A case control study to examine the pharmacological factors underlying ventricular septal defects in the North of England.

BACKGROUND: Amphetamine exposure is associated with congenital cardiac abnormalities in animals. We previously reported an association between recreational use of 2,4-methylenedioxymethamphetamine (ecstasy, MDMA) and ventricular septal defect in babies born to users. We have carried out a case control study to investigate risks in the occurrence of ventricular septal defect in a cohort of babies born in the North East of England. METHODS: Cases were identified from paediatric cardiology units in Newcastle upon Tyne and Leeds, and controls were recruited from the mothers of babies born in the same hospital as the index case. Research nurses carried out interviews using a structured questionnaire. RESULTS: A total of 296 case control pairs were studied. There was insufficient exposure to ecstasy to test the primary hypothesis. Increased risk of ventricular septal defect was found to be associated with consumption of cough and cold remedies [pre-conception OR 2.2, 95% CI 1.41, 3.51; pregnancy OR 5.1, 95% CI 2.56, 11.27; exposure in either OR 2.83, 95% CI 1.85, 4.45; P<0.005] and in the case of non-steroidals for exposures in pregnancy (OR 4.2, 95% CI 1.54, 14.26; P<0.005). CONCLUSIONS: These findings suggest that ventricular septal defect is associated with consuming the medications identified. They are also compatible with the hypothesis that sympathomimetics (pseudoephedrine, phenylephrine and phenylpropanolamine) present in cough mixtures cause the increased risk, and with our original hypothesis that sympathomimetics and amphetamines are potentially cardiotoxic in utero.

Congenital anomalies after prenatal ecstasy exposure.

Prospective follow-up of 136 babies exposed to ecstasy in utero indicated that the drug may be associated with a significantly increased risk of congenital defects (15.4% [95% CI 8.2-25.4]). Cardiovascular anomalies (26 per 1000 livebirths [3.0-90.0]) and musculoskeletal anomalies (38 per 1000 [8.0-109.0]) were predominant.

Paracetamol overdose in pregnancy analysis of the outcomes of 300 cases referred to the Teratology Information Service.

A prospective study was carried out to investigate the outcome of pregnancy in 300 women who had self-administered an overdose of paracetamol, either alone, or as part of a combined preparation. Exposure occurred in all trimesters. The most striking feature of this study is that the majority of the pregnancies had normal outcomes. Over half of the mothers (160 = 53%) required treatment for the overdose, and 49 of these had specific antidotes (33 mothers had acetylcysteine and 16 mothers had methionine). The rest of the mothers were given nonspecific treatments including ipecacuanha (52), gastric lavage (42), and charcoal (16). None of the mothers died. There were 219 liveborn infants with no malformations, 61 of whom had been exposed in the first trimester. Eleven liveborn infants had malformations; none was exposed in the first trimester. On other infant exposed at 18 weeks had a diaphragmatic hernia; this pregnancy was terminated at 22 weeks. In none of these 12 infants can the malformations be directly associated with paracetamol exposure. There were no apparent differences either in the sex ratio or the body weights of term infants. There were seven full-term infants with neonatal problems that seem unrelated to paracetamol exposure. Six premature infants also had neonatal problems, which were more likely to be related to their degree of prematurity rather than paracetamol exposure. There was no obvious relationship between the time of exposure and the time of delivery. The overall conclusion is that paracetamol overdose per se is not an indication for termination of pregnancy.

The outcome of pregnancy in 689 women exposed to therapeutic doses of antidepressants. A collaborative study of the European Network of Teratology Information Services (ENTIS).

The European Network of the Teratology Information Services (ENTIS) has collected and evaluated data on 689 pregnancies in which exposure to tricyclic and nontricyclic antidepressants occurred. Data were collected prospectively from the time of in utero exposure and all the cases were followed up to the first few weeks of postnatal life using standardized procedures. In most cases, no longer term follow-up data were available. Approximately two-thirds of the mothers were on multidrug therapy, and of those, half took a benzodiazepine. About 95% of the patients were exposed during the first trimester. The most striking feature of the pregnancy outcomes is that 97% of live-born babies were morphologically normal. The incidence of spontaneous abortion and late fetal/neonatal deaths were within the normal range. Fourteen live-born babies and one fetus had either major or minor malformations, and six had minor anomalies. However, there was no increase in either a particular type of malformation or a specific pattern of defects. Another 31 infants without malformations had neonatal problems; these were usually associated with chronic multidrug therapy, especially near term. Elective termination of pregnancy occurred more frequently in the multidrug groups (86 out of 488) than in the monotherapy groups (20 out of 201), but data concerning the condition of the fetus are not available in the majority of the cases. Overall, no causal relationship could be established between in utero exposure to antidepressants and adverse pregnancy outcome.

The safety of calcium channel blockers in human pregnancy: a prospective, multicenter cohort study.

OBJECTIVE: Our purpose was to examine the potential teratogenicity of calcium channel blockers. STUDY DESIGN: Six teratogen information services prospectively collected and followed up 78 women with first-trimester exposure to calcium channel blockers. Pregnancy outcome was compared (by paired t text of chi2 analysis) with that of a control group matched for maternal age and smoking. RESULTS: There was no increase in major malformation (2/66=3.0% [calcium channel blockers] vs 0% [nonteratogenic controls], p=0.27); a fivefold increase was ruled out (baseline 2%, alpha = 0.05, beta = 0.20). The defects reported were attributable to maternal diabetes or coingestion of teratogens. The increase in preterm delivery 28% [calcium channel blockers] vs 9% [nonteratogenic controls], p=0.003), attributed to maternal disease by stepwise regression, was the most important factor responsible for the observed decrease in birth weight (mean -334 gm vs nonteratogenic controls, p=0.08). CONCLUSION: This study suggests that calcium channel blockers do not represent a major teratogenic risk.

The effects of benzodiazepine use during pregnancy and lactation.

Although there are a number of studies and individual case reports concerning the use of benzodiazepines in human pregnancy, the data concerning teratogenicity and effects on postnatal development and behaviour are inconsistent. There is evidence from studies in the 1970s that first trimester exposure to benzodiazepines in utero has resulted in the birth of some infants with facial clefts, cardiac malformations, and other multiple malformations, but no syndrome of defects. Diazepam and chlordiazepoxide are amongst the drugs most frequently implicated in the earlier studies. However, data from later studies provide no clear evidence of significant increase in either the overall incidence of malformations or of any particular type of defect. Many of the women included in these studies has psychiatric illnesses, epilepsy, or diabetes all of which have an intrinsic risk in pregnancy, and some were on multidrug therapy. Medical-obstetric histories and family history of malformations were not always presented in the publications, which makes assessment of risk associated with benzodiazepine use per se difficult. Nevertheless, in most of the studies involving first trimester use of benzodiazepines, the majority of infants were normal at birth and had normal postnatal development. Late third trimester use and exposure during labour seems to be associated with much greater risks to the fetus/neonate. Some, but by no means all infants exposed at this time, exhibit either the floppy infant syndrome, or marked neonatal withdrawal symptoms. Symptoms vary from mild sedation, hypotonia, and reluctance to suck, to apnoeic spells, cyanosis, and impaired metabolic responses to cold stress. These symptoms have been reported to persist for periods from hours to months after birth. This correlates well with the pharmacokinetic and placental transfer of the benzodiazepines and their disposition in the neonate. However, there has been no significant increase in the incidence of neonatal jaundice and kernicterus in term infants. The prolonged use of benzodiazepines throughout pregnancy raised the concern that there may be altered transmitter synthesis and function, leading to neurobehavioural problems in the children. In approximately 550 children who were followed up for various times up to four years of age, there is no increase in either the malformation rate or adverse effects on neurobehavioural development and IQ. Although some of the data indicate that a small number of children were slower to develop during the first year or so, they did exhibit catch up growth and most had developed normally by four years of age. Where developmental deficits persisted, it was not possible to prove a cause-effect relationship with benzodiazepine exposure. These children were often from families where there was maternal illness requiring prolonged drug therapy or where there were social problems. It is important to consider poor environmental and social factors when assessing the possible prenatal influence of the benzodiazepines on the postnatal health and development of the child. There is evidence that clonazepam, clorazepate, diazepam, lorazepam, midazolam, nitrazepam, and oxazepam are excreted into breast milk. The published data indicate that the levels detected in breast milk are low; therefore, the suckling infant is unlikely to ingest significant amounts of the drug in this way. Problems may arise if the infant is premature or has been exposed to high concentrations of drug either during pregnancy or at delivery.

The consequences of iron overdose and its treatment with desferrioxamine in pregnancy.

A study was carried out to assess the effect on the outcome of pregnancy of iron overdose and its treatment with desferrioxamine. Sixty-eight cases were drawn from those reported to the United Kingdom National Poisons Information Centre and the Teratology Information Service at Guy's Hospital, London, and follow-up was obtained in 51 of these. Two were subsequently reported not to be pregnant and there were 49 records of pregnant patients who took iron overdoses and where outcome of the pregnancy was known. Twenty-five of these patients were treated with desferrioxamine. In 48 of the 49 patients the dose of iron allegedly taken was known and in 28 (60%) was over 20 mg kg-1, sufficient to put them at risk of toxicity. In the 36 whose serum iron levels were measured, 20 patients had levels in excess of 60 mumol l-1, indicating a risk of moderate or severe toxicity. Of the 49 pregnancies, 43 resulted in live babies, two had spontaneous abortions and there were four elective terminations. Of the live babies, three were premature, two of whom had problems, and there were three other babies with abnormalities. All babies with malformations were associated with overdoses after the first trimester and so the malformations cannot be directly related to the overdose. A total of 25 patients received desferrioxamine of whom two had malformed babies, but the desferrioxamine can be excluded as a cause. There was no correlation between the serum iron levels and the birthweights. In conclusion, iron overdose in pregnancy can be fatal and antidote treatment if appropriate should not be withheld.(ABSTRACT TRUNCATED AT 250 WORDS)

Paracetamol poisoning in pregnancy: an analysis of the outcomes of cases referred to the Teratology Information Service of the National Poisons Information Service.

A study was carried out to investigate the outcome of pregnancy in 115 women who had been exposed to paracetamol overdose. Follow up was obtained in 48 cases. Exposure occurred in all trimesters, and the most striking feature of this series is that the majority of the pregnancy outcomes were normal. None of the mothers died. There were 39 live born infants with no malformation, 14 of whom had been exposed in the first trimester. Four babies, exposed in the third trimester had neonatal problems, but these seem unrelated to paracetamol. There were two live born infants with gross malformations (spina bifida occulta; and cleft lip and palate). However, as the overdoses occurred at weeks 26 and 28 respectively, long after the structural development of these organs, the malformations could not have been caused by the paracetamol. There were two spontaneous abortions, both in the first trimester, which occurred two weeks after the overdose which may be related to the paracetamol. The overall conclusion is that paracetamol overdose per se is not necessarily an indication for termination of pregnancy.

Effects of administering caffeine to pregnant rats either as a single daily dose or as divided doses four times a day.

From day 6 to day 20 of pregnancy, rats were treated with caffeine in a total daily dose of 10 or 100 mg/kg by gavage, either as a single bolus dose or as four divided doses given at 3-hr intervals throughout the day. Controls were given distilled water at the same times. Maternal body weight and food and water consumption were reduced in the two groups receiving a total of 100 mg caffeine/kg/day and in the group given 2.5 mg/kg four times daily. Dose-related decreases in foetal weight, placental weight and crown-rump length and dose-related retardation of skeletal ossification were observed. Major foetal abnormalities, mainly ectrodactyly, were seen only in the group given 100 mg caffeine/kg in a single daily dose.

Studies on the teratogenic effects of different oral preparations of caffeine in mice.

Caffeine in doses up to 250 mg/kg per day in drinking water or up to 150 mg/kg per day in sustained release pellets was administered to pregnant mice. Apart from a low incidence of cleft palate, in the 50 mg/kg and 150 mg/kg caffeine pellet groups no gross abnormalities were observed which were attributable to caffeine treatment. The most important effect observed was a reduction in fetal weight. Retarded ossification particularly of the supraoccipital bones was observed in fetuses when caffeine (150 mg/kg) was administered in drinking water but not when the same dose was given as a sustained release pellet. Analysis of caffeine blood level data showed that the total exposure from the pellets was greater than from the drinking water. It would thus appear that the effect on the supraoccipital bones is an indirect one mediated through reduced food and water intake of the dams when caffeine is administered in drinking water.

Acute studies to investigate the mechanism of action of caffeine as a teratogen in mice.

1 In Charles River CD1 mice, a single dose of 100 mg kg-1 caffeine injected intraperitoneally on day 14 of pregnancy caused a low incidence of cleft palate in the fetuses. 2 Single oral doses of caffeine of 200 and 300 mg kg-1 but not 100 mg kg-1 on day 14, caused cleft palate in some of the fetuses, but was clearly toxic to the dams. 3 Oral doses of caffeine up to 300 mg kg-1 on day 14 of pregnancy did not reduce utero-placental blood flow, placental transfer function, or amniotic fluid volume. 4 An oral dose of 100 mg kg-1 caffeine induced a marked stimulation of adrenocortical secretion producing plasma corticosterone levels of 1248 +/- 129 microgram per 100 ml by 2 h and with elevated levels persisting more than 8 h. 5 It is suggested that the elevated plasma corticosterone is the cause of the cleft palate induced in mice by caffeine. Since corticosterone is a known cleft palate inducer in mice but not in man these results do not predict a hazard from normal caffeine consumption in man.

The metabolism of primidone in non-pregnant and 14-day pregnant mice.

1. Non-pregnant and day-14 pregnant mice treated with a single dose of primidone (5 to 150 mg/kg) by gastric intubation were bled at 1 and 4 h after dosage, and the plasma analysed for primidone, phenobarbitone and phenylethylmalondiamide (PEMA) by g.l.c. 2. Marked differences in the rate of metabolism were observed between the non-pregnant and day-14 pregnant mouse. Plasma levels of primidone and PEMA, but not phenobarbitone, were much lower in the day-14 pregnant mouse than in the non-pregnant animal.

Plasma level studies of primidone and its metabolites in the mouse at various stages of pregnancy.

1. Mice were treated with a teratogenic dose of primidone (100 mg/kg) by gastric intubation at three different times during pregnancy, viz. days 6-14, days 12-14 on day 14 only. Blood samples were taken on day 14 at 1, 4, 8 and 24 h after dosage. Primidone and its metabolites phenylethylmalondiamide (PEMA), and phenobarbitone, were assayed by g.l.c. 2. There was no accumulation of the parent compound or the metabolites after repeated administration of primidone; each of the substances was cleared from the plasma within 24 h. 3. The rate of metabolism of primidone increased with prolonged treatment. The peak concentration of the metabolites was higher in the two multiple-dose groups than in the single dose group. 4. The concentration of PEMA exceeded that of primidone between 3-8 h and then began to decrease in the multiple-dose groups, a similar pattern was established for phenobarbitone also, although the concentrations were lower than those of PEMA.