Fetal adverse effects following NSAID or metamizole exposure in the 2nd and 3rd trimester: an evaluation of the German Embryotox cohort.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAID) are frequently used to treat pain, fever and inflammatory conditions. Due to evidenced fetotoxicity, treatment with NSAID and metamizole should be avoided in the 3rd trimester of pregnancy. There is an ongoing debate on fetotoxic risk of 2nd trimester use which is why we have conducted this study. METHODS: In this observational cohort study outcome of pregnancies with NSAID and/or metamizole exposure in the 2nd and/or 3rd trimester (study cohort n = 1092) was compared with pregnancies exposed to NSAID and/or metamizole in the 1st trimester only (comparison cohort, n = 1154). The WHO-UMC system was used to assess causality between study medication and study endpoints. Prenatal study endpoints were constriction of ductus arteriosus Botalli, oligohydramnios, late spontaneous abortion (SAB) or stillbirth. Postnatal study endpoints were patent ductus arteriosus (PDA), anomalies of the right heart ventricle, primary pulmonary hypertension (PPHT), and neonatal impairment of kidney function. RESULTS: Ductus arteriosus constriction was diagnosed in 5/1092 (0.5%) in the study cohort versus 0/1154 pregnancies in the comparison cohort. In one fetus, ductus arteriosus constriction and oligohydramnios occurred already in the late 2nd trimester after long-term NSAID exposure. Oligohydramnios was diagnosed in 41/1092 (3.8%) in the study cohort versus 29/1154 (2.5%) cases in the comparison cohort [RR, 1.5 (95% CI 0.9-2.4)]. Limited to 2nd trimester, oligohydramnios occurred in 8/904 (0.9%) versus 2/1154 (0.2%) pregnancies [RR, 5.1 (95% CI 1.1-24.0)]. At least in four of the 2nd trimester exposed pregnancies NSAID exposure lasted several weeks. Late SAB or stillbirth occurred in 14/1092 (1.3%) versus 17/1154 (1.5%). Postnatal cardiovascular or renal pathology did not differ between the cohorts. CONCLUSIONS: NSAID use in the 2nd trimester limited to a few days does not appear to pose a relevant risk. Use for longer periods in the advanced 2nd trimester, however, may cause oligohydramnios and ductus arteriosus constriction similar to effects observed after 3rd trimester use.

Can non-responding mask or mimic drug effects on pregnancy outcome? Evaluation of case characteristics based on the national Embryotox cohort.

Women and their health care provider (HCP) often seek advice for drug safety in pregnancy at Teratology Information Services (TIS). In turn, TIS ask for details of drug exposure and pregnancy outcome. These data constitute a valuable basis for research on prenatal drug risks in many countries. Non-response to follow-up questionnaires, however, may cause biased study results. To assess the potential of non-response bias, this study based on the German Embryotox cohort compares maternal and HCP characteristics of responders and non-responders. Change in loss of follow-up rates over time is investigated using logistic regression. From 2010 until the end of 2020, 48,410 pregnant women and/or their HCP consented to participation in follow-up. Of these, 25.0 % did not return follow-up questionnaires. Loss rates were similar for patients and HCP but increased over time. Participants from semi-dense populated areas had a smaller loss rate (20.4 %) than those from rural (28.4 %) or urban areas (25.6 %). Responding women were older than non-responders, had a lower BMI, a more positive attitude towards pregnancy, a higher educational level, a lower number of previous pregnancies, smoked less, and indicated alcohol consumption more but social drugs less often. Non-response bias cannot be ruled out in studies based on observational data on drug use in pregnancy as those collected by TIS. However, differences between the complete and lost-to follow-up cohort do not suggest a particularly high or low risk profile for one of the cohorts that might substantially confound study results or even mask or mimic potential drug toxicity.

First trimester naproxen exposure and outcome of pregnancy - A German case series.

In contrast to other non-steroidal anti-inflammatory drugs (NSAIDs), naproxen use during pregnancy is not well studied. The objective of this analysis was to assess negative effects on pregnancy outcomes following naproxen exposure in the first trimester of pregnancy. Out of 121 exposed pregnancies prospectively recorded by two German teratology information services (TIS) 15 ended as spontaneous abortion and ten were electively terminated; in one case for prenatal diagnosis of anencephaly. Four pregnancies were stillborn, in these cases naproxen was discontinued more than two months before the event. Of 95 live-born infants, including three pairs of twins, two were born with major birth defects: one with dysmelia of the left hand and foot and another with a complex congenital heart defect, esophageal atresia with tracheoesophageal fistula, and choanal stenosis. The results of this case series do not suggest that naproxen has a significant teratogenic effect. However, due to the limited cohort size and lack of comparable reference group results should be interpreted with caution and better studied NSAIDs such as ibuprofen should be preferred in the first and second trimester of pregnancy. This work was supported by the German Federal Institute for Drugs and Medical Devices (BfArM).

Risk estimation of fetal adverse effects after short-term second trimester exposure to non-steroidal anti-inflammatory drugs: a literature review.

PURPOSE: Non-steroidal anti-inflammatory drugs (NSAIDs) are not recommended in the 3rd trimester of pregnancy due to known fetal adverse effects in an advanced gestational age. This investigation was performed to assess whether there is a significant risk of NSAIDs being used as an analgesic or antipyretic medication in the 2nd trimester. METHODS: A systematic search for publications reporting 2nd trimester NSAID exposure was performed in MEDLINE. The search focused on case descriptions reporting defined adverse effects including prenatal ductus arteriosus constriction, oligohydramnios, neonatal renal failure, and primary pulmonary hypertension. Original articles published until February 2018 were considered for evaluation. RESULTS: Out of 681 identified publications, 26 included relevant information on the defined adverse effects. Among these publications, premature labor was the major reason for 2nd trimester indomethacin treatment while other clinical indications and other NSAIDs were underrepresented. Narrowing or closure of the ductus arteriosus in the 2nd trimester was described in 33 fetuses. Only eight publications reported adverse effects after less than 7-day exposure during the 2nd trimester. CONCLUSIONS: Based on these results, short-term use of NSAIDs as analgesics or antipyretics in the 2nd trimester does not appear to pose a substantial risk for fetal adverse effects. Long-term use in the late 2nd trimester, however, should always be monitored.

No evidence of adverse pregnancy outcome after exposure to ibuprofen in the first trimester - Evaluation of the national Embryotox cohort.

Ibuprofen is an analgesic frequently used in the 1st and 2nd trimester of pregnancy. Most relevant studies deal with NSAID as a group and do not specifically focus on ibuprofen. In this study, 1117 women exposed to ibuprofen in the 1st trimester were compared to 2229 non-exposed women. Data were retrieved from the German Embryotox database. No significantly increased risk of major birth defects (4.8% vs. 4.1%; OR adjusted 1.11, 95% CI 0.75-1.64) or a distinct pattern of birth defects were found. The cumulative incidences of spontaneous abortions were similar across cohorts (15.5% vs. 16.6%; HR adjusted 0.85; 95% CI, 0.65-1.11). Subgroup analyses of pregnancies exposed for ≥7 (n = 223) and ≥30 days (n = 72) did not reveal a higher risk with increasing treatment duration. Ibuprofen does not seem to carry a substantial embryotoxic risk regarding the investigated endpoints.

Safety of diclofenac use during early pregnancy: A prospective observational cohort study.

Diclofenac is a widely used analgesic so that exposure during pregnancy may frequently occur. Most publications have evaluated the safety of NSAIDs on pregnancy outcome as a group of substances. Specific data on diclofenac are rare. This observational cohort study used the German Embryotox pharmacovigilance database to assess the risk of major birth defects and spontaneous abortion after first trimester exposure to diclofenac. A group of 260 women who took diclofenac during first trimester was compared to 778 non-exposed pregnancies. In the diclofenac exposed cohort 4 major birth defects were observed among 220 live-born infants and 25 spontaneous abortions occurred. Neither the rate of major birth defects (1.8% vs. 3.1%; OR adjusted 0.59; 95% CI 0.17-2.08) nor the risk of spontaneous abortion (HR adjusted 0.90; 95% CI 0.56-1.46) was increased. The study results do not indicate that diclofenac exposure during first trimester is associated with a teratogenic risk.

Exposure to cox-2 inhibitors (coxibs) during the first trimester and pregnancy outcome: a prospective observational cohort study.

PURPOSE: Cox-2-inhibitors (coxibs) are not recommended in pregnancy but early exposure may occur, for instance in unplanned pregnancies. Experience in pregnancy is limited leading to concerns in patients and their health care providers. Therefore, further data on coxibs and their effects on embryogenesis are needed. METHODS: This observational cohort study evaluates pregnancies ascertained in Germany during the study period from January 2000 to January 2016. A cohort of 174 women exposed to coxibs in the first trimester was compared to a randomly selected cohort of 521 women without exposure to coxibs, other nonsteroidal anti-inflammatory drugs or known teratogens. RESULTS: The overall rate of major birth defects was not significantly increased in the study cohort (2.9 vs. 2.7%, OR 1.08, 95% CI 0.34-3.42; OR adjusted 0.96, 95% CI 0.28-3.26). The cumulative incidence of spontaneous abortions was nonsignificantly lower in the exposed cohort (14.3 vs. 20.0%; HR, 0.90, 95% CI 0.51-1.58; HR adjusted, 0.87; 95% CI, 0.49-1.56). Elective terminations of pregnancies (ETOP), mainly for 'social' reasons, were more frequent in the coxib cohort (17.5 vs. 7.0%, HR, 2.31; 95% CI, 1.26-4.24; HR adjusted 2.12, 95% CI 1.13-3.97). CONCLUSIONS: Our study results support the assumption that coxibs are not major teratogens. Considering the still limited evidence basis on coxib exposure during pregnancy, well-established alternatives should be preferred.

Metamizole use during first trimester-A prospective observational cohort study on pregnancy outcome.

INTRODUCTION: The analgesic metamizole (dipyrone) is not recommended during pregnancy due to limited experience. In several countries, metamizole has no market authorization because of agranulocytosis as a rare but severe adverse effect. However, in others, metamizole is available and widely used as a pain reliever, and its use occurs also during pregnancy, often followed by fears of potential teratogenic risk. METHODS: This prospective observational cohort study compared pregnancy outcomes of 446 women exposed with metamizole in the first trimester with a randomly selected control cohort comprising 887 women not exposed to metamizole. Relevant data were obtained via structured questionnaires applied during the first trimester and 2 months after the expected date of birth between January 2000 and December 2015. RESULTS: The rate of major birth defects (7/373, 1.9%) was not increased in the metamizole cohort (OR adjusted 1.15, 95% CI 0.4-3.5). The cumulative incidences for spontaneous abortions did not reveal a significant difference between the exposed (12.2%, 32/446) and comparison cohort (19.4%, 77/887) (HR adjusted 0.72, 95% CI 0.5-1.1). Elective terminations of pregnancy (ETOP), mostly for "social" reasons, were more frequent in the metamizole (12.5%, 45/446) than in the comparison cohort (9.4%, 50/887; HR adjusted 1.48, 95% CI 0.98-2.2). CONCLUSIONS: Metamizole exposure in the first trimester does not seem to bear a substantial teratogenic risk. Our study results support reassurance in those instances where metamizole has been used during an unrecognized pregnancy or where its use appears indispensable.

Field studies versus database studies on the risks and benefits of medication use during pregnancy: Distinct pieces of the same puzzle.

Over the past two decades, findings on medication use during pregnancy have been accumulating from observational data. Generally, field studies with prospective recruitment of subjects have better outcome ascertainment, and more control on the longitudinal collection of data, but have lower sample sizes and thus they often lack statistical power to detect increased risks for rare events such as major congenital malformations. In addition, given the rarity of specific drug exposures in a population, even relatively common outcomes, such as low birth weight, may become rare in combination with the specific exposure. On the other hand, administrative databases usually provide larger samples and thus increased statistical power, decrease the probability of selection and recall bias, but often have missing data on potential confounders. Hence, debate amongst researchers, regulators and public health officials has been ongoing with regard to the most appropriate study populations for perinatal epidemiologic research. With this commentary, we aim to highlight the importance of both study populations, which can make complementary and crucial contributions to the iterative determination of causality as well as discuss basic epidemiologic principles that need to be applied in the field of perinatal pharmacoepidemiology for the purpose of causality assessment. This is relevant at present given that the United States Food and Drug Administration (US FDA) has modified their medication label requirements, especially given the international importance of these modifications.