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Increased catecholamine levels in cord venous plasma of distressed fetuses.

The concentrations of catecholamines in cord venous plasma were measured by trihydroxyindole fluorimetric assay in four fetuses with normal fetal heart rate (FHR) and three distressed fetuses with late deceleration of pathologic FHR. The concentrations (nmol/l) of norepinephrine and epinephrine in normal fetuses were 40.3 +/- 7.9 (mean +/- SD) and 5.4 +/- 1.5, respectively, whereas those in distressed fetuses were 156.8 +/- 48.0 and 12.1 +/- 4.5, respectively. In normal fetuses about 88% of total catecholamines consisted of norepinephrine, the remaining 12%, epinephrine. The ratio of norepinephrine to epinephrine in distressed fetuses (12.9) was thus higher than the ratio in normal fetuses (7.5). Higher levels of total catecholamine concentrations were associated with the presence of late deceleration of pathologic FHR pattern, low one-minute Apgar score, low umbilical arterial pH value (pH less than 7.20), and fetal hypertriglyceridemia (greater than 48 mg/100 ml). The relationship between fetal hypertriglyceridemia and elevated concentration of cord plasma total catecholamines is elucidated and the physiologic significance of increased secretion of catecholamines in distressed fetuses is discussed.

Apgar Score↗

Clinical features of multiple conception with partial or complete molar pregnancy and coexisting fetuses.

The estimated incidence of twin pregnancy consisting of hydatidiform mole and a coexisting fetus is 1 per 22,000-100,000 pregnancies. Since 1965, nine patients with this entity have been treated at the New England Trophoblastic Disease Center (NETDC), Boston. One patient had a partial hydatidiform mole coexisting with a normal placenta and fetus. The other eight patients had twin pregnancies with a complete hydatidiform mole (CHM) and coexisting fetus. We compared the clinical outcomes in these 8 patients and 14 additional published case reports of multiple gestations composed of CHM and coexisting fetuses with a group of 71 patients with singleton CHM treated at NETDC. Twelve of the 22 patients (55%) with CHM and coexisting fetuses developed persistent gestational trophoblastic tumor, requiring chemotherapy. Five of these patients developed metastases requiring multiple cycles of chemotherapy to achieve remission. The presenting symptoms of multiple conception with CHM and coexisting fetuses were similar to those in patients with a singleton conception and complete mole. However, as compared to singleton CHM, patients having a multiple conception with CHM and coexisting fetuses were diagnosed at a later gestational age, had higher preevacuation beta-human chorionic gonadotropin levels and had a greater propensity to develop persistent tumor. These data indicate that patients with multiple conceptions consisting of CHM and coexisting fetuses are at high risk of developing persistent gestational trophoblastic tumor.

Adult↗

Nuchal thickening or cystic hygromas in first- and early second-trimester fetuses: prognosis and outcome.

OBJECTIVE: To elucidate the relationship between nuchal abnormality, karyotype, and prognosis in fetuses with nuchal thickening or cystic hygroma observed between 10-15 weeks' gestation. METHODS: We reviewed all cases of fetal nuchal thickening (4 mm or greater) in 10-15-week fetuses over a 5-year period. Generalized hydrops and the presence of other anomalies were noted prospectively. We retrospectively measured the nuchal area and determined whether septations were present. Data consisted of karyotype, pathologic studies, and clinical follow-up of live-born infants. RESULTS: Of 100 consecutive fetuses, 29 were excluded because of pregnancy termination without karyotype or pathologic information. Of the remaining 71 fetuses, 63 had karyotyping. Abnormal karyotypes were found in 31 of 37 hydropic fetuses but in only 12 of 26 nonhydropic fetuses (P < .05). Fetuses with Turner syndrome had larger cystic hygromas than those with trisomy 18, trisomy 21, or normal karyotype (P < .05). There were ten normal live-born infants, none of whom was hydropic at the time of initial diagnosis and all of whom demonstrated spontaneous resolution of the nuchal thickening on subsequent sonograms. CONCLUSIONS: Fetuses with nuchal thickening or cystic hygromas demonstrated by ultrasound should have their karyotype determined. If the karyotype is normal and there are no hydrops or septations, the prognosis is good.

Chromosome Aberrations↗

Normal vas deferens in fetuses with cystic fibrosis.

PURPOSE: Infertility in patients with cystic fibrosis has been attributed to the congenital bilateral absence of the vas deferens. We studied the vas deferens in cystic fibrosis fetuses to determine whether this condition could be related to primary developmental abnormalities or to secondary obstructions. MATERIALS AND METHODS: Two cystic fibrosis male fetuses, with deltaF508+/+ and deltaF508/G542X genetic mutations, were examined after abortion at 12 and 18 weeks, respectively. The lumens of the vas deferens were measured using histological serial sections in the 2 cystic fibrosis fetuses and in 6 control fetuses. RESULTS: The vas deferens of cystic fibrosis and control fetuses showed a similar development. The diameters of the lumens were smaller at the extremities than in the medial part of the duct in cystic fibrosis and in control fetuses. No epithelial necrosis, focal dilatation or fibrous stenosis could be detected at any age. Secretions were observed in the lumen of the vas deferens of the homozygous fetus, but no obstruction was detected. CONCLUSIONS: The normal organogenesis of the vas deferens, the presence of secretions filling the lumen of the deltaF508 +/+ fetus and the high proportion of normal ducts reported in prepubertal male cystic fibrosis patients suggest a mechanism of luminal obstruction resulting in duct atrophy and infertility in male adults with cystic fibrosis. The term "atresia" or "inspissation" should be used in cases of congenital bilateral absence of the vas deferens associated with cystic fibrosis mutations, whereas the term "agenesis" should be used for cases of congenital bilateral absence of the vas deferens associated with urogenital abnormalities in which regional defects occur during organogenesis.

Cystic Fibrosis↗

Essential and nonessential amino acids in appropriate and small for gestational age fetuses with congenital cytomegalovirus infection.

The aim of the study was to evaluate the correlation between valine and glycine, representatives of essential and nonessential amino acids, in appropriate and small fetuses for gestational age with congenital cytomegalovirus (CMV) infection. Umbilical venous cord blood was obtained by cordocentesis at 22 to 29 weeks' gestation from 18 women (11 in appropriate for gestational age (AGA) -A, and 7 in small for gestational age (SGA) -B) fetuses with CMV infection. Plasma amino acids were measured with a Beckman M 121 amino acid analyzer. Maternal valine level was 136.0 mmol/l; fetal valine in AGA and SGA fetuses: 219 and 189 mmol/l, respectively. Fetomaternal valine ratio was significantly lower in the SGA group (1.39 mmol/l-SGA, 1.61 mmol/l AGA, t = 6.9 p < 0.001). The glycine level in maternal blood was 139.0 mmol/l; fetal in SGA and AGA fetuses 137 mmol/l, and 176 mmol/l, respectively. The fetomaternal glycine ratio was also significantly lower in the SGA group than in AGA. 1.01 and 1.27, respectively (t = -2.96, p < 0.001). Valine/glycine maternal and fetal ratio did not show any difference between groups. In the congenital CMV infected fetuses with intrauterine growth retardation there were decreased valine and glycine levels compared to the congenitally CMV infected fetuses with normal intrauterine growth. There was a lower fetal concentration of these amino acids compared to the maternal level in SGA fetuses. A decreased glycine level compared to the valine level has also been found in congenitally CMV infected fetuses with intrauterine growth retardation.

Cordocentesis↗

Nutrition of Vibrio fetus.

Smibert, Robert M. (Virginia Polytechnic Institute, Blacksburg, Va.). Nutrition of Vibrio fetus. J. Bacteriol. 85:394-398. 1963.-A chemically defined medium has been developed for the cultivation of both catalase-positive H(2)S-negative and catalase-positive H(2)S-positive strains of Vibrio fetus. A total of 87 strains of V. fetus, representing bovine, ovine, porcine, human, and chicken isolates, were grown in both semisolid and liquid defined media. The medium was also used to isolate V. fetus from the stomach contents of aborted bovine fetuses. The strains investigated did not require purines or pyrimidines. They required nicotinic acid, and were stimulated by other B vitamins. There was considerable variation in the amino acid requirements of V. fetus. Some strains required only one amino acid, and others required many more. The final complete medium contained 18 amino acids and supported growth of all 87 strains. There was no significant correlation between amino acid requirements and source of isolation or biochemical characteristics of V. fetus.

Amino Acids↗

Exposure to ethylene oxide during the early zygotic period induces skeletal anomalies in mouse fetuses.

Exposure of mouse zygotes to ethylene oxide (EtO) has been shown to increase the incidence of external malformations among late fetuses [Generoso et al. (1987) Mutat. Res., 176:267-274; Rutledge and Generoso, (1989) Teratology, 39:563-572]. The present study was designed to determine whether EtO also affects the skeletal system. We report here the effects of varying times of exposure during the zygotic period on skeletal development. Female hybrid mice were injected intraperitoneally (IP) with 125 mg/kg EtO at 1, 3, 5, or 7 hr postmating. A positive control group consisted of female mice that were injected IP with 150 mg/kg EtO once daily between the 6th to 8th days of gestation. Day 17 fetuses were double-stained for "blind" examination of skeletal deviations and degree of ossification. Zygotic exposure to EtO significantly increased loss of conceptuses as well as the incidence of external defects, skeletal anomalies, and retarded ossification in live day 17 fetuses. An increase in the number of exposed fetuses with cleft sternum was observed with the highest rate (58.5%) occurring in fetuses whose mothers were exposed to EtO 3 hours postmating. Cleft sternum was seen in only 5% of fetuses exposed during the period of organogenesis and less than 1% of control fetuses. It is concluded that zygotic exposure to EtO produces a pattern of skeletal defects that differs from those observed following treatment with EtO during organogenesis.

Abnormalities, Drug-Induced↗

Development of concentration thresholds for fetal swallowing and arginine vasopressin stimulation in the preterm ovine fetus.

We previously demonstrated that fetal swallowing was stimulated by intracarotid saline injections in the near term (130 +/- 1 days gestation) ovine fetus. In order to examine the ontogeny of the regulation of thirst-mediated swallowing behavior and arginine vasopressin (AVP) secretion, the present study examined fetal swallowing and AVP secretory responses to hypertonic NaCl and sucrose in preterm (115 days gestation) ovine fetuses. Five fetuses were chronically prepared with thyrohyoid, nuchal and thoracic esophagus, and diaphragm electromyogram (EMG) electrodes, an esophageal flow probe, and vascular catheters. Fetuses received intracarotid injections (0.15 ml/kg) of increasing concentrations of NaCl (0.15-2.55 M), administered at 2-min intervals. The threshold saline concentration for swallowing was defined as the minimum NaCl dose eliciting swallow responses (within 20 s) following 4 of 5 injections at each dose. In 2 fetuses, the threshold dose was 0.75 M (confirmed by 4 of 5 injections resulting in swallows at the next higher dose). In the other 3 animals, no swallowing threshold was observed (i.e., no dose through 2.55 M elicited swallows to 4 of 5 injections). There were no significant increases in AVP secretion. On a subsequent day, equimolar sucrose injections did not affect fetal swallowing activity or AVP secretion. Together with previous reports, these studies indicate that plasma osmolality dipsogenic mechanisms become functional in some ovine fetuses by 115 days gestation, while all fetuses exhibit intact osmotic dipsogenic responses at 130 days gestation. These results further suggest an acute process of development of dipsogenic responsiveness, rather than by gradually increasing sensitivity to osmotic stimuli.

Animals↗

Diagnosis and prognosis of fetuses with double outlet right ventricle.

OBJECTIVES: To examine the echocardiographic features, associated anomalies, and outcomes of fetuses diagnosed with double outlet right ventricle (DORV). METHODS: Fetuses with DORV were identified from 987 fetal echocardiograms performed from August 1, 2002 to August 1, 2004. The medical records of 19 fetuses with DORV were reviewed. RESULTS: Nineteen fetuses were diagnosed with DORV. The pregnancy was terminated in 15.8% (3/19) of cases. Postnatal assessment was not obtained in 26.3% (5/19) cases. Accurate prenatal diagnosis of the relationship of the ventricular septal defect (VSD) with the great arteries was achieved in 14 of 14 cases (100%). Chromosomal abnormalities (21.4%), abnormalities of body situs (35.7%), and other extracardiac abnormalities were diagnosed in association. Only 4 of 13 (30.8%) infants with confirmed DORV survived beyond 28 days. CONCLUSIONS: DORV is found in fetuses with a large spectrum of associated cardiac and extracardiac lesions. The overall prognosis for fetuses with DORV is poor throughout the spectrum of these lesions, not only related to the primary lesion but also depending on the associated intra- and extracardiac abnormalities. While the complexity of the heart disease in fetuses with DORV makes detailed fetal diagnosis challenging, it can be accomplished with a high degree of accuracy.

Abnormalities, Multiple↗

Doppler and biophysical assessment in growth restricted fetuses: distribution of test results.

OBJECTIVE: Multi-vessel Doppler ultrasonography and biophysical profile scoring (BPS) are used in the surveillance of growth restricted fetuses (IUGR). The interpretation of both tests performed concurrently may be complex. This study examines the relationship between Doppler ultrasonography and biophysical test results in IUGR fetuses. METHODS: Three hundred and twenty-eight IUGR fetuses (abdominal circumference < 5th percentile, elevated umbilical artery (UA) pulsatility index (PI)) had concurrent surveillance with UA, middle cerebral artery (MCA) and ductus venosus (DV) Doppler ultrasonography and BPS (fetal tone, movement, breathing, maximal amniotic fluid pocket and fetal heart rate). Patients were stratified into three groups according to their Doppler examination: (1) abnormal UA alone; (2) brain sparing (MCA-PI > 2 SD below mean for gestational age); and (3) abnormal DV (PI > 2 SD above the mean for gestational age) and BPS groups: (1) normal (> 6/10); (2) equivocal (6/10); and (3) abnormal (< 6/10). Predictions of short-term perinatal outcomes by both modalities were compared for stratification. The distribution and concordance of Doppler and BPS test results were examined for the whole patient group and based on delivery prior to 32 weeks' gestation. RESULTS: Abnormal UA Doppler results alone were observed in 109 fetuses (33.2%), brain sparing in 87 (26.5%) and an abnormal DV in 132 (40.2%). The BPS was normal in 158 (48.2%), equivocal in 68 (20.7%) and abnormal in 102 (31.1%). Both testing modalities stratified patients into groups with comparable acid-base disturbance and perinatal outcome. Of the nine possible test combinations the largest subgroups were: abnormal UA alone/normal BPS (n = 69; 21%) and abnormal DV Doppler/abnormal BPS (n = 62; 18.9%). Assessment of compromise by both testing modalities was concordant in 146 (44.5%) cases. In 182 fetuses with discordant results the BPS grade was better in 115 (63.2%, P < 0.0001). Marked disagreement of test abnormality was present in 57 (17.4%) fetuses. Of these, abnormal venous Doppler in the presence of a normal BPS constituted the largest group (Chi-square P < 0.002). Stratification was not significantly different in patients delivered prior to 32 weeks' gestation. CONCLUSION: Doppler ultrasonography and BPS effectively stratify IUGR fetuses into risk categories, but Doppler and BPS results do not show a consistent relationship with each other. Since fetal deterioration appears to be independently reflected in these two testing modalities further research is warranted to investigate how they are best combined.

Adolescent↗

Rapid detection of Campylobacter fetus by polymerase chain reaction combined with non-radioactive hybridization using an oligonucleotide covalently bound to microwells.

Campylobacter fetus is recognized as a human and animal pathogen. The isolation and differentiation of C. fetus in diagnostic laboratories is hindered by its relatively slow growth and lack of distinguishing biochemical characteristics. We cloned and sequenced a 1581-bp DNA fragment, IG02, isolated from a C. fetus genomic library. This fragment was used as a probe on DNAs extracted from C. fetus strains and other Campylobacter species: IG02 hybridized only with DNAs from C. fetus strains. A PCR-based test was developed for the detection of C. fetus. A pair of oligonucleotide primers was designed to amplify a 141-bp fragment of IG02. The amplified product was analysed by a non-radioactive sandwich hybridization in microtiter plate using a capture oligonucleotide and a biotin-labelled oligonucleotide for the detection. The combination of PCR and non-radioactive microplate hybridization is a convenient method for the rapid detection of C. fetus.

Animals↗

Distribution of extracellular matrix components in nuchal skin from fetuses carrying trisomy 18 and trisomy 21.

We have investigated histologically the elevations of the skin in dorsal and lateral neck (nuchal) regions of human fetuses carrying karyotypes of trisomy 18 (Edwards' syndrome) and trisomy 21 (Down's syndrome). Cavities filled with interstitial fluid were found in the dermis, epidermal basement membrane and occasionally in the epidermis of trisomy-18 fetuses, but were not delineated by an epithelium or basement membrane as judged by the absence of immunostaining for laminin, collagen IV and collagen VII. Dilated vessels were also found at the interface between dermis and subcutis. Neither normal fetal skin nor that of trisomy-21 fetuses contained cavities or dilated vessels. In order to detect possible alterations of the extracellular matrix in trisomy-18 and trisomy-21 skin, the distribution of glycoproteins, glycosaminoglycans and proteoglycans was studied immunohistochemically. In trisomy-21 and control skin, the dermis stained intensely for fibronectin, whereas the subcutis reacted only weakly. In trisomy-18 skin, the stronger staining for fibronectin appeared in the subcutis, and the prevailing collagen type was collagen III, collagen type I being absent. In the skin of trisomy-21 fetuses, collagen VI was more irregularly arranged and densely packed, whereas collagen I was more widely spaced than in normal fetuses. More hyaluronan was present in the dermis and subcutis of trisomy-21 fetuses than in that of trisomy-18 and control fetuses. A correlation seems to exist between undelimited cavities and collagen III in trisomy-18 skin, and between hyaluronan and the specific arrangement of collagen in trisomy-21 skin.

Chromosomes, Human, Pair 18↗

The association between antibody titres against Campylobacter fetus and milk production efficiency in dairy cattle.

The association between serological evidence of exposure to Campylobacter fetus and milk production performance was studied in 178 lactating cows from three California Dairy Herd Improvement Association herds using a cross-sectional study design in December 1986. ELISAs were used to determine the antibody titres against Campylobacter fetus, Haemophilus somnus and Leptospira hardjo, which were classified as either negative or positive. The status of a cow as negative or positive against C. fetus and H. somnus represents the serological evidence of natural exposure to the corresponding bacteria. However, the status against L. hardjo was assumed to be the level of vaccinal titre against this organism since all the cows studied had been vaccinated against this agent. The data on demographic and productivity variables relating to the current lactation of the cows were obtained from Dairy Herd Improvement Association individual cow records for December 1986. Four measures of milk production efficiency for the current lactation were used. The status against L. hardjo and other covariates suggested by previous studies were included in modelling the relationships of interest. Stepwise multiple linear regression was used to study the adjusted relationship of C. fetus with each measure of milk production efficiency. Multivariate analyses revealed that the adjusted relationships of C. fetus with the test-day's milk production, the extended 305-day milk production and the relative value of milk production were not significant (p > 0.1). However, after adjusting for possible covariates, C. fetus-positive cows had an average of 7.43% lower mature equivalent milk production than C. fetus-negative cows (p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Skeletal abnormalities in fetuses with Down's syndrome: a radiographic post-mortem study.

OBJECTIVE: To evaluate skeletal abnormalities on post-mortem radiographs of fetuses with Down's syndrome. MATERIALS AND METHODS: Biometrical and morphological criteria, which are used for US prenatal detection of trisomy 21, were assessed. Limb long bones, biparietal diameter (BPD)/occipito-frontal diameter (OFD) ratio, ossification of nasal bones and appearance of the middle phalanx of the fifth digit (P2) in 60 fetuses with Down's syndrome were analysed and compared with 82 normal fetuses matched for gestational age (GA) from 15 to 40 weeks' gestation (WG). RESULTS: We observed reduced growth velocity of limb long bones during the third trimester in both groups, but the reduction was more pronounced in the trisomic group. Brachycephaly was found as early as 15 WG in Down's syndrome and continued throughout gestation (sensitivity 0.28, specificity 1). Ossification of the nasal bones, which can be detected in normal fetuses from 14 WG, was absent in one quarter of trisomic fetuses, regardless of GA. The middle phalanx of the fifth digit was evaluated by comparison with the distal phalanx (P3) of the same digit. We found that P2 was not ossified in 11/31 trisomic fetuses before 23 WG, and was either not ossified or hypoplastic in 17/29 cases after 24 WG (sensitivity 0.56, specificity 1). CONCLUSIONS: Three key skeletal signs were present in trisomic fetuses: brachycephaly, absence of nasal bone ossification, and hypoplasia of the middle phalanx of the fifth digit. All these signs are appropriate to prenatal US screening. When present, they fully justify determination of the fetal karyotype by amniocentesis.

Bone and Bones↗

Natural mechanisms for evading graft rejection: the fetus as an allograft.

Most primitive multicellular animals mount allogeneic immune responses to protect themselves from invasion by foreign organisms. The reproductive success of eutherian mammals, in which the maternal immune system is in direct contact with the semi-allogeneic fetus, depends on the ability to control allogeneic immune responses. Multiple, overlapping mechanisms exist to prevent maternal allogeneic immune responses towards the fetus while maintaining the capacity to mount a defense against infectious organisms. The formation of an anatomical barrier between mother and fetus, lack of maternal immune responsiveness, and a lack of expression of allogeneic molecules by the fetus have been proposed as mechanisms to account for the lack of fetal rejection during pregnancy. These mechanisms have helped us begin to understand how rejection of the fetus is avoided; however, these mechanisms do not completely explain how the fetus evades the maternal immune system. Site-specific suppression, in which maternal immune responses are controlled locally at the maternal- fetal interface, plays a fundamental role in controlling maternal allogeneic immune responses. Stem cells, both adult and embryonic, might use mechanisms similar to those of the fetus to avoid rejection. Future discoveries in the field of reproductive immunology will help us understand not only immune regulation during pregnancy, but also how immune responses towards organ and cellular transplants might be controlled.

Animals↗

Electrocardiographic responses of rat fetuses with clamped or intact umbilical cords to acute maternal uterine ischemia.

Uterine ischemia results in severe cardiac disturbances in the fetus. It has been postulated that these effects are due to interaction between the fetus and the ischemic uterus or placenta, and not to hypoxia or buildup of metabolites in the fetus. Rat fetal cardiac responses to uterine clamping and umbilical cord clamping were compared by electrocardiography. On day 21 of gestation, fetuses in a total of 14 pregnant rats were exposed to umbilical clamping, uterine clamping, or no clamping. Electrocardiograms were recorded for each fetus immediately after clamping and at 10, 20, and 30 minutes after clamping. Immediately after clamping, the uterine clamping group alone showed severe sinus bradycardia. At all other observation times, fetuses exposed to uterine or umbilical clamping showed bradycardia and other electrocardiographic changes typically associated with hypoxia. Therefore, umbilical clamping protected the fetuses from the adverse effects of uterine clamping for only a very short time.

Animals↗

Identification of the small for gestational age fetus with the use of gestational age-independent indices of fetal growth.

This study reviews the roles of sonographic assessment of the rate of growth of the fetal abdominal circumference, the femur length/abdominal circumference ratio, and qualitative determination of amniotic fluid volume as gestational age-independent indices for identification of the small for gestational age fetus. The sensitivity and specificity for single and combinations of test results were evaluated in 50 appropriate for gestational age and 40 small for gestational age fetuses. Positive and negative predictive values were derived for the general population. Our results indicate that either a rate of growth of the fetal abdominal circumference less than or equal to 10 mm/14 days or a femur length/abdominal circumference ratio greater than or equal to 23.5 correctly identifies most small for gestational age fetuses. When the general population is screened, only 15% of small for gestational age fetuses will be missed by this combination of criteria. The presence of a pocket of amniotic fluid less than or equal to 2.0 cm is highly suggestive of a small for gestational age fetus. However, the presence of a pocket of amniotic fluid greater than 2.0 cm does not guarantee an appropriate for gestational age fetus. We conclude that these gestational age-independent indices of fetal growth offer useful tools for differentiating between the small for gestational age and appropriate for gestational age fetus.

Amniotic Fluid↗

Levels of epidermal growth factor binding in third-trimester and term human placentas: elevated binding in term placentas of male fetuses.

Specific binding of iodine 125-labeled epidermal growth factor was measured in membrane homogenates of third-trimester and term human placentas of male and female fetuses. All placentas (n = 35) generated curvilinear Scatchard plots, and all placentas had similar equilibrium dissociation constants for both high-affinity (210 pmol/L) and low-affinity (830 pmol/L) binding sites. Mean maximum number of available binding sites of term placentas from male fetuses (330 +/- 110 fmol/mg protein; n = 11) was significantly higher (p less than 0.001) than that of female fetuses (170 +/- 80 fmol/mg protein, n = 13). Occupation of epidermal growth factor receptors by endogenous epidermal growth factor could not account for the difference in levels of epidermal growth factor binding. Kendall's rank order correlation test demonstrated a significant positive correlation of the gestational age in weeks with the maximum number of epidermal growth factor receptors in placentas from male fetuses (p less than 0.002; T = 0.527; n = 17) and female fetuses (p less than 0.01; T = 0.404; n = 18). These results indicate that there is a sexual dimorphism in the level of epidermal growth factor receptors in placentas of male and female fetuses during the third trimester and that the level of epidermal growth factor receptors increases during the third trimester for placentas of both male and female fetuses.

Epidermal Growth Factor↗