Use of Acitretin Among Girls and Women of Childbearing Age and Occurrence of Acitretin-Exposed Pregnancies in Germany

BACKGROUND AND OBJECTIVE

Acitretin has long-lasting teratogenic properties. Therefore, pregnancies must be avoided during and within 3 years after acitretin treatment. We aimed to describe (i) acitretin use in women of childbearing age in Germany, (ii) the occurrence of acitretin-exposed pregnancies, and (iii) malformations among children exposed in utero.

METHODS

Using 2004-2019 data from the German Pharmacoepidemiological Research Database (GePaRD-claims data from ~ 20% of the German population), we determined annual age-standardized prevalence of acitretin use among girls and women aged 13-49 years. In longitudinal analyses, we estimated the number of exposed pregnancies by assessing whether the exposure window assigned to the last dispensation before pregnancy (days covered by dispensation plus 3 years) overlapped the onset of pregnancy or whether there was a dispensation in the first eight weeks of pregnancy. Data of live-born children with in utero exposure to acitretin were reviewed to assess the presence of congenital malformations.

RESULTS

The age-standardized prevalence of acitretin use per 1000 girls and women was 0.04 in 2019. We identified 35 acitretin-exposed pregnancies; 94.3% of these pregnancies were classified as exposed because they occurred within 3 years after stopping acitretin treatment. Among 18 live-born children linked to their mother, four children (22.2%) had congenital malformations (three children with a major malformation).

CONCLUSIONS

We observed 35 acitretin-exposed pregnancies mainly because treatment ended too late before pregnancy. Approximately one in five children born from these pregnancies had malformations, highlighting the importance of drawing more attention to the long-lasting teratogenicity of this drug.

Antithyroid drug therapy in pregnancy and risk of congenital anomalies: Systematic review and meta-analysis

OBJECTIVES

The risk of congenital anomalies following in utero exposure to thionamide antithyroid drugs (ATDs) is unresolved. Observational studies are contradictory and existing meta-analyses predate and preclude more recent studies. We undertook an updated meta-analysis of congenital anomaly risk in women exposed to carbimazole or methimazole (CMZ/MMI), propylthiouracil (PTU), or untreated hyperthyroidism in pregnancy.

METHODS

We searched Medline, Embase, and the Cochrane database for articles published up till August 2021. We pooled separate crude and adjusted risk estimates using random effects models and subgroup analyses to address heterogeneity.

RESULTS

We identified 16 cohort studies comprising 5957, 15,785, and 15,666 exposures to CMZ/MMI, PTU, and untreated hyperthyroidism, respectively. Compared to nondisease controls, adjusted risk ratio (RR) and 95% confidence intervals (95% CIs) for congenital anomalies was increased for CMZ/MMI (RR, 1.28; 95% CI, 1.06-1.54) and PTU (RR, 1.16; 95% CI, 1.08-1.25). Crude risk for CMZ/MMI was increased relative to PTU (RR, 1.20; 95% CI, 1.01-1.43). Increased risk was also seen with exposure to both CMZ/MMI and PTU, that is, women who switched ATDs in pregnancy (RR, 1.51; 95% CI, 1.14-1.99). However, the timing of ATD switch was highly variable and included prepregnancy switches in some studies. The excess number of anomalies per 1000 live births was 17.2 for patients exposed to CMZ/MMI, 9.8, for PTU exposure, and 31.4 for exposure to both CMZ/MMI and PTU. Risk in the untreated group did not differ from control or ATD groups. The untreated group was however highly heterogeneous in terms of thyroid status. Subgroup analysis showed more positive associations in studies with >500 exposures and up to 1-year follow-up.

CONCLUSIONS

ATD therapy carries a small risk of congenital anomalies which is higher for CMZ/MMI than for PTU and does not appear to be reduced by switching ATDs in pregnancy. Due to key limitations in the available data, further studies will be required to clarify the risks associated with untreated hyperthyroidism and with switching ATDs in pregnancy.

Establishing or Excluding a Diagnosis of Fetal Valproate Spectrum Disorder is a Multi-layered Process

Background In 2017/2018, the Health Products Regulatory Authority issued new guidance on the prescription of Sodium Valproate (VPA) to female patients of reproductive age. A review was initiated of VPA exposed individuals to identify whether previously unascertained cases of VPA related Embryopathy could be identified. Methods Forty patients under twenty-three years of age were reviewed. Results Eleven (27.5%) new cases of Fetal Valproate Spectrum Disorder (FVSD) were identified. Twenty-four (60%) cases were felt not to satisfy diagnostic threshold for this teratogenic disorder. Five (12.5%) cases were indeterminate. Six of the forty patients (15%) had an alternative genetic cause of developmental delay established. Conclusion There is increased awareness regarding avoidance of VPA use in women of childbearing age. An equal awareness is warranted that developmental delay in the context of VPA exposure in pregnancy does not necessarily constitute a diagnosis of FVSD but that other competing diagnostic hypotheses have to be considered.

Folic acid reduces the ethanol-induced morphological and behavioral defects in embryonic and larval zebrafish (Danio rerio) as a model for fetal alcohol spectrum disorder (FASD)

The objective of this work was to determine whether folic acid (FA) reduces the embryonic ethanol (EtOH) exposure induced behavioral and morphological defects in our zebrafish fetal alcohol spectrum disorder (FASD) model. Teratogenic effects, mortality, the excitatory light-dark locomotion (ELD), sleep (SL), thigmotaxis (TH), touch sensitivity (TS), and optomotor response (OMR) tests were evaluated in larvae (6-7 days post-fertilization) using four treatment conditions: Untreated, FA, EtOH and EtOH + FA. FA reduced morphological defects on heart, eyes and swim bladder inflation seen in EtOH exposed fish. The larvae were more active in the dark than in light conditions, and EtOH reduced the swimming activity in the ELD test. EtOH affected the sleep pattern, inducing several arousal periods and increasing inactivity in zebrafish. FA reduces these toxic effects and produced more consistent inactivity during the night, reducing the arousal periods. FA also prevented the EtOH-induced defects in thigmotaxis and optomotor response of the larvae. We conclude that in this FASD model, EtOH exposure produced several teratogenic and behavioral defects, FA reduced, but did not totally prevent, these defects. Understanding of EtOH-induced behavioral defects could help to identify new therapeutic or prevention strategies for FASD.

Administration of low doses of MK-801 during ethanol withdrawal in the developing rat pup attenuates alcohol's teratogenic effects

BACKGROUND

Alcohol exposure during development can produce severe and long-lasting central nervous system damage and consequent behavioral alterations. Recent evidence suggests that NMDA receptor-mediated excitotoxicity during periods of withdrawal may contribute to this damage. We have demonstrated that blocking the NMDA receptor with MK-801 during alcohol withdrawal can attenuate ethanol's adverse effects on behavioral development in the rat. This study examined the dose dependency of MK-801's ability to mitigate ethanol's teratogenic effects.

METHODS

Neonatal rat pups were exposed to 6.0 g/kg of ethanol in a binge-like manner on postnatal day (PD) 6, a period of brain development equivalent to a portion of the human third trimester. Alcohol administration was accomplished with an artificial rearing procedure. Twenty-one hours after ethanol treatment, pups were injected intraperitoneally with one of four doses of MK-801 (0.05, 0.1, 0.5, or 1.0 mg/kg) or saline vehicle. An artificially reared control and a normally reared control group were included. On PD 18-19, activity level was monitored, and on PD 40-42, serial spatial discrimination reversal learning was assessed.

RESULTS

Alcohol exposure on PD 6 produced significant increases in activity level and deficits in reversal learning. These alcohol-induced behavioral alterations were significantly attenuated in subjects treated with one of the three lower doses (0.05-0.5 mg/kg) of MK-801 during withdrawal. The performance of ethanol-exposed subjects treated with the high dose of MK-801 (1.0 mg/kg) did not differ from that of the Ethanol Only group.

CONCLUSIONS

These data suggest that alterations in NMDA receptor activation during alcohol withdrawal contribute to the neuropathology and consequent behavioral alterations associated with developmental alcohol exposure. These data have important implications for pregnant women and newborns undergoing ethanol withdrawal.

IGF-I treatment attenuates renal abnormalities induced by neonatal ACE inhibition

An intact renin-angiotensin system (RAS) during nephrogenesis is essential for normal renal development. We have shown previously that neonatal inhibition of the RAS, either with ANG II type 1-receptor blockade or angiotensin-converting enzyme (ACE) inhibition, induces irreversible renal abnormalities. The aim of the present study was to investigate whether an interrupted RAS can be compensated for by exogenous administration of another important renal growth-promoting factor, the insulin-like growth factor-I (IGF-I). Rats were treated daily with either the ACE inhibitor enalapril (10 mg/kg), recombinant human IGF-I (3 mg/kg), or the combination enalapril + IGF-I from perinatal day 3 to 13. Urinary concentrating ability, renal function, and renal morphology were assessed at adult age. The gene expression and localization of IGF-I, its receptor, and the growth hormone receptor (GHR) were investigated during ongoing ACE inhibition. The present study demonstrates normalized renal function and histology in enalapril + IGF-I-treated animals. Ongoing ACE inhibition suppressed the medullary IGF-I mRNA expression and altered the local distribution of both IGF-I and GHR. Thus the present study provides evidence for an interaction between the RAS and GH/IGF-I axis in renal development.

Serine-enhanced restoration of 2-methoxyethanol-induced dysmorphogenesis in the rat embryo and near-term fetus

Effects of serine on restorative growth were characterized by comparing embryo/fetal responses after maternal exposure to 2-methoxyethanol (ME) and ME + serine by gavage on gestation day (gd) 13, a day of heightened limb sensitivity. Paws (gd 20) and limb buds (gd 15) were examined after ME alone at 50, 100, and 250 mg/kg, and after ME (either 100 or 250 mg ME/kg) + serine (1734 mg serine/kg) administered within minutes (0 hr) to 24 hr after ME. Paw development was not altered after ME at 100 mg/kg, but was highly sensitive to 250 mg ME/kg with all fetuses and litters exhibiting defects (ectrodactyly, syndactyly, and short digit) in the preaxial region. In contrast, the limb bud displayed dose-related incidences of abnormalities after maternal treatment with the low and high levels of ME. The condensing (precartilaginous, pentadactyl pattern) and noncondensing (undifferentiated mesenchymal cells) regions exhibited changes in their size, number, and location. Serine administration after 250 mg ME/kg was effective in reducing the occurrence of paw dysmorphogenesis with its protection potency inversely related to its delay of administration (i.e., 0% paw defect incidence after 0-hr delay, 25% after 4-hr delay, 41-45% after 8- and 12-hr delays, and 76% after 24-hr delay). The occurrences of limb bud pattern disturbances produced by ME were also markedly decreased by serine cotreatment. Higher incidences of embryonic defects versus those of fetal defects demonstrate that restorative growth followed ME exposure. Serine attenuation of ME teratogenicity appears to emanate from enhanced restorative growth so that tissue damage, which otherwise would be expressed as a defect at parturition, is repaired and replaced to resume development of the limb toward its normal structure.

Effect of treatment with phenobarbital and stiripentol on carbamazepine-induced teratogenicity and reactive metabolite formation

A model using SWV mice was developed to investigate the mechanistic basis of carbamazepine (CBZ)-related fetotoxicity. Drug administration was initiated prior to conception and continued until day 18 of gestation. The incidence of malformation was 33% following CBZ exposure (1,500 mg/kg/day), compared with a 5% incidence in pair-fed control animals (P < 0.05). Coadministration of nonteratogenic doses of phenobarbital (PB; a cytochrome P-450 inducer) (45 mg/kg/day) and CBZ (1,000 mg/kg/day) increased the frequency of malformation from 10% to 26% (P < 0.05), compared with mice dosed with CBZ alone (1,000 mg/kg/day). Coadministration of stiripentol (STP; a cytochrome P-450 inhibitor) (300 mg/kg/day) decreased the incidence of malformations produced by CBZ (1,500 mg/kg/day) from 33% to 16.7% (P < 0.05). The effect of PB administration on the binding of 14C in maternal and fetal tissue was assessed in dams that received CBZ (1,000 mg/kg/day) with or without PB (45 mg/kg/day) or STP (300 mg/kg/day) chronically and a single i.p. dose of 14C-CBZ on day 12 of gestation. In all instances, binding was greatest in maternal liver, then in the placenta, fetal head and body, and maternal thigh muscle. In all tissues, PB caused a two-to threefold increase in binding, compared with binding in mice exposed to CBZ alone. STP administration decreased protein adduct formation only in maternal liver. The binding of 14C was also assessed in hepatic microsomes prepared from female mice exposed to CBZ and PB or STP as in the in vivo study of 14C binding. The extent of irreversible binding was 67% greater in microsomes prepared from mice pretreated with PB and CBZ than with CBZ alone, while STP resulted in only 21% inhibition of 14C adduct formation (P < 0.05). The results are consistent with the formation of a chemically reactive teratogenic metabolite of CBZ in mice by cytochrome(s) P-450.

Interactions between caffeine and adenosine agonists in producing embryo resorptions and malformations in mice

Caffeine has previously been demonstrated to be teratogenic in mice, causing primarily limb reduction defects and cleft palate. To investigate the possibility that the mechanism of caffeine teratogenesis is related to its central stimulant activity, which is thought to result from its activity as an adenosine antagonist, the effects of the stable adenosine agonists L-phenylisopropyladenosine (L-PIA) and chloroadenosine on caffeine teratogenicity were examined. It was found that these adenosine analogs have embryolethal effects when administered intraperitoneally on Days 11 and 12 of gestation at extremely low dosages (minimal effect levels of 1 and 10 mumol/kg, respectively). Caffeine at dosages as low as 129 mumol/kg ip protected against the embryolethal effects of 5 mumol/kg L-PIA if administered simultaneously with L-PIA but not if administered 30 to 60 min after L-PIA. The maternotoxicity of either of the adenosine agonists or caffeine alone was ameliorated by coadministration of the other, particularly when the molar excess of caffeine was approximately 20-fold. These results suggest that the embryotoxicity and maternotoxicity of the adenosine agonists and the maternotoxicity of caffeine are mediated by binding to adenosine receptors. When coadministered with teratogenic dosages of caffeine (1160 to 1290 mumol/kg), L-PIA and chloroadenosine at dosage levels of 1 to 100 mumol/kg did not prevent and in some cases potentiated the teratogenic effects of caffeine. This lack of protection by L-PIA and chloroadenosine suggests that adenosine receptors are not the primary site of action for caffeine-induced teratogenicity. The embryolethal effects of L-PIA and chloroadenosine and the teratogenicity of caffeine occurred only at maternotoxic dosages. However, an analysis of the correlation structure indicates that the embryotoxicities of L-PIA and caffeine were not secondary to maternotoxicity as measured by body weight change.

Methylazoxymethanol microencephaly in rats: neurochemical characterization and behavioral studies with the nootropic oxiracetam

The administration of methylazoxymethanol (MAM) to pregnant rats induced a marked reduction in the weight of the offspring's brain. This reduction was due to aplasia of the cortex and hippocampus, whose thicknesses were 50% of those of control animals. A significant reduction was also observed in the striatum. This aplasia could be ascribed to the antimitotic effect of MAM, which, when given at gestational day 15, prevented the development of neurons in the three brain areas mentioned. Indeed, we infer here that the total number of GABA-receptor complexes, as measured by [3H]muscimol and [3H]flunitrazepam binding, was reduced to the same degree as was the weight of the cortex. Similarly, total [3H]haloperidol binding sites were reduced in the striatum. From the behavioral point of view, offspring of MAM-treated rats (MAM rats) showed impaired acquisition in the water-maze and pole-climbing tests, indicating that this brain aplasia had disrupted cognitive processes. In contrast, these animals showed normal growth, and grossly their behavior appeared normal. Oxiracetam, a new compound that belongs to the recently described class of nootropic drugs, was able to restore acquisition processes in MAM rats. We propose therefore that MAM rats might become an interesting and quite simple animal model for evaluation of new acquisition-enhancing drugs. Moreover, this model could also be useful to study the neurochemical correlates of cognitive processes.