reduction of respiratory distress syndrome have failed to demonstrate benefit in very early premature gestational age groups. A randomized, double-blind, placebo-controlled clinical trial of betamethasone given to mothers with intact membranes and threatened premature delivery between 24 and 28 weeks of pregnancy was conducted. Thirty-six patients were randomized to receive betamethasone, two doses of 12 mg, 24 hours apart, and 41 received placebo. No difference was found in the overall incidence of respiratory distress syndrome between the two groups (betamethasone vs placebo 0.55 vs 0.66) or in the incidence of respiratory distress syndrome in babies delivered between 1 and 7 days after the first dose of drug (betamethasone vs placebo 0.78 vs 0.88). Nor were there any differences observed in any measure of severity of respiratory distress syndrome between the groups. The neonatal death rates were also similar (betamethasone vs placebo 0.25 vs 0.24). The only difference seen was an unexpected reduction in the betamethasone group in the incidence of grades 3 and 4 intraventricular hemorrhage (betamethasone vs placebo 1/31 vs 9/36, p = 0.01). Therefore this study was unable to demonstrate any beneficial effect of corticosteroids in reducing respiratory distress syndrome at less than 28 weeks' gestation in spite of a sample size that had an 80% likelihood of detecting a 50% reduction in the incidence of respiratory distress syndrome with p = 0.05, which is the minimum reduction seen in virtually all randomized trials in other gestational age groups.