Reinhard Meister

Vitamin K antagonists and pregnancy outcome - A multi-centre prospective study

Vitamin K antagonists (VKA) are known to act as teratogens; however, there is still uncertainty about the relative risk for birth defects and the most sensitive period. In a multi-centre (n = 12), observational, prospective study we compared 666 pregnant women exposed to phenprocoumon (n = 280), acenocoumarol (n = 226), fluindione (n = 99), warfarin (n = 63) and phenindione (n = 2) to a non-exposed control group (n = 1,094). Data were collected by institutes collaborating in the European Network of Teratology Information Services (ENTIS) during individual risk counselling between 1988 and 2004. Main outcome measures were coumarin embryopathy and other birth defects, miscarriage rate, birth-weight, and prematurity. The rate of major birth defects after 1st trimester exposure was significantly increased (OR 3.86, 95% CI 1.86-8.00). However, there were only two coumarin embryopathies (0.6%; both phenprocoumon). Prematurity was more frequent (16.0% vs. 7.6%, OR 2.61, 95% CI 1.76-3.86), mean gestational age at delivery (37.9 vs.39.4, p<0.001), and mean birth weight of term infants (3,166 g vs. 3,411 g; p < 0.001) were lower compared to the controls. Using the methodology of survival analysis, miscarriage rate reached 42% vs. 14% (hazard ratio 3.36; 95% CI 2.28-4.93). In conclusion, use of VKA during pregnancy increases the risk of structural defects and other adverse pregnancy outcomes. The risk for coumarin embryopathy is, however, very small, in particular when therapy during the 1(st) trimester did not take place later than week 8 after the 1(st) day of the last menstrual period. Therefore, elective termination of a wanted pregnancy is not recommended if (inadvertent) exposure took place in early pregnancy. Close follow-up by the obstetrician including level II ultrasound should be recommended in any case of VKA exposure during pregnancy.

Atypical antipsychotic drugs and pregnancy outcome: a prospective, cohort study.

Abstract Women of childbearing age are often affected with psychotic disorders, requiring the use of antipsychotic medication during pregnancy. In the present study, we prospectively followed the pregnancies of 561 women exposed to second-generation antipsychotic agents (SGAs; study cohort) and compared these to 284 pregnant women exposed to first-generation antipsychotic agents (FGAs; comparison cohort I) and to 1122 pregnant women using drugs known as not harmful to the unborn (comparison cohort II). Subjects were enrolled through the Institute’s consultation service. Major malformation rates of SGA exposed were higher compared to comparison cohort II (adjusted odds ratio, 2.17; 95% confidence interval, 1.20–3.91), possibly reflecting a detection bias concerning atrial and ventricular septal defects. Postnatal disorders occurred significantly more often in infants prenatally exposed to SGAs (15.6%) and FGAs (21.6%) compared to 4.2% of comparison cohort II. Cumulative incidences of elective terminations of pregnancy were significantly higher in both the study cohort (17%) and comparison cohort I (21%) compared to comparison cohort II (3%), whereas the rates of spontaneous abortions did not differ. The numbers of stillbirths and neonatal deaths were within the reference range. Preterm birth and low birth weight were more common in infants exposed to FGAs. To conclude, our findings did not reveal a major teratogenic risk for SGAs, making the better studied drugs of this group a treatment option during pregnancy. Because neonates exposed to SGAs or FGAs in the last gestational week are at higher risk of postnatal disorders, delivery should be planned in clinics with neonatal intensive care units.

Statistical methods for estimating the probability of spontaneous abortion in observational studies--analyzing pregnancies exposed to coumarin derivatives.

BACKGROUND Spontaneous abortion rates are of general interest when investigating pregnancy outcome. In most studies observations are left truncated as pregnant women enter with a delay of several weeks after conception. Apart from spontaneous abortion pregnancy may end in induced abortion or live birth. These outcomes are considered as competing events (risks). Although statistical methods for handling this setting are available since more than 10 years, studies on pregnancy outcome after drug exposure usually report crude rates of spontaneous abortions, ignoring left truncation and competing risks. METHODS The authors propose simple methods which remove bias inherent to crude rates. The probability of spontaneous abortion is estimated using an event-history based approach for the subdistribution of competing risks that handles left truncation appropriately. Variance estimation enables the construction of approximate confidence intervals and of a simple test-statistic for comparing rates between different cohorts. The proposed methods are applied to a comparative prospective study on the association of spontaneous abortion and exposure to coumarin derivatives. RESULTS The naive analysis using crude rates gives substantially different results than those based on the proposed methods, with up to a twofold change. Correctly incorporating left truncation into the analysis may increase the variance of the estimators, relative to an ideal sample where all pregnancies are followed from the time of conception. The consequences of such truncation for study design are discussed. CONCLUSION Combining corrections for left truncation and competing risks offers a powerful method for analyzing miscarriage risk.

Pregnancy Outcome After Methotrexate Treatment for Rheumatic Disease Prior to or During Early Pregnancy: A Prospective Multicenter Cohort Study

High‐dose methotrexate (MTX) exposure during pregnancy is associated with embryopathy. The teratogenic potential of MTX at dosages typically used in the treatment of rheumatic diseases remains uncertain. The aim of this study was to evaluate the risk of spontaneous abortion, major birth defects, elective termination of pregnancy, shortened gestational age at delivery, and reduced birth weight in women exposed to MTX.

A(H1N1)v2009: a controlled observational prospective cohort study on vaccine safety in pregnancy.

BACKGROUND A(H1N1)v2009 influenza vaccination of pregnant women was a challenge for health care providers, as little safety data were available. METHODS We prospectively followed the pregnancies of women who were vaccinated at any time during pregnancy or ≤ 4 weeks prior to conception and compared these outcomes to a control cohort matched by the estimated date of birth. Primary endpoints: rate of spontaneous abortion and major malformations. Secondary endpoints: preeclampsia, gestational age at birth, and birth weight. RESULTS Pregnancy outcome of 323 women immunized with adjuvanted or non-adjuvanted A(H1N1)v2009 influenza vaccines from 2009-09-28 to 2010-03-31 were compared to 1329 control subjects. The risk for spontaneous abortions (HR 0.89; 95% CI 0.36-2.19) and the rate of major malformations (all trimesters: OR 0.87; 95% CI 0.38-1.77; preconception and first trimester exposure: OR 0.79; 95% CI 0.13-2.64) did not vary between the two cohorts. Furthermore, there was no increase in preeclampsia, prematurity, and intrauterine growth retardation in the vaccinated cohort. CONCLUSION The results of our study do not indicate a risk for the pregnant woman and the developing embryo/fetus after H1N1 vaccination. We provide and apply methods novel in observational studies on pregnancy outcome, especially if a single dose exposure is investigated.

Pregnancy outcome after TNF-α inhibitor therapy during the first trimester: a prospective multicentre cohort study.

AIMS TNF-α inhibitors are considered relatively safe in pregnancy but experience is still limited. The aim of this study was to evaluate the risk of major birth defects, spontaneous abortion, preterm birth and reduced birth weight after first trimester exposure to TNF-α inhibitors. METHODS Pregnancy outcomes of women on adalimumab, infliximab, etanercept, certolizumab pegol or golimumab were evaluated in a prospective observational cohort study and compared with outcomes of a non-exposed random sample. The samples were drawn from pregnancies identified by institutes collaborating in the European Network of Teratology Information Services. RESULTS In total, 495 exposed and 1532 comparison pregnancies were contributed from nine countries. The risk of major birth defects was increased in the exposed (5.0%) compared with the non-exposed group (1.5%; adjusted odds ratio (ORadj ) 2.2, 95% CI 1.0, 4.8). The risk of preterm birth was increased (17.6%; ORadj 1.69, 95% CI 1.1, 2.5), but not the risk of spontaneous abortion (16.2%; adjusted hazard ratio [HRadj ] 1.06, 95% CI 0.7, 1.7). Birth weights adjusted for gestational age and sex were significantly lower in the exposed group compared to the non-exposed cohort (P = 0.02). As a diseased comparison group was not possible to ascertain, the influence of disease and treatment on birth weight and preterm birth could not be differentiated. CONCLUSIONS TNF-α inhibitors may carry a risk of adverse pregnancy outcome of moderate clinical relevance. Considering the impact of insufficiently controlled autoimmune disease on the mother and the unborn child, TNF-α inhibitors may nevertheless be a treatment option in women with severe disease refractory to established immunomodulatory drugs.

The safety of calcium channel blockers during pregnancy : A prospective, multicenter, observational study

OBJECTIVE To assess the safety of calcium channel blockers during the first trimester of pregnancy. STUDY DESIGN A multicenter (n=11), prospective observational study of the European Network of Teratology Information Services (ENTIS). The rate of major birth defects was compared between a cohort of pregnant women exposed to calcium channel blockers during the first trimester (n=299) and a control group not exposed to potential teratogens (n=806). RESULTS Major birth defects were not more common in the study group than in the control group. Birth weight was significantly lower in exposed term newborns. There were more preterm infants in the study group than in the control group (23.8% vs. 6.5%). These adverse effects are more likely due to the underlying disease than to the medication. CONCLUSION This study suggests that calcium channel blockers during the first trimester of pregnancy do not represent a major teratogenic risk.

Pregnancy outcome after paternal exposure to azathioprine/6-mercaptopurine ☆

There are only few studies with conflicting results on pregnancy outcome after paternal exposure to azathioprine or 6-mercaptopurine. In our study, pregnancy outcome of 115 prospectively followed pregnancies after paternal exposure to azathioprine or 6-mercaptopurine is compared to a control group of 341 pregnancies. The rate of major malformations was not increased (3.0% in exposed versus 2.2% in the control group). There was no specific pattern of birth defects and no indication for chromosomal aberrations in the exposed group. We observed a higher rate of elective terminations of pregnancy in the exposed group and a non-significant increase of spontaneous abortions (cumulative incidence 19% versus 13%, respectively). Further prospective studies are required to address the question of a possibly increased risk for spontaneous abortion.

Observational Cohort Study of Pregnancy Outcome after First-Trimester Exposure to Fluoroquinolones

ABSTRACT Fluoroquinolones are avoided during pregnancy due to developmental toxicity in animals. The aim of this study was to assess the fetal risk after intrauterine fluoroquinolone exposure. We performed an observational study of a prospectively ascertained cohort of pregnant women exposed to a fluoroquinolone during the first trimester. Pregnancy outcomes were compared to those of a cohort exposed to neither fluoroquinolones nor teratogenic or fetotoxic drugs. The outcomes evaluated were major birth defects (structural abnormalities of medical, surgical, or cosmetic relevance), spontaneous abortion, and elective termination of pregnancy. Pregnancy outcomes of 949 women with fluoroquinolone treatment were compared with those of 3,796 nonexposed controls. Neither the rate of major birth defects (2.4%; adjusted odds ratio [ORadj], 0.91; 95% confidence interval [CI], 0.6 to 1.5) nor the risk of spontaneous abortion (adjusted hazard ratio [HRadj], 1.01; 95% CI, 0.8 to 1.3) was increased. However, there was a nonsignificant increase in major birth defects after exposure to moxifloxacin (6/93, 6.5%; crude odds ratio [ORcrude], 2.40; 95% CI, 0.8 to 5.6). Neither a critical exposure time window within the first trimester nor a specific pattern of birth defects was demonstrated for any of the fluoroquinolones. The rate of electively terminated pregnancies was increased among the fluoroquinolone-exposed women (HRadj, 1.32; 95% CI, 1.03 to 1.7). The gestational ages at delivery and birth weights did not differ between groups. Our study did not detect an increased risk of spontaneous abortion or major birth defects. These reassuring findings support the recommendation to allow fluoroquinolone use in early pregnancy in selected cases. After the use of moxifloxacin, a detailed fetal ultrasound examination should be considered.

Does the average drug exposure in pregnant women affect pregnancy outcome? A comparison of two approaches to estimate the baseline risks of adverse pregnancy outcome

The results of observational cohort studies on drug effects on pregnancy outcome may depend among others on suitable comparison cohorts. The aim of this investigation was to compare two distinct definitions of maternal exposure status for comparison cohorts.