Fetal Retention Research Articles

Trends and Rates of Stillbirths: An Observational Study in a Tertiary Level Hospital, Faridpur, Bangladesh

Fetal death at any time during pregnancy is a very tragic situation for the parents and treating obstetricians. Pregnancy loss is a distressing problem and retention of dead fetus in utero has its own ill effects on physical, psychological, and social aspects. Mifepristone is commonly used for induction of labour when a fetus dies in the utero. This cross-sectional survey aimed to determine the incidence and trend of intrauterine fetal death and socio-demographic characteristics, maternal obstetric history, health seeking behavior among the women who experience a stillbirth delivery. It will also aim to evaluate the efficacy and safety of using Mifepristone in case of induction of labour. This study was done at the Obstetric & Gynecology department of Bangabandhu Sheikh Mujib Medical College and a total of 219 stillbirth deliveries were recorded out of 4275 total deliveries from January to December 2022, resulting in a stillbirth rate of 51 per thousand live births. The majority of stillbirths were preterm between 28-38 weeks, and more than half were delivered via normal vaginal deliveries. The study revealed poor distribution of prenatal care, with only 9.59% of mothers having had the recommended 4 ante natal care visits, while 29.22% were primiparous. The results underscore the need for effective prenatal care to reduce the incidence of stillbirth and highlight the importance of careful management of intrauterine fetal death cases to mitigate physical, psychological, and social effects. The findings of this study provide valuable information for clinicians, policy makers, and researchers working in the field of obstetrics and gynecology. Bangabandhu Sheikh Mujib Med. Coll. J. 2024;3(1):38-43

Ultrasonographic characteristics, genetic features, and maternal and fetal outcomes in fetuses with omphalocele in China: a single tertiary center study

BackgroundPatients with omphalocele, a midline abdominal wall defect at the umbilical cord base, have a low survival rate. However, the long-term outcomes of fetuses with prenatally diagnosed omphalocele have scarcely been studied. Therefore, we investigated the ultrasonographic features, genetic characteristics, and maternal and fetal outcomes of fetuses with omphalocele and provided a reference for the perinatal management of such cases.MethodsA total of 120 pregnant females with fetal omphalocele were diagnosed using prenatal ultrasonography at the Fujian Provincial Maternity and Child Health Hospital from January 2015 to March 2022. Amniotic fluid or cord blood samples were drawn at different gestational weeks for routine karyotype analysis, chromosomal microarray analysis (CMA) detection, and whole exome sequencing (WES). The maternal and fetal outcomes were followed up.ResultsAmong the 120 fetuses, 27 were diagnosed with isolated omphalocele and 93 with nonisolated omphalocele using prenatal ultrasonography. Cardiac anomalies were the most observed cause in 17 fetuses. Routine karyotyping and CMA were performed on 35 patients, and chromosomal abnormalities were observed in five patients, trisomy 18 in three, trisomy 13 in one, and chromosome 8–11 translocation in one patient; all were non-isolated omphalocele cases. Six nonisolated cases had normal CMA results and conventional karyotype tests, and further WES examination revealed one pathogenic variant and two suspected pathogenic variants. Of the 120 fetuses, 112 were successfully followed up. Eighty of the 112 patients requested pregnancy termination. Seven of the cases died in utero. A 72% 1-year survival rate was observed from the successful 25 live births.ConclusionThe prognosis of fetuses with nonisolated omphalocele varies greatly, and individualized analysis should be performed to determine fetal retention carefully. Routine karyotyping with CMA testing should be provided for fetuses with omphalocele. WES is an option if karyotype and CMA tests are normal. If the fetal karyotype is normal and no associated abnormalities are observed, fetuses with omphalocele could have a high survival rate, and most will have a good prognosis.

Placental CD34 immunohistochemistry in fetal vascular malperfusion in stillbirth.

To assess the use of CD34 immunostaining in diagnosing of fetal vascular malperfusion (FVM) in stillborns. We examined 25 independent clinical (pregnancy and fetal outcomes) and 48 placental phenotypes in 100 placentas of consecutive stillborns at ≥20 weeks of gestation. Group 1 comprised 34 cases with no distal villous FVM; Group 2 comprised 36 placentas with clustered distal villous FVM (sclerotic villi, hypovascularity, stromal vascular karyorrhexis, and/or mineralization) determined using hematoxylin-eosin staining not upgraded by CD34 immunostaining, and Group 3 comprised 30 placentas with FVM diagnosed or upgraded by CD34 immunostaining (distal villous endothelial fragmentation and/or villous hypovascularity). Diffuse villous lesions of fetal retention with various degrees were present in approximately 50% of the cases in all groups; however, histological evaluation for FVM was still possible in most stillborns. Abnormal clinical phenotypes were significantly less frequent than abnormal placental phenotypes of FVM (8.6% vs. 24%, respectively). Chronic hypoxic placental injury patterns, fetal blood erythroblastosis, some features of shallow placental implantation, and muscular FVM lesions were most common in Group 2. Only decidual arteriopathy (hypertrophic and or hyaline necrosis/atherosis) was most frequent in Group 3. Most distal FVM lesions can be observed on hematoxylin-eosin placental slides only several days following the inciting event. CD34 immunostaining can reveal recent distal villous lesions of FVM featuring segmental villous endothelial fragmentation for de novo diagnosis or for upgrading FVM. Routine CD34 immunostaining has demonstrated FVM to be the major pattern of placental injury in stillborns.

Chronic Uterine Infection Caused by Fetal Retention and Treatment by Unilateral Ovariohysterectomy in a Dog

A four-year-old Anatolian Shepherd bitch was brought to our clinic with an intermittent purulent-hemorrhagic vaginal discharge complaint with no general symptoms for six months following the last parturition. There were no signs of mass or lesion on the vaginal wall during physical examination. Anechogenic uterine content, hyperechoic structures freely floating in the lumen, and suspicious fetal tissue remnants were detected by ultrasonography in only the left uterine horn. Hematological parameters revealed the chronic uterine infection. The unilateral ovariohysterectomy operation was performed for the more affected left horn to maintain the patient’s fertility. Two fetal bone remnants were detected in the reddish infectious uterine content at the postsurgical uterine incision. Throughout the postoperative five months, vaginal discharge or any general signs of complication were not observed. We thought that the last fetus might have undergone uterine retention and autolysis in the following weeks, which caused the chronic uterine infection. Obstetrical controls are well-advised in all parturitions to reveal any fetal remnant cases/complications and to have a normal postpartum process.

Endogenous transplacental transmission of Neospora caninum in successive generations of congenitally infected goats

Neospora caninum is a protozoan that is considered an important agent of reproductive disorders in ruminants worldwide, and vertical transmission is the main form of infection and maintenance of neosporosis in herds. In goats, there have been no studies that have evaluated the transmission of N. caninum between successive generations. Thus, the objective of this study was to evaluate, through IFAT and PCR, the endogenous transplacental transmission of N. caninum in up to five generations of six families of dairy goats naturally infected by the parasite and whether it was possible for dairy goats to become free of infection over successive generations. Ninety-five serum samples from positive animals and 75 samples from negative animals were analyzed for N. caninum. Of the 95 samples analyzed, 93 contained anti-N. caninum antibodies (97.8 %). Titers of anti-N. caninum antibodies varied (increasing or decreasing) in the offspring; however, with an increase in the number of the goat generations, the offspring tended to have lower titers (p = 0.021) at the day of birth. Reproductive disorders such as abortions, stillbirth or fetal retention occurred at a rate of 10.4 % and were not influenced by the mother's titer of anti-N. caninum antibodies at the day of parturition or abortion. The results showed that infection by N. caninum persists throughout generations in congenitally infected goats.

Comparison of clinical efficacy of dydrogesterone and progesterone in the treatment of threatened abortion

Objective To compare the clinical effect of dydrogesterone and progesterone in the treatment of threatened abortion. Methods From March 2015 to May 2017, 50 patients with threatened abortion admitted in the Maternal and Child Health Hospital of Ninghai County were selected and randomly divided into two groups according to the digital table, with 25 cases in each group.The control group was treated with progesterone.The observation group was treated with dydrogesterone.The hormone levels, symptom disappearance time, fetal retention and adverse drug reactions were compared between the two groups. Results One week after treatment, the levels of progesterone, estradiol and human chorionic gonadotropin in the observation group were (1 12.65±6.35)nmol/L, (2 137.99±371.22)pmol/L, (4 261.54±245.55)IU/L, respectively, which in the control group were (101.56±5.32)nmol/L, (1 782.12±350.71)pmol/L, (3 642.26±210.20)IU/L, respectively, the differences between the two groups were statistically significant (t=6.694, 3.484, 9.581, all P 0.05). Conclusion The effect of dydrogesterone in the treatment of threatened abortion is better than progesterone. Key words: Abortion, threatened; Progesterone; Dydrogesterone; Receptors, progesterone; Estradiol; Chorionic gonadotropin; Drug therapy; Comparative study

An uncommon fetal retention case: Ruptured ventral hernia in a sheep

A four-year-old pluriparous sheep was brought to our clinic with the complaints of mild anorexia and a wound on the ventral abdominal area, with part of a dead lamb protruding from this lesion. Clinical examination revealed that there was a fetal retention into the ruptured gravid uterine horn that was trapped within a ventral hernia. At herniorrhaphy after removing the dead fetus, strong connections between the uterine and abdominal wall and chronic scars/necrosed tissues were detected in the wound edges, which revealed the long time lapse between the unnoticed herniation-tearing and surgery. Although many ventral hernia cases have been reported in ovine pregnancies, the high maternal resilience in this ruptured hysterocele case, which had a two-week-old history at minimum, is clinically remarkable.

Post-partum pathological conditions in the bitch - Part II

Various disorders, some of which are life-threatening, can occur in bitches during the Puerperium. In this series of two articles, a detailed review of the literature on puerperal pathological conditions, along with excerpts from the authors' clinical experience and photographs, is presented. Initially, a brief account of the physiological processes during the Puerperium is presented. The hormonal changes, the changes in the genital system and the behavioural changes taking place as the genital system progressively returns to the non-pregnant state, are described. Subsequently, the various disorders, which are distinguished into systemic diseases, diseases of the mammary glands and diseases of the uterus, are reviewed. Systemic disorders that are manifested during the Puerperium are the puerperal hypocalcaemia and the abnormal maternal behaviour. Hypocalcaemia occurs usually after whelping, as calcium requirements of the bitch are increased due to milk production. The disease is due to the increased calcium requirements coupled with either a decreased intake of calcium (primary) or an inability to absorb it from the intestine or mobilise it from the bones (secondary). Abnormal maternal behaviour can be the consequence of factors causing nervousness, pain or disturbance of the bitch. Factors, such as genetic predisposition, caesarian section, young age or even the puppies themselves, may also trigger this condition. The puerperal mammary diseases are mastitis, agalactia and galactostasis. Mastitis is a disease of bacterial aetiology {Escherichia coli, Staphylococcus spp. Streptococcus spp.) occurring with acute or subacute-chronic form. Agalactia is the inability for milk production and can be either primary or secondary; it is defined as full agalactia or hypogalactia. Galactostasis refers to the abnormal passage and expression of milk from the teats, resulting in increased accumulation into the mammary glands. The pathological conditions of the uterus include post-partum metritis, uterine prolapse, retention of foetal membranes, foetal retention, subinvolution of the placental sites and uterine haemorrhage. Post-partum metritis is caused by bacteria (mainly E. coli) invading the uterus during or immediately after whelping and occurs with systemic and genital signs. Uterine prolapse (full or partial) is usually the consequence of vigorous embryo manipulations or intense tenesmus of the bitch. Foetal retention is the consequence of dystocia or of misuse of long-acting progestagens. Subinvolution of the placental sites is the consequence of the erosion of the uterine wall by trophoblast-like cells; often, this erosion extends down to involve the entire mucosa and may even invade the myometrium. Puerperal haemorrhage occurs more frequently in bitches with pre-existing disorders of blood coagulation factors. All the above pathological conditions may cause serious problems to the affected bitches. For a successful treatment, early and correct diagnosis is important. For each condition, the clinical signs and the paraclinical findings are described and the procedure for accurate diagnosis is described. Finally, the recommended conservative or surgical treatment for each condition is presented. It should be noted that in every case, appropriate measures for the welfare of puppies need also to be taken. Measures for a frequent and efficient post-partum monitoring of bitches and puppies are proposed, in order to prevent the development of the various pathological situations.

Post-partum pathological conditions in the bitch - Part I

Various disorders, some of which are life-threatening, can occur in bitches during the Puerperium. In this series of two articles, a detailed review of the literature on puerperal pathological conditions, along with excerpts from the authors' clinicalexperience and photographs, is presented. Initially, a brief account of the physiological processes during the Puerperium is presented. The hormonal changes, the changes in the genital system and the behavioural changes taking place as the genital system progressively returns to the non-pregnant state, are described. Subsequently, the various disorders, which are distinguished into systemic diseases, diseases of the mammary glands and diseases of the uterus, are reviewed. Systemic disorders that are manifested during the Puerperium are the puerperal hypocalcaemia and the abnormal maternal behaviour. Hypocalcaemia occurs usually after whelping, as calcium requirements of the bitch are increased due to milk production. The disease is due to the increased calcium requirements coupled with either a decreased intake of calcium (primary) or an inability to absorb it from the intestine or mobilise it from the bones (secondary). Abnormal maternal behaviour can be the consequence of factors causing nervousness, pain or disturbance of the bitch. Factors, such as genetic predisposition, caesarian section, young age or even the puppies themselves, may also trigger this condition. The puerperal mammary diseases are mastitis, agalactia and galactostasis. Mastitis is a disease of bacterial aetiology {Escherichia coli, Staphylococcus spp. ήStreptococcus spp.) occurring with acute or sub acute-chronic form. Agalactia is the inability for milk production and can be either primary or secondary; it is defined as full agalactia or hypogalactia. Galactostasis refers to the abnormal passage and expression of milk from the teats, resulting in increased accumulation into the mammary glands. The pathological conditions of the uterus include post-partum metritis, uterine prolapse, retention of foetal membranes, foetal retention, subinvolution of the placental sites and uterine haemorrhage. Post-partum metritis is caused by bacteria (mainly E. coli) invading the uterus during or immediately after whelping and occurs with systemic and genital signs. Uterine prolapse (full or partial) is usually the consequence of vigorous embryo manipulations or intense tenesmus of the bitch. Foetal retention is the consequence of dystocia or of misuse of long-acting progestagens. Subinvolution of the placental sites is the consequence of the erosion of the uterine wall by trophoblast-like cells; often, this erosion extends down to involve the entire mucosa and may even invade the myometrium. Puerperal haemorrhage occurs more frequently in bitches with pre-existing disorders of blood coagulation factors. All the above pathological conditions may cause serious problems to the affected bitches. For a successful treatment, early and correct diagnosis is important. For each condition, the clinical signs and the paraclinical findings are described and the procedure for accurate diagnosis is described. Finally, the recommended conservative or surgical treatment for each condition is presented. It should be noted that in every case, appropriate measures for the welfare of puppies need also to be taken. Measures for a frequent and efficient post-partum monitoring of bitches and puppies are proposed, in order to prevent the development of the various pathological situations.

Impact of management protocols of intrauterine fetal death on perceived stress: A comparative study

Background: Pregnancy loss is a distressing problem and retention of dead fetus in utero has its own ill effects on physical, psychological, and social aspects, and hence, it is better to recommend medical induction, provided this can be safely undertaken. Aims: The aim of this study is to compare the efficacy, tolerability, induction-delivery interval, and perceived stress scores between induction methods in late intrauterine fetal death (IUFD) with misoprostol alone and mifepristone with misoprostol combination in a rural population of Eastern India. Materials and Methods: This pilot study was conducted on 125 patients after taking institutional ethical clearance and informed consent of the patients in a time span of 1 year. Group 2 patients received 200 mg of mifepristone per orally and observed for 48 h, followed by 50 μg misoprostol administered in the posterior vaginal fornix, and repeated 6th hourly up to a maximum of four doses. Group 1 received 50 μg misoprostol per vaginally 6 hourly for four doses. Induction-delivery interval was calculated. Perceived stress level was calculated on admission and before discharge. Results: Significantly lower induction-delivery interval was observed in Group 2 as compared to Group 1 with P < 0.001. There was no significant difference of Cohen's perceived stress scores on admission, but the difference was significantly lower in Group 2 on discharge with the value of P = 0.03. Group 1 had significantly lower hospital stay in days as compared to Group 2 of patients with P < 0.001. Conclusions: Patients with IUFD administered misoprostol per vaginally only may require shorter hospital stay as compared to patients administered with oral mifepristone followed by misoprostol vaginally but the delivery induction time increases significantly and may increase perceived stress levels which may have short- and long-term negative psychological impact.

Relation of placental diagnosis in stillbirth to fetal maceration and gestational age at delivery

To study the relation of retention of dead fetus resulting in its maceration and gestational age at delivery to placental diagnosis. Some 75 clinicoplacental phenotypes have been retrospectively analyzed in 520 consecutive stillbirths, 329 macerated and 191 nonmacerated, and at three gestational age interval cohorts (330 second trimester, 102 preterm third trimester, and 88 term). Chi-square and clustering methods (Ward dendrograms and multidimensional scaling) were used for statistical analysis. Maternal diabetes mellitus, induction of labor, fetal growth restriction, various umbilical cord abnormalities, and placental clusters of sclerotic/hemosiderotic chorionic villi were more common in macerated stillbirths, while clinicoplacental signs and symptoms of ascending infection and placental abruption, i.e., retroplacental hematoma, premature rupture of membranes, and acute chorioamnionitis in nonmacerated stillbirths. Placental abnormalities were less common in the second trimester, other than the acute chorioamnionitis. Patterns of chronic hypoxic placental injury were common in preterm third trimester, while signs of in-utero hypoxia (abnormal cardiotocography, meconium, and histological erythroblastosis of fetal blood) in term pregnancy. In addition to classical statistics, the clustering analyses added new information to placental investigation of cause of stillbirth. Macerated third trimester stillbirths have multifactorial etiology more likely than the second trimester stillbirths and the likely stasis-induced fetal thrombotic vasculopathy secondary to occult umbilical cord compromise should be sought in placental investigation in such cases. Nonmacerated stillbirths are associated with ascending infection and placental abruption.

Toxicokinetics of domoic acid in the fetal rat

Domoic acid (DA) is a potent neurotoxin that has both marine wildlife and human health impacts, including developmental effects during prenatal exposure in rodent models. However, little is known regarding DA toxicokinetics in the fetal unit during maternal–fetal transfer. Tissue distribution and toxicokinetics of DA were investigated in pregnant rats and their pups just prior to birth at gestational day 20. Pregnant Sprague Dawley rats were given an intravenous dose of 1.0mgDA/kg and samples of maternal plasma, fetal plasma, placenta, amniotic fluid and fetal brain were taken at intervals over 24h. Toxicokinetic parameters were determined using WinNonLin software analysis. Maternal plasma DA log concentration–time curves fit a two compartment pharmacokinetic profile, with alpha and beta half-lives of elimination of 26.9 and 297min, respectively. Placenta had a Cmax of 752ng/mL and a terminal half-life of 577min. Maternal–fetal transfer between the plasma compartments was 31% with a fetal plasma Cmax of 86ng/mL at 60min and terminal half-life of 553min. Amniotic fluid and fetal brain had overall averages of 27±12ng/mL and 8.12ng/g, respectively, and did not show evidence of elimination over 24h. The longer fetal retention of DA, particularly in amniotic fluid, indicates that the fetus may be continually re-exposed during gestation, which could potentially lead to a disease state even at small exposure dose. This has implications for the California sea lions (Zalophus californianus), which exhibit an epilepsy-like disease that arises months after DA producing blooms.

Syndrome de Ballantyne secondaire à une infection maternofœtale à Parvovirus B19 : à propos de deux cas

Ballantyne's syndrome also known as Mirror syndrome is the association of fetal hydrops and maternal hydric retention. The maternal condition is often misdiagnosed as preeclampsia. We report two cases of Ballantyne syndrome associated with materno-fetal Parvovirus B19 infection. In the first case, the syndrome occurred at 26GW in a context of premature rupture of membranes. Parents and medical staff opted for termination of pregnancy because of the poor fetal prognosis. Maternal symptoms regressed after delivery. In the second case, the patient presented a Ballantyne's syndrome at 25GW. Intrauterine transfusions reversed symptomatology. Fetal hydrops of any etiology can be associated with this syndrome. Specific treatment of the fetus can avoid maternal complication allowing continuation of the pregnancy.

Partial Foetal Retention Following Aglepristone Treatment in a Bitch

This short communication describes the case of partial foetal retention in an 18-month-old female French bulldog following induction of abortion owing to an undesired mating. Abortion was induced with aglepristone administered in two consecutive protocols of a dual injection 1 day apart. After failure of the first treatment to achieve abortion, 15 days later, a second treatment was administered. Delivering of aborted foetus occurred 2 days after the last administration. Five weeks after the abortion, the female showed a weak haemorrhagic vaginal discharge. On ultrasound examination, the presence of uterine wall distension as well as a puppy skull inside the uterus was observed. This clinical case makes clear that although aglepristone is a very reliable drug, follow-up of the female during treatment and in the immediate post-partum is necessary to ensure a good outcome.

Intrauterine fetal bone retention after late-term abortion by external force in the 20th week of pregnancy

Intrauterine retention of fetal bones is a rare complication of spontaneous miscarriages or termination of pregnancy. We present a case with fetal bone retention after a miscarriage that occurred after external assault in about the 20th week of gestation. Since the global mobility has rapidly increased, women from a totally different lifeworld (i.e. escaping from civil war areas in underdeveloped countries) could abruptly present themselves as patients in industrial countries, so every physician should be aware of the described implications.

Prolonged Foetal Retention in a Bitch Resulting in Trichogranulomatuous Panmetritis and Re‐establishment of Fertility After Unilateral Ovariohysterectomy

This case report describes the clinical course, the diagnostic and therapeutic management as well as histopathological findings in a case of foetal retention for about 5 months in a 5-year-old Boxer. Clinical symptoms included mucosanguinous vaginal discharge and a firm ovoid mass of about duck egg size palpable in mid abdomen. Sonographic examination was not suitable to visualize uterine contents, while radiography revealed a conglomeration of foetal bones focally visible in the right uterine horn, which was surgically removed together with the ipsilateral ovary in order to maintain the fertility of the bitch. After lancing the uterine wall the osseous skeleton as well as parts of hairy skin and muscles of the foetus attaching the uterine wall were detected. Histologically a unilateral necrotizing panmetritis with almost complete destruction of the endometrial structures was diagnosed. Furthermore, the endometrium, the myometrium as well as the serosa revealed a severe trichogranulomatuous inflammation with numerous foetal hairs visible within the inflammatory alterations. After treatment of the bitch with prostaglandin F(2alpha) and an antibiotic agent she became pregnant in the second heat after surgery and gave birth to two healthy puppies. This is the first report on foetal retention for several months followed by unilateral ovariohysterectomy with subsequent recovery of fertility. Furthermore, this case report describes for the first time the histomorphological diagnosis of a unilateral trichogranulomatuous panmetritis in a bitch.

The placental transfer of cerium: experimental studies and estimates of doses to the human fetus from 141 Ce and 144 Ce

Purpose : To measure the transfer of cerium from mother to fetus in experimental animals and estimate doses to the human fetus following intakes of radioisotopes of Ce. Materials and methods : Cerium-141 in chloride solution was administered intravenously to rats at different stages of pregnancy (days 9.5, 12.5 or 18.5), and retention in the embryo/fetus and associated tissues was measured 3 days later in each case. Retention in rat fetal tissues on day 21.5 (shortly before birth) was also measured after administration of 141 Ce chloride 1 month prior to conception or 141 Ce citrate on day 18.5. Cerium-141 chloride was administered to guinea pigs on day 50 for measurements of fetal retention on day 57 (shortly before birth). Results : Retention of 141 Ce in the rat embryo/fetus, measured at 3 days after administration to the mother, increased from about 0.00002% of injected activity per embryo/fetus on day 12.5 to about 0.014% on day 21.5 of gestation. However, the relative concentrations of 141 Ce in the embryo/fetus and mother (C F : C M ratio) were between 0.005 and 0.01 in each case. After 141 Ce administration prior to conception, retention by the rat fetus on day 21.5 was substantially lower than after short-term administration. Comparison of retention of 141 Ce on day 21.5 after administration on day 18.5 as either chloride or citrate showed similar levels in maternal tissues but greater transfer to the fetus (C F : C M ratio of 0.03). Retention in the guinea pig fetus in late gestation at 7 days after administration of 141 Ce chloride was about 0.05% injected activity per fetus, corresponding to a C F : C M ratio of about 0.02. Conclusion : These results and other published animal data have been used to specify C F : C M ratios for use in the calculation of doses to the human fetus. The values used were 0.05 for intakes during pregnancy and 0.01 for intakes prior to conception. Doses to the offspring after maternal ingestion of 141 Ce or 144 Ce are largely due to irradiation from activity in the maternal colon and are insensitive to C F : C M. After inhalation, however, absorption of Ce to blood is much greater and doses to the offspring are dominated by the contribution from activity in the fetus, and therefore dependent on the C F : C M ratio used.

Effect of chemically altered and modified-live infectious bovine rhinotracheitis vaccines on fetal retention in beef replacement heifers during the first four months of gestation

The objective of this study was to determine whether vaccination of pregnant heifers with either chemically altered or modified live infectious bovine rhinotracheitis (IBR) vaccine would cause abortion when previously vaccinated with a chemically altered IBR vaccine. During pre-weaning processing and at weaning, 202 crossbred Brangus heifers were administered chemically altered infectious bovine rhinotracheitis virus (IBR) vaccines. At 60 to 120 days of gestation after first fall breeding, heifers were administered either a modified live virus (MLV) or a chemically altered IBR vaccine. Heifers at 60 to 90 days gestation, and those greater than 90 and up to 120 days gestation, were assigned by gestation category to one of three treatments: (1) a single IM injection of chemically altered IBR vaccine; (2) a single IM injection of modified live IBR vaccine; or (3) controls - no injections. Heifers were palpated 56 days after treatment to determine potential fetal loss. Subsequent calving information was used to confirm post-treatment palpation data. One heifer in each group aborted after treatment; these numbers did not differ among treatments (p=1.0) nor between gestation categories (p=1.0). Calving numbers verified that no fetuses were lost after post-treatment palpation. We concluded that a single dose of these vaccines in pregnant replacement heifers did not cause increased abortion rates compared to unvaccinated control heifers.

Evidence of transnatal auditory learning.

There is converging evidence for fetal retention of auditory experience into early postnatal life, but critical tests with appropriate controls are rare due to methodological hurdles. Research has been conducted on newborn response to naturally occurring stimuli such as heartbeats, intrauterine recordings, pre- and postnatal versions of the maternal voice, father's voice, and unfamiliar voices. Postnatal experience cannot be ruled out as a possible explanation for many results. Only one critical prenatal exposure experiment with postnatal testing has been carried out and published in a peer-reviewed scientific journal. Interpretation of acoustic and linguistic information on intrauterine recordings suggests that the prosodic features of speech (pitch contours, rhythm, and stress) are available to the fetus. This is compatible with newborn responses and may contribute to language acquisition during the first year. There is no sound evidence that providing extra prenatal auditory stimulation benefits the developing child, and there are potential risks.

Hydroxylated polychlorinated biphenyls : distribution in the pregnant mouse

1. In the pregnant C57BL mouse the disposition of a single, intravenous low dose of 14C-labelled 4-hydroxy-3,5,3',4'-tetrachlorobiph enyl (4-OH-TCB) or 4-hydroxy3,5,2',3',4'-pentachloro- biphenyl (4-OH-PeCB1) was monitored by liquid scintillation counting and whole-body autoradiography. The compounds were placentally transferred and accumulated in the foetal tissues (e.g. plasma and liver). Also, maternal accumulation was observed in selected tissues, including liver, adrenal gland, adipose tissue and yolk sac placenta. 2. The foetal concentration of both hydroxy- PCBs increased with time up 24 h postexposure and the foetal plasma concentration with at this time-point two-fold of that in maternal plasma. Chemicalanalysis of maternal plasma and liver showed no metabolismof the administered compounds. 3. In the pregnant C57BL mouse at late gestation, exposure to 4-OH-TCB generally resulted in a higher foetal and maternal tissue retention than did 4-OH-PeCB1. The estimated elimination half-lives (t1/2) of 4-OH-TCB in maternal liver and plasma were 69 and 13 h respectively, and for 4-OH-PeCB1 were 17 and 13 h. 4. No differences in foetal tissue concentration of 4-OH-TCB were observed between the C57BL and NMRI mouse. In contrast, earlier studies have shown that the PCB congener CB-77, the parent compound of 4-OH-TCB, resulted in a C57BL NMRI foetal ratio of 1:5.