Drug use in pregnancy: an overview of epidemiological (drug utilization) studies

Prevalence of systemic antibacterial use during pregnancy worldwide: A systematic review

OBJECTIVES

In this study, we aimed to systematically review the literature of the prevalence of systemic antibacterial use during pregnancy and to perform a descriptive analysis focused on methodological characteristics.

MATERIALS AND METHODS

This study was registered in PROSPERO under protocol number CRD42022376634. Medline, Embase, Scientific Electronic Library Online, Biblioteca Virtual em Saúde, Cumulative Index to Nursing and Allied Health Literature, and Web of Science databases were searched (published studies until November 3rd, 2022). Selected studies were population-based cross-sectional or cohort, carried out with pregnant women, and providing information about the prevalence of systemic antibacterial use at least in one trimester of pregnancy. Reviewers conducted in pairs the title and abstract screening, eligibility criteria check, and data extraction of selected studies. Quality appraisal was performed with an adapted version of the Joanna Briggs Institute Critical Appraisal Checklist for Prevalence Studies. Data of included studies were pooled into a graphical and tabular summary.

RESULTS

A total of 16,251,280 pregnant women and 5,169,959 pregnancy registers were identified. The prevalence estimates of systemic antibacterial use during pregnancy ranged from 2.0% (95%CI 2.0-2.0) to 64.3% (95%CI not reported) in the 79 included studies. The majority were performed in high-income countries (91.5%). Overall, the studies revealed considerable prevalence heterogeneity in terms of study type and dataset used. The 95% confidence intervals were not reported in 41% of studies.

CONCLUSION

The disparities in the prevalence of systemic antibacterial use during pregnancy can be related to methodological issues and different health policies. Lack of uniform databases and changes in data collection methods over time should be taken into account in public health strategy planning. The scarce evidence in low- and middle-income settings hampers the comprehensiveness of the global prevalence of antibacterial use during pregnancy.

Improving Data Collection in Pregnancy Safety Studies: Towards Standardisation of Data Elements in Pregnancy Reports from Public and Private Partners, A Contribution from the ConcePTION Project

INTRODUCTION AND OBJECTIVE

The ConcePTION project aims to improve the way medication use during pregnancy is studied. This includes exploring the possibility of developing a distributed data processing and analysis infrastructure using a common data model that could form a foundational platform for future surveillance and research. A prerequisite would be that data from various data access providers (DAPs) can be harmonised according to an agreed set of standard rules concerning the structure and content of the data. To do so, a reference framework of core data elements (CDEs) recommended for primary data studies on drug safety during pregnancy was previously developed. The aim of this study was to assess the ability of several public and private DAPs using different primary data sources focusing on multiple sclerosis, as a pilot, to map their respective data variables and definitions with the CDE recommendations framework.

METHODS

Four pregnancy registries (Gilenya, Novartis; Aubagio, Sanofi; the Organization of Teratology Information Specialists [OTIS]; Aubagio, Sanofi; the Dutch Pregnancy Drug Register, Lareb), two enhanced pharmacovigilance programmes (Gilenya PRIM, Novartis; MAPLE-MS, Merck Healthcare KGaA) and four Teratology Information Services (UK TIS, Jerusalem TIS, Zerifin TIS, Swiss TIS) participated in the study. The ConcePTION primary data source CDE includes 51 items covering administrative functions, the description of pregnancy, maternal medical history, maternal illnesses arising in pregnancy, delivery details, and pregnancy and infant outcomes. For each variable in the CDE, the DAPs identified whether their variables were: identical to the one mentioned in the CDE; derived; similar but with a divergent definition; or not available.

RESULTS

The majority of the DAP data variables were either directly taken (85%, n = 305/357, range 73-94% between DAPs) or derived by combining different variables (12%, n = 42/357, range 0-24% between DAPs) to conform to the CDE variables and definitions. For very few of the DAP variables, alignment with the CDE items was not possible, either because of divergent definitions (1%, n = 3/357, range 0-2% between DAPs) or because the variables were not available (2%, n = 7/357, range 0-4% between DAPs).

CONCLUSIONS

Data access providers participating in this study presented a very high proportion of variables matching the CDE items, indicating that alignment of definitions and harmonisation of data analysis by different stakeholders to accelerate and strengthen pregnancy pharmacovigilance safety data analyses could be feasible.

Oral Cleft and Maternal History of Spontaneous Abortion: A Case-Control Study

To investigate and compare the occurrence of previous spontaneous abortion among mothers of children with nonsyndromic oral clefts (NSOC) and mothers of children without NSOC; to understand if previous spontaneous abortion could be a risk factor for the occurrence of NSOC in subsequent pregnancies.

Case-control study.

Nonsyndromic oral clefts is an important public health problem. In the context of investigating risk factors for the occurrence of this malformation, previous spontaneous abortion have been considered in the etiology at NSOC.

There were 1004 participants. In the case group 502 mothers of children with NSOC, and in the control group 502 mothers of children without NSOC or any other malformation or syndrome.

A standardized questionnaire was utilized to interview the maternal history of spontaneous abortion.

The data were evaluated using descriptive statistics, and comparisons were performed using the Chi-square test, adopting a significance level of 5%.

The prevalence of maternal history of spontaneous abortion was 16.3% in the case group and 15.9% in the control group. Comparing the groups there was no statistical difference (p-value = 0.93). Analyzing the occurrence of previous spontaneous abortion, separating the case group according to the type of cleft in the child, no statistical differences were observed when comparing these groups between them.

Maternal history of spontaneous abortion was not associated with NSOC, not representing an independent risk factor for NSOC in the Brazilian population.

[Drug therapy of otorhinolaryngological diseases in pregnancy : An update]

The majority of women take at least one form of medication during pregnancy. Due to often discrepant information about the risk assessment of pharmaceuticals during pregnancy, physicians are often beset by uncertainty with respect to prescription and the fear of medicolegal consequences is high. As prospective clinical trials on drug safety during pregnancy are prohibited due to ethical reasons and animal studies are of limited applicability to humans, drug recommendations often only rely on observational data. An objective examination of the topic not only contributes to effective treatment of illnesses in pregnancy but also prevents impairment of fetal outcome by omission of necessary maternal treatment. The aim of this article is to give a structured presentation of medications that can be used during pregnancy for treating medical conditions of the ear, nose and throat, in the sense of practical guidelines.

Frequency and type of medications and vaccines used during pregnancy

Providing safe pharmacotherapy for pregnant women is challenging. Nearly all pregnant women are prescribed or inadvertently receive medication during their pregnancy. We reviewed the scientific literature to identify the specific medications and vaccines that are most often used during pregnancy and described them by category and indication. Our interest was to update the research before the implementation of the recently released FDA labeling rule for pregnancy and lactation that eliminates the use of pregnancy categories in product labels. Our results confirm that most products taken during pregnancy are over-the-counter or in the former FDA pregnancy categories A or B. However, medications taken prior to pregnancy recognition (inadvertent exposures) and those prescribed for chronic illness such as allergies, depression, and pain are of concern. A better understanding of medication and vaccine utilization during pregnancy may help clinicians reduce inadvertent first trimester exposures and improve the safe and effective treatment of pregnant women.

Headache in pregnancy

PURPOSE OF REVIEW

This article provides an overview of the diagnosis and management of primary and secondary headaches that may occur during pregnancy and postpartum. Headache presenting in pregnancy is of significant concern to the affected woman. Quick and correct diagnosis leads to the optimal management, minimizing risks to the pregnancy.

RECENT FINDINGS

Several strategies have been developed to distinguish secondary headaches that need urgent assessment and management from benign primary and secondary headaches and to minimize the risk of misdiagnosis. Recent guidelines for the drug treatment of headaches are considered in the context of updated information on the safety of drugs in pregnancy and lactation.

SUMMARY

Primary headaches are common and typically improve during pregnancy. Management during pregnancy and lactation is similar to management in the nonpregnant state, with a few exceptions. Secondary causes of headache that are more likely to occur during pregnancy include cerebral venous thrombosis, posterior reversible encephalopathy syndrome resulting from eclampsia, post-dural puncture headache, stroke, and pituitary apoplexy.

Major malformations after first trimester exposure to aspirin and NSAIDs

The use of aspirin and other NSAIDs during the first trimester of pregnancy is widespread, despite inconclusive evidence regarding the possible risks for the baby. We present an overview of the current evidence relating to the associations between aspirin or NSAID use during the first trimester of pregnancy and the risk of congenital malformations. We systematically searched Medline, Embase, the Cochrane Library and the reference lists of all relevant articles from 1966 to March 2008 that examined the association between aspirin and NSAID use during the first trimester of pregnancy and the risk of congenital malformations in humans. We analyzed 30 studies that met the predefined inclusion criteria: 22 case-control studies, seven cohort studies and one randomized, controlled trial. There are not enough human data available to assess the effect of high-dose aspirin and NSAIDs in pregnant women, such as those used in the treatment of rheumatoid arthritis, osteoarthritis and pain relief. This review suggests that the exposure to aspirin or NSAIDs during the first trimester of pregnancy is associated with an increased risk of gastroschisis (aspirin), cardiac malformations (NSAIDs) and orofacial malformations (naproxen).

A simplified PBPK modeling approach for prediction of pharmacokinetics of four primarily renally excreted and CYP3A metabolized compounds during pregnancy

During pregnancy, a drug's pharmacokinetics may be altered and hence anticipation of potential systemic exposure changes is highly desirable. Physiologically based pharmacokinetics (PBPK) models have recently been used to influence clinical trial design or to facilitate regulatory interactions. Ideally, whole-body PBPK models can be used to predict a drug's systemic exposure in pregnant women based on major physiological changes which can impact drug clearance (i.e., in the kidney and liver) and distribution (i.e., adipose and fetoplacental unit). We described a simple and readily implementable multitissue/organ whole-body PBPK model with key pregnancy-related physiological parameters to characterize the PK of reference drugs (metformin, digoxin, midazolam, and emtricitabine) in pregnant women compared with the PK in nonpregnant or postpartum (PP) women. Physiological data related to changes in maternal body weight, tissue volume, cardiac output, renal function, blood flows, and cytochrome P450 activity were collected from the literature and incorporated into the structural PBPK model that describes HV or PP women PK data. Subsequently, the changes in exposure (area under the curve (AUC) and maximum concentration (C max)) in pregnant women were simulated. Model-simulated PK profiles were overall in agreement with observed data. The prediction fold error for C max and AUC ratio (pregnant vs. nonpregnant) was less than 1.3-fold, indicating that the pregnant PBPK model is useful. The utilization of this simplified model in drug development may aid in designing clinical studies to identify potential exposure changes in pregnant women a priori for compounds which are mainly eliminated renally or metabolized by CYP3A4.

Effects of ibuprofen, diclofenac, naproxen, and piroxicam on the course of pregnancy and pregnancy outcome: a prospective cohort study

OBJECTIVE

To investigate the individual effects of ibuprofen, diclofenac, naproxen, and piroxicam on pregnancy outcome.

DESIGN

Cohort study.

SETTING

Norwegian population.

POPULATION

A total of 90 417 women and singleton child pairs.

METHODS

The Norwegian Mother and Child Cohort Study and Medical Birth Registry of Norway data sets were used.

MAIN OUTCOME MEASURES

Infant survival, congenital malformations, structural heart defects, neonatal complications, haemorrhage during pregnancy and postpartum, asthma at age of 18 months.

RESULTS

One or more of the four nonsteroidal anti-inflammatory drugs (NSAIDs) were used by 6511 pregnant women (7.2%). No effect on rates of infant survival, congenital malformation, or structural heart defects was found. The use of ibuprofen in the second trimester was significantly associated with low birthweight (adjusted OR 1.7, 95% CI 1.3-2.3), and ibuprofen use in the second and third trimesters was significantly associated with asthma in 18-month-old children (adjusted OR 1.5, 95% CI 1.2-1.9; adjusted OR 1.5, 95% CI 1.1-2.1). The use of diclofenac in the second trimester was significantly associated with low birthweight (adjusted OR 3.1, 95% CI 1.1-9.0), whereas diclofenac use in the third trimester was significantly associated with maternal vaginal bleeding (adjusted OR 1.8, 95% CI 1.1-3.0). No associations with other neonatal complications were found.

CONCLUSIONS

The lack of associations with congenital malformations is reassuring. The significant association between diclofenac and ibuprofen use late in pregnancy, and maternal bleeding and asthma in the child, respectively, is consistent with their pharmacological effects. The increased risk of low birthweight may partly have been caused by underlying inflammatory conditions, and was reassuringly similar to the expected baseline risk of low birthweight.

Ethnic differences in drug utilization pattern during pregnancy: a cross-sectional study

OBJECTIVE

To investigate the differences in exposure to medications in a cohort of multi-ethnic pregnant women.

METHODS

Six hundred and forty-one pregnant women of Western, Arab/Turkish and "other origins" participated in this cross-sectional study using a questionnaire in a university hospital in Brussels, Belgium. Assessment of the drug safety was done using the food and drug administration (FDA) risk classification system. Data analysis was performed using SPSS (Chicago, IL).

RESULTS

In overall cohort, 83.8% used at least one preparation (including multivitamins) during pregnancy and 37.0% of women used at least one drug (excluding multivitamins). Significantly more Western women (43.7%) used one or more medications compared to Arab/Turkish women (28.7%; p = 0.000). This difference in exposure was most pronounced for over-the-counter (OTC) drugs for occasional and pregnancy-related complaints, and was observed for potentially unsafe drugs or drugs with unknown safety. None of the women reported use of FDA X category drugs.

CONCLUSIONS

The use of drugs known to be harmful was not observed, but a higher prevalence of exposure to potentially harmful drugs (FDA C/D) was found among Western women who also consumed more OTC drugs. This highlights the need for cautious prescribing for women in the fertile age in general and for continuous monitoring of medication use during pregnancy.

Pharmacotherapy in pregnancy; effect of ABC and SLC transporters on drug transport across the placenta and fetal drug exposure

Pharmacotherapy during pregnancy is often inevitable for medical treatment of the mother, the fetus or both. The knowledge of drug transport across placenta is, therefore, an important topic to bear in mind when deciding treatment in pregnant women. Several drug transporters of the ABC and SLC families have been discovered in the placenta, such as P-glycoprotein, breast cancer resistance protein, or organic anion/cation transporters. It is thus evident that the passage of drugs across the placenta can no longer be predicted simply on the basis of their physical-chemical properties. Functional expression of placental drug transporters in the trophoblast and the possibility of drug-drug interactions must be considered to optimize pharmacotherapy during pregnancy. In this review we summarize current knowledge on the expression and function of ABC and SLC transporters in the trophoblast. Furthermore, we put this data into context with medical conditions that require maternal and/or fetal treatment during pregnancy, such as gestational diabetes, HIV infection, fetal arrhythmias and epilepsy. Proper understanding of the role of placental transporters should be of great interest not only to clinicians but also to pharmaceutical industry for future drug design and development to control the degree of fetal exposure.

[Prescribed and unprescribed drug use among pregnant patients attended by the Unified Health System in Santa Rosa (State of Rio Grande do Sul, Brazil)]

In order to ascertain the use of prescribed and unprescribed drugs among pregnant patients of the Unified Health System (SUS), a descriptive study comprised of a sample of pregnant women was carried out in the city of Santa Rosa, State of Rio Grande do Sul, Brazil. Data were collected by means of structured interviews and consultation of patient records of pregnant women in the prenatal period. The prevalence of drug use was 90%, corresponding to an average of 4.1 drugs per pregnant woman, of which 83.6% were prescribed and 16.4% were self-medicated. Of this total, 17.5% of the drugs were included in fetal risk category C. The use of drugs during pregnancy is frequent and the majority of the pregnant women used one or more prescribed and unprescribed drugs during pregnancy. These data suggest the need for preventive measures to promote rational drug use during pregnancy.

Prescription drug use during pregnancy in developed countries: a systematic review

PURPOSE

To review the literature describing patterns of outpatient prescription drug use during pregnancy by therapeutic category, potential for fetal harm, and overall.

METHODS

We conducted a systematic review of peer-reviewed literature published from 1989 to 2010. We included studies evaluating individual-level exposures to prescription medicines during pregnancy. We selected only studies conducted in developed (Organization of Economic Co-operation and Development) countries and published in English.

RESULTS

Published drug utilization studies reveal wide variation in estimates of overall prescription drug use in pregnancy (27-93% of pregnant women filling at least one prescription excluding vitamins and minerals). Among studies of similar design, estimates were lowest in Northern European countries (44-47%) and highest in France (93%) and Germany (85%). Measured rates of use of contraindicated medicines in pregnancy ranged from 0.9% (Denmark, 1991-1996) to 4.6% (USA, 1996-2000). The use of medicines with positive evidence of risk ranged from 2.0% (Italy, 2004) to 59.3% (France, 1996).

CONCLUSION

Avoidable inconsistencies in study design and reporting attenuate conclusions that can be drawn from the literature on antenatal drug utilization. Nevertheless, the body of published research shows that antenatal prescription drug use is common, with many studies finding that a majority of women use one or more prescription medicine during pregnancy. Similarly, studies consistently report the use of drugs recognized as having potential risks in pregnancy. Given this widespread use, it is particularly important to develop standards for calculating and reporting antenatal exposures to improve the value of future research in this area.

Clinical therapeutics in pregnancy

Most drugs are not tested for use during pregnancy, consequently, labeling, which may include information about fetal safety, includes nothing about dosing, efficacy, or maternal safety. Yet these are concerns of health care providers considering treatment of disease during pregnancy. Therefore, the practitioner treats the pregnant woman with the same dose recommended for use in adults (typically men) or may decide not to treat the disease at all. However, is the choice of not treating a woman during pregnancy better than dealing with the challenges which accompany treatment? This paper, which summarizes metabolic and physiologic changes induced by pregnancy, illustrates that standard adult dosing is likely to be incorrect during pregnancy.

Medical databases in studies of drug teratogenicity: methodological issues

More than half of all pregnant women take prescription medications, raising concerns about fetal safety. Medical databases routinely collecting data from large populations are potentially valuable resources for cohort studies addressing teratogenicity of drugs. These include electronic medical records, administrative databases, population health registries, and teratogenicity information services. Medical databases allow estimation of prevalences of birth defects with enhanced precision, but systematic error remains a potentially serious problem. In this review, we first provide a brief description of types of North American and European medical databases suitable for studying teratogenicity of drugs and then discuss manifestation of systematic errors in teratogenicity studies based on such databases. Selection bias stems primarily from the inability to ascertain all reproductive outcomes. Information bias (misclassification) may be caused by paucity of recorded clinical details or incomplete documentation of medication use. Confounding, particularly confounding by indication, can rarely be ruled out. Bias that either masks teratogenicity or creates false appearance thereof, may have adverse consequences for the health of the child and the mother. Biases should be quantified and their potential impact on the study results should be assessed. Both theory and software are available for such estimation. Provided that methodological problems are understood and effectively handled, computerized medical databases are a valuable source of data for studies of teratogenicity of drugs.

Assessment of drug use among pregnant women in Addis Ababa, Ethiopia

PURPOSE

To assess the drug use among antenatal care (ANC) attendant pregnant women in Addis Ababa.

METHODS

Institution-based cross sectional study was conducted reviewing the antenatal care follow up cards and interviewing pregnant women using semi-structured questionnaire.

RESULTS

A total of 1268 women were included in the study; of which 71.3% of them were prescribed at least one drug during pregnancy. Twelve point four per cent of the pregnant women who reported illness in the 2 weeks prior to the date of the interview, self-medicated themselves with either over the counter or prescription drugs or traditional herbs. The majority of the drugs prescribed were iron and vitamins followed by anti-infectives. Nearly 4% of the pregnant women were prescribed with drugs from category D or X of the US-FDA risk classification.

CONCLUSION

A considerable proportion of pregnant women were exposed to drugs, including those with potential harm to the fetus. Furthermore, pregnant women self-medicated themselves with modern medications or traditional herbs. Health care providers should thus weigh the therapeutic benefits of the drug to the mother against its potential risk to the developing fetus before prescribing. In addition it is essential to routinely inquire about the woman's self-medication practice and provide the appropriate advice to the pregnant women.

Tissue distribution of YM758, a novel If channel inhibitor, in pregnant and lactating rats

In this study the tissue distribution of radioactivity in pregnant and lactating rats was investigated by quantitatively determining radioactivity concentrations and by whole-body autoradioluminograms after a single oral administration of 14C-YM758. In addition, the transfer of radioactivity into the reproductive tissues, foetus, and milk is discussed in terms of the localization of transporters in syncytiotrophoblast and mammary gland. The radioactivity concentrations in the liver were the highest of all the tissues and organs tested at all the sampling times. The radioactivity in main tissues (liver and kidney), including reproductive tissues (amniotic fluid, placenta, ovary, and uterus), was not retained for a long time, as in the plasma. The tissue/plasma (T/P) ratio of radioactivity in the foetus was below 1.0, which might be due to Mdr1-mediated export of YM758 into blood via the blood-placenta barrier since YM758 is a substrate for hMDR1, not for hBCRP/rBcrp. The T/P ratio of radioactivity in the maternal milk 1 and 4 h after oral administration of 14C-YM758 was 7.2 and 11.0, respectively. To understand better the distribution of new drugs into the reproductive tissues/milk, and to interpret further the results of reproductive safety studies for drug development, the contribution of transporters expressed in the blood-placenta barrier and mammary gland to the drug-transfer into placenta and milk should be considered.

In Vitro Models Using the Human Placenta to Study Fetal Exposure to Drugs

Over the recent years there has been a gradual rise in the use of pharmaceuticals during pregnancy. Knowledge on placental drug transfer and metabolism has increased during the past decades as well. Investigation of the transplacental transfer of any therapeutically useful drug is essential to the understanding of its metabolic processes and is a prerequisite for its use during pregnancy. The purpose of this review is to give insight on the various techniques that have been developed to evaluate transplacental transfer of drugs and xenobiotics.

Drug transport across the placenta, role of the ABC drug efflux transporters

The placenta serves an important role both as a protective barrier as well as in normal fetal development. The ATP-binding cassette (ABC) proteins perform crucial functions in the distribution of nutrients and exchange of waste metabolites across the placenta. They also protect the developing fetus from xenobiotics to which the pregnant mother is exposed. Recent studies in P-glycoprotein (P-gp) deficient mdr1a and mdr1b (-/-) CF-1 mice have shown pronounced increases in fetal exposure to P-gp substrates due to increased transplacental penetration demonstrating the important protective role of P-gp to the developing fetus. The role of placental ABC transporter proteins in protecting the fetus against maternal exposure to drugs, toxins and other xenobiotics is discussed. Overall, the paucity of information available on the transplacental transfer of drugs emphasizes the need to further employ preclinical in vivo models for drug development in order to best predict fetal outcomes of drug administration to pregnant mothers.

Medication use during pregnancy and the risk of childhood cancer in the offspring

The young age at onset of many cancers in childhood has led to investigations on maternal exposures during pregnancy. Data from a population-based case-control study in Germany (1992-1997) that included 1,867 cases and 2,057 controls was used to investigate this question. Maternal use of vitamin, folate or iron supplementation was associated with a reduced risk of non-Hodgkin lymphoma and tumors and, less clearly, with leukemia, but not with CNS tumors. An increased risk of neuroblastoma was associated most markedly with diuretics and other antihypertensives, but also with vitamin, folate or iron supplementation. No associations were seen with pain relievers, antinauseants or cold medications, nor with delivery by Caesarian section. The strengths of this study are its population base, the large number of cases and the inclusion of different case groups to identify disease specificity of associations. The limitation of this study is an exposure assessment relying on maternal self-reports. In conclusion, these data indicate a potential influence of some maternal medication during pregnancy on the risk of childhood cancer in the offspring; however, no clear picture is seen.

Medications during pregnancy: antihypertensives and immunosuppressives

Use of prescription and nonprescription medications is common during pregnancy and is required in many women with underlying kidney disease or hypertension and in all with solid-organ allografts. Systematic assessment of drug safety during pregnancy is lacking, as are rigorous and comprehensive studies of pharmacokinetics and pharmacodynamics to guide drug selection and dosing across pregnancy. Renal and hepatic clearances of many drugs change markedly during pregnancy and pitfalls may complicate routine therapeutic monitoring of some drugs during pregnancy. However, available data and clinical experience allow reasonable strategies for selection and dosing of immunosuppressive agents in pregnant transplant recipients and of antihypertensive agents in women with mild or more severe hypertension complicating their pregnancies.

Drug utilization and teratogenicity risk categories during pregnancy

A limited number of studies have investigated in detail the use of drugs during pregnancy. Researchers in the present study investigated the details of drug utilization in pregnant women during the month before pregnancy, at the time that they became aware of the pregnancy, and during the first trimester. Face-to-face interviews were conducted with 359 pregnant women who were admitted to the fetal medicine unit at a university hospital for diagnosis and follow-up. A questionnaire was used to document sociodemographic characteristics and details of drug use. Drugs were categorized according to the US Food and Drug Administration fetal risk classification. Mean maternal age was 29.9+/-5.1 y, and mean gestational age was 19.6+/-9.5 wk. Many of the pregnant women studied (46.6%) were university graduates, and most (61.9%) had a relatively high annual income. Mean gestational age when participants first learned of their pregnancy was 39.8+/-16.4 d. One hundred seventeen participants (32.6%) used drugs during the month before conception, 54 (15%) at the time when they learned of their pregnancy, 180 (50.1%) at the time of the interview, and 289 (80.5%) during the first trimester. The percentages of drugs in categories D and X used by these subjects were 14%, 13.5%, 2.9%, and 5.9%, respectively. Most of the drugs were hormones. The total rate of drug utilization was not high before and during the first trimester of pregnancy. A considerable number of women were using drugs from the D and X categories; however, these numbers decreased significantly when women learned of their pregnancies. Intake of folic acid, vitamins, and iron was very low during the preconception period and was not high enough during the first trimester; this suggests that particular attention should be paid to the use of beneficial "safe" drugs during the preconception and early pregnancy periods.

Treatment options for migraine during pregnancy

Migraine and pregnancy commonly co-exist and healthcare providers should be ready to give advice to women with migraine regarding treatment options that are compatible with pregnancy and lactation. A major goal of treatment is to avoid medications that may be harmful to the developing fetus or cause other pregnancy problems. Nonpharmacological behavioral methods of treatment are especially useful in pregnancy. Migraine increases the risk of pregnancy-related stroke and pre-eclampsia and women with migraine should be monitored for these problems.

National patterns of medication use during pregnancy

PURPOSE

To describe patterns of medication use during pregnancy in ambulatory care settings according to the U.S. Food and Drug Administration (FDA) pregnancy risk classification.

METHODS

A cross-sectional study of two national ambulatory care surveys, sampling all office visits made by pregnant women in 1999 and 2000, was conducted. Using the FDA pregnancy risk classification, patterns of medication use and predictive factors for FDA pregnancy risk D or X (D/X) medications were evaluated.

RESULTS

In 1999 and 2000, about half of all pregnant visits had one or more medications. Among the total visits, FDA Class A was the majority (private = 65.7%; hospital = 79.5%; p < 0.05) followed by Class C (private = 26.5%; hospital = 36.4%; p < 0.05). Class D/X medications accounted for 6.4% and 2.9% of visits in private and hospital, respectively (p < 0.05). Medications with unknown pregnancy categories were predominant in the private setting (12.0% and 3.9%; p < 0.05). Age, insurance type, region, physician specialty, and number of medications were associated with a category D/X prescription. Among hospital visits, those from the West region and with private insurance were more likely to receive category D/X prescriptions. Number of medications was strongly associated with high-risk drugs in both settings.

CONCLUSIONS

This study shows considerable medication use among pregnant women. The prevalence of visits with FDA pregnancy category D/X drugs was moderate, but still indicates exposure to high-risk medications.

Antibiotics in pregnancy: analysis of potential risks and determinants in a large German statutory sickness fund population

PURPOSE

Antibiotics are frequently prescribed drugs in pregnancy. The purpose of the study was to analyse the use, the potential risks and the determinants of systemic antibiotic prescriptions during pregnancy.

METHODS

A large, nation-wide acting German statutory sickness fund provided prescription data and personal data of 41,293 pregnant women. For this study, all prescriptions of systemic antibiotics (ATC: J01) dispensed to each woman during a 21-month period were analysed. We used the FDA risk classification system and enrolled a literature search to identify potentially harmful antibiotics. To investigate the impact of geographical and socio-economic determinants in antibiotic prescribing, a multivariate logistic regression model was performed.

RESULTS

Of the 41,293 women, 19.7% received at least one antibiotic drug during pregnancy. There was a shift to relatively safe and reduced antibiotic drug use during pregnancy. Prescribing of contraindicated antibactericals or potentially harmful drugs was seen in 521 women (1.3% of all women). In the logistic regression, being younger than 21 years (adjusted OR 2.14, 95%CI 1.80-2.53) or being welfare recipient (adjusted OR 1.57, CI 1.25-2.00) was strongly associated with higher antibiotic use. Significantly lower antibiotic use was seen in 5 of 16 German federal states (OR 0.74-0.83).

CONCLUSIONS

About 20% of pregnant women received antibiotics, and 1.3% received a harmful drug. To minimise the risks, detailed guidelines are needed for the antibiotic treatment during pregnancy.

Drug intake behaviour of immigrants during pregnancy

OBJECTIVE

To assess differences between native Spanish and immigrant pregnant women in behaviour relating to the use of medications during pregnancy.

STUDY DESIGN

This cross-sectional study was carried out at the department of obstetrics and gynaecology of an acute-care teaching hospital in the city of Barcelona, Spain. A total of 1103 women who gave birth at the hospital during a 1-year period were enrolled in the study. Each woman was interviewed by a gynaecologist during her stay in hospital after delivery, with special reference to drug use during the pregnancy. Drug exposure was assigned to trimesters, and drugs were divided into therapeutic groups, while the women taking part were divided up by nationality, educational level, parity and age. Data were analysed using bivariate, multivariate, and cluster analyses.

RESULTS

Slightly over half (55.7%) of the women were native to Spain and 44.3% were immigrants of other nationalities. About a quarter, or 25.4%, of pregnant patients had not taken any drugs during their pregnancies. The most frequent drugs taken by the others were vitamins, which were used mostly by Spanish women, followed by analgesics, which were mostly taken by non-Spanish western women. The largest group who had taken folic acid was made up of non-Spanish western women, while the Asiatic patients had taken this in the smallest proportion of cases.

CONCLUSIONS

Spanish patients and immigrants from other western countries showed a similar behaviour in terms of drug intake during pregnancy, which was different from the behavioural patterns seen in pregnant patients from developing countries.

Evaluation of gestational age and admission date assumptions used to determine prenatal drug exposure from administrative data

OBJECTIVE

Our aim was to evaluate the 270-day gestational age and delivery date assumptions used in an administrative dataset study assessing prenatal drug exposure compared to information contained in a birth registry.

STUDY DESIGN AND SETTING

Kaiser Permanente Colorado (KPCO), a member of the Health Maintenance Organization (HMO) Research Network Center for Education and Research in Therapeutics (CERTs), previously participated in a CERTs study that used claims data to assess prenatal drug exposure. In the current study, gestational age and deliveries information from the CERTs study dataset, the Prescribing Safely during Pregnancy Dataset (PSDPD), was compared to information in the KPCO Birth Registry. Sensitivity and positive predictive value (PPV) of the claims data for deliveries were assessed. The effect of gestational age and delivery date assumptions on classification of prenatal drug exposure was evaluated.

RESULTS

The mean gestational age in the Birth Registry was 273 (median = 275) days. Sensitivity of claims data at identifying deliveries was 97.6%, PPV was 98.2%. Of deliveries identified in only one dataset, 45% were related to the gestational age assumption and 36% were due to claims data issues. The effect on estimates of prevalence of prescribing during pregnancy was an absolute change of 1% or less for all drug exposure categories. For Category X, drug exposures during the first trimester, the relative change in prescribing prevalence was 13.7% (p = 0.014).

CONCLUSION

Administrative databases can be useful for assessing prenatal drug exposure, but gestational age assumptions can result in a small proportion of misclassification.

Postmarketing surveillance for drug safety in pregnancy: The Organization of Teratology Information Services Project

BACKGROUND

Although medications are frequently used during pregnancy, premarketing studies exclude pregnant women, with the result that maternal and fetal risks of medications are largely unknown prior to marketing.

METHODS

To demonstrate the feasibility of using Teratology Information Services (TISs) to identify potential subjects who may participate in postmarketing surveillance studies regarding medications taken during pregnancy, maternal characteristics and pregnancy exposure data routinely collected from callers to member agencies of the Organization of Teratology Information Services (OTIS) were pooled for two one-month periods.

RESULTS

A total of 3536 calls inquiring about 7746 different agents were received from pregnant women. Of the 40 medications about which pregnant women most frequently asked, the top two were nonprescription acetaminophen and pseudoephedrine, three were prescription drugs with a U.S. Food and Drug Administration pregnancy label category D designation, and five were prescription antidepressants.

CONCLUSIONS

TISs are well positioned to prospectively ascertain medication exposures in large numbers of pregnant women and may be an exceptional resource for conducting postmarketing surveillance for the safety of medications taken during pregnancy.

Fatores associados ao uso de medicamentos durante a gestação em seis cidades brasileiras

O objetivo deste estudo foi comparar o uso de medicamentos durante a gravidez, segundo variáveis sócio-demográficas, em gestantes que fizeram o pré-natal em serviços do SUS em seis grandes cidades brasileiras. Utilizando-se um questionário estruturado, foram entrevistadas 5.564 gestantes que se apresentaram para consulta em serviço de pré-natal do SUS, participantes do Estudo Brasileiro de Diabetes Gestacional, entre 1991 e 1995. O uso de qualquer medicamento mostrou uma associação positiva com o aumento da escolaridade, da idade e com o fato de ter companheiro, e uma associação negativa com maior número de filhos. O uso de medicamentos multivitamínicos e medicamentos que atuam sobre o aparelho digestivo mostrou aumento da associação com maior escolaridade e idade e uma associação negativa com o aumento do número de filhos. O uso de medicamentos antianêmicos mostrou uma associação negativa com o aumento da escolaridade e com o aumento da idade. O uso de multivitamínicos e medicamentos que atuam sobre o aparelho digestivo mostrou uma associação com variáveis que caracterizam gestantes de melhor nível sócio-econômico, sugerindo que o uso de medicamentos é uma expressão de cuidado com a gestação.

Drug prescription in pregnancy: analysis of a large statutory sickness fund population

OBJECTIVE

To examine the prescription of drugs in Germany prior to, during and after pregnancy.

METHODS

For the first time, prescription data of a large cohort of pregnant women, from a German statutory sickness fund, were available for scientific analysis. For each woman who gave birth between June 2000 and May 2001 reimbursed prescriptions for two periods (90 days each) before pregnancy, three during and two after delivery were considered. The drugs were classified according to the ATC code.

RESULTS

Of the 41,293 women, 96.4% received at least one drug during pregnancy. A median of 7 drugs per women was prescribed. Excluding vitamins, minerals, iodide and iron, 85.2% received at least one drug and the median was 3. Magnesium, which was seldom prescribed outside of pregnancy, was by far the most frequently prescribed substance (20% of all prescriptions, 61% of the women). Iron (54% of the women) and iodide (31%) were also prescribed often. The prescription rates of gynaecological antiinfectives (maximum in third trimester: 23% of the women), antacids (max. in third trim.: 11%), as well as antiemetics and antinauseants (max. in first trim.: 8%) during pregnancy considerably increased. A decrease was seen for analgesics, antiinflammatory and antirheumatic drugs, muscle relaxants, ophtalmologicals and anti-acne preparations, for example. Potential teratogenic drugs were prescribed to 1.3% of the women.

CONCLUSION

This analysis of a large nation-wide cohort of pregnant women showed that during pregnancy drugs were prescribed to most women, even when vitamins, minerals, iodide and iron were omitted. Magnesium and iron seemed to have been over-prescribed. On the other hand, the official recommendation for iodide substitution, to prevent thyroid diseases in mother and child, was insufficiently implemented. In our opinion, regular analysis of prescription data can identify potential harmful therapies and focal points where guidelines are needed and can check their implementation.

Prescription drug use in pregnancy

OBJECTIVE

The purpose of this study was to provide information on the prevalence of the use of prescription drugs among pregnant women in the United States.

STUDY DESIGN

A retrospective study was conducted with the use of the automated databases of 8 health maintenance organizations that are involved in the Health Maintenance Research Network Center for Education and Research on Therapeutics. Women who delivered of an infant in a hospital from January 1, 1996, through December 31, 2000, were identified. Prescription drug use according to therapeutic class and the United States Food and Drug Administration risk classification system was evaluated, with the assumption of a gestational duration of 270 days, with three 90-day trimesters of pregnancy, and with a 90-day period before pregnancy. Nonprescription drug use was not assessed.

RESULTS

During the period 1996 through 2000, 152,531 deliveries were identified that met the criteria for study. For 98,182 deliveries (64%), a drug other than a vitamin or mineral supplement was prescribed in the 270 days before delivery: 3595 women (2.4%) received a drug from category A; 76,292 women (50.0%) received a drug from category B; 57,604 women (37.8%) received a drug from category C; 7333 women (4.8%) received a drug from category D, and 6976 women (4.6%) received a drug from category X of the United States Food and Drug Administration risk classification system. Overall, 5157 women (3.4%) received a category D drug, and 1653 women (1.1%) received a category X drug after the initial prenatal care visit.

CONCLUSION

Our finding that almost one half of all pregnant women received prescription drugs from categories C, D, or X of the United States Food and Drug Administration risk classification system highlights the importance of the need to understand the effects of these medications on the developing fetus and on the pregnant woman.

Drug use by pregnant women and comparable non-pregnant women in The Netherlands with reference to the Australian classification system

OBJECTIVE

To describe drug use in pregnancy, and compare drug use of pregnant women with non-pregnant women with respect to possible teratogenicity.

STUDY DESIGN

A cross-sectional study based on pharmacy records from 1997 to 2001 was performed. Pregnant women and matched non-pregnant women (same physician and age) were identified. Prescriptions were set against the Australian risk classification.

RESULTS

Thirty-five percent of all prescriptions for non-pregnant women were safe in pregnancy (Australian classification A), in 14% the risk was unknown (B1, B2), 49% were potentially harmful drugs (B3, C, D, X), and in 3% no classification was available. For pregnant women these figures were 86, 3, 10 and 2%, respectively. In non-pregnant women the highest percentages of prescriptions for unsafe drugs were for psycholeptics (99% not classified as safe), psychoanaleptics (100%), anti-inflammatory/antirheumetic products (100%), antihistamines (94%), antacids/anti-ulcer drugs (81%), antiepileptics (100%), beta-blockers (100%), systemic antimycotics (100%), antiprotozoals (97%), diuretics (100%) and immunosuppressives (100%). In pregnant women this pattern was comparable, except for antihistamines (22%) and antacids/anti-ulcer drugs (3%).

CONCLUSION

We conclude that many drugs used by non-pregnant women should be avoided in pregnancy, and that pregnant women indeed do so. However, for some drug groups the available safe alternatives are limited.

Medication use during pregnancy: data from the Avon Longitudinal Study of Parents and Children

OBJECTIVE

To present data on the self-reported use of all types of medicinal products collected during pregnancy in a large cohort in southwest England.

METHODS

Pregnant women with a delivery date during 1991-1992 and forming part of the prospective, population-based Avon Longitudinal Study of Parents and Children (ALSPAC) were sent up to four self-completion postal questionnaires during pregnancy. Text data collected from the questions on drug usage were coded using an ALSPAC drug dictionary based on the World Health Organization Drug Dictionary.

RESULTS

At least one antenatal self-completion questionnaire was completed for 14,119 pregnancies, and 11,545 women completed all four. The data included prescription, over-the-counter, herbal and homeopathic products as well as iron, vitamins and other supplements. Only 7.6% did not report use of any medicinal product throughout their entire pregnancy. The remaining 92.4% used at least one product at some stage. After exclusion of iron, folate, vitamins, supplements, herbal and homeopathic products and skin emollients, 83% of those completing all questionnaires had used conventional therapeutic drugs. Analgesics were reported by approximately one-third of women at each stage during pregnancy, and paracetamol was the most frequently reported substance. Iron preparations were reported by 33% of the full cohort, at some stage, and folate by 21.9%. Use of anti-anaemic products increased during pregnancy with the greatest incidence at 32 weeks. Other vitamins and supplements were taken by 17.4% at some stage. Use of vitamins decreased throughout pregnancy from 9.6% in early pregnancy to 5% at 32 weeks. Antacids were reported by 23% at 32 weeks. The reported incidence of antibiotic use decreased slightly during pregnancy from 8% early on to 5.8% at 32 weeks; amoxicillin was the most frequently reported antibacterial.

CONCLUSION

Use of medicinal products was high during pregnancy in the ALSPAC cohort. This finding is consistent with data from recent publications.

Prescription of drugs to pregnant women in France: the HIMAGE study

The HIMAGE study, conducted in partnership with the principal Public Health Insurance Funds of the Loire region, analysed medicinal prescriptions during pregnancy on the basis of a representative sample of 911 pregnant women resident in this region of France. Altogether 93.5% received at least one prescription, with a mean of 10.9 different drugs per woman. The prescriptions were predominantly for drugs of the following Anatomical Therapeutic Chemical (ATC) classes: "alimentary tract and metabolism" (78%); "genito-urinary system and sex hormones" (62%); "nervous system" (62%); and "blood and blood-forming organs" (57%). Iron supplements, paracetamol, folic acid, magnesium, progesterone, oxaceprol, phloroglucinol, amoxicillin, domperidone and diosmine were the most frequently prescribed drugs. In total, 4.6% of the women were exposed to drugs involving a risk during pregnancy: principally nonsteroidal anti-inflammatory drugs (NSAIDs) prescribed from the sixth month onwards. This study revealed a high frequency of prescription of drugs to pregnant women, largely motivated by non-rational and to some extent culture-specific considerations, and it also highlighted the prescription of drugs known to involve risk during pregnancy. These results provide a basis for advising clinicians on the rational and safe use of drugs during pregnancy.

Calcium intake during pregnancy among white and African-American pregnant women in the United States

OBJECTIVE

To characterize the calcium intake in a racially mixed cohort of pregnant women, including the contribution of supplementation and antacids.

METHODS

A cohort of women was interviewed twice during their pregnancies. The interviews included a food frequency questionnaire and questions on calcium supplementation and antacid intake. Pregnant women seeking prenatal care at a Pittsburgh hospital in the first trimester were enrolled. 454 women were enrolled and did not miscarry; 385 completed two interviews and were of white or African-American race.

RESULTS

Mean and median intakes of calcium were 1671 mg/day and 1482 mg/day. 36% of the women were under the former RDA level (1200 mg/day) for calcium, while 26% were under the current AI (1000 mg/day). Six percent were taking in less than 600 mg/day, and 15% over 2500 mg/day, the tolerable upper limit. Young women were particularly likely to have low intakes (12% of those less than 21 years of age had less than 600 mg/day). Black women were slightly overrepresented among those with low intake (8% vs. 5% of whites), but, overall, their intake was quite similar to whites. Milk and cheese provided more calcium than other food items. Many women took antacids, especially during the second half of pregnancy, and these were a major source of calcium for some members of the cohort.

CONCLUSIONS

Although mean and median calcium intake in the cohort were above the AI, many women had calcium intakes that were too high or low. Dairy products provided the most calcium for most pregnant women, and antacids were an important source for many.

Drug Transfer and Metabolism by the Human Placenta

The major function of the placenta is to transfer nutrients and oxygen from the mother to the foetus and to assist in the removal of waste products from the foetus to the mother. In addition, it plays an important role in the synthesis of hormones, peptides and steroids that are vital for a successful pregnancy. The placenta provides a link between the circulations of two distinct individuals but also acts as a barrier to protect the foetus from xenobiotics in the maternal blood. However, the impression that the placenta forms an impenetrable obstacle against most drugs is now widely regarded as false. It has been shown that that nearly all drugs that are administered during pregnancy will enter, to some degree, the circulation of the foetus via passive diffusion. In addition, some drugs are pumped across the placenta by various active transporters located on both the fetal and maternal side of the trophoblast layer. It is only in recent years that the impact of active transporters such as P-glycoprotein on the disposition of drugs has been demonstrated. Facilitated diffusion appears to be a minor transfer mechanism for some drugs, and pinocytosis and phagocytosis are considered too slow to have any significant effect on fetal drug concentrations. The extent to which drugs cross the placenta is also modulated by the actions of placental phase I and II drug-metabolising enzymes, which are present at levels that fluctuate throughout gestation. Cytochrome P450 (CYP) enzymes in particular have been well characterised in the placenta at the level of mRNA, protein, and enzyme activity. CYP1A1, 2E1, 3A4, 3A5, 3A7 and 4B1 have been detected in the term placenta. While much less is known about phase II enzymes in the placenta, some enzymes, in particular uridine diphosphate glucuronosyltransferases, have been detected and shown to have specific activity towards marker substrates, suggesting a significant role of this enzyme in placental drug detoxification. The increasing experimental data on placental drug transfer has enabled clinicians to make better informed decisions about which drugs significantly cross the placenta and develop dosage regimens that minimise fetal exposure to potentially toxic concentrations. Indeed, the foetus has now become the object of intended drug treatment. Extensive research on the placental transfer of drugs such as digoxin and zidovudine has assisted with the safe treatment of the foetus with these drugs in utero. Improved knowledge regarding transplacental drug transfer and metabolism will result in further expansion of pharmacological treatment of fetal conditions.

Prescription drugs during pregnancy and lactation--a Finnish register-based study

OBJECTIVE

To examine the use of prescription drugs in Finnish women before and during pregnancy and lactation.

METHODS

A register-based study linking four nation-wide registers in Finland: the Maternal Grants Register, the Drug Prescription Register, and the Special Refund Register (all maintained by the Social Insurance Institution in Finland; KELA), and the Finnish Population Register. The study included all women applying for maternity support (maternal grants) during the year 1999, and non-pregnant control women matched by age and hospital district. Data collection included the number and type of prescription drugs purchased by the two cohorts during preconception (3 months before pregnancy), each trimester, and lactation.

RESULTS

Of the 43,470 pregnant women, 46.2% purchased at least one drug and 12.7% three or more different drugs during pregnancy. Corresponding proportions for the control cohort were 55.2% (OR 0.7, 95% CI 0.6-0.7) and 23.0% (OR 0.5, 95% CI 0.5-0.5). The drugs most frequently purchased during pregnancy were systemic antibiotics (24.1% of pregnant women vs 27.3% controls; OR 0.8, 95% CI 0.8-0.9) and gynaecological anti-infective agents (8.3% vs 1.5%; OR 5.5, 95% CI 5.5-6.5). For pregnant women, purchases of most drug groups had already declined during the first trimester, but no reduction was apparent in drugs for chronic illnesses (epilepsy, asthma, diabetes).

CONCLUSIONS

Although drugs were purchased abundantly during pregnancy, a significant decline occurred for most drug groups. The medication pattern for chronic illnesses remained unchanged. The purchase of several different drugs was relatively common and raises concerns.

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

It is a major clinical and public health problem that there is no clear strategy as to how we best make use of information obtained when pregnant women take drugs. For this reason, some pregnant women are not treated as they should be and some are given drugs they should not use. We suggest a monitoring system that combines some of the available datasets in Europe. Using these sources as a starting point, one can develop a system that has sufficient power to detect even rare diseases like congenital malformations and sufficient diversity to detect several possible outcomes from spontaneous abortions to childhood disorders. We also suggest that case-crossover designs should be used in case-control monitoring systems that carry a high risk of recall bias. These considerations are based upon our results from a European Union-funded concerted action called EuroMaP (Medicine and Pregnancy).

[Prevalence of drug use during pregnancy: a pharmacoepidemiological approach]

INTRODUCTION

Few Brazilian papers on the use of medication in pregnancy have been found in the indexed medical literature. This paper describes the use of medication during pregnancy among women who gave birth in a teaching maternity hospital in the city of Campinas, Brazil.

METHODS

A retrospective study on the pattern of drug use during pregnancy was conducted among 1,000 mothers who were interviewed using a structured questionnaire after delivery, while they were still in hospital. The following parameters were registered: sociodemographic characteristics, obstetric and contraceptive history, data on prenatal care and medications used during pregnancy. Statistical analysis was performed using ANOVA and chi-square test at p = 0.05.

RESULTS

Among the interviewed patients, 94.6% had taken at least one medication during pregnancy, and 46.1% had used medication in the first trimester. Of 3,778 medications reported, 88.8% had been prescribed by a doctor. The median of medications taken was 3 (ranging from 0 to 18). The six most used classes of medications were: analgesics, spasmolytics, gynecological antiinfectious agents, antianemics, antacids and systemic antibiotics. The five most used medications were: butyl scopolamine, ferrous sulfate, dipirone, nistatin and multivitamin tablets. Only 27.7% of the patients had been alerted to the risk of taking medication during pregnancy.

CONCLUSION

Knowing the profile of medications used during pregnancy may help devising programs to provide information to the patients and continuing education to health care professionals.

[Drug use by pregnant women in six Brazilian cities]

OBJECTIVE

To describe drugs used during pregnancy by women attending prenatal clinics of the national public health system (SUS) in Brazilian cities.

METHODS

Using a structured questionnaire, 5,564 pregnant women between the week 21 to 28 who attended prenatal visits of the SUS in six Brazilian cities were interviewed. The interview questions were grouped in "guided use" to cover pain, cramps, nausea, cough, and others, and "guided medicine" to cover vitamins, iron, and fluoride. The Food and Drug Administration gestational risk classification (1991-1995) was applied.

RESULTS

Of a total of 5,564 women, 4,614 (83.8%) used at least one drug during pregnancy, with a total of 9,556 drugs used. The drugs most frequently used were vitamins associated with anti-anemics (33.5%), gastrointestinal drugs (31.3%), analgesics and anti-inflammatory drugs (22.2%), anti-anemics (19.8%), and antibiotics (11.1%). Regarding gestational risk, 3,243 drugs used (34%) belonged to category A risk, 1,923 (22.6%) to category B, 3,798 (39.7%) to category C, 289 (3.0%) to category D, and 55 (0.6%) to category X.

CONCLUSIONS

A large variation in drug use across the cities was observed, especially for anti-anemics and vitamins associated with anti-anemics, revealing the lack of a national consensus regarding the use of these drugs during pregnancy. There was no literature data about safety during pregnancy for 12.9% of the drugs used. This percentage, plus the 26.9% of category C drugs, shows that 40% of the drugs used during pregnancy do not belong to the approved safety categories. However, only 3% of the 9,956 drugs used were clearly contraindicated during pregnancy.

Collaborative study on drug use in pregnancy: the results of the follow-up 10 years after (Novi Sad Centre)

An international multicenter study entitled Collaborative Study on Drug Use in Pregnancy (DUP) was initiated in 1987 by the Mario Negri Institute (Milano) and co-sponsored by the WHO Regional Office for Europe (Copenhagen). The study covered the use of medicines during pregnancy, labour and postpartum period. The Novi Sad centre contributed with 296 questionnaires. The aim of the study was to evaluate the pharmacotherapy by means of comparison, to identify problems in a particular settings and to plan actions toward improvement. The prescribing of some medicines in the Novi Sad center was found to be at the extreme, being among the lowest in the use of iron preparations during pregnancy and among the highest in the use of ergot alkaloids in the postpartum period. Educational efforts have been made to change this practice after the conclusion of the study in 1989. Ten years later, in 1999, the same questionnaire was applied to 100 women in the postpartum period in the same nursery, the Department of Obstetrics and Gynecology in Novi Sad. The results have shown a distinct improvement with the increase of iron prescribing during pregnancy and almost complete abandonment of postpartum use of ergot alkaloids. In the second study period some other inconsistencies with accepted therapeutical principles were identified. For example, although the use of analgesics fell from 22.3 to 8%, the selection changed towards the high use of metamizole (noraminophenazone) and no use of paracetamol (acetaminophen). It was concluded that international pharmacoepidemiological studies such as DUP, could substantially contribute to the improvement of pharmacotherapy if followed by appropriate actions in changing the prescribing behaviour of the physicians and information directed to the target population.

Risk of adverse birth outcome and miscarriage in pregnant users of non-steroidal anti-inflammatory drugs: population based observational study and case-control study

OBJECTIVE

To estimate the risk of adverse birth outcome in women who take non-steroidal anti-inflammatory drugs during pregnancy.

DESIGN AND SETTING

Population based cohort study and a case-control study, both based on data from a prescription registry, the Danish birth registry, and one county's hospital discharge registry.

PARTICIPANTS

COHORT STUDY: 1462 pregnant women who had taken up prescriptions for non-steroidal anti-inflammatory drugs in the period from 30 days before conception to birth and 17 259 pregnant women who were not prescribed any drugs during pregnancy. CASE-CONTROL STUDY: 4268 women who had miscarriages, of whom 63 had taken non-steroidal anti-inflammatory drugs, and 29 750 primiparous controls who had live births.

MAIN OUTCOME MEASURES

Incidences of congenital abnormality, low birth weight, preterm birth, and miscarriage.

RESULTS

Odds ratios for congenital abnormality, low birth weight, and preterm birth among women who took up prescriptions for non-steroidal anti-inflammatory drugs were 1.27 (95% confidence interval 0.93 to 1.75), 0.79 (0.45 to 1.38), and 1.05 (0.80 to 1.39) respectively. Odds ratios for the taking up of prescriptions in the weeks before miscarriage ranged from 6.99 (2.75 to 17.74) when prescriptions were taken up during the last week before the miscarriage to 2.69 (1.81 to 4.00) when taken up between 7 and 9 weeks before. The risk estimates were no different when the analysis was restricted to missed abortions.

CONCLUSIONS

Use of non-steroidal anti-inflammatory drugs during pregnancy does not seem to increase the risk of adverse birth outcome but is associated with increased risk of miscarriage.