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PubMed2005

Aberrant right subclavian artery as a new cardiac sign in second- and third-trimester fetuses with Down syndrome.

OBJECTIVE: The right subclavian artery arises normally as the first vessel from the brachiocephalic artery of the aortic arch. An aberrant right subclavian artery arises as a separate vessel from the aortic isthmus and crosses to the right, behind the trachea. This variant is present in <1% of the normal population; however, in subjects with Down syndrome, an incidence between 19% and 36% was reported. The purpose of this study was to assess the possibility of the detection of an aberrant right subclavian artery in fetuses with Down syndrome. STUDY DESIGN: Fourteen consecutive fetuses with prenatally detected Down syndrome were examined between 18 and 33 weeks of gestation. The presence of an aberrant right subclavian artery was determined by visualization of the transverse 3-vessel trachea view of the upper thorax with color Doppler ultrasonography. RESULTS: The right subclavian artery was visualized in 100% of fetuses (14/14) with Down syndrome. An aberrant right subclavian artery was identified in 35.7% of trisomy 21 fetuses (5/14). In 1 fetus, the aberrant right subclavian artery was the only abnormal ultrasound finding. In 3 fetuses, an aberrant right subclavian artery was associated with an intracardiac echogenic focus plus additional extracardiac markers. In the fourth fetus, an aberrant right subclavian artery was associated with an atrioventricular septal defect. All 9 fetuses with Down syndrome with a normal origin of the right subclavian artery had additional cardiac and/or extracardiac abnormalities. In 12 cases, pregnancy was terminated; 2 fetuses were live born. CONCLUSION: This preliminary study suggests that the in utero identification of an aberrant right subclavian artery may be a new ultrasound marker to be found in fetuses with Down syndrome. Further studies are required to assess the incidence of aberrant right subclavian artery in normal fetuses.

Adult↗

PubMed2004

Urogenital anomalies in human male fetuses.

BACKGROUND: There are few studies in the literature performed in human fetuses evaluating the incidence of genitourinary anomalies. AIMS: Analyze the incidence of congenital urogenital malformations in human male fetuses. STUDY DESIGNS AND SUBJECTS: We analyzed 166 human male fetuses well preserved. The gestational age was determined in weeks post conception (WPC) according to the foot length criterion and ranged from 10 to 35 WPC. The fetuses were dissected with the aid of a stereoscopic lens with 2.5x magnification. We performed abdominal and pelvic incisions to expose the urogenital organs. We studied the incidence of renal, ureteral, vesicle, urethral, testicular, epididymal, vas deferens, prostate and penile anomalies. RESULTS: Of the 166 fetuses, 7 (4.2%) presented some kind of anomaly of the urogenital system. Renal anomalies were found in two fetuses (1.2%). Unilateral renal agenesis was found in a 25 WPC fetus. Horseshoe kidney was found in a 20 WPC fetus. In a 23 WPC fetus (0.6%) the two testes were absent. Epididymal disjunction anomalies were found in four fetuses (2.4%). CONCLUSIONS: The urogenital anomalies in human male fetuses are rare and have an incidence around 4%.

Epididymis↗

PubMed2001

Evaluation of systolic and diastolic ventricular performance of the right ventricle in fetuses with ductal constriction using the Doppler Tei index.

Fetal ductal constriction (DC) can depress right ventricular (RV) function. However, noninvasive assessment of fetal RV function remains difficult. We evaluated RV and left ventricular (LV) performance in fetuses with DC using the Doppler-derived Tei index. The Tei index measures the ratio of total time spent in isovolumic contraction and relaxation (isovolumic time) to the ejection time. Tricuspid inflow and RV outflow Doppler traces for the derivation of RV Tei indexes and mitral inflow and LV outflow traces for LV Tei indexes were measured in 78 fetuses of pregnant women who received indomethacin and 70 normal fetuses (gestational ages ranging from 20 to 39 weeks). DC occurred in 23 fetuses, defined as pulsatility index <1.9. In fetuses with DC, the RV isovolumic time was prolonged and RV ejection time was shortened, and the RV Tei index was high compared with those in fetuses that received indomethacin without DC and normal fetuses. Also, the RV Tei index clearly separated the fetuses with DC from normal and fetuses that received indomethacin without DC (0.74 +/- 0.14 vs 0.35 +/- 0.07 and 0.37 +/- 0.06, respectively; p <0.0001). The LV Tei index was not affected by DC. Serial study in 7 fetuses with DC showed that the RV Tei index decreased from 0.69 +/- 0.12 to 0.38 +/- 0.04 (p = 0.0002) after discontinuation of indomethacin coincident with ductal relaxation, although it remained elevated in 2 cases at the time of ductal relaxation. Thus, the Tei index is a useful and sensitive indicator for detecting abnormal RV performance in fetuses with DC.

Echocardiography, Doppler↗

PubMed2001

Bovine nuclear transfer embryo development using cells derived from a cloned fetus.

Many different cell types have been used to generate nuclear transfer embryos and fetuses. However, little is known about the potential of fibroblasts derived from a nuclear transfer fetus as donor cells for nuclear transfer. The ability of cloned fetuses or animals to be cloned themselves is of great interest in determining whether successive generations of clones remain normal or accumulate genetic or phenotypic abnormalities. We generated a bovine fibroblast cell line from a cloned fetus, that continued to divide beyond 120 days (94 doublings,18 passages) in continuous culture. As long-term survival of cells in culture is a desirable characteristic for use in transgenic cell production, passage 2 and 18 cells were compared as donor cells for nuclear transfer (NT). When cells from passage 2 (2 weeks in culture) and passage 18 (4 months in culture) were used for nuclear transfer, there was no significant difference in development rate to blastocyst (35.4 versus 44.6%, P=0.07). A greater proportion of late passage cells were in G0/G1 whether under serum-fed (64 versus 56%, P<0.01) or serum-starved (95 versus 88%, P<0.01) culture conditions. Following embryo transfer, equivalent day 30 pregnancy rates were observed for each group (P 2: 2/19 versus P 18: 2/13). A slightly retarded fetus was surgically removed at day 56 and the remaining three fetuses died in utero by day 60 of gestation. Our results show that fibroblast cells derived from regenerated cloned fetuses are capable of both in vitro and in vivo development. The longevity of this regenerated cell line would allow more time for genetic manipulations and then to identify stable transfected cells prior to their use as NT donor cells. Although no live fetuses were produced in this study the results provide encouraging data to show that a cloned fetus can itself be recloned to produce another identical cloned fetus. Further studies on this and other recloned fetuses are necessary to determine whether the failure to produce live offspring was a result of inadequate sample size or due to the cell type selected.

Animals↗

PubMed1999

Cardiac blood flow studies in fetuses with homozygous alpha-thalassemia-1 at 12-13 weeks of gestation.

OBJECTIVE: Fetuses affected by homozygous alpha-thalassemia-1 develop anemia as early as the first trimester. Our objective was to study hemodynamic indices in affected fetuses at 12-13 weeks of gestation to determine whether these would be useful in the prediction of anemia. DESIGN: Prospective observational study. SUBJECTS: Women referred before 14 weeks of gestation for the prenatal diagnosis of homozygous alpha-thalassemia-1. METHODS: Transabdominal and/or transvaginal Doppler sonography was performed to measure the flow velocities in the fetal ascending aorta and pulmonary artery at 12-13 weeks. The Doppler indices were compared between those that were subsequently confirmed to be affected by homozygous alpha-thalassemia-1 and those that were unaffected. RESULTS: Between June 1997 and April 1998, 60 eligible women were recruited. Doppler examination was successful in 58 fetuses. Of these, 22 were subsequently confirmed to be affected by homozygous alpha-thalassemia-1. The diagnosis was made by chorionic villus sampling and DNA analysis in two affected fetuses and by cordocentesis and hemoglobin evaluation in 20 affected fetuses. Hemoglobin concentrations could be measured in ten fetuses and these ranged from 4 to 8 g/dl. The affected fetuses had significantly higher peak velocities at the pulmonary valve and ascending aorta and a larger inner diameter of the pulmonary valve than that in unaffected fetuses. The total cardiac output was increased by one-third in affected fetuses and was mainly due to an increase of the right-side cardiac output. CONCLUSION: In the early stage of anemia, the fetus responds mainly by increasing its right-side cardiac output. However, there is extensive overlap of the values of cardiac output between the affected and the unaffected fetuses, precluding its use in the prediction of anemia.

Adult↗

PubMed2001

Arterial Doppler ultrasound in 115 second- and third-trimester fetuses with congenital heart disease.

OBJECTIVE: To assess the influence of isolated congenital heart disease (CHD) on fetal arterial Doppler blood flow velocity waveforms. METHODS: Doppler flow velocimetry was performed in the umbilical artery and middle cerebral artery in 115 consecutive fetuses with antenatally diagnosed CHD. Gestational age ranged between 19 and 41 weeks. Fetuses with isolated CHD were defined as group A (n = 55), showing cardiogenic hydrops fetalis in six cases; group B included 60 cases complicated by chromosomal or non-chromosomal extracardiac malformation, uteroplacental dysfunction or non-cardiogenic non-immune hydrops fetalis. The control group comprised 100 healthy fetuses of uncomplicated pregnancies. Individual pulsatility index measurements were converted into their Z-scores (delta values) for statistical analysis. RESULTS: In regard to the umbilical artery pulsatility index, 115 fetuses with CHD showed a significantly greater (P < 0.001) difference from the normal mean for gestation (delta values) than the control group. However, 29 of the 33 cases with indices above the 95% reference interval were additionally associated with extracardiac malformations, uteroplacental dysfunction or non-cardiogenic non-immune hydrops fetalis. While fetuses with isolated CHD still showed significantly higher values than healthy fetuses (P < 0.01), only in 4 of 55 (7%) fetuses did the measured umbilical artery pulsatility index exceed the 95% reference interval. There was no significant difference from the control group, in which 4 of 100 cases showed an umbilical artery pulsatility index above the 95% reference interval. Elevated umbilical artery pulsatility indices were seen in only four cases of severe obstruction of the outflow tracts leading to reverse perfusion of the affected great artery and in one case of Ebstein's anomaly with pulmonary insufficiency. Although all four fetuses with isolated CHD and elevated umbilical artery pulsatility index died, 14 of 18 fetuses with lethal outcome had normal pulsatility index values in the umbilical artery. Investigations of the middle cerebral artery blood flow revealed no significant difference between fetuses with and without CHD or any subgroups. CONCLUSIONS: This study shows that arterial blood flow velocity waveforms in fetuses with isolated CHD do not show sufficient alterations to be of diagnostic value. Only in severe outflow tract obstructions due to a 'steal effect' or in significant insufficiencies of semilunar valves leading to an impaired 'wind-kessel function' may the special hemodynamic changes induced by CHD result in a significant increase of pulsatility index in the umbilical artery. In the majority of cases with CHD the increase of pulsatility index of umbilical arterial blood flow velocity waveforms, however, results from extracardiac anomalies, especially uteroplacental dysfunction and chromosomal abnormalities. Furthermore, umbilical artery Doppler sonography is not clinically helpful in predicting fetal outcome.

Blood Flow Velocity↗

PubMed1999

Male fetuses are particularly affected by maternal alloimmunization to D antigen.

BACKGROUND: It is hypothesized that male fetuses are more severely affected by fetomaternal alloimmunization to D antigen than female fetuses. STUDY DESIGN AND METHODS: One hundred four consecutive pregnancies with single D+ fetuses (51 males, 53 females) and maternal anti-D titers >16 were analyzed retrospectively. RESULT: Sixty fetuses (58%) received intrauterine transfusions. Male fetuses required more transfusions than females (5.0 vs. 2.0, p = 0.0001). At the initial transfusion, male fetuses had a lower gestational age (24.5 vs. 31.0 weeks, p = 0.0007), cord blood hemoglobin content (6.45 vs. 8.75 g/dL, p = 0.01), and hematocrit (19.8 vs. 26.8%, p = 0.004) than female fetuses. After adjustment for maternal gravidity, parity, and history of affected offspring, the odds ratio for development of hydrops by male fetuses was 13.1 (95% CI 2.69-63.6, p = 0.001). Perinatal mortality was higher in male (18%) fetuses than in female (6%) (adjusted odds ratio for males 3.38; 95% CI 0.59-19.46, p = 0.17). CONCLUSION: Male fetuses are particularly affected by maternal alloimmunization to D and require more intense antepartum surveillance than female fetuses.

Adult↗

PubMed2001

Erythrocyte and erythropoietin responses to hemorrhage in the immature and near term ovine fetus.

OBJECTIVE: Previous reports suggested that immature ovine fetuses have a greater erythropoietin response to hemorrhage than those near term. This study tested the hypothesis that immature ovine fetuses would expand their red cell mass more rapidly than near term fetuses after hemorrhage. STUDY DESIGN: Chronically catheterized immature ovine fetuses at 109.5 +/- 0.3 (mean +/- SE) days' gestation (term = 150 days) were studied over a 10-day period. They either underwent hemorrhage of 40% of their measured blood volume on day 3 or were in a time control group monitored without hemorrhage. Red cell mass, hematocrit, blood volume, plasma volume, and plasma erythropoietin concentrations were measured at 24- and 48-hour intervals. Responses in the immature fetuses were compared with responses in near term fetuses. RESULTS: In the control group red cell mass, hematocrit, blood, and plasma volumes increased significantly, whereas plasma erythropoietin concentration decreased significantly with advancing gestational age. In immature fetuses that underwent hemorrhage, the relative changes in red cell mass, hematocrit, and plasma erythropoietin concentration were not significantly different from those seen in the near term fetuses. The only significant posthemorrhage difference was that the increases in blood and plasma volumes were greater in the immature compared with the near term fetuses. CONCLUSION: Immature and mature fetuses have similar erythrocyte and erythropoietin responses to moderately severe hemorrhage. The larger blood and plasma volume responses in the immature fetuses are consistent with the concept that they have a greater extracellular fluid volume.

Animals↗

PubMed1996

Luteinizing hormone, follicle-stimulating hormone, testosterone and dihydrotestosterone during testicular descent in the pig fetus.

To investigate the relationship between gonadotrophins, androgens and testicular descent in the pig fetus, serum concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and serum concentrations and testicular content of testosterone (T) and 5 alpha-dihydrotestosterone (DHT) were determined by radioimmunoassay in 95 fetuses (48 males, 47 females) between Day 60 and Day 90 post coitum (p.c.). The testes were descended in 0% of fetuses at Day 60, 8% of fetuses at Day 70, 40% of fetuses at Day 80 and 87% of fetuses at Day 90 p.c. There was a significant increase in mean serum concentrations of LH in both male and female fetuses from Day 60 to Day 90, with a significant difference in mean serum concentrations of LH between male fetuses with a body mass < 350 g (4% of testes descended) and those with a body mass > 450 g (87% of testes descended), but not between male and female fetuses < 350 g or > 450 g in body mass. There was no significant difference in mean serum concentrations of FSH between male and female fetuses. Mean serum concentrations of T were significantly higher in male fetuses at Day 60 than in those at Days 70-90, with no significant difference in serum concentrations of DHT from Day 60 to Day 90 p.c. Testicular content of T and DHT showed a non-linear increase from Day 60 to Day 90 p.c. Although the serum concentration of T is elevated before, and decreased during, the period of descent, the testicular content of T and DHT increases during the period of descent, indicating that serum concentrations of LH and FSH may have an indirect effect on descent by stimulating testicular androgen synthesis.

Dihydrotestosterone↗

PubMed1991

Catecholamines in experimentally growth-retarded rat fetus.

This study was designed to evaluate the sympathoadrenal system in rat IUGR fetuses prepared by the Wigglesworth method. Samples were obtained on day 20 of gestation. In the amniotic fluid, concentrations of norepinephrine (NE) and particularly epinephrine (E) were significantly higher in IUGR fetuses than in normally developed fetuses (NE: p less than 0.05, E: p less than 0.01). L-Dopa and three catecholamines in the adrenal glands were decreased in IUGR fetuses. The mol ratios (L-dopa: dopamine: NE: E) were 1: 4: 35: 63 in IUGR fetuses and 1: 5: 39: 87 in normal fetuses. The ratio for epinephrine to L-dopa was significantly lower in IUGR fetuses (p less than 0.05). Adrenal phenylethanolamine-N-methyltransferase activities showed no difference between the two groups. From these results, adrenal epinephrine synthesis in IUGR fetuses was thought to be normal. Because of the depletion of adrenal epinephrine in IUGR fetuses, the plasma epinephrine concentrations were significantly lower after acute hemorrhagic shock (p less than 0.01). However, the plasma concentrations of dopamine and norepinephrine were significantly higher (dopamine: p less than 0.01, NE: p less than 0.001) in IUGR fetuses. These findings suggest that the hypersecretion of adrenal epinephrine is a protective response to chronic stress and the decrease of adrenal epinephrine may be a causative factor for the reduced reserves in the defense mechanism of IUGR fetuses.

Adrenal Glands↗

PubMed1982

Regulation of extraadrenal steroid 21-hydroxylase activity. Increased conversion of plasma progesterone to deoxycorticosterone during estrogen treatment of women pregnant with a dead fetus.

We measured deoxycorticosterone (DOC) and progesterone (P) in plasma of 47 women pregnant with a dead fetus and sequentially throughout gestation in 35 women pregnant with a live fetus. When P levels in plasma were low, the plasma levels of DOC in women pregnant with a dead fetus varied but usually were similar to those in women pregnant with a live fetus. However, when P levels were high, the levels of DOC in some women pregnant with a dead fetus were considerably lower than those in women pregnant with a live fetus. To test whether this finding was due to loss of transfer of DOC from fetus to mother or else loss of extraadrenal steroid 21-hydroxylase activity in the mother after death of the fetus, we conducted several studies. The levels of P and DOC in plasma of one woman remained constant from 30 min after fetal death until delivery occurred 13 h later. Estrogen treatment of four women pregnant with a dead fetus brought about an increase in plasma levels of DOC in three of the women. In one woman the ratio of plasma DOC to P was 0.015, a value similar to that found before fetal death, but was 0.003 after fetal death but before estrogen treatment. In two women pregnant with a dead fetus the transfer constants of conversion of plasma P to DOC were 0.011 and 0.005 before, and 0.024 and 0.013, respectively, during estrogen treatment. In one woman pregnant with a deformed fetus with adrenal agenesis, the metabolic clearance rates of DOC before and during estrogen treatment were similar, whereas the plasma production rates of DOC were 2.75 before and 4.31 mg/24 h during estrogen treatment. We suggest that (a) the DOC in plasma of near-term pregnant women arises in part by extraadrenal 21-hydroxylation of plasma P and (b) estrogen stimulates steroid 21-hydroxylase activity in extraadrenal tissues.

Adrenal Glands↗

PubMed1992

Comparison of the virulence of two isolates of porcine parvovirus in 72-day-old porcine fetuses.

Two strains of porcine parvovirus (PPV), designated Kresse and NADL-8, were compared for relative virulence in porcine fetuses. Strain Kresse was injected into the amniotic fluid of all fetuses of 1 uterine horn of each of 2 pregnant gilts at 72 days of gestation. Strain NADL-8 was administered similarly to fetuses of 4 other gilts at the same stage of gestation. All gilts were killed and necropsied 35 days later. Selected tissues of all fetuses were tested for infectious virus and viral antigen. Sera from live fetuses were tested for antibody to PPV. These tests confirmed that most fetuses exposed to PPV by intra-amniotic injection became infected. All of 11 fetuses exposed to strain Kresse by intra-amniotic injection were alive at the time of necropsy, and all appeared clinically normal. In contrast, 8 of 24 fetuses exposed similarly to strain NADL-8 were dead. Many of the fetuses from the uterine horns contralateral to the uterine horns inoculated with virus were infected after 72 days of gestational age by intrauterine spread of the virus. Four such fetuses, 3 infected with the NADL-8 strain and 1 infected with the Kresse strain, were dead at the time of necropsy. These findings were inconsistent with those of a previous report, which indicated that the Kresse strain of PPV was markedly more virulent than the NADL-8 strain of PPV for porcine fetuses. A possible reason for this apparent discrepancy is discussed.

Animals↗

PubMed2000

Neonatal nucleated red blood cell counts in small-for-gestational-age fetuses: relationship to fetoplacental Doppler studies.

OBJECTIVE: To study the influence of pathologic umbilical and middle cerebral artery and uterine artery Doppler studies on the nucleated red blood cell count in small-for-gestational-age (SGA) fetuses. MATERIALS AND METHODS: Cord blood was prospectively collected during a 18-month period. 80 SGA fetuses (fetal abdominal circumference < 5th percentile) with Doppler ultrasound of the umbilical, the middle cerebral artery and both uterine arteries were enrolled in the study. SGA fetuses with normal Doppler flow velocity waveforms were allocated to group 1 (n = 23). Group 2 (n = 13) were fetuses with abnormal umbilical Doppler studies and group 3 (n = 44) were fetuses with both, pathologic umbilical and uterine artery Doppler studies. 2 fetuses in group 3 showed evidence of brain sparing, 3 fetuses presented absent-end-diastolic flow in the umbilical artery. Outcome measures included nucleated red blood cell count, Apgar scores, arterial pH and arterial base excess, venous pH, birth weight, gestational age at delivery, mode of delivery, rate of neonatal intensive care unit admission and length of stay in the neonatal intensive care unit. RESULTS: Highest nucleated red blood cell counts with lowest birth weight and gestational age were found in group 3. Decelerations of the fetal heart rate were more frequent in study group 3 and caesarean section for fetal indication was performed more often in this group. Those fetuses had to be transfered more often to the neonatal intensive care unit than fetuses of the other study groups. There was a tendency in group 3 towards lower arterial pH values and arterial base excess values. Fetuses with absent-end-diastolic flow in the umbilical artery presented highest nucleated red blood cell counts. CONCLUSION: In SGA fetuses increasing Doppler pathology seems to be correlated with increasing nucleated red blood cell count post-partum. Pathologic uterine artery flow results might have an additional impact on the number of nucleated red blood cells at birth.

Apgar Score↗

PubMed1992

Transport of steroids between fetuses via amniotic fluid in relation to the intrauterine position phenomenon in rats.

In litter-bearing mammals, the course of development of male and female fetuses is affected by the presence of other fetuses of the same or opposite sex located nearby within the uterus. The transport of testosterone between rat fetuses was examined by implanting a Silastic capsule containing [3H]testosterone into the amniotic sac of a fetus at either the ovarian or cervical end of a uterine horn on days 19 and 20 of pregnancy. The amount of testosterone that was recovered from the amniotic fluid of other fetuses 12 h later was determined. The amniotic fluid surrounding the adjacent fetus on the cervical side of the implanted fetus contained three times as much [3H]testosterone as did the adjacent fetus on the ovarian side, regardless of where in the uterus the implant was made. The movement of dye injected into the uterine lumen was towards the cervix. Intraluminal fluid movement may thus mediate the greater transport of [3H]testosterone towards the cervix than towards the ovary. Our findings support the hypothesis that transport of testosterone between fetuses occurs across the fetal membranes via diffusion, such that any fetus (male or female) located between male fetuses receives the greatest supplement of testosterone.

Amniotic Fluid↗

PubMed1998

Studies on the role of ACTH in the regulation of adrenal responsiveness and the timing of parturition in the ovine fetus.

A dramatic late-gestation increase in fetal plasma cortisol concentrations is critical for the timing of parturition in the sheep. This increase appears to depend upon an intact hypothalamo-pituitary unit and is characterised by increasing responsiveness of the fetal adrenal gland to ACTH. ACTH has been postulated as the critical determinant of the late-gestation cortisol increase; however, recent evidence has suggested that other factors, including the ACTH precursor, pro-opiomelanocortin, may also be involved. To further define the role of ACTH in determining the timing of parturition and the responsiveness of the fetal adrenal gland, intact (INT/ACTH) and hypophysectomised (HX/ACTH) fetuses received a continuous infusion of ACTH(1-24) from the time of surgery (approximately 115 days gestational age (GA)) at a rate we have previously shown to generate normal fetal cortisol concentrations and term parturition in HX fetuses. A third group of saline-infused intact fetuses (INT/SAL) served as the control group. Adrenal responsiveness was assessed by cortisol responses to ACTH(1-24) challenges at 120, 130 and 140 days GA. There were no differences between the three groups of fetuses in the timing of parturition, the late-gestation increase in cortisol concentrations or the size of the adrenal cortex. In both INT/SAL and INT/ACTH fetuses, there were significant increases in basal immunoreactive-ACTH concentrations with advancing GA, although no such increase was observed in HX/ACTH fetuses. The proportion of total ACTH immunoreactivity present in low molecular weight (LMW) forms in INT/ACTH fetuses was greater than that in INT/SAL fetuses, while the level of LMW ACTH in HX/ACTH fetuses was intermediate. Both ACTH(1-24)-infused groups of fetuses had dramatically enhanced adrenal responsiveness to ACTH(1-24) at all GAs tested when compared with INT/SAL fetuses and there was a correlation (in rank order) between the proportion of LMW ACTH immunoreactivity and adrenal responsiveness. From these observations it appears that there is a separate regulation of adrenal responsiveness from basal cortisol concentrations and that an increase in basal cortisol concentrations can occur in the absence of an increase in basal ACTH concentrations. Furthermore, an increase in adrenal responsiveness does not appear to predict the timing of parturition nor basal cortisol concentrations. Taken together with previous studies it appears that ACTH plays an essential role in maintaining the growth of the fetal adrenal and enhancing its responsiveness, but a late-gestation increase in ACTH concentrations is not required to regulate basal cortisol concentrations or the timing of parturition.

Adrenal Glands↗

PubMed1989

Histochemical studies of muscle development in decapitated and hypophysectomized pig fetuses: blood vessel development.

In Exp. 1, fetuses were decapitated in utero on d 45 of gestation and examined at 110 d of gestation; in Exp. 2, fetuses were hypophysectomized (hypox) in utero with a cauterizing needle at d 70 of gestation and examined at 110 d of gestation. Semitendinosus muscles were sampled and transverse cryostat sections were cut from the medial portion of the muscle. Quantitative analysis of lectin-stained sections showed that capillary:fiber ratios (C/F) were lower (P less than .01) for sections from decapitated and hypox fetuses than for sections from control fetuses. The superficial and deep aspects of muscle sections from control fetuses had markedly different C/F ratios (deep region, 24.1 +/- 2; superficial region, 11.2 +/- .5). Fetal decapitation and hypophysectomy abolished differences in C/F ratios between deep and superficial regions of muscle sections (hypox fetuses; deep region, 6.9 +/- 1; superficial region, 6.4 +/- .6). Capillaries in sections from control fetuses were reactive for several enzymes, whereas capillaries in sections from experimental fetuses (decapitated and hypox) were not reactive for these enzymes. The number of small arterioles was reduced in sections from experimental fetuses (decapitated and hypox) compared with sections from control fetuses. These studies demonstrate that lowering the levels of pituitary hormones in the fetus retards the development of blood vessels in muscle tissue both quantitatively and qualitatively.

Animals↗

PubMed2003

[Results of prenatal management of fetuses with supraventricular tachycardia. A series of 66 cases].

OBJECTIVE: To describe the prenatal management and outcome of a series of 66 fetuses with supraventricular tachycardia (SVT). MATERIAL AND METHODS: The perinatal data of 66 fetuses with SVT were retrospectively studied from January 1990 to December 2000. Junctional tachycardia was found in 50 fetuses and atrial flutter was found in 16 fetuses. Two groups were studied depending on the absence (n=40) or the presence of hydrops (n=26) at the time of the diagnosis. All fetuses but one were treated prenatally via the mother. Anti-arrhythmic drugs used were: digoxin, sotalol, flecainide or amiodarone. RESULTS: Group of fetuses with no hydrops: digoxin was used in 32 cases and allowed 26 fetuses to be converted to sinus rhythm (80%). One intra uterine death (IUD) occurred in this group. Hydropic fetuses group: nine fetuses were converted to sinus rhythm using either flecainide (n=7) or amiodarone (n=2) as first line therapy, whilst digoxin alone or in association with sotalol failed to restore sinus rhythm in all cases. After first line therapy, SVT persisted in 10 fetuses. Nine fetuses received amiodarone alone or in association with digoxin as second line therapy, five of whom were converted to sinus rhythm. Among the 18 alive neonates treated by amiodarone in utero, three presented elevated thyroid stimulating hormone at day 3-4 and required thyroid hormonal substitution therapy for 2-6 months with normal outcome.

Amiodarone↗

PubMedDate not supplied

[Fetal movement and heart acceleration behavior in eutrophic and hypotrophic fetuses in the 36th to 40th week of pregnancy].

By means of combined ultrasonic and cardiographic monitoring, the movement and acceleration behaviours of 44 eutrophic fetuses were compared to those of 19 fetuses with body weights between the 6th and 10th weight percentiles according to Kyank and to 21 fetuses with body weight not greater than the 5th weight percentile. The eutrophic fetuses moved more frequently and--related to 10 minutes examination time--over longer total periods than did the fetuses with intrauterine growth retardation. The longest mean duration of isolated fetal movement, however, was observed in the hypotrophic fetuses. With regard to fetal resting and activity stages, the highest percentage (10%) of fetal resting stages was found in the fetuses less than or equal to the 5th weight percentile. 93% of all accelerations in fetal heart rate obviously resulted from fetal movements, duration and amplitude of the accelerations depending on the duration of fetal movements. The degree of heart rate responses to fetal movements was different in the three groups examined. Standard weight fetuses responded most intensively. The percentage of fetal movements resulting in accelerations was highest (76%) in the group of the eutrophic fetuses as well. The mean duration of acceleration was most marked in the group of fetuses less than or equal to the 5th weight percentile (32.8 sec) and so was the mean acceleration amplitude in the normotrophic fetuses (19.7 bpm). Decelerations following accelerations in fetal heart rate did not differ in the three groups examined with regard to their number, amplitude and duration.

Female↗