Folic acid transport to the human fetus is decreased in pregnancies with chronic alcohol exposure

BACKGROUND

During pregnancy, the demand for folic acid increases since the fetus requires this nutrient for its rapid growth and cell proliferation. The placenta concentrates folic acid into the fetal circulation; as a result the fetal levels are 2 to 4 times higher than the maternal level. Animal and in vitro studies have suggested that alcohol may impair transport of folic acid across the placenta by decreasing expression of transport proteins. We aim to determine if folate transfer to the fetus is altered in human pregnancies with chronic alcohol consumption.

METHODOLOGY/PRINCIPAL FINDINGS

Serum folate was measured in maternal blood and umbilical cord blood at the time of delivery in pregnancies with chronic and heavy alcohol exposure (n = 23) and in non-drinking controls (n = 24). In the alcohol-exposed pairs, the fetal:maternal serum folate ratio was ≤ 1.0 in over half (n = 14), whereas all but one of the controls were >1.0. Mean folate in cord samples was lower in the alcohol-exposed group than in the controls (33.15 ± 19.89 vs 45.91 ± 20.73, p = 0.04).

CONCLUSIONS/SIGNIFICANCE

Our results demonstrate that chronic and heavy alcohol use in pregnancy impairs folate transport to the fetus. Altered folate concentrations within the placenta and in the fetus may in part contribute to the deficits observed in the fetal alcohol spectrum disorders.

Passive transfer of maternal GnRH antibodies does not affect reproductive development in elk (Cervus elaphus nelsoni) calves

Gonadotropin-releasing hormone is intermittently released from the hypothalamus in consistent patterns from before birth to final maturation of the hypothalamic-pituitary-gonadal axis at puberty. Disruption of this signaling via GnRH vaccination during the neonatal period can alter reproduction at maturity. The objective of this study was to investigate the long-term effects of GnRH-antibody exposure on reproductive maturation and function in elk calves passively exposed to high concentrations of GnRH antibodies immediately after birth. Fifteen elk calves (eight males and seven females) born to females treated with GnRH vaccine or sham vaccine during midgestation were divided into two groups based on the concentration of serum GnRH antibodies measured during the neonatal period. Those with robust (>15 pmol (125)I-GnRH bound per mL of serum) titers (N = 10; four females and six males) were designated as the exposed group, whereas those with undetectable titers (N = 5; three females and two males) were the unexposed group. Onset of puberty, reproductive development, and endocrine function in antibody-exposed and unexposed male and female elk calves were compared. Neonatal exposure to high concentrations of GnRH antibodies had no effect on body weight (P = 0.968), endocrine profiles (P > 0.05), or gametogenesis in either sex. Likewise, there were no differences between groups in gross or histologic structure of the hypothalamus, pituitary, testes, or ovaries. Pituitary stimulation with a GnRH analog before the second potential reproductive season induced substantial LH secretion in all experimental elk. All females became pregnant during their second reproductive season and all males exhibited similar mature secondary sexual characteristics. There were no differences between exposure groups in hypothalamic GnRH content (P = 0.979), pituitary gonadotropin content (P > 0.05) or gonadal structure. We concluded that suppressing GnRH signaling through immunoneutralization during the neonatal period likely does not alter long-term reproductive function in this species.

[Progress in mechanisms underlying melamine toxicity in central nervous system]

In recent years there have been more widely and deeply studies in investigating melamine toxicity. Generally, it is believed that the main target of melamine is the urinary system. However, previous studies revealed that it also had additional biological actions. Obviously, the toxicity mechanisms of melamine have not been fully clarified. It is well known that fetus and infant periods play the most fundamental role in the brain development. And melamine can pass through the placental and blood-brain barrier, and then exerts toxic effects on the central nervous system. This article reviewed the reports about the topic in recent years, for better understanding the dangers of melamine to infants and providing experimental data for further study.

Maternal bodies and medicines: a commentary on risk and decision-making of pregnant and breastfeeding women and health professionals

BACKGROUND

The perceived risk/benefit balance of prescribed and over-the-counter (OTC) medicine, as well as complementary therapies, will significantly impact on an individual's decision-making to use medicine. For women who are pregnant or breastfeeding, this weighing of risks and benefits becomes immensely more complex because they are considering the effect on two bodies rather than one. Indeed the balance may lie in opposite directions for the mother and baby/fetus. The aim of this paper is to generate a discussion that focuses on the complexity around risk, responsibility and decision-making of medicine use by pregnant and breastfeeding women. We will also consider the competing discourses that pregnant and breastfeeding women encounter when making decisions about medicine.

DISCUSSION

Women rely not only on biomedical information and the expert knowledge of their health care professionals but on their own experiences and cultural understandings as well. When making decisions about medicines, pregnant and breastfeeding women are influenced by their families, partners and their cultural societal norms and expectations. Pregnant and breastfeeding women are influenced by a number of competing discourses. "Good" mothers should manage and avoid any risks, thereby protecting their babies from harm and put their children's needs before their own - they should not allow toxins to enter the body. On the other hand, "responsible" women take and act on medical advice - they should take the medicine as directed by their health professional. This is the inherent conflict in medicine use for maternal bodies.

SUMMARY

The increased complexity involved when one body's actions impact the body of another - as in the pregnant and lactating body - has received little acknowledgment. We consider possibilities for future research and methodologies. We argue that considering the complexity of issues for maternal bodies can improve our understanding of risk and public health education.

The morphometry of materno-fetal oxygen exchange barrier in a baboon model of obesity

INTRODUCTION

More than one-fourth of U.S. women are overweight; more than one-third are obese. Maternal obesity has been linked to an increased incidence of stillbirths, fetal macrosomia, fetal intrauterine growth restriction and pre-eclampsia. The placenta plays a key role in the nutrients and oxygen supply to the fetus. The data about structural changes in the placental villous membrane (VM), a major component of the feto-maternal nutrient and oxygen exchange barrier, during obesity are sparse and inconsistent. Our objective was to evaluate the morphometric changes in the placental exchange barrier in a baboon model of obesity.

MATERIALS AND METHODS

The previously described baboon model of maternal obesity was studied. We compared 4 obese to 4 non-obese baboons. Placental stereology with the use of transmission electron microscopy was performed to estimate VM oxygen diffusing capacities and morphometry.

RESULTS

The specific placental oxygen diffusing capacities per unit of fetal weight were similar in baboons and humans. Maternal leptin concentrations correlated negatively with placental basement membrane thickness (r = -0.78, p < 0.05), while fetal leptin levels correlated negatively with endothelial thickness of fetal capillaries (r = -0.78, p < 0.05). The total and specific villous membrane oxygen diffusing capacities were not different between the two groups.

CONCLUSION

To the best of our knowledge this is the first report of placental oxygen diffusing capacities and placental ultrastructural changes in a baboon model of obesity. Previously reported placental inflammation in maternal obesity is not associated with changes in the VM diffusing capacities and ultrastructure.

Neonatal neurodevelopment and prenatal exposure to dichlorodiphenyldichloroethylene (DDE): a cohort study in Mexico

Prenatal exposure to dichlorodiphenyldichloroethylene (DDE) is associated with decreased motor development during the first year of life, though the effects of DDE in the neonatal stage are not conclusive. The main aim of this study was to evaluate the association between prenatal DDE exposure and neonatal neurodevelopment in a cohort from four municipalities in the state of Morelos, Mexico. The children (265), born from pregnancies with no perinatal complications, were evaluated at 1 month of age (± 7 days) for the presence of abnormal reflexes with the Brazelton Scale (NBAS), neurological soft signs with the Graham-Rosenblith Scale, as well as mental and psychomotor development by the Bayley Scales of Infant Development. Maternal DDE concentrations during each trimester of the pregnancy were determined by gas chromatography. Multiple linear and ordinal logistic models assessed the association between DDE and the outcomes of interest. Prenatal exposure to DDE was associated with a non-significant increase in neurological soft signs (6-8%) and a decrease in psychomotor (β(1T) = -0.02) and mental (β(2T) = -0.03 and β(3T) = -0.19) development. Our results are consistent with previous studies and suggest that prenatal DDE exposure is not associated with neurological functions present in the neonatal stage.

The use of bisphosphonates in women prior to or during pregnancy and lactation

OBJECTIVE

The unique pharmacokinetics of bisphosphonates (BPs) in conjunction with their use by an increasing number of women at reproductive age has raised serious concerns about their safety during pregnancy and lactation. Bisphosphonates cross the placenta. Animal studies have shown adverse effects on both the fetus and the mother, mostly at doses much higher than those commonly used in humans. Protracted parturition, maternal mortality, embryolethality, severe general underdevelopment and marked skeletal retardation of the fetuses (increased amount of diaphyseal bone trabeculae, decreased diaphyseal length), small fetal weight and abnormal tooth growth have been observed.

DESIGN

We conducted a thorough research of the literature in order to identify human studies concerning this issue.

RESULTS

We identified a total of 78 cases involving fetuses whose mothers had been exposed to BPs before conception or during pregnancy, along with 7 cases of BPs exposure prior to or during lactation. The vast majority of mothers and infants did not demonstrate serious adverse effects. However, there were cases of shortened gestational age, low neonatal birth weight and transient hypocalcaemia of the newborns, while the very few reported cases of spontaneous abortions and congenital anomalies probably resulted from maternal underlying diseases and concomitant medication.

CONCLUSION

The administration of bisphosphonates in pregnancy should be assessed in view of their potential hazardous effects on both mother and fetus. In cases of absolute or relative indications of BPs prior to pregnancy, close observation of the mother and the infant, especially during the first two weeks of life, is imperative for the successful outcome of pregnancy.

Insights into the regulatory mechanism controlling the inhibition of vaccine-induced seroconversion by maternal antibodies

The inhibition of vaccination by maternal antibodies is a widely observed phenomenon in human and veterinary medicine. Maternal antibodies are known to suppress the B-cell response. This is similar to antibody feedback mechanism studies where passively transferred antibody inhibits the B-cell response against particulate antigens because of epitope masking. In the absence of experimental data addressing the mechanism underlying inhibition by maternal antibodies, it has been suggested that epitope masking explains the inhibition by maternal antibodies, too. Here we report that in the cotton rat model of measles virus (MV) vaccination passively transferred MV-specific immunoglobulin G inhibit B-cell responses through cross-linking of the B-cell receptor with FcγRIIB. The extent of inhibition increases with the number of antibodies engaging FcγRIIB and depends on the Fc region of antibody and its isotype. This inhibition can be partially overcome by injection of MV-specific monoclonal IgM antibody. IgM stimulates the B-cell directly through cross-linking the B-cell receptor via complement protein 3d and antigen to the complement receptor 2 signaling complex. These data demonstrate that maternal antibodies inhibit B-cell responses by interaction with the inhibitory/regulatory FcγRIIB receptor and not through epitope masking.

[Remifentanil may in certain cases be used as an alternative to epidural analgesia for parturients]

Epidural analgesia remains the gold standard during labour, but is contraindicated in several clinical settings due to increased risk of serious complications. There are few effective alternatives to epidural analgesia. However, there is an increasing interest for the use of remifentanil as a labour analgesic. In this focused review, we describe the effect, dose and safety of remifentanil for the mother and fetus/neonate. Remifentanil appears to have a potential as labour analgesic. Careful monitoring of the parturient and the newborn is advised.

Effect of insulin and dexamethasone on fetal assimilation of maternal glucose

The growing fetus depends upon transfer of glucose from maternal blood to fetal tissues. Insulin and glucocorticoid impact maternal glucose metabolism, but the effects of these hormones on fetal glucose assimilation in vivo are understudied. We thus used positron emission tomography imaging to determine the disposition of [(18)F]fluorodeoxyglucose (FDG) in rats on gestational d 20, quantifying the kinetic competition of maternal tissues and fetus for glucose. Three fasting maternal states were studied: after 2-d dexamethasone (DEX), during euglycemic hyperinsulinemic clamp insulin receiving (INS), and control (CON). In CON and DEX mothers, FDG accumulation in fetuses and placentae was substantial, rivaling that of maternal brain. By contrast, FDG accumulation was reduced in INS fetuses, placentae, and maternal brain by approximately 2-fold, despite no diminution in FDG extraction kinetics from maternal blood into these structures. The reduced FDG accumulation was due to more rapid clearance of FDG from the circulation in INS mothers, related to increased FDG avidity in INS select maternal tissues, including skeletal muscle, brown adipose tissue, and heart. DEX treatment of mothers reduced fetal weight by nearly 10%. Nonetheless, the accumulation of FDG into placentae and fetuses was similar in DEX and CON mothers. In our rat model, fetal growth restriction induced by DEX does not involve diminished glucose transport to the fetus. Maternal insulin action has little effect on the inherent avidity of the fetal-placental unit for glucose but increases glucose utilization by maternal tissues, thus indirectly reducing the glucose available to the fetus.

[Barrier role of ABC family of proteins in human placenta]

Both a pregnant woman and a fetus are exposed to a wide range of xenobiotics. Placenta provides the only link between the mother and the developing fetus. It plays a major protective role acting as a semi-permeable barrier to minimize fetal exposure to exogenous compounds. Membrane proteins taking part in the xenobiotic transport were found in human placenta, both in syncytiotrophoblast and fetal capillaries. Most importantly placental ABC transporters--P-glycoprotein, BCRP and MRP--protect placental and fetal tissues by the efflux of their substrates. However; a decline in placental ABC transporter expressions was observed in some disorders. As a result, many drugs may cross the placental barrier increasing the risk of teratogenic effects. Thus, knowledge about placental transport proteins and pharmacological control of ABC proteins activity has important clinical implications. It is very important in the context of effective and safe pharmacotherapy during pregnancy. In this review, we summarized the current state of knowledge about the barrier role of ABC transporters in the human placenta.

[Effects of shoutai pills on expression of Th1/Th2 cytokine in maternal-fetal interface and pregnancy outcome]

OBJECTIVE

To evaluate its mechanism of inducing the maternal-fetal immune tolerance by studying the effects of Shoutai pills on the expression of Th1/Th2 cytokine and pregnancy in maternal-fetal interface of mice with recurrent spontaneous abortion (RSA).

METHOD

The normal pregnancy and RSA model were respectively induced with CBA/J x BALB/c and CBA/J x DBA/2. The mice with RSA were randomly divided into model group and low, middle and high dose groups of Shoutai pills. The mice were killed in 14 days after administration and embryo resorption rate was counted and their decidual and placental tissues were co-cultured to detect the expressions of IL-4, IL-10, IFN-gamma and TNF-alpha with ELISA.

RESULT

The embryo resorption rate of the model group was significantly higher than the normal pregnancy, middle and high dose groups of Shoutai pills could decreased the embryo resorption rate of the mice with RSA (P < 0.05). All the doses in 3 groups of Shoutai pills could decreased the expression of IFN-gamma and TNF-alpha (P < 0. 05) and there was no obvious difference between normal pregnancy group and all groups of Shoutai pills. Middle and high doses of Shoutai pills could increased the expression of IL-4 and IL-10 (P < 0.05) and there was no obvious differences between normal pregnancy and high dose group of Shoutai pills.

CONCLUSION

The mechanism about Shoutai pills can change Th1 /Th2 cytokine towards Th2 bias, which induced the maternal-fetal immune tolerance.

Maternal high-fat diet alters methylation and gene expression of dopamine and opioid-related genes

Maternal obesity during pregnancy increases the risk of obesity in the offspring. Obesity, arising from an imbalance of energy intake and expenditure, can be driven by the ingestion of palatable [high fat (HF), high sugar], energy-dense foods. Dopamine and opioid circuitry are neural substrates associated with reward that can affect animals' preference for palatable foods. Using a mouse model, the long-term effect of maternal consumption of a HF diet on dopamine and opioid gene expression within the mesocorticolimbic reward circuitry and hypothalamus of the offspring was investigated. Mice from dams fed a HF diet during pregnancy and lactation showed an increased preference for sucrose and fat. Gene expression, measured using quantitative real-time PCR, revealed a significant approximately 3- to 10-fold up-regulation of dopamine reuptake transporter (DAT) in the ventral tegmental area, nucleus accumbens, and prefrontal cortex and a down-regulation of DAT in the hypothalamus. Additionally, expression of both μ-opioid receptor (MOR) and preproenkephalin (PENK) was increased in nucleus accumbens, prefrontal cortex, and hypothalamus of mice from dams that consumed the HF diet. Epigenetic mechanisms have been associated with long-term programming of gene expression after various in utero insults. We observed global and gene-specific (DAT, MOR, and PENK) promoter DNA hypomethylation in the brains of offspring from dams that consumed the HF diet. These data demonstrate that maternal consumption of a HF diet can change the offsprings' epigenetic marks (DNA hypomethylation) in association with long-term alterations in gene expression (dopamine and opioids) and behavior (preference for palatable foods).

In ovo nanoinjection of triclosan, diclofenac and carbamazepine affects embryonic development of medaka fish (Oryzias latipes)

We examined the toxicity of three pharmaceuticals and personal care products (PPCPs) - triclosan (TCS), diclofenac (DCF), and carbamazepine (CBMZ) - on embryonic development of Japanese medaka (Oryzias latipes) using in ovo nanoinjection. Medaka eggs (8h post-fertilization; late blastula stage) were injected with 0.5nL of triolein (vehicle control) or 0.5nL of PPCPs, using different doses of TCS (1, 5, or 9ng), DCF (1, 5, or 12ng), or CBMZ (1, 5, or 12ng) per egg in triolein, in addition to uninjected control. Following injection, we recorded survival, embryonic lesions, delay in embryonic development (eye, embryonic body and internal organs), heart beat rate, hatchability, and hatching time of embryos and upward swimming of larvae. As a result, injected PPCPs caused toxic responses to medaka embryos during embryonic development and around the day of hatching. Based on estimated EC(50) values of PPCPs doses on survival of injected embryos at hatching, TCS (at a dose of 4.2ngegg(-1)) was generally more toxic to medaka embryos, followed by DCF (6.0ngegg(-1)), and CBMZ (13.1ngegg(-1)). We conclude that the nanoinjection medaka embryos model is a valuable tool for analyzing the effects of chemicals on the development of fish embryos and feasibility of nanoinjecting PPCPs into small fish eggs perhaps mimicking early exposure resulting from oocyte uptake of contaminants from maternal extra gonadal tissues.

[Permeability of exogenetic recombine human erythropoietin through placenta barrier to fetal rats with transient uteroplacental ischemia]

OBJECTIVE

To investigate whether recombine human erythropoietin can cross the placenta barrier in rats with transient uteroplacental ischemia.

METHODS

Rats on day 19 of pregnancy were divided into ischemia-reperfusion group, sham-operated group and rhEPO treated group. Fetal ischemia was induced by bilateral occlusion of the utero-ovarian artery for 20 minutes. 125I-rhEPO or saline were administered intravenously 30 min before the induction of hypoxic-ischemic injury. Fetal rat organs were removed to measure the radioactivity post injury.

RESULTS

A small amount of radioactive activity (1.26 +/- 0.28) pg/g was detected in the fetal rats with ischemia-reperfusion. 125I-rhEPO radioactivity increased gradually with time in the placenta, amniotic fluid and fetal tissues of vital organs in the rats of sham-operated group and rhEPO treatment group. There were significant differences in 125I-rhEPO between placental organs and other organs (P < 0.05). The permeability of 125I-rhEPO through the blood brain barrier changed with reperfusion time and peaked about 6 h after reperfusion, and significant differences were found between rhEPO treatment group and sham operation group (P < 0.05).

CONCLUSION

Exogenous rhEPO can cross the placenta barrier and blood-brain barrier and reach hypoxic-ischemic fetal rats.

Transplacental transfer and biotransformation of genistein in human placenta

OBJECTIVE

To study transplacental transfer and biotransformation of genistein in the human placenta. STUDY DESIGN AND OUTCOMES: Human placentae obtained from healthy term singleton pregnancies were utilised in a dual re-circulating model of ex-vivo placental perfusion. Four placentae were perfused for 180min following addition of genistein (10ng/mL) to the maternal perfusate. Antipyrine and FITC dextran were used as positive and negative controls respectively to validate integrity of the circuits. Concentrations of genistein and its conjugates were determined by liquid chromatography-mass spectrometry (LC-MS).

RESULTS

The transfer percentage for antipyrine and genistein was 25.6+/-1.40% and 22.1+/-1.61% respectively and the transfer index for genistein was 0.90+/-0.04 after 180min of perfusion. 12.0+/-2.40% of genistein in the fetal compartment and 7.36+/-4.73% of genistein in the maternal compartment were in the conjugated form.

CONCLUSIONS

Genistein can transfer across the human placenta at environmentally relevant levels. Placental metabolizing enzymes conjugate a small fraction of genistein into the glucuronide/sulphate form, which is devoid of estrogenic action.

Maternal buprenorphine dose, placenta buprenorphine, and metabolite concentrations and neonatal outcomes

Buprenorphine is approved as pharmacotherapy for opioid dependence in nonpregnant patients in multiple countries and is currently under investigation for pregnant women in the United States and Europe. This research evaluates the disposition of buprenorphine, opiates, cocaine, and metabolites in five term placentas from a US cohort. Placenta and matched meconium concentrations were compared, and relationships among maternal buprenorphine dose, placenta concentrations, and neonatal outcomes after controlled administration during gestation were investigated. Buprenorphine and/or metabolites were detected in all placenta specimens and were uniformly distributed across this tissue (coefficient of variation less than 27.5%, four locations), except for buprenorphine in three placentas. In two of these, buprenorphine was not detected in some locations and in the third placenta was totally absent. Median (range) concentrations were 1.6 ng/g buprenorphine (not detected to 3.2), 14.9 ng/g norbuprenorphine (6.2-24.2), 3 ng/g buprenorphine-glucuronide (1.3-5.0), and 14.7 ng/g norbuprenorphine-glucuronide (11.4-25.8). Placenta is a potential alternative matrix for detecting in utero buprenorphine exposure, but at lower concentrations (15- to 70-fold) than in meconium. Statistically significant correlations were observed for mean maternal daily dose from enrollment to delivery and placenta buprenorphine-glucuronide concentration and for norbuprenorphine-glucuronide concentrations and time to neonatal abstinence syndrome onset and duration, for norbuprenorphine/norbuprenorphine-glucuronide ratio and maximum neonatal abstinence syndrome score, and newborn length. Analysis of buprenorphine and metabolites in this alternative matrix, an abundant waste product available at the time of delivery, may be valuable for prediction of neonatal outcomes for clinicians treating newborns of buprenorphine-exposed women.

Cocaine is pharmacologically active in the nonhuman primate fetal brain

Cocaine use during pregnancy is deleterious to the newborn child, in part via its disruption of placental blood flow. However, the extent to which cocaine can affect the function of the fetal primate brain is still an unresolved question. Here we used PET and MRI and show that in third-trimester pregnant nonhuman primates, cocaine at doses typically used by drug abusers significantly increased brain glucose metabolism to the same extent in the mother as in the fetus (approximately 100%). Inasmuch as brain glucose metabolism is a sensitive marker of brain function, the current findings provide evidence that cocaine use by a pregnant mother will also affect the function of the fetal brain. We are also unique in showing that cocaine's effects in brain glucose metabolism differed in pregnant (increased) and nonpregnant (decreased) animals, which suggests that the psychoactive effects of cocaine are influenced by the state of pregnancy. Our findings have clinical implications because they imply that the adverse effects of prenatal cocaine exposure to the newborn child include not only cocaine's deleterious effects to the placental circulation, but also cocaine's direct pharmacological effect to the developing fetal brain.