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PubMed1995

The use of color Doppler ultrasound to identify fetuses at increased risk for trisomy 21: an alternative for high-risk patients who decline genetic amniocentesis.

OBJECTIVE: To compare color Doppler ultrasound with real-time ultrasound to determine whether it increased the identification of fetuses with trisomy 21. METHODS: Consecutive fetuses with a second trimester risk greater than 1:270 for trisomy 21 were examined with real-time ultrasound (n = 1028) or real-time plus color Doppler ultrasound (n = 1028) before second trimester genetic amniocentesis. The type of abnormal ultrasound findings were compared between fetuses with normal and abnormal chromosomes. Using the Bayes theorem, the ultrasound-adjusted maternal age-related risk (posterior risk) for trisomy 21 was computed after a normal or abnormal real-time plus color Doppler examination. RESULTS: A significantly greater number of fetuses with trisomy 21 (87% [13 of 15] versus 29% [5 of 17], P < .002) were identified with real-time plus color Doppler than with real-time ultrasound. Color Doppler ultrasound identified a significantly higher rate of cardiovascular abnormalities in fetuses with trisomy 21 (60% [9 of 15] versus 12% [2 of 17], P < .008) than did real-time ultrasound. Identification of abnormal fetal anatomy using real-time plus color Doppler in patients 35 years and older increases the likelihood of detecting trisomy 21. A normal real-time plus color Doppler examination of the fetus decreases the risk for trisomy 21 to less than 1:270 until the maternal age of 42, above which the risk for trisomy 21 is greater than 1:270. CONCLUSION: Real-time plus color Doppler ultrasound examination of the fetus is an alternative for the identification of trisomy 21 for patients who may decline genetic amniocentesis based on their age-related risk.

Adult↗
PubMed1996

Outcome of twin gestations complicated by a single anomalous fetus.

OBJECTIVE: To compare the outcome of twin gestations complicated by a single anomalous fetus with twin gestations with no fetal anomalies. METHODS: The study included all patients with twin gestations diagnosed with a fetal anomaly in one fetus during 1990-1994, and excluded twin gestations with anomalies in both fetuses. The control twin group was composed of all other normal twin pregnancies followed and delivered at our center in the preceding 2 years. RESULTS: We reviewed 24 twin gestations with at least one anomalous fetus. Five cases were excluded because of anomalies in both fetuses, and a further five pregnancies had selective termination or termination of the entire pregnancy. There were 14 ongoing twin pregnancies with one anomalous fetus, and their median gestational age at diagnosis was 18 weeks (range 16-20). All twin anomalies were correctly diagnosed antenatally. Gestational age at delivery and birth weight were significantly lower for twins complicated by an anomaly compared with control twins (P = .008 and P = .001, respectively). The cesarean delivery and perinatal mortality rates of twin pregnancies with anomalies were significantly higher than those of normal twins (P = .01 and P < .001, respectively). CONCLUSION: The presence of a single anomalous fetus in a twin gestation significantly increases the risk of preterm delivery compared with nonanomalous twin gestations.

Adult↗
PubMed1990

Relationship between heart rate and rhythm, and cardiac performance assessed in the human fetus in utero.

To evaluate the relationship between heart rate and rhythm, and cardiac performance, in the human fetus in utero, observed over a long-term period in gestation, we made a total of 138 studies in 114 fetuses from 18 to 41 weeks of gestation; 104 having heart rate changes without rhythm disturbances ("control group"), 6 with complete atrioventricular block and 4 with supraventricular tachycardia. Using M-mode echocardiogram, we measured end-diastolic dimension and fractional shortening in the right and left ventricles. The corresponding heart rate for each cardiac cycle was measured using the interval between two consecutive end-systolic points. In fetuses in the group of controls, the values for fractional shortening in both ventricles were almost constant with advancing gestational age, unrelated to an increase in end-diastolic dimensions of either ventricle. There was no correlation between changes in heart rate and changes in the value of ventricular fractional shortening at any period of gestation studied. In the fetuses with atrioventricular block, dimensions and fractional shortenings in both ventricles were significantly larger than those in the group of control fetuses at the same stage of gestation. This indicates that the fetal heart is capable of acclimatizing itself, beginning as early as 18-25 weeks of gestation, to long-lasting bradycardia in which an increased stroke volume would be required. In fetuses with supraventricular tachycardia, end-diastolic dimensions were larger and fractional shortening was significantly smaller in both ventricles than in fetuses from the control group from 26-30 weeks of gestation onwards. This suggests tachycardia-induced cardiomyopathy occurring during intrauterine life.

Echocardiography↗
PubMed1985

Motor behaviour in the growth retarded fetus.

In ten growth retarded fetuses (IUGR) a qualitative and quantitative analysis was made of various movement patterns. The results were compared with those of ten matched appropriate-for-gestational age fetuses (AGA). The aim of the study was to see whether malnourished, growth retarded fetuses move differently to well nourished, normal fetuses. The real-time ultrasound recordings were of one hour's duration and the analysis of motility was carried out during replay of video recordings. The qualitative analysis of each separate general movement was performed with 'Gestalt perception' describing the speed, force and amplitude of each movement as well as the variability of these descriptors. Interobserver agreement was evaluated by displaying general movements of both groups to 8 observers. There was an overall interobserver agreement of 89%. The IUGR fetuses moved less, but in individual cases an overlap existed with control fetuses. There was a reduction of both number and duration of general movements in the IUGR group. Furthermore the markedly reduced incidence of startles, twitches and isolated limb movements was striking. The qualitative analysis of general movements revealed a reduction of the quicker components leading to slow and monotonous movement patterns. There was also a marked reduction of variability of speed and intensity within each movement pattern. We speculate that the reduced variability of motor patterns may find its origin in a change of central neural function, just as the reduced heart rate variability and decreased breathing irregularity found in IUGR fetuses.

Adult↗
PubMed1989

Behavioural state transitions in healthy and growth retarded fetuses.

The transitions, i.e. time intervals between two different behavioural states, were studied in 10 healthy and 10 growth retarded fetuses (IUGR) in near term pregnancies. In healthy fetuses, transitions usually lasted less than 3 min whereas IUGR fetuses showed a longer duration when compared to healthy fetuses. Moreover, a significant trend in the change of state variables (fetal heart rate, fetal eye movements and fetal gross body movements) was evident in healthy fetuses: fetal heart rate was the first variable to change in transitions from 1F to 2F and the last variable to change in transitions from 2F to 1F. On the other hand IUGR fetuses showed a random sequence in order of change. These findings were substantiated by the intraindividual consistency evidenced in repeated recordings. In conclusion the analysis of transitions differentiates between healthy fetuses and those affected by IUGR.

Blood Flow Velocity↗
PubMed1990

Abnormal velocity waveforms of the umbilical artery in growth retarded fetuses: relationship to antepartum late heart rate decelerations and outcome.

In 70 intrauterine growth-retarded (IUGR) fetuses with antepartum late heart rate decelerations recordings of velocity waveforms of the umbilical artery were made with Doppler ultrasound and calculated as pulsatility indexes (PI). In 29 of these fetuses longitudinal recordings were made. Abnormal PIs preceded the occurrence of late heart rate decelerations in 27 (93%) of the 29 fetuses. The median duration of the interval between the first abnormal PI and the first appearance of antenatal heart rate decelerations was 17 days (range 0-60 days). This wide range can mainly be attributed to the gestational age at which the first abnormal velocity wave-form was recorded; during early gestation the interval was much longer than later in pregnancy. Absent end-diastolic velocity (AEDV) was found in 17 of the 29 fetuses (59%) and preceded the occurrence of decelerations with a median interval of 12 days. In the total group, 4 of the 70 IUGR fetuses with antepartum decelerations had a normal velocity waveform of the umbilical artery. Fetuses with AEDV (n = 45) were more severely growth retarded and were delivered at an earlier gestational age than those with end-diastolic velocity (n = 25). Also perinatal mortality and morbidity were higher in the group with AEDV. Yet, when fetuses were matched for gestational age and birth weight no differences in perinatal outcome were found in the groups with and without end-diastolic velocity.

Adult↗
PubMed1991

Tricuspid valve disease with significant tricuspid insufficiency in the fetus: diagnosis and outcome.

The echocardiographic studies and clinical course of 27 fetuses (mean gestational age 26.9 weeks) diagnosed in utero with tricuspid valve disease and significant tricuspid regurgitation were reviewed. The diagnosis of Ebstein's anomaly was made in 17 of the fetuses, 7 had tricuspid valve dysplasia with poorly developed but normally attached leaflets and 2 had an unguarded tricuspid valve orifice with little or no identifiable tricuspid tissue. One fetus was excluded from data analysis because a more complex heart lesion was documented at autopsy. All fetuses had massive right atrial dilation and most who were serially studied had progressive right-sided cardiomegaly. Hydrops fetalis was found in six cases and atrial flutter in five. Associated cardiac lesions included pulmonary stenosis in five cases and pulmonary atresia in six. Four fetuses with normal forward pulmonary artery flow at the initial examination were found at subsequent study to have retrograde pulmonary artery and ductal flow in association with the development of pulmonary stenosis (n = 1) and pulmonary atresia (n = 3). On review of the clinical course of the 23 fetuses (excluding 3 with elective abortion), 48% of the fetuses died in utero and 35% who were liveborn died despite vigorous medical and, when necessary, surgical management, many of whom had severe congestive heart failure. Of the four infants who survived the neonatal period, three had a benign neonatal course, all of whom were diagnosed with mild to moderate Ebstein's anomaly; only one had pulmonary outflow obstruction. An additional finding at autopsy was significant lung hypoplasia documented in 10 of 19 autopsy reports.(ABSTRACT TRUNCATED AT 250 WORDS)

Ebstein Anomaly↗
PubMed2005

Right ventricular pre-ejection myocardial velocity and myocardial acceleration in normal fetuses assessed by Doppler tissue imaging.

Myocardial acceleration during isovolumic contraction obtained from Doppler tissue imaging has been introduced as an index of right ventricular contractile function that is unaffected by the shape of the ventricle and loading conditions, but normal value of myocardial acceleration during isovolumic contraction and the effect of aging on the index are not known in normal fetuses. We studied 61 normal fetuses aged 20 to 39 weeks (29.8 +/- 5.1 weeks). Fetuses were divided into 4 age groups: 20 to 24 weeks (n = 11); 25 to 29 weeks (n = 20); 30 to 34 weeks (n = 20); and 35 to 39 weeks (n = 10). Using Doppler tissue imaging, peak pre-ejection myocardial velocity was measured at the base of right ventricular free wall from 4-chamber view. Myocardial acceleration was calculated by dividing pre-ejection velocity by the time interval from onset of the pre-ejection myocardial velocity to the time at peak velocity of this wave. The mean pre-ejection myocardial velocity was 5.0 +/- 1.1 cm/s. There was a stepwise increase in the pre-ejection myocardial velocity from the fetuses of 20 to 24 weeks to the fetuses of 35 to 39 weeks. The mean myocardial acceleration was 160 +/- 30 cm/s 2 . The mean myocardial acceleration did not differ between the fetuses aged 20 to 24 weeks (139 +/- 13 cm/s 2 ) and the fetuses aged 25 to 29 weeks (143 +/- 21 cm/s 2 ), but after 30 weeks increased with gestational age. For the total group combining the 4 different gestational age groups, the pre-ejection myocardial velocity and myocardial acceleration correlated with gestational age ( r = 0.85 and 0.75). This study demonstrated the gestational age-related changes in pre-ejection myocardial velocity and myocardial acceleration. The load-independent index of contractility, myocardial acceleration, increased mainly after 30 weeks' gestation.

Echocardiography, Doppler↗
PubMed2005

The fetus cannot exercise like an astronaut: gravity loading is necessary for the physiological development during second half of pregnancy.

On the basis of published Magnetic Resonance Images and the values of the specific fetal and amniotic fluid weights, apparent weight of the fetus from the 18th week of gestation until term was determined. Up to the 21-22nd gestation week the fetus is in conditions similar to neutral floating, while after the 26th gestation week the apparent weight of the fetus is 60-80% of the actual weight. Decreased effect of the buoyant forces that affect the fetus in human species during the last trimester has a number of implications for the colonization of the solar system. During space flight it is impossible to apply the existing countermeasures against microgravity deconditioning of the muscular and cardiovascular systems to the fetus. Absence of gravitational loading during the last trimester of gestation would cause hypotrophy of the spinal extensors and lower extremities muscles, reduction in the amount of myosin heavy chain type I in the extensor muscles of the trunk and legs, hypoplasy and osteopeny of the vertebras and lower extremities long bones, and hypotrophy of the left ventricle of the heart muscle. Because of decreased capacity of postural and locomotor stability, acquisition of the gross developmental milestones such as sitting, standing and walking could be delayed. In the authors' opinion, only artificial gravity (rotating platform) during space flight will allow physiological development of the human fetus. Independency of offspring's of the guinea pig as regards locomotion and nursing increases probability of successful breeding in microgravity compared with rat offspring's, and make this species a candidate for future experiments under conditions of microgravity and hypergravity. Examining the gestation of this species in different gravities requires first the experimental determination of the amount of buoyant force to which the fetus is exposed in physiological conditions.

Animals↗
PubMed2006

Auditory processing deficits in growth restricted fetuses affect later language development.

An increased risk for language deficits in infants born growth restricted has been reported in follow-up studies for more than 20 years, suggesting a relation between fetal auditory system development and later language learning. Work with animal models indicate that there are at least two ways in which growth restriction could affect the development of auditory perception in human fetuses: a delay in myelination or conduction and an increase in sensorineural threshold. Systematic study of auditory function in growth restricted human fetuses has not been reported. However, results of studies employing low-risk fetuses delivering as healthy full-term infants demonstrate that, by late gestation, the fetus can hear, sound properties modulate behavior, and sensory information is available from both inside (e.g., maternal vascular) and outside (e.g., noise, voices, music) of the maternal body. These data provide substantive evidence that the auditory system is functioning and that environmental sounds are available for shaping neural networks and laying the foundation for language acquisition before birth. We hypothesize that fetal growth restriction affects auditory system development, resulting in atypical auditory information processing in growth restricted fetuses compared to healthy, appropriately-grown-for-gestational-age fetuses. Speech perception that lays the foundation for later language competence will differ in growth restricted compared to normally grown fetuses and be associated with later language abilities.

Child↗
PubMed1984

Management of ventriculomegaly in the fetus.

We studied 24 human fetuses with cerebral ventriculomegaly by serial obstetric ultrasound to define the natural history of fetal ventricular enlargement and to develop a management strategy. In 10 fetuses, ventriculomegaly was associated with other severe anomalies; nine of these families chose to terminate the pregnancy. In three other severely affected fetuses in whom ventriculomegaly was detected serendipitously late in gestation, routine obstetrical management was performed; none survived. Eleven fetuses had ventriculomegaly without associated severe anomalies. Ventriculomegaly remained stable or of moderate severity throughout gestation in nine, resolved gradually in one, and progressed in one who did not have signs of increased intracranial pressure at birth. All of these fetuses were viable; three patients required shunting in the neonatal period, and two others by 5 months of age. Although obstetric ultrasound usually can detect anomalies associated with fetal ventriculomegaly, three fetuses with isolated ventriculomegaly had midline brain malformations that could not be distinguished in utero from hydrocephalus, even in retrospect. Prenatal diagnosis improves perinatal management by allowing counseling, and selective pregnancy termination, or selection of the timing, mode, and place of delivery to optimize outcome. Most fetuses with ventriculomegaly do not require intervention before birth.

Abnormalities, Multiple↗
PubMed1991

Presence of a low capacity androgen receptor in the gubernaculum of the pig fetus.

The aim of our study was to investigate the theory that the gubernaculum is an androgen-responsive structure responsible for fetal testicular descent. Using 3H-methyltrienolone (3H-R1881) as ligand, we performed a seven-point Scatchard analysis of androgen receptor binding in the gubernaculum, prostate, urethra and striated muscle tissue obtained from pig fetuses between 60 and 109 days of gestation. The gubernaculum demonstrated androgen receptor binding with an affinity and capacity significantly lower than that of fetal pig prostate and urethra, but not significantly different from that of striated muscle taken from both male and female fetuses. A marked increase in the size and mass of the gubernaculum of male (but not female) fetuses is known to accompany testicular descent. If the dramatic increase in the mass of the gubernaculum observed in male (but not female) fetuses were the result of androgen stimulation, it may be expected that the striated muscle mass (and therefore total body mass) of male fetuses should be greater than that of female fetuses, since the androgen receptor affinity and capacity of the gubernaculum is similar to that of striated muscle. However, we found no significant difference in total body mass between male and female pig fetuses at the same period of gestation. These findings raise doubt concerning the theory that growth of the gubernaculum during descent is the result of androgen stimulation.

Animals↗
PubMed2002

Echogenic bowel in intrauterine growth restriction fetuses: does this jeopardize the gut?

OBJECTIVE: To investigate the association between intrauterine growth restriction (IUGR) fetuses with echogenic bowel and high resistance in the umbilical artery and increased risk of developing neonatal necrotizing enterocolitis. METHODS: We analyzed two groups: group 1, singleton IUGR fetuses with echogenic bowel or reversed diastolic flow in the umbilical artery, and group 2, neonates who were diagnosed as having neonatal necrotizing enterocolitis. In group 1, the pulsatility index of the superior mesenteric artery and celiac trunk were determined. In group 2, a retrospective analysis was carried out from the medical records of the neonates. RESULTS: Fifteen fetuses with echogenic bowel and severe IUGR were evaluated by Doppler studies, and 21 neonates with neonatal necrotizing enterocolitis were reviewed. In group 1, none of the IUGR fetuses developed neonatal necrotizing enterocolitis, whereas in group 2, only one neonate was defined as IUGR. The mean gestational age at delivery did not differ statistically between the two groups (28.8 +/- 2.3 weeks versus 30.1 +/- 3.3 weeks), whereas the mean birth weight was significantly lower in the first group (700 +/- 200 g versus 1431 +/- 466 g in the second group, P <.001). The mean pulsatility index +/- standard deviation in the superior mesenteric artery and celiac trunk of the IUGR fetuses were 1.5 +/- 0.14 and 1.2 +/- 0.17, respectively, both being found significantly lower than those of normal, appropriate controls (1.9 +/- 0.15 and 1.7 +/- 0.1, respectively, P <.005). CONCLUSION: Fetal echogenic bowel in IUGR fetuses is not associated with development of neonatal necrotizing enterocolitis. In these fetuses, vasodilatation in the superior mesenteric artery and celiac trunk have been demonstrated.

Enterocolitis, Necrotizing↗
PubMed1997

Cerebral and umbilical vascular resistance response to vibroacoustic stimulation in growth-restricted fetuses.

OBJECTIVE: To test the hypothesis that after vibroacoustic stimulation the ratio between cerebral vascular and umbilical vascular resistance in the growth-restricted fetus is different from that in the normal fetus. METHODS: The pulsatility index (PI) of the middle cerebral artery and that of the umbilical artery (UA) were measured by pulsed Doppler velocimetry in 30 normal and 14 growth-restricted fetuses before and after vibroacoustic stimulation. The ratios of cerebral PI to UA PI and the changes in PI after vibroacoustic stimulation were calculated. Comparisons were made using the Wilcoxon rank-sum test or signed-rank test. The statistical power of the study was 80%. RESULTS: Mean (+/- standard deviation) cerebral PI values before vibroacoustic stimulation (1.50 +/- 0.29) in normals and 1.29 +/- 0.26 in the fetal growth restriction [FGR] group) and UA PI values (1.00 +/- 0.18 in normals and 1.15 +/- 0.24 in the FGR group) were significantly different between groups (P < .04) and significantly decreased after vibroacoustic stimulation (P < .05). Although the cerebral to UA PI ratios (1.50 +/- 0.38 in normals and 1.13 +/- 0.33 in the FGR group) were significantly different between groups (P < .008), the values remained the same after vibroacoustic stimulation (P = .39 and .80, respectively). In all fetuses the fetal heart rate accelerated after vibroacoustic stimulation. CONCLUSION: Cerebral vascular resistance was lower and umbilical vascular resistance higher in the growth-restricted fetuses than in normals. The vascular resistance response after vibroacoustic stimulation in the growth-restricted fetus was not significantly different from the response of the normal fetus, suggesting preservation of regulation of resistance.

Acoustic Stimulation↗
PubMed1998

Weekly nuchal translucency measurements in normal fetuses.

OBJECTIVE: To examine the longitudinal course of nuchal translucency thickness by weekly measurements between 10 and 15 weeks' gestation in normal fetuses. METHODS: Nuchal translucency was measured weekly from 10 to 15 weeks' gestation in 64 fetuses with normal pregnancy outcome. The median and the fifth, 25th, 75th, and 95th percentiles were calculated. RESULTS: Nuchal translucency measurements varied considerably with gestational age; this variation followed a fetus-specific pattern. In 94% of cases, we observed an increase followed by a steady decrease in nuchal translucency measurement. A visible nuchal translucency was found after 76 and 86 days' gestation in 97% (95% confidence interval [CI] 89, 100) and 100% (95% CI 94, 100) of the fetuses, respectively. The median nuchal translucency increased from 0.7 mm at 70 days' gestation to 1.7 mm at 91 days' gestation, after which it declined to 1.0 mm at 105 days' gestation. CONCLUSION: A progressive increase and subsequent decrease in nuchal translucency thickness occurs with advancing gestation in most fetuses, but the timing of the peak thickening appears to be fetus-specific. In this study, each fetus developed a visible nuchal translucency. If the nuchal translucency measurement is 0 mm before 12 weeks, it may be advisable to repeat the measurement at 12 weeks' gestation. In contrast, a nuchal translucency that cannot be measured from 12 weeks' gestation onward suggests that this temporary anatomic entity is already in its waning phase.

Adult↗
PubMed1999

Outcome of fetuses diagnosed with atrioventricular septal defect.

OBJECTIVE: To quantify the association of prenatally diagnosed atrioventricular septal defect with Down syndrome and to evaluate its impact on obstetric and neonatal outcomes. METHODS: Charts of 42 cases of atrioventricular septal defect diagnosed by fetal echocardiography from July 1985 to July 1997 were reviewed for prenatal history and outcome data (pregnancy outcome, pathologic confirmation, postnatal echocardiographic findings, and neonatal outcome). Statistical analysis was done using Fisher exact test and odds ratios. RESULTS: The mean gestational age at diagnosis was 26 weeks. Four cases could not be confirmed antenatally on repeat echocardiograms and were excluded. Reasons for referral of the remaining 38 fetuses included an abnormal four-chamber view in 76%. Twenty-two fetuses (58%) had abnormal karyotypes: 19 trisomy 21, one trisomy 18, one trisomy 13, and one mosaicism. The cardiac lesions were isolated in 20 fetuses (53%). After excluding cases of termination, ten of 12 fetuses (83%) with Down syndrome survived, compared with seven of 13 (54%) with normal karyotypes (P = .125). The odds of trisomy 21 were 16 times higher (95% confidence interval 3.0, 85.3) in fetuses with isolated cardiac lesions compared with those with associated cardiac anomalies. CONCLUSION: Prenatal diagnosis of atrioventricular septal defect was associated with a 58% risk of aneuploidy (mainly trisomy 21). Down syndrome fetuses with this cardiac anomaly appeared to have a better survival rate than fetuses with normal karyotypes. Our sample did not have enough power to show a statistically significant difference. When an isolated atrioventricular septal defect was diagnosed prenatally, the odds of trisomy 21 were significantly higher than when other associated cardiac lesions were diagnosed. This information should be considered in prenatal counseling for atrioventricular septal defect.

Adult↗
PubMed1998

The effects of fetal adrenalectomy at 110 days gestational age on AVP and CRH mRNA expression in the hypothalamic paraventricular nucleus of the ovine fetus.

AVP and CRH produced in the parvocellular neurons of the paraventricular nucleus (PVN) have both been implicated in the regulation of anterior pituitary ACTH synthesis and secretion. In sheep, fetal ACTH secretion increases around 120 days gestational age (dGA). Little is known about adrenal regulation of AVP and CRH immediately prior to this critical period. We investigated the effects of adrenalectomy and subsequent cortisol (F) administration on PVN AVP and CRH mRNA in the fetal sheep PVN at 109-125 dGA. At 109-113 dGA, fetal sheep adrenals were removed (ADX)(n = 8); or sham surgery performed (CONT)(n = 4). From day 6 post ADX, maternal plasma cortisol and fetal plasma ACTH and cortisol levels were determined daily by radioimmunoassays. From day 7 post ADX, cortisol (4 micrograms/min) was continuously infused intravenously to four ADX fetuses (ADX + F). Fetal hypothalami were collected at 123-125 dGA, and studied by in-situ hybridization and quantitative autoradiography for AVP and CRH mRNA. Plasma cortisol levels remained low in CONT and ADX fetuses (< 4.9 ng/ml), while during cortisol infusion to ADX + F fetuses, plasma F increased to 16.4 +/- 2.2 and 22.3 +/- 3.2 ng/ml (mean +/- S.E.M.) on day 10 and 13, respectively. Plasma ACTH levels increased significantly in ADX compared with CONT fetuses. This ACTH increase was completely suppressed in ADX + F fetuses. AVP mRNA abundance in the whole PVN was the same in all three groups, however, a separate analysis of AVP mRNA abundance in parvocellular and magnocellular regions of the PVN revealed that AVP mRNA in the parvocellular PVN showed a significant increase in ADX and suppression in ADX + F fetuses when compared to CONT. AVP mRNA in the magnocellular PVN remained unchanged. PVN CRH mRNA expression was augmented in ADX and suppressed in ADX + F when compared to CONT fetuses. We conclude that in fetal sheep at 109-125 dGA: AVP and CRH mRNA abundance in the parvocellular region of the PVN are increased by adrenalectomy and that cortisol inhibits this increase.

Adrenal Glands↗
PubMed1997

Assessment of mitral A-wave transit time to cardiac outflow tract and isovolumic relaxation time of left ventricle in the appropriate and small-for-gestational-age human fetus.

Mitral A-wave transit time (Ta; ms) from the mitral valve to the left ventricular outflow tract and left ventricular isovolumic relaxation time (IRT) were studied by pulsed Doppler ultrasound in 17 appropriate-for-gestational-age fetuses (AGA, 30-39 wk) and 12 small-for-gestational-age fetuses (SGA, 30-36 wk). Ta was measured from the peak of the A-wave to the peak of the reflected A-wave (Ar) from the left ventricular wall. IRT was determined from the interval between the aortic valve closure artefact and the onset of transmitral flow. The mean Ta in the SGA fetus (42 +/- 7 [1 SD] ms) was significantly shorter (p < 0.03) than in the AGA fetus (47 +/- 11 [1 SD] ms), whereas this was not so for IRT (51 +/- 8 [1 SD] ms vs. 60 +/- 15 [1 SD] ms). In the SGA fetus, a positive correlation (r = +0.82, p < 0.01) was established between Ta (ms) and gestational age. No such correlation existed for the AGA fetus. It is speculated that, in the SGA fetus, the shorter Ta may reflect an increase in left ventricular stiffness.

Adolescent↗