A maternal complex partial seizure in labor can affect fetal heart rate

We describe a 33-year-old woman who had a complex partial seizure during labor. Intrauterine pressure catheter and fetal heart monitoring during the seizure revealed a strong, prolonged uterine contraction and simultaneous significant fetal heart rate deceleration for 3.5 minutes. This patient demonstrates that complex partial seizures may result in uterine hyperactivity during labor, which may result in fetal hypoxia.     

The placental transfer of sufentanil: effects of fetal pH, protein binding, and sufentanil concentration

This study investigated factors that influence the placental transfer of sufentanil using the dual-perfused, single-cotyledon human placental model. Placentas were collected from healthy women. Experiments were designed to elucidate the effects of maternal protein binding, changing maternal sufentanil concentration (1, 10, 20, and 100 ng/mL) and decreasing fetal pH (fetal acidemia 7.2, 7.0, 6.8) on the placental transfer of sufentanil. Sufentanil crossed the placenta rapidly at a rate two-thirds that of the transfer marker, antipyrine. Sufentanil transfer increased linearly with the maternal concentration (r = 0.999). Sufentanil/antipyrine maternal to fetal (M-->F) transfer ratios were significantly reduced (0.66 +/- 0.05 vs 0.40 +/- 0.04, P < 0.05) when fresh frozen plasma was added to the maternal circuit to enhance protein binding. Fetal pH and sufentanil transfer were related because sufentanil M-->F clearance increased significantly as the fetal pH decreased (r = 0.973, P < 0.05). Sufentanil appears to cross the placenta by passive diffusion but is modulated by the degree of maternal protein binding. Sufentanil M-->F transfer is enhanced by fetal acidemia.     

Intrathecal narcotics for labor analgesia

Intrathecal narcotics are a relatively recent addition to the list of analgesic options that are available for the management of labor pain. Pain during the first stage of labor is related to repetitive uterine contractions and resultant cervical dilatation, while pain during the second stage is due to stretching of the perineum. Traditionally, continuous epidural analgesia has been used as the reference standard for providing comfort during labor. Intrathecal narcotics represent a safe and effective alternative that provides significant, rapid relief of labor pain during the first stage of labor. The drugs most often used for intrathecal administration include sufentanil, fentanyl, meperidine and morphine. Use of intrathecal narcotics does not significantly affect the natural progression of labor, and no adverse fetal outcomes have been reported.     

A flat decelerative fetal heart rate tracing with normal fetal heart rate variability

We report two cases for which computer interpretation of nonstress test indicated a flat decelerative trace in spite of normal fetal heart rate variability. Fetal behavioral state in the first case and signal loss in the second case were possibly responsible for this computerized interpretation of the tracings in the absence of fetal distress.     

Dexamethasone and fetal heart rate variation

OBJECTIVE: To determine the effect of maternal administration of dexamethasone on fetal heart rate and its variation. DESIGN: Retrospective analysis of computerised data derived from cases studied over three years. SETTING: High risk pregnancy unit, John Radcliffe Hospital, Oxford. SUBJECTS: Twenty-eight pregnant women, at 27 to 32 weeks of gestation, to whom dexamethasone was given to accelerate pulmonary maturation in the expectation of preterm delivery. METHODS: Dexamethasone (two doses of 12 mg intramuscularly, 12 h apart) was given on 51 occasions at weekly intervals (one to four occasions per patient). Complete data were available for cardiotocograph analysis from computerised measurement of fetal heart rate variables for two days before and four days after dexamethasone and, in 19 women, measurements of umbilical arterial flow velocity waveforms before and after dexamethasone. RESULTS: In 10 pregnancies without fetal distress there was a highly significant (P < 0.01) transient rise in short term fetal heart rate variation after dexamethasone administration, from means (SE) 6.4 (0.28) to 9.8 (0.4) ms. In 18 pregnancies with subsequent delivery for fetal distress (abnormal fetal heart rate pattern) and high umbilical arterial resistance index [mean 0.93 (0.06 SE)], the rise in short term fetal heart rate variation was less (P < 0.01), from mean (SE) 5.4 (0.26) to 6.1 (0.48) ms. In a further case of discordant twin pregnancy, the larger twin continued to respond to dexamethasone administrations with a rise in fetal heart rate variation for five weeks; the smaller twin, with maintained tachycardia and reduced umbilical arterial end-diastolic flow velocity, failed to respond after the first two weeks. CONCLUSION: The results show that maternal dexamethasone administration normally causes a rise in fetal heart rate variation for up to a day. This rise is reduced in pre-eclampsia or intrauterine growth retardation, associated with a reduction in umbilical flow, perhaps because of a consequential lower concentration of steroid in the fetus. The results contrast with those for betamethasone which has been reported to reduce fetal heart rate variation.     

Effects of intravenous meperidine and meperidine with promethazine on uterine activity and fetal heart rate during labor

A prospective study of the effects of the i.v. injection of 75 mg meperidine, alone or combined with 25 mg promethazine, was conducted by continuous and direct monitoring of the fetus and of intrauterine pressure. The study was carried out in 16 primiparas and 24 multiparas in active spontaneous labor with cervical dilatation of 3 to 4 cm. Administration of meperidine and of meperidine with promethazine was associated with an increase in uterine activity of 31 to 45% (Montevideo units), respectively. The most marked effects were on the amplitude of the uterine contractions. There was no significant change in uterine tone. A tetanic response was recorded in two patients who vomited after the administration of meperidine with promethazine and was followed by slowing of the fetal heart rate. In no other cases were there significant changes in fetal heart rate. Except for the latter two patients, no adverse effect of meperidine or of meperidine with promethazine on the fetal heart rate was noted. The condition of the newborns at birth was excellent in all but three cases, in two of which maternal amniotic infection and high fever were present.     

Sinusoidal fetal heart rate pattern with intrapartum fetal death

A case of sinusoidal fetal heart rate pattern with intrapartum fetal death is presented. This pattern has been observed infrequently during both the antepartum and intrapartum periods. Not all sinusoidal patterns may be ominous. A reasonable plan of management includes maternal position change, oxygen administration, scalp sampling and preparation for immediate delivery.     

Gender does not affect fetal heart rate variation

There is a widespread but erroneous view among the lay public that there is a difference in the baseline fetal heart rate between male and female fetuses. It has been suggested that this perception might reflect an actual difference in fetal heart rate variability. Therefore, we studied the fetal heart rate variation in 79 white European women using the Sonicaid System 8002 computer. Fourty-four of the fetuses were male and 35 were female. There was no significant gender difference in any measured aspect of fetal heart rate variation.     

Pearson's fetal movement count (FMC) and antepartum fetal heart rate testing (AFHRT) for antepartum fetal well-being

To evaluate the accuracy of Pearson's fetal movement count (FMC) and antepartum fetal heart rate testing (AFHRT) in 380 high risk pregnancies at Rajavithi Hospital in 1994, the result of the 4 test FMC, AFHRT, FMC + AFHRT (serial test), and FMC + AFHRT (parallel test) were compared in sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), false positive rate (FPR), false negative rate (FNR) and accuracy. All tests had equal specificity and FPR. FMC + AFHRT (serial test) had the highest value of sensitivity (66.67%) but lowest value of FNR, NPV and accuracy (33.33%, 40%, 72.73% respectively). PPV was 100 per cent in AFHRT and FMC + AFHRT (serial test). FMC might be used as a first line antepartum fetal well being screening test.     

Intermittent sinusoidal heart rate pattern in vagotomized fetal lambs

OBJECTIVES: Our aims were to investigate the relationship between the dose of arginine vasopressin and the pattern and duration of arginine vasopressin-induced sinusoidal fetal heart rate and to elucidate the correlation between intermittent sinusoidal heart rate and fetal sleep cycle. STUDY DESIGN: Sinusoidal heart rate pattern was induced by intravenous arginine vasopressin infusion at doses from 2 to 78 mlU/min into 11 chronically instrumented fetal lambs with bilateral cervical vagotomy. Appearance and frequency of sinusoidal heart rate, intermittent sinusoidal heart rate, and persistent sinusoidal heart rate were observed along with fetal tracheal pressure and electrooculogram. RESULTS: Intermittent sinusoidal heart rate response to low, medium, and high doses of arginine vasopressin appeared in 73.3%, 50.0%, and 33.3% of experiments, respectively. Intermittent sinusoidal heart rate appeared more frequently than persistent sinusoidal heart rate with lower doses (p < 0.02). When intermittent sinusoidal heart rate was induced, the incidence of sinusoidal patterns significantly increased during non-rapid-eye-movement sleep in comparison with rapid-eye-movement sleep (p < 0.01). CONCLUSIONS: Appearance of sinusoidal heart rate seems to be related to the dose of arginine vasopressin infused. Appearance of sinusoidal heart rate is also influenced by fetal sleep cycle; sinusoidal heart rate is more likely to appear during non-rapid-eye-movement sleep than during rapid-eye-movement sleep. These results support the hypothesis that persistent sinusoidal heart rate correlates with severity of stress.     

The response of the fetal heart rate of amniocentesis

Fetal heart rate monitoring during 107 amniocenteses suggested that acceleration of the fetal heart rate indicated fetal well-being. Eight out of the 19 fetuses who did not show this response (as against 2 out of the 88 others) had a low Apgar score at birth.     

Nonstressed fetal heart rate monitoring in the antepartum period

The role of nonstressed monitoring of the fetal heart rate (HR) in determining fetal well-being during the antepartum period was assessed in 125 high-risk patients. Observations on HR, variability, and HR response to fetal movement (FM) and uterine contractions (UC) over a 30 minute period were made with an external microphone and tocotransducer. A total of 625 tests were performed; the earliest gestation tested was 28 weeks, and the latest was 46 weeks. A reactive pattern (variability greater than 6 b.p.m. and accelerations with FM) appears to be a reliable indicator of fetal well-being. All the 51 fetuses exhibiting this pattern survived. This group also had the lowest incidence of neonatal complications. On the other hand, of the babies who failed to show variability greater than 6 b.p.m. or accelerations with FM (nonreactive pattern), 40% died in the perinatal period. Thirty-five patients showed features of both a reactive and nonreactive pattern (combined pattern). Poor outcome in this group was confined to those in whom the majority of the pattern was nonreactive. An undulating HR pattern with virtually absent variability (sinusoidal pattern) was found in 20 Rh-sensitized fetuses, 50% of whom died in the perinatal period. Bradycardia and tachycardia were not found to be reliable signs of fetal distress antepartum. Of the 12 fetuses who died during observation, six showed late decelerations with spontaneous UC but all showed diminished variability. The close correlation between nonstressed patterns and neonatal outcome demonstrated by this preliminary study warrants further use of this technique for fetal evaluation.     

Recording fetal heart rate as a behavioral measure.

Employed the fetal EKG with 4 electrodes placed on the maternal abdomen 1 just above the symphysis pubis, and the other across the abdomen at the level of the fundus uteri. The relationship between maternal and fetal heart rates were explored by also recording the maternal EKG. Difficulties in measuring fetal heart rate are discussed and possible solutions presented. It is concluded that fetal heart rate is a difficult but possible measure for exploration of fetal behavior. (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heart rate variability and newborn heart rate responses to illumination changes.

Investigated heart rate (HR) response patterns to the onset and offset of a 30-sec increase in illumination in 16 human newborns. Ss were divided into 2 groups based on a measure of pretrial HR variability. Only Ss with the high pretrial HR variability responded significantly to the change in stimulation. The response to onset was characterized by a significant quartic trend containing both decelerative and accelerative components. The response to offset only approached significance and had a pattern similar to the onset response. Although the occurrence of systematic response patterns was related to the level of pretrial HR variability, this measure of autonomic lability may have been related to influences associated with delivery and not to stable individual differences. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acceleration patterns of the fetal heart rate before and during labour

In infants in whom accelerations of the fetal heart rate were present during the first stage of labour, the incidence of low Apgar scores was significantly less than in those in whom accelerations were not present. Absence of acceleration patterns during the contraction stress test (CST) was associated with a lower birth weight. In patients in whom acceleration patterns were observed during a positive CST, fetal distress occurred in the minority of subsequent labours. When accelerations as well as late decelerations are observed during a CST, the possibility of a false positive test should be excluded.     

Human fetal heart rate dishabituation between thirty and thirty-two weeks gestation

Few studies of human fetal habituation have included dishabituation procedures (i.e., assessment of the reemergence of a habituated response) to determine if response decrements are the result of reevaluation of information (a brain process) or fatigue of peripheral receptors. The purpose of this study is to describe the ability of the human fetus to learn and recall information with procedures to assess the central nervous system. Fetal heart rate (FHR) of 84 fetuses between 30 and 32 weeks gestational age was examined in response to 3 series of vibroacoustic (VA) stimuli presented at pseudorandom intervals of 25-45 s over the head of the fetus. Responses to the first series of 15 stimuli (S1) were compared with an identical second series of 15 stimuli (S1) presented over the head of the fetus. Between the 2 series, a novel (dishabituating) VA stimulus (S2) was presented, differing from S1 in intensity and frequency. The third series of S1s was applied to the mother's thigh as a control for possible maternal responses to the stimulus. Prestimulus FHR was computed during a 5 s interval before each stimulus, and mean FHR was computed during the intertrial interval (average FHR). The response to S1 during the first series of trials (1-15) produced a sustained rise in both prestimulus and average FHR, r(83) = .90, p < .001. After the novel S2 (trial 16) the rate of change was attenuated for average FHR, r(83) = .12, ns, to S1 for trials 17-31 but not prestimulus FHR, r(83) = .50, p < .001. The decrease in FHR response was reestablished when stimulation was applied to mother's thigh, trials 32-41, r(83) = .92, p < .001. A significant habituation pattern across trials was observed for the first series of S1s when prestimulus HR was subtracted from each preceding average FHR value (delta FHR). After the single novel stimulus (S2), the FHR response to S1 reemerged. All combinations of beginning and ending series slopes were compared, and only the rate of change during the last 4 trials of the initial presentation of S1 and the first 4 trials after the novel stimulus was significant, F(1, 82) = 9.21, p < .003. Uterine contractions collected from the continuous record were not related to the presentation of the novel stimulus, chi 2(1, N = 84) = 0.59, p < .50, ns, or delta FHR slope after the novel stimulus, chi 2(9, N = 84) = 10.52, p < .50, ns. These results established that the 32 week human fetus is capable of detecting, habituating, and dishabituating to an external stimulus and support the premise that areas of the human fetal central nervous system critical for detecting and discriminating information and for learning and memory have developed by the early third trimester.     

The effect of carotid sinus denervation on fetal heart rate variation in normoxia, hypoxia and post-hypoxia in fetal sheep

BACKGROUND: Previous reports documented high rates of tobacco use among Alaska Natives (Eskimos, Indians, and Aleuts). In this population, tobacco use is the leading preventable cause of death. Lung cancer is the leading cause of cancer death among Alaska Natives and tobacco is responsible for over one-third of all cancer deaths in this population. Until recently there has been no systematic surveillance of the prevalence of tobacco use in this high-risk population. Data that did exist were not readily available to those primarily responsible for the health care of this population. This is the first time since 1990 that data on Alaska Natives have been collected in one analysis; this permits a more representative evaluation of tobacco use. METHODS: Data on tobacco use were obtained and analyzed from national and state surveys and selected research projects from 1988 to 1993. RESULTS: Alaska Natives have high prevalence of tobacco use, including both cigarettes and smokeless tobacco. Tobacco use prevalence among Alaska Natives exceeds that of Alaska non-Natives, U.S. whites, and American Indians/Alaska Natives in the United States outside of Alaska. Smoking prevalence among Alaska Native women is twice that of non-Native women in Alaska and nearly twice as high among pregnant Alaska Natives than pregnant non-Natives. Overall, prevalence of smokeless tobacco use was four times higher among Alaska Natives than comparative state and national populations. CONCLUSION: Because this population has such high rates of tobacco use, it is important to public health that monitoring and educational programs be in place and that data specific to Alaska Natives be made available.