Neurological morbidity after fetal supraventricular tachyarrhythmia.
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BACKGROUND: Fetal tachyarrhythmia is a well-documented entity which, in the absence of pharmacological intervention, may lead to congestive heart failure, fetal hydrops and eventually fetal demise. The success rate of the implemented treatment is generally measured by survival and achievement of control of the arrhythmia. We report on the occurrence of associated cerebral damage in three patients with fetal tachycardia. METHODS: We describe three patients with a history of fetal supraventricular tachyarrhythmia who developed cerebral complications in utero. RESULTS: Two patients had cerebral hypoxic-ischemic lesions and one had hemorrhagic lesions present at birth. They had developed severe congestive heart failure and fetal hydrops secondary to fetal tachyarrhythmia, and there were no other obvious causes for the cerebral pathology. Two of these patients were referred to us antenatally. Therapy was instituted and resulted in control of the tachycardia and resolution of hydrops. The third patient was referred to our clinic shortly after birth because of severe circulatory problems secondary to fetal tachyarrhythmia. CONCLUSION: From these observations, we believe that a fetus with tachyarrhythmia and subsequent hydrops is at increased risk for the development of cerebral complications, due to the circulatory disturbances and sudden changes in heart rate which may lead to fluctuations in cerebral perfusion. This would imply that it is of the utmost importance to aim at immediate and complete control of the heart rate in the treatment of fetal tachyarrhythmia. (+info)
Mechano- and chemoreceptor modulation of renal sympathetic nerve activity at birth in fetal sheep.
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Physiological responses at birth include increases in heart rate (HR), blood pressure, sympathetic nerve activity, and circulating vasoactive peptides. The factors mediating these responses are not known. To test the hypothesis that afferent input from peripheral mechanoreceptors (arterial and cardiopulmonary baroreceptors) and chemoreceptors contribute to the sympathoexcitatory and hormonal responses at birth, we studied the effects of sinoaortic denervation (SAD) and SAD with vagotomy (Vx) on changes in HR, mean arterial blood pressure (MABP), renal sympathetic nerve activity (RSNA), and catecholamine, arginine vasopressin (AVP), and ANG II levels at birth in term sheep. One hour after delivery by cesarean section, RSNA increased by 168 +/- 49 and 192 +/- 32% (relative to fetal values) in SAD and SAD-Vx animals, respectively. Significant increases in HR (18 +/- 5 and 20 +/- 6%) and MABP (24 +/- 4 and 20 +/- 5%) were also observed 1 h after delivery in SAD and SAD-Vx lambs, respectively. These responses are similar to those seen in intact sheep delivered at the same gestational age. AVP levels markedly increased after birth (19.8 +/- 6.7 to 136.1 +/- 75.9 pg/ml) in SAD-Vx lambs, whereas SAD animals displayed no change in AVP concentrations. Plasma ANG II also did not change after birth in either group, although levels were consistently higher (P < 0.01) in SAD compared with SAD-Vx animals. In the presence of SAD, Vx resulted in significantly greater plasma levels of norepinephrine, although levels did not change after birth in either group. The epinephrine responses at birth were similar in both groups of animals. The present data suggest that afferent input from peripheral chemoreceptors and mechanoreceptors contributes little to the hemodynamic and sympathetic responses after delivery by cesarean section. On the other hand, these peripheral mechanisms appear to be involved in modulating endocrine responses at birth. (+info)
Interpretation of the electronic fetal heart rate during labor.
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Electronic fetal heart rate monitoring is commonly used to assess fetal well-being during labor. Although detection of fetal compromise is one benefit of fetal monitoring, there are also risks, including false-positive tests that may result in unnecessary surgical intervention. Since variable and inconsistent interpretation of fetal heart rate tracings may affect management, a systematic approach to interpreting the patterns is important. The fetal heart rate undergoes constant and minute adjustments in response to the fetal environment and stimuli. Fetal heart rate patterns are classified as reassuring, nonreassuring or ominous. Nonreassuring patterns such as fetal tachycardia, bradycardia and late decelerations with good short-term variability require intervention to rule out fetal acidosis. Ominous patterns require emergency intrauterine fetal resuscitation and immediate delivery. Differentiating between a reassuring and nonreassuring fetal heart rate pattern is the essence of accurate interpretation, which is essential to guide appropriate triage decisions. (+info)
Fetal heart rate and umbilical artery velocity variability in pregnancies complicated by insulin-dependent diabetes mellitus.
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OBJECTIVES: To examine the variability in fetal heart rate and absolute flow velocity, which are possible hemodynamic markers of cardiovascular homeostasis in pregnancies complicated by diabetes mellitus. METHODS: Doppler studies of umbilical artery velocity waveforms were performed at 12-21 weeks of gestation in 16 women with well-controlled type I (insulin-dependent) diabetes mellitus. From umbilical artery velocity waveforms of at least 13 s in duration, we determined absolute values and beat-to-beat variability for fetal heart rate and umbilical artery flow velocities and compared these findings with normal controls matched for gestational age. RESULTS: Fetuses of diabetic women displayed increased fetal heart rate variability and umbilical artery peak systolic velocity. Fetal heart rate, umbilical artery time-averaged velocity and variability in umbilical artery flow velocity were not essentially different between the two groups. CONCLUSION: Fetal heart rate variability and umbilical artery peak systolic velocity may be markers for fetal cardiovascular homeostasis in pregnancies complicated by insulin-dependent diabetes mellitus. (+info)
Bupivacaine augments intrathecal fentanyl for labor analgesia.
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BACKGROUND: fentanyl has been shown to be an effective analgesic for labor; this study investigated the analgesic effect of low-dose bpivacaine added to intrathecal fentanyl for labor analgesia METHODS: Ninety parturients in active labor who requested regional analgesia were randomized to receive an intrathecal injection of either fentanyl, 25 microg; bupivacaine, 1.25 mg, with fentanyl, 25 microg; or bupivacaine, 2.5 mg, with fentanyl, 25 microg, as part of a combined spinal-epidural technique. Visual analog pain scores were recorded before and at intervals after injection until the patient requested further analgesia. Maternal blood pressure and fetal heart rate were recorded before and at intervals after injection. Lower-extremity muscle strength was tested before and 30 min after injection; anesthetic level to cold sensation and the presence and severity of pruritus were recorded. RESULTS: Duration of analgesia was longer in the group receiving bupivacaine, 2.5 mg, and fentanyl, 25 microg, than the group receiving plain fentanyl (108 vs. 92 min; P < 0.05). Onset of analgesia was faster in both groups receiving bupivacaine compared with plain fentanyl (P < 0.05). No differences in muscle strength after injection were found in any group, although anesthetic levels to cold were documented in all patients in the bupivacaine groups, and 21 of 30 in the plain fentanyl group. Baseline fetal heart rates did not change after injection in any group, and maternal blood pressure was unchanged. CONCLUSIONS: The addition of 2.5 mg isobaric bupivacaine to 25 microg fentanyl for intrathecal labor analgesia modestly increases duration and speeds onset of analgesia compared with plain intrathecal fentanyl. (+info)
Long-term prognosis of pregnancies complicated by slow embryonic heart rates in the early first trimester.
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Slow embryonic heart rates at gestational age 7 weeks or less are associated with high risk of first trimester death. Our goal was to determine the prognosis for those embryos with slow early heart rates who survive the first trimester. We prospectively recorded embryonic heart rates for all obstetrical sonograms obtained on singleton pregnancies at or before 7.0 weeks' gestation since 1993. We collected information about pregnancy outcome, including date of live birth or in utero death and presence and nature of congenital anomalies. First trimester survival rate was 61.6% among 531 embryos with slow early heart rates (< 100 bpm at < or = 6.2 weeks, < 120 bpm at 6.3 to 7.0 weeks), lower than the survival rate of 91.5% among 1501 embryos with normal heart rates (p < 10(-8), Fisher's exact test). Among 299 pregnancies in which the early heart rate was slow and the fetus was still alive at the end of the first trimester, 277 (92.6%) resulted in liveborn infants without congenital anomalies, similar to the frequency of 95.1% in cases with normal early heart rates (p > 0.10, Fisher's exact test). Structural and chromosomal anomalies, however, occurred more than twice as frequently in cases with slow early heart rates: 5.4% (16 of 299) of the first trimester survivors with slow early heart rates proved to have anomalies, as compared to 2.4% (31 of 1281) of cases with normal early heart rates (p < 0.05, Fisher's exact test). In conclusion, a pregnancy in which the embryo has a slow heart rate at or before 7.0 weeks' gestation and which continues beyond the first trimester has a high likelihood (> 90%) of resulting in a liveborn neonate without congenital anomalies. Embryos with slow early heart rates do, however, have a greater risk of having anomalies than embryos with normal early heart rates. (+info)
Prenatal diagnosis of acute massive fetomaternal hemorrhage.
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We present here 2 cases of acute and 2 cases of chronic massive fetomaternal hemorrhage. A sinusoidal fetal heart rate pattern may indicate chronic fetomaternal hemorrhage, but, when increased variability is observed in fetal monitoring, maternal hemoglobin F should be measured to exclude acute fetomaternal hemorrhage. (+info)
Positive outcome after preimplantation diagnosis of aneuploidy in human embryos.
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usromosomal abnormalities are responsible for a great deal of embryo wastage, which is reflected, at least partially, in decreased implantation and increased miscarriage in older women. To address this problem the transfer of only chromosomally normal embryos previously selected by preimplantation genetic diagnosis (PGD) has been proposed. We designed a multi-centre in-vitro fertilization (IVF) study to compare controls and a test group that underwent embryo biopsy and PGD for aneuploidy. Patients were matched retrospectively, but blindly, for average maternal age, number of previous IVF cycles, duration of stimulation, oestradiol concentrations on day +1, and average mature follicles. All these parameters were similar in test and control groups. Only embryos classified as normal for those chromosomes were transferred after PGD. The results showed that the rates of fetal heart beat (FHB)/embryo transferred between the control and test groups were similar. However, spontaneous abortions, measured as FHB aborted/FHB detected, decreased after PGD (P < 0.05), and ongoing pregnancies and delivered babies increased (P < 0.05) in the PGD group of patients. Two conclusions were obtained: (i) PGD of aneuploidy reduced embryo loss after implantation; (ii) implantation rates were not significantly improved, but the proportion of ongoing and delivered babies was increased. (+info)