Polypharmacy during pregnancy and associated risk factors: a retrospective analysis of 577 medication exposures among 1.5 million pregnancies in the UK, 2000-2019

BACKGROUND

The number of medications prescribed during pregnancy has increased over the past few decades. Few studies have described the prevalence of multiple medication use among pregnant women. This study aims to describe the overall prevalence over the last two decades among all pregnant women and those with multimorbidity and to identify risk factors for polypharmacy in pregnancy.

METHODS

A retrospective cohort study was conducted between 2000 and 2019 using the Clinical Practice Research Datalink (CPRD) pregnancy register. Prescription records for 577 medication categories were obtained. Prevalence estimates for polypharmacy (ranging from 2+ to 11+ medications) were presented along with the medications commonly prescribed individually and in pairs during the first trimester and the entire pregnancy period. Logistic regression models were performed to identify risk factors for polypharmacy.

RESULTS

During the first trimester (812,354 pregnancies), the prevalence of polypharmacy ranged from 24.6% (2+ medications) to 0.1% (11+ medications). During the entire pregnancy period (774,247 pregnancies), the prevalence ranged from 58.7 to 1.4%. Broad-spectrum penicillin (6.6%), compound analgesics (4.5%) and treatment of candidiasis (4.3%) were commonly prescribed. Pairs of medication prescribed to manage different long-term conditions commonly included selective beta 2 agonists or selective serotonin re-uptake inhibitors (SSRIs). Risk factors for being prescribed 2+ medications during the first trimester of pregnancy include being overweight or obese [aOR: 1.16 (1.14-1.18) and 1.55 (1.53-1.57)], belonging to an ethnic minority group [aOR: 2.40 (2.33-2.47), 1.71 (1.65-1.76), 1.41 (1.35-1.47) and 1.39 (1.30-1.49) among women from South Asian, Black, other and mixed ethnicities compared to white women] and smoking or previously smoking [aOR: 1.19 (1.18-1.20) and 1.05 (1.03-1.06)]. Higher and lower age, higher gravidity, increasing number of comorbidities and increasing level of deprivation were also associated with increased odds of polypharmacy.

CONCLUSIONS

The prevalence of polypharmacy during pregnancy has increased over the past two decades and is particularly high in younger and older women; women with high BMI, smokers and ex-smokers; and women with multimorbidity, higher gravidity and higher levels of deprivation. Well-conducted pharmaco-epidemiological research is needed to understand the effects of multiple medication use on the developing foetus.

Epidemiology of pre-existing multimorbidity in pregnant women in the UK in 2018: a population-based cross-sectional study

BACKGROUND

Although maternal death is rare in the United Kingdom, 90% of these women had multiple health/social problems. This study aims to estimate the prevalence of pre-existing multimorbidity (two or more long-term physical or mental health conditions) in pregnant women in the United Kingdom (England, Northern Ireland, Wales and Scotland).

STUDY DESIGN

Pregnant women aged 15-49 years with a conception date 1/1/2018 to 31/12/2018 were included in this population-based cross-sectional study, using routine healthcare datasets from primary care: Clinical Practice Research Datalink (CPRD, United Kingdom, n = 37,641) and Secure Anonymized Information Linkage databank (SAIL, Wales, n = 27,782), and secondary care: Scottish Morbidity Records with linked community prescribing data (SMR, Tayside and Fife, n = 6099). Pre-existing multimorbidity preconception was defined from 79 long-term health conditions prioritised through a workshop with patient representatives and clinicians.

RESULTS

The prevalence of multimorbidity was 44.2% (95% CI 43.7-44.7%), 46.2% (45.6-46.8%) and 19.8% (18.8-20.8%) in CPRD, SAIL and SMR respectively. When limited to health conditions that were active in the year before pregnancy, the prevalence of multimorbidity was still high (24.2% [23.8-24.6%], 23.5% [23.0-24.0%] and 17.0% [16.0 to 17.9%] in the respective datasets). Mental health conditions were highly prevalent and involved 70% of multimorbidity CPRD: multimorbidity with ≥one mental health condition/s 31.3% [30.8-31.8%]). After adjusting for age, ethnicity, gravidity, index of multiple deprivation, body mass index and smoking, logistic regression showed that pregnant women with multimorbidity were more likely to be older (CPRD England, adjusted OR 1.81 [95% CI 1.04-3.17] 45-49 years vs 15-19 years), multigravid (1.68 [1.50-1.89] gravidity ≥ five vs one), have raised body mass index (1.59 [1.44-1.76], body mass index 30+ vs body mass index 18.5-24.9) and smoked preconception (1.61 [1.46-1.77) vs non-smoker).

CONCLUSION

Multimorbidity is prevalent in pregnant women in the United Kingdom, they are more likely to be older, multigravid, have raised body mass index and smoked preconception. Secondary care and community prescribing dataset may only capture the severe spectrum of health conditions. Research is needed urgently to quantify the consequences of maternal multimorbidity for both mothers and children.

Mining Primary Care Electronic Health Records for Automatic Disease Phenotyping: A Transparent Machine Learning Framework

(1) Background: We aimed to develop a transparent machine-learning (ML) framework to automatically identify patients with a condition from electronic health records (EHRs) via a parsimonious set of features. (2) Methods: We linked multiple sources of EHRs, including 917,496,869 primary care records and 40,656,805 secondary care records and 694,954 records from specialist surgeries between 2002 and 2012, to generate a unique dataset. Then, we treated patient identification as a problem of text classification and proposed a transparent disease-phenotyping framework. This framework comprises a generation of patient representation, feature selection, and optimal phenotyping algorithm development to tackle the imbalanced nature of the data. This framework was extensively evaluated by identifying rheumatoid arthritis (RA) and ankylosing spondylitis (AS). (3) Results: Being applied to the linked dataset of 9657 patients with 1484 cases of rheumatoid arthritis (RA) and 204 cases of ankylosing spondylitis (AS), this framework achieved accuracy and positive predictive values of 86.19% and 88.46%, respectively, for RA and 99.23% and 97.75% for AS, comparable with expert knowledge-driven methods. (4) Conclusions: This framework could potentially be used as an efficient tool for identifying patients with a condition of interest from EHRs, helping clinicians in clinical decision-support process.

Development of an algorithm for determining smoking status and behaviour over the life course from UK electronic primary care records

Background

Patients’ smoking status is routinely collected by General Practitioners (GP) in UK primary health care. There is an abundance of Read codes pertaining to smoking, including those relating to smoking cessation therapy, prescription, and administration codes, in addition to the more regularly employed smoking status codes. Large databases of primary care data are increasingly used for epidemiological analysis; smoking status is an important covariate in many such analyses. However, the variable definition is rarely documented in the literature.

Methods

The Secure Anonymised Information Linkage (SAIL) databank is a repository for a national collection of person-based anonymised health and socio-economic administrative data in Wales, UK. An exploration of GP smoking status data from the SAIL databank was carried out to explore the range of codes available and how they could be used in the identification of different categories of smokers, ex-smokers and never smokers. An algorithm was developed which addresses inconsistencies and changes in smoking status recording across the life course and compared with recorded smoking status as recorded in the Welsh Health Survey (WHS), 2013 and 2014 at individual level. However, the WHS could not be regarded as a “gold standard” for validation.

Results

There were 6836 individuals in the linked dataset. Missing data were more common in GP records (6%) than in WHS (1.1%). Our algorithm assigns ex-smoker status to 34% of never-smokers, and detects 30% more smokers than are declared in the WHS data. When distinguishing between current smokers and non-smokers, the similarity between the WHS and GP data using the nearest date of comparison was κ = 0.78. When temporal conflicts had been accounted for, the similarity was κ = 0.64, showing the importance of addressing conflicts.

Conclusions

We present an algorithm for the identification of a patient’s smoking status using GP self-reported data. We have included sufficient details to allow others to replicate this work, thus increasing the standards of documentation within this research area and assessment of smoking status in routine data.

Electronic supplementary material

The online version of this article (doi:10.1186/s12911-016-0400-6) contains supplementary material, which is available to authorized users.

Vitamin A is excreted in the urine during acute infection

Episodes of acute infection are thought to deplete body stores of vitamin A. The mechanism by which this might occur is not known, but increased metabolic requirements are presumed to play a role. We have found, however, that significant amounts of retinol and retinol-binding protein (RBP) were excreted in the urine during serious infections, whereas only trace amounts were found in the urine of healthy control subjects. The geometric mean excretion rate in 29 subjects with pneumonia and sepsis was 0.78 mumol retinol/d. Subjects with fever (temperature > or = 38.3 degrees C) excreted significantly more retinol (geometric mean = 1.67 mumol/d) than did those without fever (0.18 mumol/d; t = 3.53, P < 0.0015). Aminoglycoside administration and low glomerular filtration rates (< 35 mL/min) were also associated with higher rates of urinary retinol excretion. Thirty-four percent of patients excreted > 1.75 mumol retinol/d, equivalent to 50% of the US recommended dietary allowance. These data show that vitamin A requirements are substantially increased during serious infections because of excretion of retinol in the urine, and suggest that these losses are due to pathologic changes associated with the febrile response.

Alteration of cellular cytosolic calcium and chemotactic peptide binding by an inhibitor of neutrophil function

The lung is frequently exposed to particulate material that can potentially stimulate release of factors that attract polymorphonuclear neutrophils (PMN). However, few PMN are noted in the airways of normal subjects, suggesting there is some mechanism to dampen influx of these cells. We have isolated from bronchial lavage a peptide that inhibits PMN chemotaxis to formyl-methionyl-leucyl-phenylalanine (FMLP). In the present study we examined effects of this molecule on 1) chemotaxis to other agonists, 2) FMLP-stimulated PMN superoxide production, 3) PMN calcium fluxes, and 4) binding of FMLP. Our results show that purified inhibitor attenuates PMN chemotaxis to C5a and leukotriene B4. This molecule also inhibits PMN superoxide release in response to FMLP. Exposure to this inhibitor causes an abrupt rise in cytosolic calcium concentration due to a pertussis toxin-sensitive shift of intracellular calcium and attenuates subsequent influx of extracellular calcium in response to FMLP. Binding studies demonstrate the inhibitor induces increased FMLP binding at 37 degrees C but has no effects at 4 degrees C. Inhibition of chemotaxis and increased FMLP binding mediated by this molecule are attenuated by buffering PMN calcium transients. These studies suggest an inhibitor of neutrophil function present in the bronchial environment alters PMN through effects on calcium homeostasis.

Bronchiolitis obliterans organizing pneumonia associated with systemic lupus erythematosus

Bronchiolitis obliterans organizing pneumonia (BOOP) is a pathologic entity characterized by the formation of plugs of fibrous tissue in bronchioles and alveolar ducts. It has been described in association with several connective tissue diseases including rheumatoid arthritis, polymyositis-dermatomyositis, and mixed connective tissue disease. Well-documented reports of BOOP in patients with systemic lupus erythematosus (SLE) are limited. We report two patients with SLE who presented with subacute respiratory illnesses due to BOOP, adding further strength to the association of this entity with SLE.

Clinical aspects of amiodarone pulmonary toxicity

Amiodarone pulmonary toxicity is a major clinical problem limiting the utility of this powerful therapeutic agent. The clinical manifestations of amiodarone lung toxicity are protean, but the most common presentation is that of an indolent illness characterized by dyspnea and often associated with cough and/or fever. Diffuse radiographic abnormalities are common, but localized infiltrates can be seen as well. The typical physiologic changes are the development of diffusing impairment and a restrictive ventilatory defect. In the absence of a 15% decline in DLCO from the pretreatment value, significant amiodarone toxicity appears to be unlikely. The diagnosis is made by the careful exclusion of other causes for the observed illness and the finding of clinical, radiographic, physiologic, and pathologic abnormalities compatible with amiodarone toxicity. Although the pathologic findings of amiodarone lung can be distinctive, the histologic demonstration of foam cells and ultrastructural lamellar inclusions alone does not distinguish toxic from nontoxic patients receiving amiodarone. If reasonable alternative antiarrhythmic therapy is available, amiodarone should be withdrawn. If the severity of illness warrants, a trial of corticosteroid therapy is reasonable. Some patients can be maintained on continued therapy despite toxicity, if the drug is deemed to be absolutely essential and clinical deterioration does not continue. The prognosis of patients who develop amiodarone pulmonary toxicity seems to be poor, but may be largely determined by the underlying cardiac disease.

Dietary fish oil inhibits bleomycin-induced pulmonary fibrosis in the rat

Intratracheal bleomycin induces pulmonary fibrosis in experimental animals, but the mechanisms involved are poorly understood. Since altered levels of fatty acid metabolites are associated with bleomycin-induced lung injury, we examined the effects of a change in dietary fat on bleomycin-induced fibrosis. Previously we have shown that an essential fatty acid-deficient diet can reduce the severity of bleomycin-induced pulmonary fibrosis. The present study examined the effect of replacement of usual dietary fat with menhaden oil, rich in eicosapentaenoic acid, on the development of pulmonary fibrosis. Weanling rats were raised on a standard laboratory diet or a diet consisting of a fat-free powder to which was added 25% (w/w) of menhaden oil. After 8 weeks of feeding, the animals received either 1.5 units of bleomycin or an equivalent volume of saline intratracheally. In animals receiving the laboratory diet, bleomycin treatment produced a 44% increase in total lung protein content when compared to saline-treated controls (p less than 0.001) and a 77% increase in total lung hydroxyproline content (p less than 0.01). In contrast, bleomycin-treated animals receiving the menhaden oil diet had only small increases, which did not reach statistical significance, in protein and hydroxyproline content in the lung. Bronchoalveolar lavage cellularity did not differ among the treatment groups, but the percentage of lavage macrophages was slightly diminished in bleomycin-treated animals receiving the laboratory diet. Cellular differentials of lavage fluid did not differ significantly between bleomycin- and saline-treated animals receiving the menhaden oil diet. Bleomycin-induced histologic changes, quantitated by morphometric analysis, were significantly reduced with the menhaden oil diet. We conclude that a diet rich in eicosapentaenoic acid can significantly ameliorate bleomycin-induced pulmonary fibrosis, possibly via alterations in eicosanoid metabolism.

Effect of iron deficiency on bleomycin-induced lung fibrosis in the hamster

Bleomycin produces a dose- and time-dependent interstitial pulmonary fibrosis in humans, and is widely used to produce an animal model for the study of interstitial pulmonary fibrosis. The mechanism(s) for bleomycin-induced pulmonary fibrosis is (are) unknown, but the production of oxygen radicals by a ferrous ion-molecular oxygen pathway might be related to the fibrosis. Therefore, we studied the effect of iron deficiency on the biochemical, inflammatory, and morphologic parameters of bleomycin-induced pulmonary fibrosis in the hamster. Mild iron deficiency was induced in hamsters by bleeding via the retro-orbital sinus and maintenance on an iron-deplete diet. After intratracheal administration of bleomycin (1 U), there was no accumulation of lung collagen in the iron-deficient bleomycin-treated animals. In comparison, iron-replete animals treated with bleomycin exhibited a significant (p less than 0.01) increase in lung collagen. In addition, bleomycin-treated iron-replete animals had increased lung lipid peroxidation (p less than 0.05), whereas bleomycin-treated iron-deficient animals did not (p greater than 0.05). Lung DNA and morphometric estimates of the lesion severity were significantly increased in both iron-replete and iron-deficient bleomycin-treated animals. These data indicate that iron deficiency is associated with a reduction in the severity of bleomycin-induced pulmonary fibrosis, possibly by the prevention of iron-catalyzed oxygen-radical formation and lipid peroxidation.

Amiodarone lung: pathologic findings in clinically toxic patients

Lung biopsy and autopsy specimens of 12 patients with amiodarone pulmonary toxicity were studied to better characterize the pathology of amiodarone lung. For comparison, the autopsy specimens of five patients taking amiodarone without pulmonary side effects also were examined. Interstitial pneumonia was the most common manifestation of amiodarone lung and was characterized by interstitial inflammation, fibrosis, and hyperplasia of type II pneumocytes. Hyaline membranes were present in two cases. Foamy alveolar macrophages were present in all but one patient, and in four associated organizing pneumonia was present. Foamy alveolar macrophages also were present in three of five clinically nontoxic patients. Electron microscopy demonstrated membrane-bound lamellar inclusions in all of the three cases of amiodarone lung examined. Inclusions also were present in two of five patients who died of other causes. The authors conclude that amiodarone lung is primarily an interstitial pneumonia. Foamy alveolar macrophages and cytoplasmic lamellar inclusions are characteristic, but neither is specific, and their presence alone does not distinguish toxic from nontoxic patients.

Amiodarone pulmonary toxicity. Clinical, radiologic, and pathologic correlations

We have studied 15 patients with amiodarone pulmonary toxicity and compared them with five amiodarone patients without evidence of toxic effect. Six of 15 patients who had toxic reactions presented with an acute illness that resembled an infectious disease. While diffuse interstitial disease was frequent on chest roentgenogram, seven of 15 had airspace opacities, and five had well-localized infiltrates. Physiologic changes were not uniformly found. An interstitial pneumonia with foamy alveolar macrophages was the most common pathologic finding. Foamy macrophages were also present in three of five nontoxic patients. Three of three patients who had toxic reactions, and two of five patients without toxic reactions had lamellated inclusion bodies by electron microscopy. We conclude that all features of amiodarone toxicity are protean, and it may mimic infectious diseases. While pathologic changes are often characteristic, neither foamy alveolar macrophages nor lamellated cytoplasmic inclusions reliably distinguish toxic from nontoxic patients.

Effects of dietary fats on bleomycin-induced pulmonary fibrosis

Bleomycin treatment has been used for the experimental induction of pulmonary fibrosis, but the mechanisms involved are poorly understood. Since alterations in the levels of certain fatty acid metabolites have been associated with bleomycin-induced lung injury, we examined the effects of different dietary fats on the development of bleomycin-induced pulmonary fibrosis. Weanling rats were raised on standard laboratory feed or a diet consisting of a fat-free powder to which was added either coconut oil or beef tallow (25% w/w). After 8 weeks of feeding, animals received either 1.5 units bleomycin or an equivalent volume of saline intratracheally. Bleomycin treatment resulted in significant increases in total lung hydroxyproline content in the groups fed the standard lab diet (p less than 0.001) and beef tallow diet (p less than 0.001), but not in the group receiving the coconut oil diet. Furthermore, the lung hydroxyproline content in bleomycin-treated animals was less with the beef tallow diet compared with standard lab feed (p less than 0.05). Bleomycin treatment resulted in an increase in thiobarbituric acid-reactive products, an index of lipid peroxidation, in lungs from animals fed the standard lab diet, but not in the other diet groups. The percentage of diseased lung, as determined by morphometric analysis, was increased in bleomycin-treated animals from all diet groups (p less than 0.05). We conclude that alterations in dietary fats can reduce the severity of pulmonary fibrosis resulting from bleomycin treatment. Possible mechanisms for this effect include alterations in eicosanoid metabolism or changes in immune or effector cell function.

Studies of membrane receptors, phagocytosis, and morphology of subpopulations of rat lung interstitial macrophages

Recent data suggest that pulmonary macrophages may be heterogeneous. Several studies have demonstrated that alveolar macrophages are functionally and biochemically heterogeneous. In addition, interstitial macrophages, which are believed to be the precursors to alveolar macrophages, have been suggested to be heterogeneous. Therefore, this study was undertaken to determine if density-defined interstitial macrophages (DD-IM) are heterogeneous with respect to receptors for zymosan, immunoglobulin, and complement as well as morphologically. Furthermore, avidity for IgG was defined by opsonizing sheep red blood cells (SRBC) with different amounts of IgG. Interstitial macrophages were harvested and separated into 18 DD-IM subpopulations by centrifugation through a continuous iso-osmotic gradient of colloidal silica. Interstitial macrophages showed marked heterogeneity in cellular volume. Furthermore, macrophages of density 1.046 to 1.075 g/ml exhibited higher receptor activity capability of attaching and phagocytizing SRBC opsonized with small amounts of IgG and towards zymosan. All DD-IM exhibited similar abilities to attach complement-coated SRBC. These results demonstrate the functional heterogeneity of interstitial macrophages with respect to IgG and zymosan.

Effects of central administation of probenecid on fevers produced by leukocytic pyrogen and PGE2 in the rabbit

1. Single intracerebroventricular (I.C.V.) injections of probenecid (PBCD, 0.125--0.5 mg) enhanced and prolonged fever caused by I.V. administration of leukocytic pyrogen (LP) in rabbits resting in neutral (23 degrees C), cold (10 degrees C) and hot (30 degrees C) environments. Similar effects were produced by single I.C.V. injections of PBCD given before PGE2 (0.5 microgram) was injected I.C.V. in the three ambient temperatures. 2. Fever produced by IV. LP was also prolonged by infusion and by multiple injections of PBCD. 3. PBCD given I.P. (100 mg/kg) enhanced and prolonged fever caused by I.V. injection of Salmonella typhosa endotoxin. 4. Hyperthermia produced by I.C.V. PGE2 was not augmented by subsequent PBCD infusion. However, pre-treatment with PBCD followed by PGE2 injection and PBCD infusion caused hyperthermia that was very high and prolonged, and, in some cases, lethal. 5. Acetaminophen (2 mg, I.C.V.) and indomethacin (10 mg/kg, I.V.) lowered body temperature when given during fever induced by LP and prolonged by PBCD infusion. 6. The concentration of PGE in cerebrospinal fluid (c.s.f.) samples taken from the third or lateral ventricles rose or stabilized during PBCD infusions made during LP fever. However, similar changes in PGE concentration also occurred during control infusions when body temperature was low. 7. We conclude that termination of the actions of both central endogenous pyrogen and centrally administered PGE2, and the subsequent reduction of fevers produced by them, require a PBCD-sensitive facilitated transport system. The reduction of PBCD-prolonged PL fevers by antipyretics which block PGE synthesis suggests that prolongation by PBCD of LP fever is not due to blockade of PGE transport in a subsequent step in fever mediation per se, but is due to inhibition of transport of LP itself, or of other mediators associated with it.

Central thermosensitivity during fever produced by intra-PO/AH and intravenous injections of pyrogen

Squirrel monkeys with thermodes implanted in the preoptic/anterior hypothalamic (PO/AH) region and the medulla oblongata were used to examine three questions about central thermoresponsiveness in fever: Does thermoresponsiveness of the PO/AH region and medulla change during fevers caused by injection of bacterial endotoxin IV or directly into the PO/AH region? Does thermosensitivity of these brain regions determine the upper fever limit? Is thermoresponsiveness of the PO/AH region affected by local injections of salicylate? Changes in rectal temperature and oxygen consumption in response to heating and cooling the PO/AH region were reduced during fever caused by intra-PO/AH injections of bacterial endotoxin compared with changes produced during afebrile periods. PO/AH thermosensitivity was also reduced during fever caused by IV administration of bacterial pyrogen. Prolonged cooling of the PO/AH region or the medulla oblongata during fever produced by peripheral and central pyrogen injections did not cause rectal temperature (Tre) to rise above 41.1 degrees C although local heating reduced Tre or limited the fever maximum. From the latter result it is concluded that both pools of central thermoreceptors can limit maximal fever by reacting to local high temperature but that lowered temperature in neither region can raise Tre above a level determined by antagonistic input from thermoreceptors in other parts of the body. Injections of sodium salicylate into the PO/AH region had no effect on thermoresponsiveness of the region. This finding reinforces the idea that salicylates do not produce antipyresis by acting directly on thermosensitive cells of the central temperature control system.

Technique for casting chronic extradural and intracerebral cannula arrays

A technique for fixing multiple brain cannulae in uniform arrays by embedding guide cannulae in molded plastic pedestals is described. Methods for producing corresponding threaded caps for protection of the outer ends of the cannulae, and procedures for reducing mortality and morbidity when large number of cannulae are implanted in brain tissue, are presented.

Simple "planilabe" for rapid establishment of the stereotaxic horizontal zero plane in rabbits

A device for rapid determination of the stereotaxic horizontal zero plane in the rabbit is described. The instrument is designed to provide reference points needed to establish the appropriate relative position of the commonly used calvarial landmarks, bregma and lambda, in a single operation.