Use of benzodiazepines and benzodiazepine receptor agonists during pregnancy: maternal characteristics

Prescription Patterns and Predisposing Factors of Benzodiazepine and Z-Hypnotic Use During Pregnancy: A Nationwide Cohort Study

PURPOSE

The use of benzodiazepines and Z-hypnotics during pregnancy has raised significant concerns in recent years. However, there are limited data that capture the prescription patterns and predisposing factors in use of these drugs, particularly among women who have been long-term users of benzodiazepines and Z-hypnotics before pregnancy.

METHODS

This population-based cohort study comprised 2 930 988 pregnancies between 2004 and 2018 in Taiwan. Women who were dispensed benzodiazepines or Z-hypnotics during pregnancy were identified and further stratified into groups based on their status before pregnancy: long-term users (with a supply of more than 180 days within a year), short-term users (with a supply of less than 180 days within a year), and nonusers. Trends in the use of benzodiazepines or Z-hypnotics and concomitant use with antidepressants or opioids were assessed. Logistic regression models were utilized to identify factors associated with use of these drugs during pregnancy, and interrupted time series analyses (ITSA) were employed to evaluate utilization patterns of these drugs across different pregnancy-related periods.

RESULTS

The overall prevalence of benzodiazepine and Z-hypnotic use was 3.5% during pregnancy. Among prepregnancy long-term users, an upward trend was observed. The concomitant use of antidepressants or opioids among exposed women increased threefold (from 8.6% to 23.1%) and sixfold (from 0.3% to 1.7%) from 2004 to 2018, respectively. Women with unhealthy lifestyle behaviors, such as alcohol abuse (OR 2.48; 95% CI, 2.02-3.03), drug abuse (OR 10.34; 95% CI, 8.46-12.64), and tobacco use (OR 2.19; 95% CI, 1.96-2.45), as well as those with psychiatric disorders like anxiety (OR 6.99; 95% CI, 6.77-7.22), insomnia (OR 15.99; 95% CI, 15.55-16.45), depression (OR 9.43; 95% CI, 9.07-9.80), and schizophrenia (OR 21.08; 95% CI, 18.76-23.69), and higher healthcare utilization, were more likely to use benzodiazepines or Z-hypnotics during pregnancy. ITSA revealed a sudden decrease in use of benzodiazepines and Z-hypnotics after recognition of pregnancy (level change -0.55 percentage point; 95% CI, -0.59 to -0.51). In contrast, exposures to benzodiazepines and Z-hypnotics increased significantly after delivery (level change 0.12 percentage point; 95% CI, 0.09 to 0.16).

CONCLUSIONS

In this cohort study, an increased trend of benzodiazepine and Z-hypnotic use during pregnancy among prepregnancy long-term users, as well as concomitant use with antidepressants or opioids were found. The findings have highlighted the existence of various risk factors associated with the use of these drugs during pregnancy. Utilization patterns varied across different stages of pregnancy, highlighting the need for prescription guidelines and educational services for women using these drugs during pregnancy.

Benzodiazepine Interference with Fertility and Embryo Development: A Preliminary Survey in the Sea Urchin Paracentrotus lividus

Psychotropic drugs and benzodiazepines are nowadays among the primary substances of abuse. This results in a large and constant release into aquatic environments where they have potentially harmful effects on non-target organisms and, eventually, human health. In the last decades, evidence has been collected on the possible interference of benzodiazepines with reproductive processes, but data are few and incomplete. In this study, the possible negative influence of delorazepam on fertilization and embryo development has been tested in Paracentrotus lividus, a key model organism in studies of reproduction and embryonic development. Sperm, eggs, or fertilized eggs have been exposed to delorazepam at three concentrations: 1 μg/L (environmentally realistic), 5 μg/L, and 10 μg/L. Results indicate that delorazepam reduces the fertilizing capacity of male and female gametes and interferes with fertilization and embryo development. Exposure causes anatomical anomalies in plutei, accelerates/delays development, and alters the presence and distribution of glycoconjugates such as N-Acetyl-glucosamine, α-linked fucose, and α-linked mannose in both morulae and plutei. These results should attract attention to the reproductive fitness of aquatic species exposed to benzodiazepines and pave the way for further investigation of the effects they may exert on human fertility. The presence of benzodiazepines in the aquatic environment raises concerns about the reproductive well-being of aquatic species. Additionally, it prompts worries regarding potential impacts on human fertility due to the excessive use of anxiolytics.

Hypnotic benzodiazepine receptor agonist exposure during pregnancy and the risk of congenital malformations and other adverse pregnancy outcomes: A systematic review and meta-analysis

OBJECTIVE

To determine if there is an association between antenatal hypnotic benzodiazepine receptor agonist exposure and congenital malformations or other adverse pregnancy outcomes in the offspring.

METHODS

Databases were searched to January 31, 2021. Cohort studies published in English on congenital malformations or other adverse pregnancy outcomes in infants following exposure compared with those unexposed, were summarized and meta-analyzed where possible.

RESULTS

Following screening, 25 studies were assessed for eligibility and seven included in the meta-analyses. Five studies were pooled for congenital malformations following first trimester exposure and not statistically significant (OR 0.87, 95% CI 0.56-1.36). The five studies that assessed for preterm birth following anytime exposure did pool to a statistically significant effect (OR 1.49, 95% CI 1.19-1.86); study quality, control for other psychotropic drugs and psychiatric diagnosis did not appear to be moderators. There were two missing studies when examining for publication bias in both of the main analyses above but the revised estimates were similar to the original. Low birth weight (LBW) was significant (three studies, any time exposure, OR 1.51, 1.27-1.78) as was small for gestational age (SGA) (three studies with anytime exposure, OR 1.34, 1.22-1.48). There were too few studies to summarize birth weight, gestational age, respiratory difficulties, APGAR score at 5 min and NICU admission.

CONCLUSIONS

Pregnancy exposure to hypnotics was not associated with a higher risk for congenital malformations but was associated with an increased risk for preterm birth, LBW and SGA compared with those infants who were not exposed. These findings are consistent with the antidepressant and benzodiazepine literature.

Maternal use of sedative drugs and its effects on pregnancy outcomes: a Finnish birth cohort study

Our aim was to evaluate maternal use of sedative drugs before, during, and after pregnancy and to assess the influence of use of these drugs on pregnancy outcomes. The study cohort (N = 6231) consists of all primiparous women, who lived in the city of Vantaa, Finland, and who delivered a singleton between 2009 and 2015. Data were obtained from Finnish national health registers. Of the women, 3.2% (n = 202) purchased at least once sedative drugs within 90 days before conception, during pregnancy and/or within 90 days after delivery. Sedative drug users were older, less likely to cohabitate, more often smokers, had lower educational attainment and had more mental diseases (for all p < 0.001) compared with non-users. Sedative drug users purchased more often antidepressants and drugs for the alimentary tract, musculoskeletal and nervous system than non-users (for all p < 0.001). No adverse birth or pregnancy outcomes were found in the group using sedative drugs compared with the non-users. Studies in larger cohorts are needed to confirm our study findings.

Optimal Sedation and Pain Management: A Patient- and Symptom-Oriented Paradigm

In the critically ill patient, optimal pain and sedation management remains the cornerstone of achieving comfort, safety, and to facilitate complex life support interventions. Pain relief, using multimodal analgesia, is an integral component of any orchestrated approach to achieve clinically appropriate goals in critically ill patients. Sedative management, however, remains a significant challenge. Subsequent studies including most recent randomized trials have failed to provide strong evidence in favor of a sedative agent, a mode of sedation or ancillary protocols such as sedative interruption and sedative minimization. In addition, clinical practice guidelines, despite a comprehensive evaluation of relevant literature, have limitations when applied to individual patients. These limitations have been most apparent during the coronavirus disease 2019 pandemic. As such, there is a need for a mindset shift to a practical and achievable sedation strategy, driven by patients' characteristics and individual patient needs, rather than one cocktail for all patients. In this review, we present key principles to achieve patient-and symptom-oriented optimal analgesia and sedation in the critically ill patients. Sedative intensity should be proportionate to care complexity with due consideration to an individual patient's modifiers. The use of multimodal analgesics, sedatives, and antipsychotics agents-that are easily titratable-reduces the overall quantum of sedatives and opioids, and reduces the risk of adverse events while maximizing clinical benefits. In addition, critical considerations regarding the choice of sedative agents should be given to factors such as age, medical versus operative diagnosis, and cardiovascular status. Specific populations such as trauma, neurological injury, and pregnancy should also be taken into account to maximize efficacy and reduce adverse events.

Use of Prescribed Psychotropics during Pregnancy: A Systematic Review of Pregnancy, Neonatal, and Childhood Outcomes

This paper reviews the findings from preclinical animal and human clinical research investigating maternal/fetal, neonatal, and child neurodevelopmental outcomes following prenatal exposure to psychotropic drugs. Evidence for the risks associated with prenatal exposure was examined, including teratogenicity, neurodevelopmental effects, neonatal toxicity, and long-term neurobehavioral consequences (i.e., behavioral teratogenicity). We conducted a comprehensive review of the recent results and conclusions of original research and reviews, respectively, which have investigated the short- and long-term impact of drugs commonly prescribed to pregnant women for psychological disorders, including mood, anxiety, and sleep disorders. Because mental illness in the mother is not a benign event, and may itself pose significant risks to both mother and child, simply discontinuing or avoiding medication use during pregnancy may not be possible. Therefore, prenatal exposure to psychotropic drugs is a major public health concern. Decisions regarding drug choice, dose, and duration should be made carefully, by balancing severity, chronicity, and co-morbidity of the mental illness, disorder, or condition against the potential risk for adverse outcomes due to drug exposure. Globally, maternal mental health problems are considered as a major public health challenge, which requires a stronger focus on mental health services that will benefit both mother and child. More preclinical and clinical research is needed in order to make well-informed decisions, understanding the risks associated with the use of psychotropic medications during pregnancy.

Benzodiazepines I: Upping the Care on Downers: The Evidence of Risks, Benefits and Alternatives

Benzodiazepines are some of the most commonly prescribed medications in the world. These sedative-hypnotics can provide rapid relief for symptoms like anxiety and insomnia, but are also linked to a variety of adverse effects (whether used long-term, short-term, or as needed). Many patients take benzodiazepines long-term without ever receiving evidence-based first-line treatments (e.g., psychotherapy, relaxation techniques, sleep hygiene education, serotonergic agents). This review discusses the risks and benefits of, and alternatives to benzodiazepines. We discuss evidence-based indications and contraindications, and the theoretical biopsychosocial bases for effectiveness, ineffectiveness and harm. Potential adverse effects and drug-drug interactions are summarized. Finally, both fast-acting/acute and delayed-action/chronic alternative treatments for anxiety and/or insomnia are discussed. Response to treatment-whether benzodiazepines, other pharmacological agents, or psychotherapy-should be determined based on functional recovery and not merely sedation.

Prenatal exposure to anxiolytic and hypnotic medication in relation to behavioral problems in childhood: A population-based cohort study

Benzodiazepines and benzodiazepine-related medications (BBRMs) are anxiolytics and hypnotics acting on γ-amino butyric acid (GABA)_A receptors. BBRMs are assumed to have a low potential for major congenital malformations, but research on more subtle and protracted developing symptoms of these medications is lacking. Therefore, we prospectively investigated the association between BBRM use in pregnancy and long-term effects on child behavior in a large population-based cohort study. The study population consisted of 104 children prenatally exposed to BBRM, 527 children exposed to maternal prenatal anxiety or phobic anxiety symptoms (without exposure to BBRM), and 5609 control children. At child age, 6years, Oppositional Defiant Disorder (ODD), Aggressive Behavior and Anxiety Problems were assessed by the Child Behavior Checklist (CBCL) reported by the mother and the Teacher Report Form (TRF). Children prenatally exposed to BBRM had higher scores of ODD and aggressive behavior, but not of anxiety. However, these associations were explained by maternal anxiety symptoms during pregnancy. Moreover, prenatal exposure to anxiety (without exposure to BBRM) was associated with increased scores of child ODD, aggressive behavior, and anxiety. In conclusion, the current study demonstrates that prenatal BBRM exposure was not independently associated with ODD and aggressive behavior in childhood when prenatal anxiety symptoms were taken into account.

[Psychopharmacotherapy during pregnancy : Which antipsychotics, tranquilizers and hypnotics are suitable?]

BACKGROUND

When administering psychotropic drugs during pregnancy not only the potential teratogenic effects on the child must be addressed but also the fetotoxic implications for pregnancy and/or the peripartum phase as well as possible neurocognitive developmental disorders must be considered.

OBJECTIVE

Evaluation of the risks and benefits of administering psychotropic drugs during pregnancy or for women who wish to become pregnant.

METHODS

The literature has been reviewed with the purpose of providing information on psychotropic drugs which can safely be administered during pregnancy. The review considers antipsychotics as well as tranquilizers and hypnotics.

RESULTS

Data are available for a multitude of psychotropic drugs that allow a safe estimation on their suitability for use during pregnancy.

CONCLUSION

When treating mental illnesses during pregnancy the option of administering drugs must not principally be ruled out. What is required is an individual assessment of benefits and risks. The risk of an untreated mental illness versus the benefit of a suitable treatment, which may include the use of medication and the potential harm to the infant must be evaluated. If certain rules are observed and a suitable drug is selected the risk to the newborn child and/or mother during pregnancy can be minimized. During pregnancy, therapeutic drug monitoring is indicated and increases the safety for use of drugs and preventing harm to both mother and infant.

Apparent Life-Threatening Event following Maternal Use of Temazepam during Labour

Benzodiazepines are one of the most frequently prescribed psychotropic drugs during pregnancy. Despite the fact that these drugs have been in use for a long time, there is still debate about the safety for the developing fetus and neonate. We present a case of a newborn with an apparent life-threatening event shortly after birth following maternal temazepam use during labour and advise to be reserved in prescribing any dose of any kind of benzodiazepine during labour.

Maternal Characteristics of Women Exposed to Hypnotic Benzodiazepine Receptor Agonist during Pregnancy

Background. There is little knowledge regarding the characteristics of women treated with hypnotic benzodiazepine receptor agonists (HBRAs) during pregnancy. In this large Danish cohort study, we characterize women exposed to HBRA during pregnancy. We determined changes in prevalence of HBRA use from 1997 to 2010 and exposure to HBRAs in relation to pregnancy. Methods. We performed a retrospective cohort study including 911,017 pregnant women in the period from 1997 to 2010. Information was retrieved from The Danish Birth Registry and The Registry of Medicinal Product Statistics to identify pregnant women redeeming a prescription of HBRAs. Results. We identified 2,552 women exposed to HBRAs during pregnancy, increasing from 0.18% in 1997 to 0.23% in 2010. Compared to unexposed women, exposed women were characterized by being older, with higher BMI, in their third or fourth parity, of lower income and education level, more frequently smokers, and more likely to be comedicated with antipsychotic, anxiolytic, or antidepressant drugs (P < 0.0001). Conclusion. Women using HBRAs during their pregnancy differ from unexposed women in socioeconomic factors and were more likely to receive comedication. The consumption of HBRAs was reduced during pregnancy compared to before conception.

Benzodiazepine exposure in pregnancy and risk of major malformations: a critical overview

OBJECTIVE

Benzodiazepines (BDZs) safety profiles in pregnancy suggest that the risk of major malformations (MMs) cannot be considered simply as a "class effect". The aim of this paper was to review and update the available literature on the risks of MMs in women exposed to BDZs in the first trimester of pregnancy.

METHODS

PubMed was searched for English-language articles, from January 2001 to November 2011, introducing as keywords "teratogens", " major malformation", "foetus", "infant", "newborn", "pregnancy", in conjunction with "benzodiazepines" as a keyword or BDZ generic name as text words.

RESULTS

Twelve studies were selected for the review. BDZ exposure during the first trimester of pregnancy seems not to be associated with an increasing risk of congenital MMs. Diazepam and chlordiazepoxide should be considered drugs of first choice.

CONCLUSIONS

Data published in the last 10 years did not indicate an absolute contraindication in prescribing BDZs during the first gestational trimester. In any case, studies analyzed suffer from a number of methodological limitations such as lack of careful report of BDZ patterns of use in pregnancy, possible influences of recall bias, lack of controlling for confounding factors and lack of data concerning possible MMs in aborted fetuses.

Newborns of mothers with intellectual disability have a higher risk of perinatal death and being small for gestational age

OBJECTIVE

To study mode of birth, perinatal health and death in children born to mothers with intellectual disability (ID) in Sweden.

DESIGN

Population-based register study.

SETTING

National registers; the National Patient Register linked to the Medical Birth Register.

SAMPLE

Children of first-time mothers with ID (n = 326; classified in the International Classification of Diseases 8-10) were identified and compared with 340 624 children of first-time mothers without ID or any other psychiatric diagnosis between 1999 and 2007.

METHODS

Population-based data were extracted from the National Patient Register and the Medical Birth Register.

MAIN OUTCOME MEASURES

Mode of birth, preterm birth, small for gestational age, Apgar score, stillbirth and perinatal death.

RESULTS

Children born to mothers with ID were more often stillborn (1.2 vs. 0.3%) or died perinatally (1.8 vs. 0.4%) than children born to mothers without ID. They had a higher proportion of cesarean section birth (24.5 vs. 17.7%) and preterm birth (12.2 vs. 6.1%), were small for gestational age (8.4 vs. 3.1%) and had lower Apgar scores (<7 points at five minutes; 3.7 vs 1.5%) compared with children born to mothers without ID. Logistic regression adjusted for maternal characteristics confirmed an increased risk of small for gestational age (odds ratio 2.25), stillbirth (odds ratio 4.53) and perinatal death (odds ratio 4.25) in children born to mothers with ID.

CONCLUSIONS

Unborn and newborn children of mothers with ID should be considered a risk group, and their mothers may need better individual-based care and support.

Pharmacologic management of the opioid neonatal abstinence syndrome

Opioid use in pregnant women has increased over the last decade. Following birth, infants with in utero exposure demonstrate signs and symptoms of withdrawal known as the neonatal abstinence syndrome (NAS). Infants express a spectrum of disease, with most requiring the administration of pharmacologic therapy to ensure proper growth and development. Treatment often involves prolonged hospitalization. There is a general lack of high-quality clinical trial data to guide optimal therapy, and significant heterogeneity in treatment approaches. Emerging trends in the treatment of infants with NAS include the use of sublingual buprenorphine, transition to outpatient therapy, and pharmacogenetic risk stratification.

Are hypnotic benzodiazepine receptor agonists teratogenic in humans?

BACKGROUND

Hypnotic benzodiazepine receptor agonists (HBRAs; zolpidem, zopiclone, and zaleplon) are used in the treatment of insomnia. Little is known about the safety of HBRAs during pregnancy.

METHODS

Data from the Swedish Medical Birth Registry from July 1, 1995, up to 2007 were used to identify 1318 women who reported the use of HBRAs in early pregnancy. They gave birth to 1341 infants. Maternal characteristics and the presence of congenital malformations were compared with all other women who gave birth (n = 1,106,001) and all other infants (n = 1,125,734) born during the study period.

RESULTS

Use and/or reporting of HBRAs increased with maternal age and were higher at first than higher parity. Maternal smoking was strongly associated with reported use of HBRAs. The probability of using HBRAs increased in women who had had 3 or more earlier miscarriages or 5 or more years of involuntary childlessness. An excess use of other drugs and above all psychoactive drugs were seen in women reporting use of HBRAs.Hypnotic benzodiazepine receptor agonists were not associated with an increased risk for congenital malformations. A statistically significant high risk for other intestinal malformations than atresias/stenosis was based on only 4 infants.

CONCLUSIONS

Maternal use of HBRAs does not seem to increase malformation risk. The tentative association with some intestinal malformations may be due to chance because of multiple testing and needs confirmation.

Management of the obstetric patient with status asthmaticus

Status asthmaticus requiring mechanical ventilation is an uncommon, life-threatening disorder in obstetric patients. The unique physiologic changes of pregnancy, impact of the fetus on the maternal condition, and concerns for fetal and maternal health and survival are particular concerns in critical illness. Furthermore, the issues of hypoxemia and hypercapnia, ventilator management and complications make this disease of respiratory failure an especially important area for review. There is abundant literature on the management of asthma during pregnancy; however the literature is very limited in those with status asthmaticus who require intensive care unit admission. We report our intensive care unit experience in the management of status asthmaticus in 5 pregnant patients and review the literature on management of status asthmaticus during pregnancy.

Sublingual buprenorphine for treatment of neonatal abstinence syndrome: a randomized trial

OBJECTIVE

In utero exposure to drugs of abuse can lead to neonatal abstinence syndrome, a condition that is associated with prolonged hospitalization. Buprenorphine is a partial mu-opioid agonist used for treatment of adult detoxification and maintenance but has never been administered to neonates with opioid abstinence syndrome. The primary objective of this study was to demonstrate the feasibility and, to the extent possible in this size of study, the safety of sublingual buprenorphine in the treatment of neonatal abstinence syndrome. Secondary goals were to evaluate efficacy relative to standard therapy and to characterize buprenorphine pharmacokinetics when sublingually administered.

METHODS

We conducted a randomized, open-label, active-control study of sublingual buprenorphine for the treatment of opiate withdrawal. Thirteen term infants were allocated to receive sublingual buprenorphine 13.2 to 39.0 mug/kg per day administered in 3 divided doses and 13 to receive standard-of-care oral neonatal opium solution. Dose decisions were made by using a modified Finnegan scoring system.

RESULTS

Sublingual buprenorphine was largely effective in controlling neonatal abstinence syndrome. Greater than 98% of plasma concentrations ranged from undetectable to approximately 0.60 ng/mL, which is less than needed to control abstinence symptoms in adults. The ratio of buprenorphine to norbuprenorphine was larger than that seen in adults, suggesting a relative impairment of N-dealkylation. Three infants who received buprenorphine and 1 infant who received standard of care reached protocol-specified maximum doses and required adjuvant therapy with phenobarbital. The mean length of treatment for those in the neonatal-opium-solution group was 32 compared with 22 days for the buprenorphine group. The mean length of stay for the neonatal-opium-solution group was 38 days compared with 27 days for those in the buprenorphine group. Treatment with buprenorphine was well tolerated.

CONCLUSIONS

Buprenorphine administered via the sublingual route is feasible and apparently safe and may represent a novel treatment for neonatal abstinence syndrome.

Use of herbal drugs during early pregnancy in relation to maternal characteristics and pregnancy outcome

PURPOSE

To study characteristics of women using herbal drugs and the possible impact of use in early pregnancy on pregnancy outcome.

METHODS

Data on the use of herbal drugs during pregnancy were obtained from the Swedish Medical Birth Register during the period 1st July 1995 to end of 2004. Women who reported use of herbal drugs were compared to all women giving birth during the period. Outcome variables were prematurity, birth weight, Apgar score, number of infants in delivery and congenital malformations.

RESULTS

Among the 860 215 women in the register, 787 (0.9%) reported use of herbal drugs during early pregnancy. The most frequently used herbal drugs were Floradix (iron-rich herbs), ginseng and valerian. Use of such drugs was independently associated with high maternal age, normal weight and 14-15 years of education. Risk factors for valerian differed from those for other herbal drugs, for example with respect to maternal smoking and country of birth. Concomitant drug use was common and the most frequently used drugs were multivitamins, folic acid, cardiovascular drugs (mainly antihypertensive drugs), non-steroid anti-inflammatory drugs (NSAIDs), analgesics and psycholeptics. None of the infant characteristics studied were influenced significantly by the mother's use of the examined herbal drugs during early pregnancy.

CONCLUSIONS

The most commonly reported herbal drugs used during pregnancy were Floradix (iron-rich herbs), ginseng and valerian. No signs of unfavourable effect on pregnancy outcome were seen. The number of exposures, however, was low and therefore effects on rare outcomes (e.g. specific malformations) cannot be excluded.

Use of benzodiazepines and benzodiazepine receptor agonists during pregnancy: neonatal outcome and congenital malformations

BACKGROUND

Exposure to Benzodiazepines (BZD) during foetal life has been suggested to contribute to neonatal morbidity and some congenital malformations, for example, orofacial clefts. Here we aimed to study the neonatal outcome and congenital malformations in neonates whose mothers reported use of BZD and/or hypnotic benzodiazepine receptor agonists (HBRA) during pregnancy.

METHODS

In the Swedish Medical Birth Register we identified 1979 infants whose mothers (n = 1944) reported use of BZD and/or HBRA in early pregnancy. An additional 401 infants were studied, born to 390 mothers who were prescribed such drugs during late pregnancy. Neonatal outcome including congenital malformations after exposure was compared with that of all births (n = 873 879).

RESULTS

An increased risk for preterm birth and low birth weight was detected in the exposed population. The rate of relatively major congenital malformations was moderately increased among infants exposed in early pregnancy (adjusted OR = 1.24, 95%CI 1.00-1.55), not explained by known teratogenic maternal co-medication. A higher than expected number of infants with pylorostenosis or alimentary tract atresia (especially small gut) was found. This was, however, based on only seven infants for each group of malformation without association to any specific BZD or HBRA. The earlier proposed increased risk for orofacial clefts was not confirmed in our study.

CONCLUSIONS

Maternal use of BZD and/or HBRA may increase the risk for preterm birth and low birth weight and cause neonatal symptoms, but does not appear to have a strong teratogenic potential. The tentative association with pylorostenosis and alimentary tract atresia needs confirmation.