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Biomedical subjects

T H Hasaart

Publications and source records attributed to T H Hasaart.

At least 19 recordsLinked to original sources
PubMed2000

The PR interval-fetal heart rate relationship during repetitive umbilical cord occlusions in immature fetal sheep.

OBJECTIVE: To evaluate the relationship of the PR interval and fetal heart rate during repetitive umbilical cord occlusions in immature sheep fetuses. STUDY DESIGN: In seven chronically cannulated immature sheep fetuses [gestational age 90.6 days (mean)], we analyzed continuous fetal electrocardiogram recordings during repetitive cord occlusions for 2 out of every 5 min until fetal mean arterial pressure dropped to 50% of baseline value. PR interval-fetal heart rate correlation coefficients (Pearson) was measured on consecutive blocks of 2.5 min. R-values of the baseline and the repetitive occlusion period were compared by Fisher's exact test. RESULTS: Repetitive cord occlusions resulted in acidosis and hypotension. Two fetuses died at the end of the repetitive occlusion period. Four out of seven fetuses showed a significant change from a negative relationship between the PR interval and fetal heart rate during baseline to a predominantly positive relationship during the repetitive occlusion period. CONCLUSION: In immature fetal sheep, a change from a negative relationship between the PR interval and fetal heart rate to a predominantly positive relationship between the PR interval and fetal heart rate was observed in four out of seven fetuses following the initiation of repetitive umbilical cord occlusions.

Acidosis↗
PubMed1999

[Third circulation: twin transfusion syndrome].

The estimated incidence in the Netherlands of serious previable twin-to-twin transfusion syndrome is 50-100 cases per year. The polyhydramnion-oligohydramnion sequence is the most prominent feature. Prognosis without treatment is dismal: previable preterm birth. Risk of serious morbidity in the surviving twin in case of foetal demise of the other is impressive. Once the diagnosis of monochorionicity has been made in the first trimester, detailed ultrasound examination is mandatory for early recognition of the development of the syndrome, as therapeutic options exist. Therapeutic options include piercing of the intertwin membrane, repeated amniocenteses or laser occlusion of the chorionic vasculature. In seven Dutch centres over three years time 61 cases were identified: 36 needed intervention; 63 (of the 122) children survived, 10 with longterm morbidity.

Amniocentesis↗
PubMed1999

Fetal arterial pressure and heart rate changes in surviving and non-surviving immature fetal sheep following brief repeated total umbilical cord occlusions.

OBJECTIVES: To describe the changes in fetal heart rate and mean arterial pressure during repetitive total umbilical cord occlusions in immature sheep fetuses, resulting in severe asphyxia or fetal death. To describe the relationship between these changes and concurrent changes in acid-base status. STUDY DESIGN: We performed brief repeated total umbilical cord occlusions, two out of every five min, in 14 immature sheep fetuses (at 90 days of gestation), until fetal mean arterial pressure dropped below 50% of baseline value during two successive occlusions. Fetal blood gas analyses were performed at regular intervals just before cord occlusions. RESULTS: Progressive acidemia and hypotension developed with ongoing occlusions. The degree of hypotension during occlusions increased with ongoing occlusions. The minimum fetal arterial blood pressure during occlusions correlated well with the progressive acidemia. Six fetuses died at the end of the repetitive occlusion period. In the non-survivors, acidemia was more severe and paCO2 gradually increased during the entire repetitive occlusion period. In the survivors group, a period of transient hypoxia and hypotension was observed with a nadir at +60 min following the final occlusion. CONCLUSION: Repetitive umbilical cord occlusions in immature sheep fetuses resulted in repetitive periods of hypotension, bradycardia, progressive fetal acidemia and ultimately fetal demise. Minimum fetal arterial blood pressure during occlusions correlated well with the progressive fetal acidemia.

Animals↗
PubMed1998

Fetal Candida sepsis at midgestation: a case report.

A patient presented with intrauterine fetal death at 21 weeks. A Candida vaginitis was treated at 18 weeks of gestation. Fatal fetal Candida sepsis caused by Candida albicans can occur in the absence of known risk factors such as prolonged rupture of membranes, the presence of an intrauterine contraceptive device or cervical cerclage.

Administration, Intravaginal↗
PubMed1997

Absence of neuronal damage after umbilical cord occlusion of 10, 15, and 20 minutes in midgestation fetal sheep.

OBJECTIVES: Our purpose was to determine whether neuronal damage results after total umbilical cord occlusion of increasing duration in midgestation fetal sheep. STUDY DESIGN: We performed total umbilical cord occlusion during 10 (n = 11), 15 (n = 8), or 20 (n = 4) minutes in chronically instrumented midgestation fetal sheep. Nine fetuses served as sham controls. During the experiment fetal blood pressure (mean arterial pressure) and heart rate were continuously recorded. Fetal blood gas analyses were performed at regular intervals before, during, and after the occlusion. Three days after the occlusion neuronal damage was evaluated histologically in three regions of the fetal brain. RESULTS: Total umbilical cord occlusion resulted in hypotension, bradycardia, severe mixed acidemia, hypoxia, and hypercapnia. All fetuses survived the occlusion. No neuronal damage nor macroscopic intraventricular or germinal matrix hemorrhages were observed in either group. CONCLUSION: Prolonging the duration of total umbilical cord occlusion in midgestation fetal sheep resulted in a progressive increase in the severity of asphyxia, not in neuronal damage.

Animals↗
PubMed1997

The influence of head position and head position change on spontaneous body posture and motility in full-term AGA and SGA newborn infants.

No consensus exists concerning the influence of head position and head position change on body posture and motility. Especially the existence of an asymmetric tonic neck reflex (ATNR) in full-term newborns is an issue of discussion. Three-hour video recordings were made of 15 full-term appropriate for gestational age (AGA) and 15 full-term small for gestational age (SGA) infants between the third and eight postnatal day. During a playback of the video recording head position, head position change and several movement patterns of the four limbs were fed into a computer using an event-detecting program. Furthermore, spontaneous head turnings were selected and body posture just before, immediately at and 1 min after the head turning were sketched. The data were analyzed concerning: (1) influence of head position on symmetry of movement of the four limbs; (2) the existence of an ATNR and ATNR-related patterns. In both AGA and SGA infants all movement patterns except hand-face and hand-mouth contact showed a symmetrical distribution, independent of head position. Furthermore, the occurrence of an ATNR following a spontaneous head turning in both AGA and SGA infants was rare. From our results it may be concluded that the ATNR is rare in full-term AGA and SGA newborns. Furthermore, this study demonstrates that head position is not a major factor influencing quantitative aspects of spontaneous motor behaviour. The results are of clinical importance as they imply that in the examination of the neurological condition of the full-term newborn infant by means of observation of spontaneous posture and motility, head position is not of major importance.

Functional Laterality↗
PubMed1997

Transcutaneous and arterial carbon dioxide tension at various conditions of fetal stress in lambs.

In an acute fetal lamb model the relation between arterial PCO2 (PaCO2), transcutaneous PCO2 (tcPCO2) and pH was studied at different conditions of stress. Occlusion of the maternal common iliac artery for 8 min, umbilical cord obstruction for 5 min and placental embolization were performed subsequently, every time with an interval of 1 h for fetal recuperation. During the first 2 experiments arterial values changed rapidly after occlusion and returned nearly to normal within 30-60 min after the end of occlusion. TcPCO2 started to increase several minutes after occlusion and reached its maximum about 5 min after the end of occlusion. Afterwards a gradual decrease towards the onset value was observed. During placental embolization tcPCO2 did not increase until 15 min before fetal death. It is concluded that tcPCO2 can follow a gradual trend, but not quick changes in PaCO2.

Acid-Base Imbalance↗
PubMed1997

Transcutaneous and arterial carbon dioxide tension during intermittent umbilical cord occlusion in fetal sheep.

To study the relationship between arterial PCO2 (PaCO2) and transcutaneous PCO2 (tcPCO2) intermittent 2-min total umbilical cord occlusions were performed with a 3-min interval (n = 12) in 5 fetal sheep, tcPCO2 was measured continuously. Arterial acid-base balance was analyzed at the end of occlusion periods and at the end of occlusion intervals. During each occlusion, PaCO2 increased 1.9 kPa (p < 0.001) and pH decreased 0.07 units (p < 0.001). Partial recovery occurred between occlusion intervals resulting in development of mild fetal acidemia. The quick fluctuations in PaCO2 during occlusions were not followed by tcPCO2, but tcPCO2 was capable following the trend in PaCO2. Measurement of tcPCO2 may therefore be an additional tool in the detection of the development of fetal acidemia.

Acid-Base Equilibrium↗
PubMed1996

Essential fatty acid status measured in umbilical vessel walls of infants born after a multiple pregnancy.

The essential fatty acid (EFA) status of full-term infants born after an uneventful, singleton pregnancy has been reported to be marginal. If this low EFA status is caused by a limiting maternal EFA supply, the higher total fetal EFA demand associated with a multiple pregnancy would result in an even lower EFA status of the infants born after a multiple pregnancy. Therefore, we compared the EFA status at birth of 30 pairs of twins, seven sets of triplets, and one set of quintuplets with that of 94 infants (51 preterm, 43 full-term) born after a singleton pregnancy. Phospholipid-associated EFA profiles of the umbilical vessel walls, considered a longer-term reflection of the fetal EFA status, were studied. After correction for gestational age at birth, levels of n-6 and n-3 EFAs were generally lower, while levels of EFA-deficiency indicating n-9 polyunsaturated fatty acids were significantly higher both in the draining umbilical arteries and the supplying veins of infants born after a multiple pregnancy. EFA profiles of twins and triplets were similar, but the average EFA status of the set of quintuplets was lower than that of twins and triplets. In conclusion, the observation that the EFA status of infants born after a multiple pregnancy is lower than that of infants born after a singleton pregnancy supports the view that the maternal EFA supply to the fetus is limiting. Considering the importance of EFAs and their longer chain derivatives for proper growth and development, this finding warrants further studies of the adequacy of the maternal EFA intake during pregnancy.

Adult↗
PubMed1996

Fetal and maternal transcutaneous PCO2 levels during labour and the influence of epidural analgesia.

The Departments of Obstetrics and Gynaecology of the Hvidovre University of Copenhagen and the Free University of Amsterdam collaborated in a study on the relationship of maternal and fetal acid-base state in the intrapartum period. Transcutaneous PCO2 levels of mother (tcPCO2m) and fetus (tcPCO2f) were continuously recorded in 52 patients during labour. TcPCO2f and tcPCO2m correlated significantly (r = 0.42, P < 0.002). During the first stage of labour, a rather stable level was found for tcPCO2f (7.7 +/- 1.6 kPa) and tcPCO2m (4.4 +/- 0.8 kPa). TcPCO2m decreased significantly to 3.8 +/- 0.7 kPa (P < 0.01) in the hour before full cervical dilatation, probably due to maternal hyperventilation as a reaction to painful uterine contractions. TcPCO2f likewise showed a tendency to a decrease to a mean value of 7.4 +/- 1.5 kPa. In eight cases epidural analgesia was applied because of painful uterine contractions. Prior to the epidural analgesia, tcPCO2m (3.8 +/- 0.8 kPa) and tcPCO2f (6.7 +/- 1.7 KPa) were significantly lower in this subgroup compared to the total population. After pain relief by application of epidural analgesia, tcPCO2m and tcPCO2f returned to the population mean.

Acid-Base Equilibrium↗
PubMed1996

Changes in the PR interval--fetal heart rate relationship of the electrocardiogram during fetal compromise in chronically instrumented sheep.

OBJECTIVES: The evaluation of the changes in the relationship of the PR interval and fetal heart rate during prolonged fetal compromise in sheep at levels of acidosis comparable to those seen during human fetal compromise and to see whether these changes are potentially of use in the detection of fetal distress. STUDY DESIGN: A retrospective analysis of continuous fetal electrocardiogram recordings during graded fetal hypoxemia in 20 chronically cannulated fetal sheep was performed. Baseline recordings during normoxemia were compared with recordings during hypoxemia by use of Fisher's exact test and the Student t test. RESULTS: Sixteen of the 20 cases could be used for final analysis. Twelve showed a statistically significant change from a predominantly negative relationship between the PR interval and the fetal heart rate during normoxemia to a predominantly positive relationship during hypoxemia. Two cases showed an obvious trend in the same direction, which was statistically not significant. In two other cases no change in the relationship was observed. CONCLUSION: A changing relation between the PR interval and the fetal heart rate is of potential use in the detection of fetal compromise.

Animals↗
PubMed1996

Influence of feeding artificial-formula milks containing docosahexaenoic and arachidonic acids on the postnatal long-chain polyunsaturated fatty acid status of healthy preterm infants.

In view of the importance of long-chain polyunsaturated fatty acids (LCP) for growth and development of fetal and infant neural tissue, the influence of the dietary n-3 and n-6 LCP intake on the LCP status of forty-three preterm infants (birth weight < 1800 g) was studied. Thirty-one formula-fed infants were randomly assigned to receive a conventional formula lacking LCP (n 16), or an 22:6n-3- and 20:4n-6-enriched formula (n 15); twelve infants received their own mother's breast milk. Fatty acid compositions of plasma and erythrocyte (RBC) phospholipids (PL) were determined in umbilical venous blood, in weekly postnatal samples until day 35 of life and, for the formula-fed infants, at 3 months of corrected age. Both in plasma (P < 0.001) and RBC (P < 0.01) PL, the changes with time until day 35 for 22:6n-3 and 20:4n-6 in the two groups of formula-fed infants were significantly different, with higher values, comparable with those of human-milk-fed infants, in the LCP-enriched-formula group. At 3 months of corrected age, differences between the two formula-fed groups were even more pronounced. In conclusion, adding 22:6n-3 and 20:4n-6 to artificial formulas in balanced ratios and in amounts similar to those found in preterm human milk raises both the 22:6n-3 and the 20:4n-6 status of formulated preterm infants to values found for human-milk-fed preterm infants. Additional studies are necessary to evaluate the potentially favourable effects of this combined addition on the neurodevelopmental outcome of preterm infants.

Arachidonic Acids↗
PubMed1996

Fat intake of women during normal pregnancy: relationship with maternal and neonatal essential fatty acid status.

OBJECTIVE: To study the relationships between the essential fatty acid (EFA) composition of maternal diet, maternal EFA status and the EFA status of healthy newborn infants. METHODS: A prospective longitudinal study was performed in which 176 pregnant women completed a food frequency questionnaire (FFQ) before 13, at 22, and at 32 weeks of gestation, so that changes in nutrient intake throughout pregnancy could be recorded. Around 22 weeks, a dietary history was performed and a maternal blood sample was collected. Immediately after delivery, a blood sample from the umbilical vein and a piece of the umbilical cord were collected. Fatty acid compositions were determined for phospholipids (PLs) isolated from maternal and umbilical plasma and from umbilical vein and artery vessel walls. RESULTS: No significant differences in the mean daily intake of total fat, saturated fat, mono-unsaturated fat, polyunsaturated fat and linoleic acid (18:2(n-6), LA) were observed between the three trimesters. Maternal LA intake was positively associated with LA levels in maternal and umbilical plasma and negatively associated with 20:3(n-9), 18:3(n-3), 20:4(n-3) and 22:5(n-3) levels in maternal plasma, with 20:5(n-3) levels in umbilical plasma and with 22:6(n-3) levels in umbilical vein vessel walls. Significant positive correlations for almost all (n-6) and (n-3) fatty acids were observed between maternal and umbilical plasma levels. CONCLUSIONS: The maternal dietary fat composition appears to be consistent during pregnancy. A high maternal LA intake may have a lowering effect on the maternal as well as on the neonatal (n-3) fatty acid status. Finally, neonatal EFA status is strongly related to maternal EFA status.

Adult↗
PubMed1995

The T/QRS ratio of the electrocardiogram does not reliably reflect well-being in fetal lambs.

OBJECTIVE: Our purpose was to determine the diagnostic power of the T/QRS ratio of the electrocardiogram to predict fetal well-being. STUDY DESIGN: In 47 fetal lambs (3 to 5 days after surgery, gestational age 123.5 +/- 3.0 days) asphyxia was induced by restriction of uterine perfusion. Fetuses were either pretreated with an adenosine transport inhibitor (n = 16) or a calcium channel blocker (n = 12) or served as controls (n = 19). Arterial oxygen content > or = 1.5 mmol/L or pH > or = 7.15 were chosen as limits for fetal well-being. RESULTS: Arterial oxygen content was reduced from 3.3 (+/- 1.0) to 1.3 (+/- 0.5) mmol/L, and pH decreased to 7.03 (+/- 0.10). Mortality was 53%. Both drugs did not affect well-being, survival, or the T/QRS ratio. Maximum T/QRS ratios were reached at the peak of asphyxia. Sensitivity and specificity of the T/QRS ratio were 24.0% and 42.6% to predict hypoxemia and 25.1% and 45.3% to predict acidemia. Pearson correlation coefficients for T/QRS ratio versus oxygen content and pH were 0.169 and 0.192, respectively. CONCLUSIONS: (1) In fetal lambs the T/QRS ratio failed to predict hypoxemia or acidemia. (2) Fetal survival was not correlated with the height of the T/QRS ratio during or after asphyxia.

Acids↗
PubMed1995

The essential fatty acid status of mother and child in pregnancy-induced hypertension: a prospective longitudinal study.

OBJECTIVE: Our purpose was to investigate, in a prospective way, whether the altered essential fatty acid status observed in pregnancy-induced hypertension is a consequence of the disease or may contribute to its cause. STUDY DESIGN: Pregnant women healthy at the start of the study were asked to give a blood sample before 16 weeks, at 22 weeks, and at 32 weeks of gestation. After delivery a blood sample from the umbilical vein, a piece of the umbilical cord, and a maternal blood sample were collected. Fatty acid compositions were determined of the phospholipids isolated from plasma and umbilical arterial and venous vessel walls. The nutrient intake of the pregnant women was assessed by use of the dietary history method and food frequency questionnaires. The results of each woman with pregnancy-induced hypertension were compared with the results of three matched healthy controls. RESULTS: During pregnancy (16 to 32 weeks) no significant differences were observed in nutrient intake and maternal plasma fatty acid composition between the group with pregnancy-induced hypertension (n = 52) and the control group (n = 156). After delivery the relative amounts of 18:2(n-6) and 18:3(n-3) in maternal plasma were significantly lower in pregnancy-induced hypertension than in normal pregnancy. This was associated with significantly higher levels of (n-6) long-chain polyenes and cervonic acid (22:6[n-3]). In comparison with the situation at 32 weeks, the postpartum cervonic acid status increased in pregnancy-induced hypertension, whereas it decreased in normal pregnancy. The cervonic acid levels in umbilical plasma phospholipids were significantly higher after pregnancy-induced hypertension than after normal pregnancy. No significant differences were observed for the fatty acid content in umbilical vessel walls. CONCLUSION: The results indicate that the altered essential fatty acid status in pregnancy-induced hypertension is a late phenomenon and is therefore unlikely to have contributed to the pathogenesis of pregnancy-induced hypertension. Moreover, the neonatal essential fatty acid status is not negatively affected by pregnancy-induced hypertension.

Adult↗
PubMed1995

Neuronal death after perinatal asphyxia.

During perinatal asphyxia several mechanisms aim to limit cerebral damage. However, when the degree of asphyxia passes beyond a certain threshold, brain damage is inevitable. This review focuses on the various factors determining the final cerebral outcome. Metabolic and biochemical events, such as the intracellular level of calcium, the formation of oxygen derived free radicals, the release of excitotoxic neurotransmitters and the interrelationship of these parameters are discussed. Furthermore, steps possibly useful to pharmacologic intervention aiming to reduce cerebral damage are presented.

Asphyxia Neonatorum↗
PubMed1995

Long-chain polyunsaturated fatty acids in preterm infants: status at birth and its influence on postnatal levels.

To determine the influence of the prenatal long-chain polyunsaturated fatty acid (LCP) supply on prenatal growth and on postnatal LCP levels, we studied 52 preterm infants and assessed the relations between the LCP status at birth (reflecting the prenatal LCP supply), gestational age and prenatal growth, and the relation between the LCP status at birth and at 37 to 42 weeks of gestational age. After a correction for gestational age at birth, significant relations (p < or = 0.05) were observed between anthropometric measurements at birth (weight, head circumference, and length) and LCP levels in the umbilical artery wall, the LCP content of which reflects the long-term fetal LCP status. Independent of the neonatal diet (human milk or formula), LCP levels in erythrocyte phospholipids at term were positively related to levels in the umbilical artery wall (docosahexaenoic acid (22:6n-3): p < or = 0.0003; arachidonic acid (20:4n-6): p = 0.02). Postnatal diet significantly influenced LCP levels in plasma phospholipids at term (docosahexaenoic acid: p < or = 0.004; arachidonic acid: p = 0.02); formula-fed infants had lower values. We conclude that the LCP status of preterm infants at birth is related to prenatal growth. Moreover, next to the postnatal enteral diet, the LCP status at birth significantly affects LCP levels at term postconceptional age. This finding may warrant further studies of the effects of essential fatty acid-enriched maternal diets during pregnancy on the neonatal LCP status at birth.

Anthropometry↗