How do we best detect toxic effects of drugs taken during pregnancy? A EuroMap paper

The impact of anti-TNFα therapy on colectomy rates and corticosteroid treatment among 3001 paediatric and adolescent patients with ulcerative colitis-a nationwide study from 1995 to 2015

BACKGROUND

The long-term effects of anti-TNFα therapy in ulcerative colitis are debatable.

AIM

To examine whether anti-TNFα therapy changed the colectomy proportion and reduced the use of corticosteroids.

METHODS

A nationwide cohort study among patients (age 0-20) diagnosed with ulcerative colitis through 1995-2015 from Danish health registries. We calculated the cumulative 5-year risk of colectomy after diagnosis and used a Cox regression model for comparison between a historical pre-anti-TNFα cohort 1 (1995-2003) and a cohort 2 for the era of anti-TNFα (2004-2015). Based on anti-TNFα users, defined as patients who had at least four anti-TNFα treatments within 4 months, we examined the subsequent need for corticosteroids.

RESULTS

We identified 3001 patients from 1995 to 2015. The 5-year cumulative proportion of colectomy in cohort 2 was 9.7% (95% confidence interval [CI] 8.4-11.1) and 12.3% (95% CI 10.4-14.6) in cohort 1. The adjusted 5-year hazard ratio (HR) was 0.76 (95% CI 0.60-0.96) for colectomy in cohort 2 compared to cohort 1. A total of 334 patients received anti-TNFα treatments, and 16.8% (56/334) were prescribed corticosteroids in the subsequent 3-month period. Corticosteroid treatment declined with follow-up after 6 and 12 months, 5.4% and 1.2%, respectively.

CONCLUSION

In patient's ≤20 years, the HR for colectomy within a period of 5 years from the time of diagnosis was reduced in the era of anti-TNFα compared to a historical cohort. In patients treated with anti-TNFα, prescriptions of corticosteroids were virtually ceased after 12 months.

Anti-TNF-α Use During the Third Trimester of Pregnancy in Women with Moderate-severe Inflammatory Bowel Disease and the Risk of Preterm Birth and Low Birth Weight

BACKGROUND

Little knowledge exists about the association between anti-tumor necrosis factor-alpha (anti-TNF-α) therapy for inflammatory bowel disease during late pregnancy and adverse birth outcomes. We aimed to examine whether treatment with anti-TNF-α during the third trimester affected preterm birth and low birth weight (LBW), compared with women who discontinued anti-TNF-α therapy before the third trimester.

METHODS

We identified a nationwide cohort of 219 women treated with anti-TNF-α during the pregnancy period and reviewed the medical records to extract clinical details. The exposed cohort (n = 113, 51.6%) constituted pregnancies exposed to anti-TNF-α during the third trimester, and the unexposed cohort (n = 106, 48.4%) constituted pregnancies with no anti-TNF-α during the third trimester. The association between anti-TNF-α therapy in the third trimester and adverse birth outcomes was studied (1) in those women who had clinical disease activity during pregnancy and (2) in women who had no clinical disease activity during pregnancy.

RESULTS

In women with disease activity, treated with anti-TNF-α during the third trimester, we found an adjusted odds ratio of 2.23 (95% confidence interval [CI], 0.80-6.20) for preterm birth and 1.16 (95% CI, 0.26-5.23) for LBW. Among women without disease activity, treated with anti-TNF-α therapy during the third trimester, we found an adjusted odds ratio of 3.36 (95% CI, 0.31-36.46) for preterm birth and 0.86 (95% CI, 0.05-14.95) for LBW.

CONCLUSIONS

For anti-TNF-α therapy in the third trimester, we found no statistically significant increased risk of either LBW or preterm birth.

Pre-operative use of anti-TNF-α agents and the risk of post-operative complications in patients with ulcerative colitis - a nationwide cohort study

BACKGROUND

It is still controversial whether pre-operative anti-tumour necrosis factor-alpha (anti-TNF-α) agents increase post-operative complications in patients with ulcerative colitis (UC).

AIM

In a nationwide Danish cohort of patients with UC, we aimed to examine the impact of pre-operative use of anti-TNF-α agents on post-operative adverse outcomes after colectomy for UC. Outcomes (within 30 and 60 days after surgery) were reoperation, anastomosis leakage, intra-abdominal abscess, bacteremia and death.

METHODS

Based on the Danish National Patient Registry we identified all UC patients, aged ≥15 years, having their first surgery for UC in the period of 1 January 2003-31 December 2010 (n = 1226). Patients were classified according to use of anti-TNF-α agents within 12 weeks before surgery or not. Outcome data were obtained from Danish registries. Logistic regression analyses were used to estimate adjusted risks [with 95% confidence intervals (CI)] of post-operative outcomes among patients treated with anti-TNF-α agents, relative to those not treated.

RESULTS

A total of 199 UC patients were exposed to anti-TNF-α agents within 12 weeks before colectomy, and 1027 were not. Among exposed, the adjusted odds ratio of reoperation and anastomosis leakage within 30 days after colectomy was 1.07 (95% CI: 0.71-1.59) and 0.52 (95% CI: 0.06-4.11) respectively. No deaths, cases of abscess drainage or bacteremia occurred among exposed within 30 days. Furthermore, no increased relative risks were found within 60 days after colectomy.

CONCLUSIONS

Based on nationwide data on UC patients having colectomies, pre-operative use of anti-TNF-α agents did not increase the risk of post-operative complications.

Nationwide register-based surveillance system on drugs and pregnancy in Finland 1996-2006

PURPOSE

The aim of this population-based nationwide drugs and pregnancy surveillance system was to get basic information on the use of prescribed drugs during pregnancy and to achieve more detailed information on drug exposure-outcome associations with data obtained from the Finnish national health registers.

METHODS

The data are based on information on all pregnancies ending in births (n = 632,629) or termination of pregnancy (TOP) (n = 117,255) in Finland between 1996 and 2006. The data containing information on maternal background factors, chronic diseases and drug purchases during pregnancy, born children, induced abortions, perinatal health and major congenital malformations were obtained from the Finnish national health registers. Information from the different registers was merged through record linkages based on unique personal identification numbers. Statistical analyses were conducted between the exposed and unexposed for individual drugs or Anatomical Therapeutic Chemical (ATC) classification drug groups in multivariate logistic regression including potential confounding factors.

RESULTS

Nearly half of parturients and almost every third woman with TOP purchased drugs at least once 1 month prior to pregnancy and/or during pregnancy. The most frequent chronic diseases during pregnancy were asthma, hypothyroidism, epilepsy, rheumatoid arthritis and diabetes. Previously known causal connections between maternal chronic diseases and/or medication and perinatal health risks were already seen in the ATC-group-level analysis.

CONCLUSIONS

Comprehensive and detailed information for pharmacoepidemiological research on the effects of drug use during pregnancy in a cohort setting is possible with long-term and cumulative data collection.

Effects of nicotine during pregnancy: human and experimental evidence

Prenatal exposure to tobacco smoke is a major risk factor for the newborn, increasing morbidity and even mortality in the neonatal period but also beyond. As nicotine addiction is the factor preventing many women from smoking cessation during pregnancy, nicotine replacement therapy (NRT) has been suggested as a better alternative for the fetus. However, the safety of NRT has not been well documented, and animal studies have in fact pointed to nicotine per se as being responsible for a multitude of these detrimental effects. Nicotine interacts with endogenous acetylcholine receptors in the brain and lung, and exposure during development interferes with normal neurotransmitter function, thus evoking neurodevelopmental abnormalities by disrupting the timing of neurotrophic actions. As exposure to pure nicotine is quite uncommon in pregnant women, very little human data exist aside from the vast literature on prenatal exposure to tobacco smoke.

The current review discusses recent findings in humans on effects on the newborn of prenatal exposure to pure nicotine and non-smoke tobacco. It also reviews the neuropharmacological properties of nicotine during gestation and findings in animal experiments that offer explanations on a cellular level for the pathogenesis of such prenatal drug exposure.

It is concluded that as findings indicate that functional nAChRs are present very early in neuronal development, and that activation at this stage leads to apoptosis and mitotic abnormalities, a total abstinence from all forms of nicotine should be advised to pregnant women for the entirety of gestation.

Risk of miscarriage for pregnant users of pivmecillinam: a population-based case-control study

Few data exist on the risk of miscarriage after exposure to pivmecillinam. We therefore conducted a population-based case-control study in a Danish county with 0.5 million inhabitants during the period 1997-2002. We included 1,599 women with a miscarriage recorded in the Hospital Discharge Registry and selected 10 controls per case among primiparous women who had a live birth during the study period. Controls were selected from the Danish Medical Birth Registry. We obtained data on use of pivmecillinam and sulfamethizole from a prescription database. Five cases (0.30%) and 24 controls (0.15%) were exposed to pivmecillinam in the last week before the miscarriage/index date. After adjustment for maternal age, use of antidiabetics or antiepileptics, the odds ratio for miscarriages among users of pivmecillinam compared with non-users was 2.03 (95% confidence interval: 0.77-5.33) and the corresponding odds ratio for use of sulfamethizole was 1.53 (95% confidence interval: 0.76-3.09). Exposure within 2 to 12 weeks before the miscarriage was not associated with an increased risk. We concluded that use of pivmecillinam was associated with an increased risk of miscarriage, but the risk was not significantly (p=0.64) different from the risk associated with use of sulfamethizole.

Data resources for investigating drug exposure during pregnancy and associated outcomes: the General Practice Research Database (GPRD) as an alternative to pregnancy registries

Pregnancy registries are the most commonly used data resource for the post-marketing surveillance of drug teratogenicity. However, the limited sample size and potential selection bias in these registries has led us to investigate the potential of the UK General Practice Research Database (GPRD) as an alternative data source for monitoring drug safety during pregnancy. In addition, a literature review identified further observational data sources that monitor pregnancy outcomes for future evaluation. Initial feasibility studies focused on the ability of the GPRD to capture pregnancy outcomes for a range of drug class exposures, all of which are currently under investigation in pregnancy registries, during pregnancy. The comparator pregnancy registries were identified via a MEDLINE search, whilst eligible pregnancies, in which women received one or more prescriptions for the drug of interest during pregnancy, were identified in the GPRD using the mother-baby link. The number of pregnancy outcomes following exposure to medication for a range of conditions with varying prevalence, including depression, migraine, epilepsy, herpes simplex and HIV, captured by the two data sources were compared. For depression, a relatively prevalent condition, the GPRD recorded the same number of mean annual intrauterine exposures to fluoxetine as the pregnancy registry (118 exposures/year). Ascertainment of intrauterine exposure to drug treatments for less prevalent conditions was found to be higher for the pregnancy registries than the GPRD; for the older antiepileptic drugs (valproate and carbamazepine), the pregnancy registry recorded between four and five times as many mean annual exposures as the GPRD. Virtually no antiretroviral exposures (three) were identified during the time period of interest on the GPRD, compared with 3946 in the Antiretroviral Pregnancy Registry. Data from the GPRD meet established criteria for evaluating outcomes of pregnancy. For prevalent conditions, it has the potential to replace or work alongside standard pregnancy registries and the alternative data sources identified. Further studies are now needed to assess its ability to replicate known teratogenic associations.

Risk of miscarriage for pregnant users of pivmecillinam: a population-based case-control study

Few data exist on the risk of miscarriage after exposure to pivmecillinam. We therefore conducted a population-based case-control study in a Danish county with 0.5 million inhabitants during the period 1997-2002. We included 1,599 women with a miscarriage recorded in the Hospital Discharge Registry and selected 10 controls per case among primiparous women who had a live birth during the study period. Controls were selected from the Danish Medical Birth Registry. We obtained data on use of pivmecillinam and sulfamethizole from a prescription database. Five cases (0.30%) and 24 controls (0.15%) were exposed to pivmecillinam in the last week before the miscarriage/index date. After adjustment for maternal age, use of antidiabetics or antiepileptics, the odds ratio for miscarriages among users of pivmecillinam compared with non-users was 2.03 (95% confidence interval: 0.77-5.33) and the corresponding odds ratio for use of sulfamethizole was 1.53 (95% confidence interval: 0.76-3.09). Exposure within 2 to 12 weeks before the miscarriage was not associated with an increased risk. We concluded that use of pivmecillinam was associated with an increased risk of miscarriage, but the risk was not significantly (p=0.64) different from the risk associated with use of sulfamethizole.

Maternal use of Loratadine during pregnancy and risk of hypospadias in offspring

To examine the risk of hypospadias after exposure to loratadine and other antihistamines during pregnancy, we conducted a population-based case-control study in four Danish counties, which account for 30% of the Danish population (approximately 1.6 M). We obtained data on maternal use of antihistamines from prescription databases, and data on birth outcomes from the Danish Medical Birth Registry (MBR) and the Hospital Discharge Registry (HDR). A total of 65,383 male births with a full prescription history of the mother in the study period from 1989-2002 were available for analysis. Within this cohort, we identified cases with a diagnosis of hypospadias, and 10 selected controls per case without such a diagnosis (matched on birth month, gender and year of birth). We identified 227 cases of hypospadias recorded in the HDR within six months postpartum and 2270 controls. One case (0.4%) and eight (0.4%) controls were exposed to loratadine in the first trimester and up to 30 days before the time of conception. The adjusted odds ratio (OR) for hypospadias among users of loratadine relative to non-users was 1.4 (95% CI: 0.2-11.2) and the corresponding OR for other antihistamines was 1.9 (95% CI: 0.7-5.7). In this study, maternal exposure to loratadine did not appear to be associated with an increased risk of hypospadias when compared with other antihistamines, although it should be noted that the statistical precision of the risk estimates might be limited.

Recruiting pregnant smokers for a placebo-randomised controlled trial of nicotine replacement therapy

BACKGROUND

Smoking in pregnancy is a public health problem and effective methods for reducing this are required. Although nicotine replacement therapy (NRT) is effective for smoking cessation in non-pregnant people, there is no direct evidence concerning its effectiveness in pregnancy. Despite this, clinical guidelines recommend the cautious use of NRT during pregnancy. Randomised controlled trials are needed to determine the safety and efficacy of NRT when used by pregnant women for smoking cessation, but the feasibility of recruiting women to such trials is unknown. Consequently, in this study we aimed to determine i) the feasibility of recruiting women to a RCT of NRT in pregnancy as they attend hospital antenatal ultrasound examinations, ii) the proportion of such women who are eligible for and interested in trial enrollment and iii) research staff perceptions of how one method of trial recruitment could be improved.

METHODS

During a one month period, all women attending for antenatal ultrasound examination in an English teaching hospital were asked to complete a questionnaire which determined their eligibility to enroll in a proposed placebo controlled randomised trial investigating the effectiveness of NRT in pregnancy. Women who were eligible to participate were asked whether they would do so and those who accepted enrollment were offered an appointment with a smoking cessation advisor.

RESULTS

Over 99% (851/858) of women agreed to complete a questionnaire about smoking habits whilst waiting for ultrasound examinations. 10.3% (88/851) of women attending for antenatal ultrasound fitted eligibility criteria for a proposed RCT of NRT in pregnancy, but only 3.6% [(31/851), 95% CI, 2.4 to 4.9%] indicated on the questionnaire that they would like to take part in a study involving randomisation to placebo or active patches. Researchers offered trial enrollment to 26 of these 31 women and 96% (25) accepted. Staff recruiting women believed that trial recruitment would be maximised if women attending the ultrasound department knew about trial recruitment before attending and greater staff resources were made available for this. It was also perceived that women generally under-reported the amount they smoked on questionnaires completed whilst waiting in ultrasound department areas.

CONCLUSIONS

It is feasible to recruit women for a trial of NRT in pregnancy as they wait for antenatal ultrasound examinations. Using similar recruitment methods, researchers can expect to recruit between 24 and 49 women per 1000 approached.

Developmental toxicity evaluation of ibuprofen and tolmetin administered in triple daily doses to Wistar CRL:(WI)WUBR rats

BACKGROUND

Ibuprofen and tolmetin are popular non-steroidal anti-inflammatory drugs. Previous animal studies taken with single daily doses showed their good prenatal tolerability. However, since both cyclooxygenase (COX) inhibitors have a short half-life, the current report presents drug developmental effects after triple daily doses administration, as they are used in human.

METHODS

Drugs were separately, orally dosed to pregnant rats triple daily 8 hr apart from day 8 to 21 (GD=1-plug day). The total daily doses were set at 25.5, 255.0, and 600.0 mg/kg for ibuprofen and 25.5, 255.0, and 2550.0 mg/kg for tolmetin. Fetuses were delivered on GD 21 and routinely examined. Comprehensive clinical and developmental measurements were done.

RESULTS

Maternal toxicity and intrauterine growth retardation were found in groups exposed to the highest doses of both drugs. An increase of external variations was reported in groups exposed to the middle and highest dose of ibuprofen and to the highest dose of tolmetin. Skeletal variations were significantly different only in litters treated with the highest doses of the drugs. Pooled statistical analysis showed a higher incidence of midline and ventricular septal (VSD) defect in rat fetuses exposed to COX inhibitors when compared with historical control data. For ibuprofen, the influence on VSD was similar to aspirin.

CONCLUSION

Both COX inhibitors were toxic to dams in the highest doses evaluated, which caused a significantly greater incidence of intrauterine growth retardation and developmental variations.