Acetaminophen use in pregnancy: Examining prevalence, timing, and indication of use in a prospective birth cohort

Maternal intake of paracetamol during pregnancy and biomarkers of male fecundity in young adult sons

Paracetamol is suggested to have endocrine disrupting properties possibly affecting fetal programming of reproductive health that might lead to impaired semen quality and changes in reproductive hormones. In this longitudinal study, we included 1058 young adult men born 1998-2000 into the Danish National Birth Cohort with follow-up at 18-21 years of age. The exposure, maternal intake of paracetamol, was modelled in three ways: dichotomized, trimester-specific, and as duration of exposure categorized into: short (1-2 weeks), medium (3-9 weeks) or long duration (>9 weeks) vs. no intake. Outcomes included semen characteristics, self-measured testis volume, and reproductive hormone levels. We used negative binominal regression to estimate the percentage difference and 95% confidence interval (CI) for each outcome. In total, 547 (48%) sons were prenatally exposed to paracetamol due to maternal intake at least once. Maternal intake of paracetamol during pregnancy was not associated with any of the biomarkers in the dichotomized or trimester-specific exposure models. For duration of exposure, sons of mothers with long duration of maternal intake of paracetamol showed tendencies towards lower semen concentration (-14% [95% CI: -31%; 8%]), a higher proportion of nonprogressive and immotile spermatozoa (8% [95% CI: -4%; 21%]) and higher DNA Fragmentation Index (16% [95% CI: -1%; 36%]) compared to son of mothers with no intake. Maternal intake of paracetamol during pregnancy was not clearly associated with biomarkers of male fecundity in adult sons. However, it cannot be ruled out that long duration of maternal intake of paracetamol might be associated with impaired semen characteristics.

Prenatal exposure to acetaminophen at different doses, courses and time causes testicular dysplasia in offspring mice and its mechanism

Epidemiological investigation suggested that the use of acetaminophen during pregnancy may cause offspring testicular dysplasia, but no systematic study has been conducted. In this study, Kunming mice were given acetaminophen at different doses (100/200/400 mg/kg.d), courses (single/multiple), time (second/third trimester) during pregnancy. Fetal blood and testes were collected on gestaional day 18 for detection. The results indicated abnormal testicular development in the PAcE (prenatal acetaminophen exposure) groups. The maximum diameter/cross-sectional area decreased, the interstitial space widened, and decreased proliferation/increased apoptosis were observed, especially in the high-dose, multi-course and second-trimester groups. Meanwhile, the serum testosterone level decreased in PAcE groups, and the steroid synthesis function in Leydig cells, Sertoli and spermatogenic cell function were inhibited, it was more significant in high-dose, multi-course and second-trimester groups. Furthermore, Wnt signal pathway was activated but Notch signal pathway was inhibited in the PAcE groups. Finally, in vitro experiment, acetaminophen could inhibit spermatogonial cell proliferation, enhance apoptosis, and change Wnt/Notch signal pathway. In conclusion, this study confirmed that PAcE can change fetal testicular development in a dose, course and time-dependent manner, and found that multicellular function impaired. This study provides theoretical and experimental basis for systematically elucidating the developmental toxicity of acetaminophen in testis.

Acetaminophen for the patent ductus arteriosus: has safety been adequately demonstrated?

Patent ductus arteriosus (PDA) is the most common cardiovascular condition diagnosed in premature infants. Acetaminophen was first proposed as a potential treatment for PDA in 2011. Since that time acetaminophen use among extremely preterm neonates has increased substantially. The limited available data demonstrate that acetaminophen reduces PDA without evident hepatotoxicity. These findings have led some to suggest that acetaminophen is a safe and effective therapy for PDA closure. However, the lack of apparent hepatoxicity is predictable. Acetaminophen induced cellular injury is due to CYP2E1 derived metabolites; and hepatocyte CYP2E1 expression is low in the fetal and neonatal period. Here, we review preclinical and clinical data that support the hypothesis that the lung, which expresses high levels of CYP2E1 during fetal and early postnatal development, may be particularly susceptible to acetaminophen induced toxicity. Despite these emerging data, the true potential pulmonary risks and benefits of acetaminophen for PDA closure are largely unknown. The available clinical studies in are marked by significant weakness including low sample sizes and minimal evaluation of extremely preterm infants who are typically at highest risk of pulmonary morbidity. We propose that studies interrogating mechanisms linking developmentally regulated, cell-specific CYP2E1 expression and acetaminophen-induced toxicity as well as robust assessment of pulmonary outcomes in large trials that evaluate the safety and efficacy of acetaminophen in extremely preterm infants are needed.

Course-, dose-, and stage-dependent toxic effects of prenatal acetaminophen exposure on fetal long bone development

Acetaminophen is a common analgesic and fever reduction medicine for pregnant women. Epidemiological studies suggest that prenatal acetaminophen exposure (PAcE) affects offspring health and development. However, the effects of PAcE on fetal long bone development and its potential mechanisms have not been elucidated. Based on clinical dosing characteristics, fetal mouse femurs were obtained for detection after oral gavage of acetaminophen at different doses (0, 100 or 400 mg/kg d), courses (single or multiple times) or stages (mid- or late pregnancy) during pregnancy in Kunming mice. The results showed that compared with the control group, PAcE reduced the length of total femur and the primary ossification center (POC), delayed the mineralization of POC and the ossification of epiphyseal region, and down-regulated the mRNA expression of osteogenic function markers (such as Runx2, Bsp, Ocn , Col1a1) in fetal femur, particularly in the high dose, multiple courses, and mid-pregnancy group. Meanwhile, the osteoclast and angiogenic function were also inhibited by PAcE at high dose, multiple courses, and mid-pregnancy, but the inhibition level was less than osteogenic function. Moreover, the alteration of canonical Wnt signalling pathway in PAcE fetal bone were consistent with its osteogenesis function changes. In conclusion, PAcE caused development toxicity and multi-cellular function inhibition in fetal long bone, particularly in the high dose, multiple treatments and mid-pregnancy group, and the alteration of canonical Wnt signalling pathway may be its potential mechanism.

Paracetamol use in pregnancy: Not as safe as we may think?

Paracetamol is used by more than 50% of women worldwide during pregnancy; headache representing the most frequent indication. Several studies report that long-term exposure to paracetamol in utero is associated with adverse neurodevelopmental outcomes in children, indicating a dose-response effect. However, less or no risk is found to be associated with short-term exposure. Paracetamol most likely crosses the placenta through passive diffusion, and there are several possible mechanisms for how paracetamol might affect fetal brain development. Although the literature suggests an association between prenatal paracetamol exposure and neurodevelopmental outcomes, the role of confounders cannot be ruled out. Consequently, as a precaution, we believe that pregnant women should be recommended ideally to only use paracetamol to treat conditions that might harm the fetus, such as severe pain or a high fever. This Comment aims to put focus on the potential fetal risks of paracetamol exposure in utero.

Potential adverse actions of prenatal exposure of acetaminophen to offspring

Acetaminophen (APAP) is a widely used as analgesic and antipyretic drug. APAP is also added as an active ingredient in various medications to relieve pain and reduce fever. APAP has been widely used in pregnant women in the past decades because it is considered a relatively safe drug with recommended dose in different countries. However, an increasing number of epidemiological and experimental studies have shown that APAP exposure during pregnancy may increase the risk of inducing reproductive and neurobehavior dysfunctions, hepatotoxicity in offspring. This review aims to assess the potential effects of prenatal APAP exposure on offspring growth and development.

Safety of drugs used for the treatment of migraine during pregnancy: a narrative review

INTRODUCTION

Migraine is common in females of childbearing age and negatively impacts quality of life. The majority of those with migraine who become pregnant see an improvement in their condition but not all do. Providing evidence-based recommendations for the pharmacological management of migraine in pregnancy is challenging.

AREAS COVERED

This narrative review provides an update on the safety of drugs used for migraine in pregnancy. National and international guidelines on the management of episodic migraine in adults were used to select the drugs of relevance to pregnant women. The final list of drugs was chosen by a pain specialist who categorized them according to drug class and use in acute management or prevention. PubMed was searched from inception to 31st July 2022 for evidence on drug safety.

EXPERT OPINION

Obtaining high-quality drug safety data in pregnant migraineurs is difficult not least because exposing a fetus to research-related risks is often considered unethical. There is reliance on observational studies which often group drugs together and lack specificities pertinent to drug prescribing like timing, dosing and duration. Improved statistical tools, study designs and the creation of international collaborative frameworks are ways to advance knowledge on drug safety in pregnancy.

Prenatal exposure to acetaminophen and adolescent assessment of behavior: Discrepancies by age and reporter

Acetaminophen, which is one of the most commonly used medications during pregnancy, has been linked to adverse neurodevelopmental outcomes among offspring during childhood. Less is known about associations with outcomes occurring later in adolescence. Methods: We conducted a follow-up study of children born between 1996 and 2002. Data on illnesses and medications, including acetaminophen, during pregnancy were collected through a standardized interview after delivery. Behavioral assessments were conducted at two subsequent time points, childhood (ages 5-10) and adolescence (ages 11-17). Outcomes examined included internalizing, externalizing, and total behavior problems based on the parent-completed Child Behavior Checklist (CBCL), the teacher-completed Teacher Report Form (TRF), and the youth-completed Youth Self Report (YSR, adolescent follow-up only). Adjusted linear regression models were used to calculate mean differences (MD) and 95% confidence intervals (95% CI) in T-scores comparing those with prenatal acetaminophen exposure to those without. Stabilized inverse probability weights were used to account for attrition. Results: Among the 216 mother-child dyads with completed parent and teacher behavioral assessments at both childhood and adolescence, prenatal acetaminophen exposure was not associated with behavioral problems according to either parent or teacher assessments. Modest increases in externalizing and total behavior problems were observed according to youth report (MD: 1.9). Compared to associations observed during the childhood follow-up, associations at adolescence were attenuated according to parent-report. Conclusion: Reported associations between prenatal acetaminophen exposure and behavioral outcomes were not consistent over time nor between reporters.

Maternal use of acetaminophen during pregnancy and neurobehavioral problems in offspring at 3 years: A prospective cohort study

Background

Acetaminophen is one of the most commonly used drugs during pregnancy globally. Recent studies have reported associations between prenatal exposure to acetaminophen and neurobehavioral problems in children, including attention-deficit hyperactivity disorders. Little research has investigated these associations in preschool-age children or the potential confounding effects of prenatal stress. The purpose of this study was to examine associations between prenatal acetaminophen exposure and offspring neurobehavioral problems at the age of 3 years, with a focus on the potentially confounding effects of prenatal stress.

Methods

We used data from the First Baby Study, a prospective cohort study conducted in Pennsylvania, USA, with 2,423 mother-child pairs. Women reported medication use and completed a prenatal stress inventory during their third trimester. Child behavioral problems were measured at the age of 3 years, using the 7 syndrome scale scores from the Child Behavior Checklist (CBCL) for ages 1 ½ to 5.

Results

There were 1,011 women (41.7%) who reported using acetaminophen during pregnancy. Children who were exposed to acetaminophen during pregnancy scored significantly higher on 3 of the 7 CBCL syndrome scales: withdrawn, sleep problems and attention problems. Scores on all 7 of the CBCL syndrome scales were significantly associated with prenatal stress. After adjustment for prenatal stress and other confounders, 2 syndrome scales remained significantly higher in children exposed to acetaminophen: sleep problems (aOR = 1.23, 95% CI = 1.01–1.51) and attention problems (aOR = 1.21, 95% CI = 1.01–1.45).

Conclusions

These findings corroborate previous studies reporting associations between prenatal exposure to acetaminophen and attention problems in offspring and also show an association with sleep problems at age 3 years. Because use of acetaminophen during pregnancy is common, these results are of public health concern and suggest caution in the use of medications containing acetaminophen during pregnancy.

Headaches in Pregnancy and Postpartum: ACOG Clinical Practice Guideline No. 3

PURPOSE

To provide updated evidence-based recommendations for the evaluation and treatment of primary and secondary headaches in pregnancy and postpartum.

TARGET POPULATION

Pregnant and postpartum patients with a history of or experiencing primary or new secondary headaches.

METHODS

This guideline was developed using an a priori protocol in conjunction with a writing team consisting of two specialists in obstetrics and gynecology appointed by the ACOG Committee on Clinical Practice Guidelines-Obstetrics and one external subject matter expert. ACOG medical librarians completed a comprehensive literature search for primary literature within Cochrane Library, Cochrane Collaboration Registry of Controlled Trials, EMBASE, PubMed, and MEDLINE. Studies that moved forward to the full-text screening stage were assessed by two authors from the writing team based on standardized inclusion and exclusion criteria. Included studies underwent quality assessment, and a modified GRADE (Grading of Recommendations Assessment, Development, and Evaluation) evidence-to-decision framework was applied to interpret and translate the evidence into recommendation statements.

RECOMMENDATIONS

This Clinical Practice Guideline includes recommendations on interventions to prevent primary headache in individuals who are pregnant or attempting to become pregnant, postpartum, or breastfeeding; evaluation for symptomatic patients presenting with primary and secondary headaches during pregnancy; and treatment options for primary and secondary headaches during pregnancy and lactation. Recommendations are classified by strength and evidence quality. Ungraded Good Practice Points are included to provide guidance when a formal recommendation could not be made because of inadequate or nonexistent evidence.

Association between paracetamol use during pregnancy and perinatal outcomes: Prospective NISAMI cohort

Background

Paracetamol is widely used to manage fever and pain during pregnancy worldwide. However, paracetamol may affect the pregnant woman and fetus, once this drug crosses the placental barrier after therapeutic doses and may impair fetal liver function, affecting fetus growth and development. Thus, this study aimed to investigate the association between paracetamol use during pregnancy and perinatal outcomes as preterm birth, low birth weight, and small for gestational age.

Methods and findings

Data from 760 pregnant women within the NISAMI Cohort between June 2012 and February 2014 were analyzed. Logistic regression was used to estimate the association among paracetamol use during pregnancy and preterm birth, low birth weight, and small for gestational age. Multivariate analyses were adjusted for socioeconomic, maternal, pregnancy, and newborn covariates. Around 14% of women were exposed to paracetamol during pregnancy. A decrease in paracetamol use throughout pregnancy was observed. Lower risk of low birth weight in infants born to women exposed to the drug (OR 0.21; IC 95% 0.01–0.99) was found. Paracetamol use during pregnancy was not statistically associated with preterm birth or small for gestational age.

Conclusions

The findings of this study do not suggest an increased risk of perinatal outcomes. However, it should not be assumed that paracetamol is a risk-free medication and its use must be rational.

Eicosanoid Biosynthesis in Male Reproductive Development: Effects of Perinatal Exposure to NSAIDs and Analgesic Drugs

Increasing rates of infertility associated with declining sperm counts and quality, as well as increasing rates of testicular cancer are contemporary issues in the United States and abroad. These conditions are part of the Testicular Dysgenesis Syndrome, which includes a variety of male reproductive disorders hypothesized to share a common origin based on disrupted testicular development during fetal and neonatal stages of life. Male reproductive development is a highly regulated and complex process that relies on an intricate coordination between germ, Leydig, and Sertoli cells as well as other supporting cell types, to ensure proper spermatogenesis, testicular immune privilege, and endocrine function. The eicosanoid system has been reported to be involved in the regulation of fetal and neonatal germ cell development as well as overall testicular homeostasis. Moreover, non-steroidal anti-inflammatory drugs (NSAIDs) and analgesics with abilities to block eicosanoid synthesis by targeting either or both isoforms of cyclooxygenase enzymes, have been found to adversely affect male reproductive development. This review will explore the current body of knowledge on the involvement of the eicosanoid system in male reproductive development, as well as discuss adverse effects of NSAIDs and analgesic drugs administered perinatally, focusing on toxicities reported in the testis and on major testicular cell types. Rodent and epidemiological studies will be corroborated by findings in invertebrate models for a comprehensive report of the state of the field, and to add to our understanding of the potential long-term effects of NSAID and analgesic drug administration in infants.

Association of Prenatal Acetaminophen Exposure Measured in Meconium With Adverse Birth Outcomes in a Canadian Birth Cohort

BACKGROUND

The small number of studies examining the association of prenatal acetaminophen with birth outcomes have all relied on maternal self-report. It remains unknown whether prenatal acetaminophen exposure measured in a biological specimen is associated with birth outcomes.

OBJECTIVES

To investigate the association of acetaminophen measured in meconium with birthweight, gestational age, preterm birth, size for gestational age, gestational diabetes, preeclampsia, and high blood pressure.

METHODS

This birth cohort from Sherbrooke, QC, Canada, included 773 live births. Mothers with no thyroid disease enrolled at their first prenatal care visit or delivery. Acetaminophen was measured in meconium for 393 children at delivery. We tested associations of prenatal acetaminophen with birthweight, preterm birth, gestational age, small and large for gestational age, gestational diabetes, preeclampsia, and high blood pressure. We imputed missing data via multiple imputation and used inverse probability weighting to account for confounding and selection bias.

RESULTS

Acetaminophen was detected in 222 meconium samples (56.5%). Prenatal acetaminophen exposure was associated with decreased birthweight by 136 g (β = -136; 95% CI [-229, -43]), 20% increased weekly hazard of delivery (hazard ratio = 1.20; 95% CI [1.00, 1.43]), and over 60% decreased odds of being born large for gestational age (odds ratio = 0.38; 95% CI [0.20, 0.75]). Prenatal acetaminophen was not associated with small for gestational age, preterm birth, or any pregnancy complications.

CONCLUSION

Prenatal acetaminophen was associated with adverse birth outcomes. Although unobserved confounding and confounding by indication are possible, these results warrant further investigation into adverse perinatal effects of prenatal acetaminophen exposure.

Effect of acetaminophen use during pregnancy on adverse pregnancy outcomes: a systematic review and meta-analysis

INTRODUCTION

A high number of women are exposed to acetaminophen during pregnancy worldwide. This drug safety during pregnancy regarding preterm birth, birth weight, and fetal development has not been well described. This study investigated the effect of acetaminophen use during pregnancy on selected adverse pregnancy outcomes.

AREAS COVERED

Databases were searched to identify studies reporting the effects of acetaminophen use during pregnancy on preterm birth, low birth weight, and small for gestational age. The studies' quality was assessed by the Newcastle-Ottawa Scale and the Methodological Index for Non-Randomized Studies. Relative risk with 95% confidence intervals of each outcome was estimated using a fixed or random-effects model. Six studies were included for final review, four cohort and two case-control studies. We found no increased risk of preterm birth (RR 0.97; 95% CI 0.59-1.58), and decreased risks of low birth weight (RR 0.65; 95% CI 0.59-0.72) and small for gestational age (RR 0.69; 95% CI 0.50-0.97). Acetaminophen exposure during the third trimester revealed non-significantly in the outcomes.

EXPERT OPINION

Exposure to acetaminophen during pregnancy appears to not increase the risk of the outcomes analyzed. However, there is a lack of information regarding the exposure dose and frequency of acetaminophen use.

Paracetamol use during pregnancy - a call for precautionary action

Paracetamol (N-acetyl-p-aminophenol (APAP), otherwise known as acetaminophen) is the active ingredient in more than 600 medications used to relieve mild to moderate pain and reduce fever. APAP is widely used by pregnant women as governmental agencies, including the FDA and EMA, have long considered APAP appropriate for use during pregnancy when used as directed. However, increasing experimental and epidemiological research suggests that prenatal exposure to APAP might alter fetal development, which could increase the risks of some neurodevelopmental, reproductive and urogenital disorders. Here we summarize this evidence and call for precautionary action through a focused research effort and by increasing awareness among health professionals and pregnant women. APAP is an important medication and alternatives for treatment of high fever and severe pain are limited. We recommend that pregnant women should be cautioned at the beginning of pregnancy to: forego APAP unless its use is medically indicated; consult with a physician or pharmacist if they are uncertain whether use is indicated and before using on a long-term basis; and minimize exposure by using the lowest effective dose for the shortest possible time. We suggest specific actions to implement these recommendations. This Consensus Statement reflects our concerns and is currently supported by 91 scientists, clinicians and public health professionals from across the globe.

Paracetamol (Acetaminophen) and the Developing Brain

Paracetamol is commonly used to treat fever and pain in pregnant women, but there are growing concerns that this may cause attention deficit hyperactivity disorder and autism spectrum disorder in the offspring. A growing number of epidemiological studies suggests that relative risks for these disorders increase by an average of about 25% following intrauterine paracetamol exposure. The data analyzed point to a dose-effect relationship but cannot fully account for unmeasured confounders, notably indication and genetic transmission. Only few experimental investigations have addressed this issue. Altered behavior has been demonstrated in offspring of paracetamol-gavaged pregnant rats, and paracetamol given at or prior to day 10 of life to newborn mice resulted in altered locomotor activity in response to a novel home environment in adulthood and blunted the analgesic effect of paracetamol given to adult animals. The molecular mechanisms that might mediate these effects are unknown. Paracetamol has diverse pharmacologic actions. It reduces prostaglandin formation via competitive inhibition of the peroxidase moiety of prostaglandin H2 synthase, while its metabolite N-arachidonoyl-phenolamine activates transient vanilloid-subtype 1 receptors and interferes with cannabinoid receptor signaling. The metabolite N-acetyl-p-benzo-quinone-imine, which is pivotal for liver damage after overdosing, exerts oxidative stress and depletes glutathione in the brain already at dosages below the hepatic toxicity threshold. Given the widespread use of paracetamol during pregnancy and the lack of safe alternatives, its impact on the developing brain deserves further investigation.

Prenatal acetaminophen use in women with autoimmune disorders and adverse pregnancy and birth outcomes

OBJECTIVES

Most women may have temporary pain for which they use analgesics, but those with autoimmune disorders have chronic pain that may be exacerbated for some during pregnancy. This study aimed to determine whether prenatal acetaminophen use was associated with an increased risk of adverse pregnancy and birth outcomes in women with autoimmune disorders.

METHODS

Participants were enrolled between 2004 and 2018 in the MotherToBaby cohort study and limited to women with an autoimmune disorder (n = 1,821). Self-reported acetaminophen use was characterized over gestation for indication, timing of use and duration. Cumulative acetaminophen use through 20 and 32 weeks was categorized into quintiles, with no acetaminophen use as the reference category. The association between acetaminophen quintile and preeclampsia or pregnancy induced hypertension, small for gestational age (SGA), and preterm birth was examined using adjusted multiple log-linear regression.

RESULTS

Overall, 74% of women reported acetaminophen use during pregnancy. The most often reported indication for using acetaminophen was headache/migraines, followed by pain and injury. Risk of preeclampsia was 1.62 times greater for those in the fifth quintile of cumulative acetaminophen use through 20 weeks compared with those with no acetaminophen use (95% CI: 1.10, 2.40). There were no associations with lower use quintiles, nor for the other outcomes.

CONCLUSION

The highest quintile of cumulative acetaminophen was associated with a modestly increased risk for preeclampsia. Some women with autoimmune conditions have pain throughout pregnancy; clinicians and patients should discuss approaches to best avoid high levels of acetaminophen in their pain management strategies.

Is Maternal Use of Paracetamol during Pregnancy Associated with Anogenital Distance in Male Newborns? The Results from the NELA Birth Cohort

Paracetamol is the one of the most commonly used medications during pregnancy. However, its potential antiandrogenic effect has been suggested. The objective of this study was to evaluate associations between maternal paracetamol use during pregnancy and anogenital distance (AGD) in male newborns from a Spanish birth cohort. The study included two hundred and seventy-seven mother-male child pairs with self-reported paracetamol use and frequency during each trimester of pregnancy. AGD measurements were taken employing standardized methods. The associations between maternal paracetamol use and AGD measures were evaluated using linear regression models, adjusting for potential confounders and covariates. Overall, 61.7% of pregnant women consumed paracetamol at any time of pregnancy with an average of 9.43 (SD = 15.33) days throughout pregnancy. No associations between the maternal use of paracetamol or its frequency and AGD measures among different trimesters or during the whole pregnancy were found in the adjusted final models. A non-differential misclassification error may have occurred—the recall of paracetamol intake independent of AGD measurements—introducing bias towards the null hypothesis. Nevertheless, the current evidence suggests that paracetamol might have a potential antiandrogenic effect especially in the early stages of fetal development. Thus, it would be highly recommendable to pursue further studies to elucidate the potential effects of paracetamol in human perinatal health and its use among pregnant women.

Perinatal exposure to paracetamol: Dose and sex-dependent effects in behaviour and brain's oxidative stress markers in progeny

Paracetamol (PAR) has been employed worldwide for pain and fever treatment during pregnancy and lactation. Epidemiologic studies have shown that exposure to PAR can increase the risk for developmental disorders, such as attention-deficit hyperactive disorder and autism spectrum disorder. This study aimed to investigate if gestational and lactational exposure to human-relevant doses of PAR could alter behavioural and brain oxidative stress parameters in the rat`s offspring. Wistar dams were gavaged daily with water or PAR (35 mg/kg/ or 350 mg/kg) during gestational day 6 to weaning (postnatal day 21). Behavioural assessments occurred at post-natal days 10 (nest seeking test), 27 (behavioural stereotypy) and 28 (three chamber sociability test and open field). Concentration of advanced oxidation protein products (AOPP), reduced glutathione (GSH), lipid hydroperoxides (LOOH) and activity of superoxide dismutase (SOD) were estimate in prefrontal cortex, hippocampus, striatum and cerebellum of 22-day-old rats. Compared to CON animals, males exposed to PAR during pregnancy and lactation augmented apomorphine-induced stereotyped behaviour (350 mg/kg) and ambulation in open-field test (35 mg/kg). Reduced exploratory behaviour in three chamber sociability test was observed in pups exposed to PAR at 350 mg/kg in both sexes. PAR treatment decreased hippocampal GSH level and striatal SOD activity in males exposed to 35 mg/kg, suggesting the vulnerability of these areas in PAR-induced developmental neurotoxicity. Findings suggest PAR use during pregnancy and lactation as a potential risk factor for neurodevelopmental disorders with males being more susceptible.

Increased risk of preeclampsia after use of paracetamol during pregnancy - causal or coincidence?

Background

The maternal use of paracetamol during pregnancy has been associated with the development of preeclampsia. This study aims to clarify whether the connection is causal or whether it is due to reverse causation.

Methods

This study is a continuation of the retrospective case cohort study examining 2,508 pregnant women using a variety of drugs and the development of preeclampsia (1,252 women with preeclampsia and 1,256 controls). For the purposes of this study, more precise data was collected from several hospital databases of the women among this cohort who had reported taking paracetamol during pregnancy (indications, gestational period etc.); this was evaluated in association with the development of preeclampsia.

Results

5.5% (100 cases and 37 controls) of all the study population (2,508) had clearly reported paracetamol use. Women with preeclampsia had used significantly more often paracetamol during pregnancy compared to controls (cases 8.0%, controls 2.9%, p < 0.001). The difference was most evident in the third trimester (after the 29th GW) and the use of paracetamol was associated with both mild and severe preeclampsia. Headache and “general pain” were the most common indications for medication among all paracetamol users.

Conclusions

The use of paracetamol in the third trimester of pregnancy was associated with preeclampsia. This observation indicates that association between paracetamol use and preeclampsia is probably due to reverse causation, i.e. women with preeclampsia experience more headaches due to preeclampsia symptoms since this association was not detected with the use of paracetamol in earlier stages of pregnancy.

Intrauterine Exposure to Acetaminophen and Adverse Developmental Outcomes: Epidemiological Findings and Methodological Issues

PURPOSE OF REVIEW

Acetaminophen (or paracetamol) is one of the most commonly used medications during pregnancy. We reviewed recent epidemiological evidence regarding intrauterine exposure to acetaminophen and risk for asthma, neurodevelopment disorders, and reproductive health in childhood.

RECENT FINDINGS

An increasing number of cohort studies have suggested that maternal use of acetaminophen during pregnancy was associated with increased risk for asthma; neurodevelopmental disorders, especially ADHD and behavioral problems; and genital malformations in the offspring. Oxidative stress and inflammation or endocrine effects are plausible shared biological mechanisms for the exposure to influence multiple developmental outcomes. We discussed methodological challenges that can threaten the validity of these observational data, including confounding and measurement errors. Novel statistical methods and research designs that can be used to mitigate these issues were introduced. Given the high prevalence of use, findings regarding intrauterine exposure to acetaminophen on multiple child health outcomes raise concerns. Research on causal and non-causal mechanisms that might explain these associations should be a priority.

Nature and nurture of sexual partner preference: Teachings from prenatal administration of acetaminophen in male rats

The organizational-activational hypothesis indicates that activation of adult sexual behavior in males depends on organization of the masculine brain during the perinatal sensitive period. In the medial preoptic area such masculinization depends on a neuroendocrine cascade that includes exposure to testosterone, aromatization to estradiol, activation of estrogen receptors, synthesis of cyclooxygenase (COX), increase of prostaglandins, release of glutamate, and activation of AMPA receptors that result in the formation of more dendritic spines. Thus, in the present study we assessed the sexual partner preference (SPP) of adult male rats prenatally treated with acetaminophen (APAP), an analgesic/antipyretic drug that inhibits COX-2 and is commonly used and prescribed during pregnancy. Female rats received either saline (2 ml/kg s.c.) or APAP (50 mg/kg s.c.) every 12 h, during days 16-20 of pregnancy. At postnatal day PD60 half of the male offspring were exposed to sexual experience with receptive females during 5 trials, and the other half remained sexually naïve. At PD90 all them were tested for SPP with one sexually receptive female and one stud male. The results indicated that only APAP-naïve males failed to display SPP. However, APAP-experienced males displayed SPP for females. We discuss the effects of prenatal APAP in the disruption of unconditioned responses towards females (nature mechanisms), and the effects of sexual experience (nurture mechanisms) in the development of conditioned heterosexual preference.