Teratogen update: pseudoephedrine

Pseudoephedrine is contained in decongestants such as the Sudafed line of products. It is an alpha-adrenergic receptor agonist, which causes blood vessel constriction, including the therapeutic effect of reducing airflow resistance in the nasal cavity. Pseudoephedrine is one of the most commonly used medications in pregnancy, with an estimated 25% of women exposed. It has been demonstrated that alpha-adrenergic receptor agonists slow uterine blood flow, but their effects have not been studied in relation to most reproductive outcomes in animals or humans. Two analyses of health maintenance organization pharmacy data identified 9 malformed infants among 902 first-trimester pseudoephedrine exposures, suggesting no association with birth defects overall; however, studies of such data sets often lack sufficient power to identify risks for specific birth defects. The related compounds, epinephrine, ephedrine, and phenylephrine, have been associated with hemorrhages and cardiovascular and limb malformations in animal models. Risk of ventricular septal defects was associated with decongestant use in pregnant women in 1 recent study. The vasoconstrictive effects of these drugs raise the hypothesis that their use in early pregnancy might increase the risk of vascular disruption defects. Case-control studies, which often do have power to identify risks related to specific birth defects, have explored this hypothesis. Decongestant use in the first trimester has been associated with small increases in risks of 3 defects thought to arise, at least in some instances, from vascular disruption-gastroschisis, small intestinal atresia, and hemifacial microsomia. These findings are somewhat consistent in terms of magnitude of effect and suggest that risks are even greater among women also exposed to the vasoconstrictive effects of cigarette smoking. There are, however, limitations to these studies, including the possibilities of inaccurate recall of exposures and confounding by indication. In addition, the majority of decongestant use is in oral form and the question of whether intranasal formulations carry risk has not been adequately addressed.     

Early pregnancy azathioprine use and pregnancy outcomes

BACKGROUND: Azathioprine (AZA) is used during pregnancy by women with inflammatory bowel disease (IBD), other autoimmune disorders, malignancy, and organ transplantation. Previous studies have demonstrated potential risks. METHODS: The Swedish Medical Birth Register was used to identify 476 women who reported the use of AZA in early pregnancy. The effect of AZA exposure on pregnancy outcomes was studied after adjustment for maternal characteristics that could act as confounders. RESULTS: The most common indication for AZA use was IBD. The rate of congenital malformations was 6.2% in the AZA group and 4.7% among all infants born (adjusted OR: 1.41, 95% CI: 0.98–2.04). An association between early pregnancy AZA exposure and ventricular/atrial septal defects was found (adjusted OR: 3.18, 95% CI: 1.45–6.04). Exposed infants were also more likely to be preterm, to weigh <2500 gm, and to be small for gestational age compared to all infants born. This effect remained for preterm birth and low birth weight when infants of women with IBD but without AZA exposure were used as a comparison group. A trend toward an increased risk of congenital malformations was found among infants of women with IBD using AZA compared to women with IBD not using AZA (adjusted OR: 1.42, 95% CI: 0.93–2.18). CONCLUSIONS: Infants exposed to AZA in early pregnancy may be at a moderately increased risk of congenital malformations, specifically ventricular/atrial septal defects. There is also an increased risk of growth restriction and preterm delivery. These associations may be confounded by the severity of maternal illness. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.     

Exposure to non-steroidal anti-inflammatory drugs during pregnancy and the risk of selected birth defects: a prospective cohort study

Background

Since use of non-steroidal anti-inflammatory drugs (NSAIDs) during pregnancy is common, small increases in the risk of birth defects may have significant implications for public health. Results of human studies on the teratogenic risks of NSAIDs are inconsistent. Therefore, we evaluated the risk of selected birth defects after prenatal exposure to prescribed and over-the-counter NSAIDs.

Methods and Findings

We used data on 69,929 women enrolled in the Norwegian Mother and Child Cohort Study between 1999 and 2006. Data on NSAID exposure were available from a self-administered questionnaire completed around gestational week 17. Information on pregnancy outcome was obtained from the Medical Birth Registry of Norway. Only birth defects suspected to be associated with NSAID exposure based upon proposed teratogenic mechanisms and previous studies were included in the multivariable logistic regression analyses. A total of 3,023 women used NSAIDs in gestational weeks 0–12 and 64,074 women did not report NSAID use in early pregnancy. No associations were observed between overall exposure to NSAIDs during pregnancy and the selected birth defects separately or as a group (adjusted odds ratio 0.7, 95% confidence interval 0.4–1.1). Associations between maternal use of specific types of NSAIDs and the selected birth defects were not found either, although an increased risk was seen for septal defects and exposure to multiple NSAIDs based on small numbers (2 exposed cases; crude odds ratio 3.9, 95% confidence interval 0.9–15.7).

Conclusions

Exposure to NSAIDs during the first 12 weeks of gestation does not seem to be associated with an increased risk of the selected birth defects. However, due to the small numbers of NSAID-exposed infants for the individual birth defect categories, increases in the risks of specific birth defects could not be excluded.     

Disturbances in Maternal Steroidogenesis and Appearance of Intrauterine Growth Retardation at High-Altitude Environments Are Established from Early Pregnancy. Effects of Treatment with Antioxidant Vitamins

Pregnancies at high-altitudes are influenced by hypoxia and oxidative stress and frequently affected by IUGR. However, a common thought is that early pregnant women visiting altitude have no major complications for gestation development, since IUGR is developed during the second half of pregnancy. Thus, using a well-characterized sheep-model, we aimed to determine whether long- and/or short-term exposure to high-altitude may affect maternal steroidogenesis and therefore embryo-fetal growth from conception. The second aim was to differentiate the relative role of hypoxia and oxidative stress by assessing the effects of supplementation with antioxidant agents during this early-pregnancy stage, which were previously found to be useful to prevent IUGR. The results indicate that both long- and short-term exposure to high-altitude causes disturbances in maternal ovarian steroidogenesis and negatively affects embryo-fetal growth already during the very early stages of gestation, with the consequences being even worsened in newcomers to high-altitude. The supply of antioxidant during this period only showed discrete effects for preventing IUGR. In conclusion, the present study gives a warning for clinicians about the risks for early-pregnant women when visiting high-altitude regions and suggests the need for further studies on the effects of the length of exposure and on the interaction of the exposure with the pregnancy stage.     

Birth defects after maternal exposure to corticosteroids: prospective cohort study and meta-analysis of epidemiological studies

BACKGROUND: Corticosteroids are first-line drugs for the treatment of a variety of conditions in women of childbearing age. Information regarding human pregnancy outcome with corticosteroids is limited. METHODS: We collected prospectively and followed up 184 women exposed to prednisone in pregnancy and 188 pregnant women who were counseled by Motherisk for nonteratogenic exposure. The primary outcome was the rate of major birth defects. A meta-analysis of all epidemiological studies was conducted. The Mantel-Haenszel summary odds ratio was calculated for the pooled studies with 95% confidence intervals. A cumulative summary odds ratio was also calculated by combining studies in chronological order. Chi-squared for homogeneity was determined to establish the comparability of the studies. RESULTS: In our prospective study, there was no statistical difference in the rate of major anomalies between the corticosteroid-exposed and control groups. In the meta-analysis, the Mantel-Haenszel summary odds ratio for major malformations with all cohort studies was 1.45 [95% CI 0.80, 2.60] and 3.03 [95% CI 1.08, 8. 54] when Heinonen et al. ('77) was removed. This suggests a marginally increased risk of major malformations after first-trimester exposure to corticosteroids. In addition, summary odds ratio for case-control studies examining oral clefts was significant (3.35 [95% CI 1.97, 5.69]). CONCLUSIONS: Although prednisone does not represent a major teratogenic risk in humans at therapeutic doses, it does increase by an order of 3.4-fold the risk of oral cleft, which is consistent with the existing animal studies.     

Human teratogens: update 2010

A wide variety of human teratogens have been identified. The characteristics of human teratogens can be used in the assessment of apparent “new” teratogens, when postulated. Information is available through online databases, such as TERIS and Reprotox, telephone‐based counseling resources (e.g., Organization of Teratogen Information Systems [OTIS] and European Network Teratology Information Services [ENTIS]), reference books, annual meetings of the Teratology Society, and published articles. There are significant deficiencies in the information available: (1) lack of knowledge about the molecular and cellular basis for most teratogenic effects; (2) the inability to genetically identify more susceptible women before pregnancy; (3) little information is available on dermal and airborne exposures during pregnancy; and (4) most clinicians receive little, if any, training in the identification of or counseling for exposure to potential teratogens. There are many current dilemmas in counseling about exposures in pregnancy, including: (1) Is exposure to specific drugs, such as selected serotonin re‐uptake inhibitors (SSRIs) and the inhibitors of tumor necrosis factor‐alpha, teratogenic in the first trimester of pregnancy? (2) Are the increased risks of birth defects associated with assisted reproductive technology due, in part, to epigenetic effects? (3) What are the “safe” levels of exposure to the plasticizers phthalates during pregnancy? (4) How do we convince busy physicians, nurses, and pharmacists not to use the drug categories A, B, C, D, and X in counseling and to use more accurate sources? There is a need for a national advisory center for pregnancy registries to provide guidance when new registries are being developed. Birth Defects Research (Part A), 2011. © 2011 Wiley‐Liss, Inc.     

The all-or-none phenomenon revisited

One of the more pervasive tenets of teratology is the "all-or-none" phenomenon, which refers to the concept that embryonic exposure that occurs before organogenesis results in either no adverse embryonic outcome or in embryonic death. This concept has been used extensively in genetic counseling of pregnant women who have inadvertently undergone an exposure in the very early stages of pregnancy, frequently before the pregnancy has been recognized. Herein, we review the data that supports the all-or-none concept and the exceptions to this general rule. In the absence of further human evidence to the contrary, and given the many women exposed to medications or environmental agents before learning of their pregnancies, it would be prudent to continue to counsel pregnant women using the all-or-none hypothesis to avoid needless interruption of pregnancy out of unfounded fear of an adverse pregnancy outcome. Birth Defects Research (Part A) 94:664-669, 2012. ? 2012 Wiley Periodicals, Inc.     

Reducing harm from tobacco smoke exposure during pregnancy

In addition to the health risks that maternal tobacco smoke exposure in pregnancy poses to women, this is a cause of substantial fetal morbidity and mortality. In pregnancy, maternal tobacco smoke exposure can arise because women either smoke or are passively exposed to environmental tobacco smoke as a consequence of other's smoking. This article discusses the scope for clinicians to help reduce both types of tobacco smoke exposure in pregnancy, with a specific focus on available and effective interventions for smoking cessation by pregnant women. Behavioral support with smoking cessation is the only intervention that has been proven to encourage smoking cessation in pregnancy and reduces smoking rates in late pregnancy by 6 to 7%. There are physiological reasons to suspect that nicotine replacement therapy (NRT) will be less or (in)effective for smoking cessation in pregnancy when compared with its use by nonpregnant smokers. However, there are also strong theoretical reasons to suspect that NRT is likely to be safer than continued smoking in pregnancy. Consequently, this article reviews evidence for the safety and effectiveness of NRT when used for smoking cessation in pregnancy and recommendations concerning the use of NRT in pregnancy are presented.     

Women's perspectives on counseling about risks for medication‐induced birth defects

PURPOSE : This qualitative study explored women's experiences with counseling about medication‐induced birth defects, as well as how and when they would like to receive information on medication‐induced birth defects from their health care providers (HCPs). METHODS : We conducted four focus groups with 36 women of reproductive age (18–45 years old) in Pittsburgh, Pennsylvania. Twenty‐one women were using medications to treat a chronic health condition, and two were pregnant. Content analysis was performed by three independent coders using a grounded theory approach. Discrepancies were resolved by consensus. RESULTS : Women reported depending on their HCPs for information about the risks of teratogenic effects of medications on a pregnancy, but felt the information they had been provided was not always comprehensive. Women want HCPs to initiate discussions about potentially teratogenic medications at the time the medications are prescribed, regardless of whether the woman is sexually active or planning a pregnancy. Women want clear information about all potential outcomes for a fetus. Factors women reported as being critical to effective teratogenic risk counseling included privacy, sufficient time to discuss the topic, and a trusting relationship with their HCP. CONCLUSIONS : Women of reproductive age think that providing information about the possible teratogenic effects of medications could be improved by routine discussions of teratogenic risks at the time medications are prescribed. Birth Defects Research (Part A), 2010. © 2009 Wiley‐Liss, Inc.     

Live and Non-Live Pregnancy Outcomes among Women with Depression and Anxiety: A Population-Based Study

Background

Women taking antidepressant or anti-anxiety medications during early pregnancy have high risks of non-live pregnancy outcomes, although the contribution of the underlying illnesses to these risks remains unclear. We examined the impacts of antenatal depression and anxiety and of commonly prescribed treatments on the risks of non-live pregnancy outcomes.

Methods

We identified all pregnancies and their outcome (live birth, perinatal death, miscarriage or termination) among women aged 15–45 years between 1990 and 2009 from a large primary care database in the United Kingdom. Women were grouped according to whether they had no history of depression and anxiety, a diagnosis of such illness prior to pregnancy, illness during pregnancy and illness during pregnancy with use of medication (stratified by medication type). Multinomial logistic regression models were used to compare risks of non-live outcomes among these groups, adjusting for major socio-demographic and lifestyle characteristics.

Results

Among 512,574 pregnancies in 331,414 women, those with antenatal drug exposure showed the greatest increased risks for all non-live pregnancy outcomes, relative to those with no history of depression or anxiety, although women with prior (but not currently medicated) illness also showed modest increased risks. Compared with un-medicated antenatal morbidity, there was weak evidence of an excess risk in women taking tricyclic antidepressants, and stronger evidence for other medications.

Conclusions

Women with depression or anxiety have higher risks of miscarriage, perinatal death and decisions to terminate a pregnancy if prescribed psychotropic medication during early pregnancy than if not. Although underlying disease severity could also play a role, avoiding or reducing use of these drugs during early pregnancy may be advisable.     

Opioids and breathing

This review summarizes recent developments on the effects of opiate drugs and the various endogenous opioid peptides on breathing. These developments include demonstration of receptors and site-specific effects of application of opioids in the pons and medulla, demonstration of variable tolerance of respiratory responses in addicted individuals as well as their offspring, and demonstration of an endogenous opioid influence on breathing in early neonatal life and in certain physiological settings and disease states. The validity and limitations of using naloxone as a tool to uncover postulated endogenous opioid influences are also discussed as well as the potential problems imposed by the various settings in which this opiate antagonist drug is used. It is concluded that some parallelism exists between the role of endogenous opioids in pain modulation and their role in respiration especially in adults. Although more studies are needed especially with regard to defining specific effects of the various opioid receptors and ligands, it is felt that the effects of endogenous opioids on the control of breathing will probably be one of modulating the responses to drugs or nociceptive respiratory stimuli through inhibitory pathways.     

Induction of pain facilitation by sustained opioid exposure: relationship to opioid antinociceptive tolerance

Opioid analgesics are frequently used for the long-term management of chronic pain states, including cancer pain. The prolonged use of opioids is associated with a requirement for increasing doses to manage pain at a consistent level, reflecting the phenomenon of analgesic tolerance. It is now becoming clearer that patients receiving long-term opioid therapy can develop unexpected abnormal pain. Such paradoxical opioid-induced pain, as well as tolerance to the antinociceptive actions of opioids, has been reliably measured in animals during the period of continuous opioid delivery. Several recent studies have demonstrated that such pain may be secondary to neuroplastic changes that result, in part, from an activation of descending pain facilitation mechanisms arising from the rostral ventromedial medulla (RVM). One mechanism which may mediate such pain facilitation is through the increased activity of CCK in the RVM. Secondary consequences from descending facilitation may be produced. For example, opioid-induced upregulation of spinal dynorphin levels seem to depend on intact descending pathways from the RVM reflecting spinal neuroplasticity secondary to changes at supraspinal levels. Increased expression of spinal dynorphin reflects a trophic action of sustained opioid exposure which promotes an increased pain state. Spinal dynorphin may promote pain, in part, by enhancing the evoked release of excitatory transmitters from primary afferents. In this regard, opioids also produce trophic actions by increasing CGRP expression in the dorsal root ganglia. Increased pain elicited by opioids is a critical factor in the behavioral manifestation of opioid tolerance as manipulations which block abnormal pain also block antinociceptive tolerance. Manipulations that have blocked enhanced pain and antinociceptive tolerance include reversible and permanent ablation of descending facilitation from the RVM. Thus, opioids elicit systems-level adaptations resulting in pain due to descending facilitation, upregulation of spinal dynorphin and enhanced release of excitatory transmitters from primary afferents. Adaptive changes produced by sustained opioid exposure including trophic effects to enhance pain transmitters suggest the need for careful evaluation of the consequences of long-term opioid administration to patients.     

Drug interactions associated with methadone, buprenorphine, cocaine, and HIV medications: implications for pregnant women

Pregnancy in substance-abusing women with HIV/AIDS presents a complex clinical challenge. Opioid-dependent women need treatment with opioid therapy during pregnancy to protect the health of mother and developing fetus. However, opioid therapies, methadone and buprenorphine, may have drug interactions with some HIV medications that can have adverse effects leading to suboptimal clinical outcomes. Further, many opioid-dependent individuals have problems with other forms of substance abuse, for example, cocaine abuse, that could also contribute to poor clinical outcomes in a pregnant woman. Physiological changes, including increased plasma volume and increased hepatic and renal blood flow, occur in the pregnant woman as the pregnancy progresses and may alter medication needs with the potential to exacerbate drug interactions, although there is sparse literature on this issue. Knowledge of possible drug interactions between opioids, other abused substances such as cocaine, HIV therapeutics, and other frequently required medications such as antibiotics and anticonvulsants is important to assuring the best possible outcomes in the pregnant woman with opioid dependence and HIV/AIDS.     

Maternal exposure to folic acid antagonists and placenta-mediated adverse pregnancy outcomes

Background

In previous studies, maternal exposure to folic acid antagonists was associated with increased risks of neural tube defects, cardiovascular defects, oral clefts and urinary tract defects. The objective of the current study was to assess the possible effects of using folic acid antagonists in pregnancy on placenta-mediated adverse outcomes of pregnancy.

Methods

We used data from an administrative database to retrospectively compare the occurrence of placenta-mediated adverse pregnancy outcomes between pregnant women exposed to folic acid antagonists and women without exposure to these agents.

Results

We included in the analysis a total of 14 982 women who had been exposed to folic acid antagonists and 59 825 women who had not been exposed. Sulfamethoxazole–trimethoprim was the most frequently prescribed dihydrofolate reductase inhibitor (a total of 12 546 exposures during the preconception period and all 3 trimesters), and phenobarbital was the most frequently prescribed among the other folic acid antagonists (a total of 1565 exposures). The risks of preeclampsia (adjusted odds ratio [OR] 1.52, 95% confidence interval [CI] 1.39–1.66), severe preeclampsia (OR 1.77, 95% CI 1.38–2.28), placental abruption (OR 1.32, 95% CI 1.12–1.57), fetal growth restriction defined as less than the 10th percentile (OR 1.07, 95% CI 1.01–1.13), fetal growth restriction defined as less than the 3rd percentile (OR 1.22, 95% CI 1.11–1.34) and fetal death (OR 1.35, 95% CI 1.07–1.70) were greater among mothers with exposure to folic acid antagonists. In general, the risks associated with exposure to other folic acid antagonists were higher than those associated with exposure to dihydrofolate reductase inhibitors. Supplementary analyses involving tight matching with propensity score, restriction of the analysis to women with exposure during the first and second trimesters and restriction of the analysis to specific categories of folic acid antagonists yielded similar results.

Interpretation

Maternal exposure to folic acid antagonists appears to increase the risk of placenta-mediated adverse outcomes of pregnancy.     

Endogenous opiates and behavior: 2012

This paper is the thirty-fifth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2012 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).     

Pregnancy outcome after gestational exposure to metronidazole: a prospective controlled cohort study

BACKGROUND: Metronidazole is an important antibacterial agent commonly used in women of reproductive age. Its use in pregnancy is a reason for concern for women and their health care providers. The objective was to examine the fetal safety of metronidazole. METHODS: The Israeli Teratogen Information Service prospectively collected and followed up 228 women exposed to metronidazole in pregnancy, 86.2% of whom with first-trimester exposure. Pregnancy outcome was compared with that of a control group, who were counseled during the same period for nonteratogenic exposure. RESULTS: There was no difference in the rate of major malformations between the groups (3/190; 1.6% [metronidazole] vs. 8/575; 1.4% [control], P = 0.739). The rate of major malformations did not differ between the groups even after including elective terminations of pregnancy due to prenatally diagnosed malformations (5/192; 2.6% [metronidazole] vs. 12/579; 2.1% [control], P = 0.777). A reduced neonatal birth weight was found in the metronidazole group compared with controls without significant differences in the rate of prematurity or in gestational age at delivery. The mean birth weight was lower in the metronidazole group when comparing the subgroup of term infants. CONCLUSIONS: This study confirms that metronidazole does not represent a major teratogenic risk in humans when used in the recommended doses.     

Emerging data on the use of anti-tumor necrosis factor-alpha medications in pregnancy

Anti-tumor necrosis factor (TNF) α medications are used for the treatment of a number of autoimmune diseases. Evaluation of pregnancy safety for these medications is complicated by the contribution of the underlying maternal disease to adverse pregnancy outcomes, such as preterm delivery and reduced birth weight. Placental transport of these medications is thought to be minimal in the first trimester, thereby providing some reassurance regarding theoretical risks for congenital malformations. Available human exposure data are sparse; however, to date there has been no convincing evidence to support an increased risk for a specific pattern of major congenital malformations with any of the drugs in this group for which some data is currently available. As a result of the improvement of symptoms during pregnancy in some women with autoimmune diseases, it may be possible to discontinue treatment before or shortly after conception. However, in some cases the benefits of treatment and concerns for disease flares in pregnancy have warranted continued treatment during pregnancy. Because of the relatively long half-life of these medications, and theoretical concerns for immune compromise of the infant following exposure in the latter two trimesters, some clinicians recommend discontinuation of treatment in the third trimester to avoid potentially prolonged infant exposure in the postpartum period. Currently ongoing controlled cohort studies for some of the TNF blocker medications will help to provide more definitive answers for clinicians and patients. Birth Defects Research (Part A) 94:607-611, 2012. ? 2012 Wiley Periodicals, Inc.