摘要:

Ritodrine hydrochloride has become the first drug approved in the United States specifically for use in preterm labor. The drug is a β-sympathomimetic agent with predominant effects upon β2receptors of the uterus. In this report, the pharmacology, distribution, disposition, and excretion are briefly reviewed. Recommendations for selecting patients most likely to benefit from ritodrine are given, together with the dosage and administration schedules that have been found most effective. Although this drug is not without side effects, it has been more thoroughly evaluated in prospective double-blind controlled trials than any of the other agents commonly used in preterm labor. In comparison with these agents, it seems relatively safe and the side effects are usually well tolerated. Part 2 of the paper discusses the evidence for efficacy

ISSN:0029-7844    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

In a multicenter series of randomized prospective doubleblind controlled studies, ritodrine hydrochloride was compared with either ethanol or placebo in treatment of idiopathic preterm labor. When compared with controls, there was, among offspring of ritodrine-treated mothers, a significantly reduced incidence of neonatal death and respiratory distress syndrome (P<.05 in both comparisons) and a significantly higher proportion of infants achieving 36 weeks' gestation (P<.05) or birth weight greater than 2500 g (P<.05). There was also a significant improvement in gestational age at delivery (P<.05) and in the number of days gained in utero (P<.001) among ritodrine-treated patients as compared with controls. These results, coupled with a finding of generally acceptable side effects, have contributed to ritodrine's becoming the first drug approved for the treatment of preterm labor in the United States

ISSN:0029-7844    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Five physicians subspecializing in maternal-fetal medicine individually evaluated 50 oxytocin challenge tests (OCTs), of which 33 were originally read as positive. There was considerable disagreement among the study physicians (SPs) such that 2 SPs would agree, on the average, only 52% of the time on any one OCT. The SPs were also asked to evaluate fetal heart rate (FHR) reactivity patterns, if present. Again, there was great disagreement. When the majority (3 of 5 or more) of SPs agreed on the OCT result and/or reactivity, there was reasonable correlation with neonatal outcome, indicating the validity of the physiologic premise of the test. In particular, the presence or absence of FHR accelerations with fetal motion, regardless of the OCT reading, correlated extremely well with eventual neonatal outcome. This indicates that the most significant variable in antepartum FHR monitoring is the FHR acceleration pattern

ISSN:0029-7844    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Based on analyses of the oxytocin challenge test (OCT) in 293 cases, an OCT-reactivity classification is proposed to improve the predictive value of OCT for fetal outcome. All of the 6 perinatal deaths occurred in the 2 groups associated with nonreactive pattern. The positive nonreactive test had 90% accuracy of predicting a sick infant, and the negative reactive test assured good fetal outcome. A nonreactive pattern seems to reflect a compromised fetus, as a high incidence of this pattern was found in patients with preeclampsia- hypertension, intrauterine growth retardation (IUGR), low and falling estriol levels, and suspected fetal problems. A positive OCT seems to reflect the limits of fetoplacental reserve under the stressed condition. A high incidence of positive OCT was associated with IUGR, low estriol levels, and a small placenta

ISSN:0029-7844    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Continuous measurements of human fetal breathing movements and gross fetal body movements were made with an ultrasonic real-time scanner for periods of 24 hours in 9 women at 30 to 31 weeks' and 11 women at 38 to 39 weeks' gestation. At 30 to 31 weeks' gestation, a significant increase in fetal breathing movements occurred during the second and third hours after meals; this pattern apparently followed an increase in maternal plasma glucose concentrations. At 38 to 39 weeks' gestation, fetal breathing movements increased during the second and third hours after breakfast, but the troughs seen before lunch and supper at 30 to 31 weeks' gestation were not present. Fetal breathing movements diminished over the day and reached a minimum between 1900 and 2400 hours. Fetal breathing activity increased in both groups between 0400 and 0700 hours while mothers were asleep; this was not related to an increase in maternal glucose concentrations. Absence of fetal breathing movements was observed for up to 122 minutes in this analysis of 480 hours in 20 patients. These data show that much more information must be obtained on factors that normally influence fetal breathing activity. Only then can research strategies be suggested for clinical evaluation of the usefulness of fetal breathing movements in the assessment of fetal health

ISSN:0029-7844    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

In an effort to determine if a changing clinical picture for placenta accreta exists in the late 1970s, 22 cases from January 1, 1975, to May 30, 1979, at Los Angeles County/University of Southern California (LAC/USC) Medical Center were reviewed. An incidence of clinically diagnosed placenta accreta of 1 per 2562 deliveries for all cases and 1 per 4027 for pathologically confirmed cases (ie, hysterectomy specimens) was found. Mean age of the patients was 29.5 years, and mean gravidity, parity, and abortion were 3.4, 2, and 0.27, respectively. Placenta previa was found in 14 patients (63.6%), 6 of whom had previously undergone cesarean section. No obvious etiology was found in 1 patient. Sixteen patients underwent cesarean section. Hysterectomy was performed on 14 patients, and conservative measures were employed in 8 patients. One maternal death (4.5%) occurred, but there was no perinatal mortality. The clinical picture of placenta accreta today is one of higher reported incidence, lower parity, greater incidence of associated placenta previa, individualized management, and decreasing maternal and perinatal mortality

ISSN:0029-7844    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Fetal breathing during labor was investigated in a 3-part study of 42 normal singleton pregnancies. In the first part fetal breathing movements (FBM) were compared antenatally and during labor in 22 patients to determine whether FBM persisted during labor in fetuses in whom these movements had been demonstrated antenatally. In the second part a double-blind trial was conducted on the responsiveness of fetal breathing in labor to maternal glucose infusion in 12 patients. In the third part the influence of artificial rupture of the membranes (ARM) to induce labor was examined in 8 patients. Fetuses spent 36% of their time making breathing movements antenatally but this decreased to less than 1% during labor. Fetal trunk movements also decreased during labor but not significantly. Fetal breathing and trunk movements were not stimulated by maternal glucose infusion. Fetal breathing but not trunk movements were significantly inhibited by ARM prior to the onset of labor. Cessation of fetal breathing in labor is normal, but the cause of this change in behavior has not been positively identified

ISSN:0029-7844    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

A prospective study of 12 unmedicated pregnant women in the second stage of labor was undertaken to assess the effects of bearing down efforts on brachial and popliteal blood pressure. Inferior vena cava compression, usually detected by reductions in mean and/or pulse pressure in the brachial artery, did not occur at any time, whether or not the uterus was displaced to the left. Abdominal aortic compression, suggested by popliteal pressure fall, was maintained into the second stage of labor, was aggravated when the woman bore down, and was alleviated only when bearing down efforts ceased and the uterus was displaced to the left. Bearing down efforts are therefore yet another mechanism by which distal aortic and possibly uteroplacental blood flow can be prejudiced. Their avoidance can be advantageous to the fetus at risk

ISSN:0029-7844    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

Seventy-four fetal heart rate (FHR) records that were continued to vaginal delivery were selected for study from more than 2000 intrapartum FHR tracings. Thirty-six of the births were associated with neonatal depression and Apgar scores of 3 or less and/or 6 or less at 1 and 5 minutes, respectively; 38 patients exhibited normal Apgar scores (7 and 10 at 1 and 5 minutes, respectively). Twenty minutes of heart rate activity immediately prior to birth was the basis of analysis. All categories of loss of short-term beat-to-beat variability (BBV), both baseline and with decelerations, were observed more frequently in the group with low Apgar scores (P<.001). In assessing variability, duration of observed loss of BBV appears to be an extremely critical factor. If BBV was lost 50% or less of observation time, a wide range of Apgar scores was observed. When more than 50% of the record showed loss of BBV, the number of depressed neonates was relatively high. Bradycardia (heart rate of less than 120 beats per minute) was present frequently in the records of the normal group. The number of variable decelerations and the amount of uterine activity were relatively high during second stage labor; a similar frequency was noted in both groups. Decelerations were nearly uniformly associated with uterine contractions in both groups, and accelerations were also noted in both groups. Uniform decelerations (late) were also present in both groups, with a greater frequency in the group with lower Apgar scores, but there were no distinguishing characteristics noted

ISSN:0029-7844    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

The nonstress portions of 42 abnormal oxytocin challenge tests (OCT) and 50 negative OCT tracings were redefined by 9 criteria in the literature. The results showed that the criteria of Trierweiler et al are the most predictive of fetal outcome but would lead to unnecessary OCTs in 46% of cases. However, the criteria of Trierweiler et al in combination with a new criteria modified from those of Paul and Miller and Evertson et al are the most predictive and lead to unnecessary OCTs in only 14% of cases

ISSN:0029-7844    

出版商:OVID    

年代:1980

数据来源: OVID