The Spectrum of Adverse Pregnancy Outcomes Based on Kidney Disease Diagnoses: A 20-Year Population Study

2019 ◽  
Vol 49 (5) ◽  
pp. 400-409 ◽  
Author(s):  
Alyssa Fitzpatrick ◽  
Kamalesh Venugopal ◽  
Wendy Scheil ◽  
Stephen P. McDonald ◽  
Shilpanjali Jesudason
Keyword(s):  
Preterm Birth ◽  
Caesarean Section ◽  
Pregnancy Outcomes ◽  
Clinical Care ◽  
Vesicoureteric Reflux ◽  
Population Level ◽  
Diagnostic Code ◽  
Benign Condition ◽  
Increased Risk ◽  
In Pregnancy

Background and Objectives: Kidney disorders in pregnancy may be under-recognized and have variable impact on outcomes depending on diagnosis. Population-level data are limited, particularly for Australia, and comparison of impact of different kidney disorders on pregnancy has rarely been assessed. This study examined the prevalence and outcomes of varied kidney disorders using population-level perinatal data from a large cohort. Methods: Women with singleton pregnancies > 20 weeks’ gestation from the South Australian Pregnancy Outcomes Unit (1990–2012). Women with a kidney disorders diagnostic code were grouped into categories (immunological, cystic/genetic, urological, vesicoureteral reflux (VUR), pyelonephritis and “other”). Key pregnancy outcomes were assessed, with adjustment for demographic variables. Results: Kidney disorders were reported in 1,392 (0.3%) of 407,580 births. These pregnancies had increased risk of pregnancy-induced hypertension (OR 2.16, 95% CI 1.82–2.56), induction of labor (RRR vs. spontaneous birth 2.10, 95% CI 1.87–2.36), all Caesarean section (OR 1.31, 95% CI 1.17–1.47) as well as Caesarean section without labor (RRR 1.82, 95% CI 1.57–2.10), preterm birth (< 37 weeks; 2.76, 95% CI 2.40–3.18), low birth weight (< 2,500 g) infants (OR 2.43, 95% CI 2.07–2.84), and neonatal intensive care admission (OR 2.64, 95% CI 2.12–3.29). Diagnostic subgroups demonstrated differing patterns of adverse outcomes, enabling the development of a matrix of risk. Women with immunological renal conditions and VUR had greatest risk overall, and only women with immunological diseases had increased risk of small-for-gestational age < 10th centile (OR 2.36, 95% CI 1.26–4.42). Women with nonchronic urological conditions and pyelonephritis had increased risk of preterm birth, but not other adverse events. VUR conferred particularly increased risk of Caesarean section and induced labor. Conclusions: In a cohort of > 1,300 women with varied kidney disorders, increased adverse obstetric and perinatal events were observed, and the nature and magnitude of risk differed according to diagnosis. In particular, vesicoureteric reflux is not a benign condition in pregnancy. Women with nonchronic conditions still had increased risk of preterm birth. We confirm that women with kidney disorders warrant vigilant and tailored prepregnancy care and clinical care in pregnancy.

scholarly journals Epilepsy in pregnancy: an emergency care context

2020 ◽  
Vol 12 (4) ◽  
pp. 1-6
Author(s):  
Catherine Hayes ◽  
Yitka Graham
Keyword(s):  
Preterm Birth ◽  
Caesarean Section ◽  
Sudden Death ◽  
Emergency Care ◽  
Pregnancy Outcomes ◽  
Significant Risk ◽  
Multidisciplinary Care ◽  
Seizure Duration ◽  
Adverse Pregnancy ◽  
In Pregnancy

Epilepsy is a heterogeneous neurological condition that manifests clinically in seizure, and diagnosis depends on seizure duration, frequency and characteristics. Seizures can lead to injury and poorly controlled epilepsy can cause sudden death. Women with epilepsy have a small but significant risk of adverse pregnancy outcomes such as antepartum and postpartum haemorrhaging, miscarriage, preterm birth or needing an induced birth or a caesarean section; two-thirds will not experience an increase in the severity or number of seizures during pregnancy. Paramedics should be aware that women with pre-eclampsia and eclampsia may have seizures, and that women may stop taking their anti-epileptic drugs or reduce dosage because of concerns over congenital malformation. Multidisciplinary care is essential for these women.

scholarly journals Early-pregnancy intermediate hyperglycaemia and adverse pregnancy outcomes among women without gestational diabetes

2021 ◽  
Author(s):  
Yunzhen Ye ◽  
Yu Xiong ◽  
Qiongjie Zhou ◽  
Xirong Xiao ◽  
Xiaotian Li
Keyword(s):  
Preterm Birth ◽  
Caesarean Section ◽  
Gestational Diabetes ◽  
Early Pregnancy ◽  
Pregnancy Outcomes ◽  
Adverse Pregnancy Outcomes ◽  
Large For Gestational Age ◽  
Oral Glucose ◽  
Increased Risk ◽  
Adverse Pregnancy

Abstract Aims Universal early-pregnancy screening for overt diabetes reveals intermediate hyperglycaemia [fasting plasma glucose (FPG) (5.1–6.9 mM)]. We evaluated the association between early-pregnancy intermediate hyperglycaemia and adverse pregnancy outcomes among women without gestational diabetes. Methods This retrospective cohort study, conducted at the Obstetrics and Gynaecology Hospital, Shanghai, China, from 2013-2017. All singleton pregnancies with FPG≤6.9mM in early pregnancy and receiving 75-g oral glucose tolerance test (OGTT) were included. Women with pre-pregnancy diabetes were excluded. Subjects with normal OGTT were analysed. Pregnancy outcomes for FPG&lt;5.1 mM and intermediate hyperglycaemia were evaluated. The primary outcomes were large for gestational age (LGA) and primary caesarean section. Multivariate logistic regressions were conducted. Significance was defined as P&lt;0.05. Results Totally, 24479 deliveries were included, of which 23450 (95.8%) had normal OGTTs later in pregnancy (NGT). There were 807 (3.4%) women had FPG=5.1–6.9 mM in early pregnancy. Compared to the NGT group with FPG&lt;5.1 mM in early pregnancy (N=20692), the intermediate hyperglycaemia NGT group (N=693) had a higher age and BMI, and significantly higher rates of LGA, primary caesarean section, preterm birth, preeclampsia and neonatal distress. The rates of primary caesarean section (AOR 1.24, 95% CI 1.05–1.45), preterm birth (AOR 1.75, 95% CI 1.29–2.36) and neonatal distress (adjusted OR 3.29, 95% CI 1.57–6.89) remained significantly higher after adjustments for maternal age, BMI and other potential confounding factors. Conclusions Women with intermediate hyperglycaemia in early pregnancy are at an increased risk for adverse maternal-foetal outcomes, even with normal future OGTTs.

scholarly journals Endometriosis and Risk of Adverse Pregnancy Outcome: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 10 (4) ◽  
pp. 667
Author(s):  
Kjerstine Breintoft ◽  
Regitze Pinnerup ◽  
Tine Brink Henriksen ◽  
Dorte Rytter ◽  
Niels Uldbjerg ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Cesarean Section ◽  
Placental Abruption ◽  
Gestational Hypertension ◽  
Adverse Pregnancy Outcome ◽  
Placenta Previa ◽  
Meta Analysis ◽  
Increased Risk ◽  
Spontaneous Hemoperitoneum ◽  
In Pregnancy

Background: This systematic review and meta-analysis summarizes the evidence for the association between endometriosis and adverse pregnancy outcome, including gestational hypertension, pre-eclampsia, low birth weight, and small for gestational age, preterm birth, placenta previa, placental abruption, cesarean section, stillbirth, postpartum hemorrhage, spontaneous hemoperitoneum in pregnancy, and spontaneous bowel perforation in pregnancy. Methods: We performed the literature review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), by searches in PubMed and EMBASE, until 1 November 2020 (PROSPERO ID CRD42020213999). We included peer-reviewed observational cohort studies and case-control studies and scored them according to the Newcastle–Ottawa Scale, to assess the risk of bias and confounding. Results: 39 studies were included. Women with endometriosis had an increased risk of gestational hypertension, pre-eclampsia, preterm birth, placenta previa, placental abruption, cesarean section, and stillbirth, compared to women without endometriosis. These results remained unchanged in sub-analyses, including studies on spontaneous pregnancies only. Spontaneous hemoperitoneum in pregnancy and bowel perforation seemed to be associated with endometriosis; however, the studies were few and did not meet the inclusion criteria. Conclusions: The literature shows that endometriosis is associated with an increased risk of gestational hypertension, pre-eclampsia, preterm birth, placenta previa, placental abruption, cesarean section, and stillbirth.

scholarly journals Interpregnancy Body Mass Index Changes: Distribution and Impact on Adverse Pregnancy Outcomes in the Subsequent Pregnancy

2018 ◽  
Vol 36 (05) ◽  
pp. 517-521 ◽  
Author(s):  
Whitney Bender ◽  
Adi Hirshberg ◽  
Lisa Levine
Keyword(s):  
Body Mass Index ◽  
Preterm Birth ◽  
Body Mass ◽  
Pregnancy Outcomes ◽  
Subsequent Pregnancy ◽  
Adverse Pregnancy Outcomes ◽  
Increased Risk ◽  
History Of ◽  
Index Changes ◽  
Adverse Pregnancy

Objective To examine the change in body mass index (BMI) categories between pregnancies and its effect on adverse pregnancy outcomes. Study Design We performed a retrospective cohort study of women with two consecutive deliveries from 2005 to 2010. Analysis was limited to women with BMI recorded at <24 weeks for both pregnancies. Standard BMI categories were used. Adverse pregnancy outcomes included preterm birth at <37 weeks, intrauterine growth restriction (IUGR), pregnancy-related hypertension, and gestational diabetes mellitus (GDM). Women with increased BMI category between pregnancies were compared with those who remained in the same BMI category. Results In total, 537 women were included, of whom 125 (23%) increased BMI category. There was no association between increase in BMI category and risk of preterm birth, IUGR, or pregnancy-related hypertension. Women who increased BMI category had an increased odds of GDM compared with women who remained in the same BMI category (6.4 vs. 2.2%; p = 0.018). The increased risk remained after controlling for age, history of GDM, and starting BMI (adjusted odds ratio: 8.2; 95% confidence interval: 2.1–32.7; p = 0.003). Conclusion Almost one-quarter of women increased BMI categories between pregnancies. This modifiable risk factor has a significant impact on the risk of GDM.

scholarly journals Maternal Lipidomic Signatures in Relation to Spontaneous Preterm Birth and Large-For-Gestational Age Neonates

2021 ◽  
Author(s):  
Max Aung ◽  
Pahriya Ashrap ◽  
Deborah Watkins ◽  
Bhramar Mukherjee ◽  
Zaira Rosario ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Preterm Birth ◽  
Free Fatty Acids ◽  
Gestational Age ◽  
Pregnancy Outcomes ◽  
Lipid Analysis ◽  
Lipid Classes ◽  
Large For Gestational Age ◽  
Spontaneous Preterm Birth ◽  
Increased Risk

Abstract Background: Lipidome-wide metabolites may be useful biomarkers of pregnancy outcomes. We sought to characterize maternal lipidomic signatures associated with preterm birth and neonatal anthropometric parameters. Methods: Plasma samples were collected 24-28 weeks gestation, and lipidomic profiling was quantified using high-performance liquid chromatography tandem mass spectrometry. Lipid metabolites were analyzed individually and as whole lipid classes and subgroups based on degree of hydrocarbon chain saturation. Associations were estimated using linear and logistic regression.Results: After false discovery adjustment (q<0.15), four plasmenyl-phosphatidylethanolamines and three free fatty acids associated with increased risk for spontaneous preterm birth. Five phosphatidylinositols, two phosphatidylglycerols, and one phosphatidic acid were associated with large for gestational age neonates. The saturated plasmenyl-phosphatidylethanolamines held the association with increased risk for spontaneous preterm birth. Both the mono- and poly-unsaturated free fatty acids held the association for increased risk for spontaneous preterm birth. Mono- and poly-unsaturated phosphatidylinositols were associated with large for gestational age neonates. Whole lipid classes (plasmenyl-phophatidylcholines and plasmenyl-phosphatidylethanolamines) were associated with increased risk for large for gestational age at delivery.Conclusions: This study provides evidence that finer omics-scale analysis of the maternal lipidome may be more informative biomarkers of pregnancy outcomes compared to whole class level lipid analysis.

scholarly journals Pregnancy outcomes in women with immunoglobulin A nephropathy: a nationwide population-based cohort study

2021 ◽  
Author(s):  
Simon Jarrick ◽  
Sigrid Lundberg ◽  
Olof Stephansson ◽  
Adina Symreng ◽  
Matteo Bottai ◽  
...  
Keyword(s):  
Cohort Study ◽  
Preterm Birth ◽  
Cesarean Section ◽  
Pregnancy Outcomes ◽  
Apgar Score ◽  
Immunoglobulin A ◽  
Reference Population ◽  
Immunoglobulin A Nephropathy ◽  
Childbearing Age ◽  
Increased Risk

Abstract Background Immunoglobulin A nephropathy (IgAN) incidence peaks in childbearing age. Data on pregnancy outcomes in women with IgAN are limited. Methods We performed a register-based cohort study in a nationwide cohort of women with biopsy-verified IgAN in Sweden, comparing 327 pregnancies in 208 women with biopsy-verified IgAN and 1060 pregnancies in a matched reference population of 622 women without IgAN, with secondary comparisons with sisters to IgAN women. Adverse pregnancy outcomes, identified by way of the Swedish Medical Birth Register, were compared through multivariable logistic regression and presented as adjusted odds ratios (aORs). Main outcome was preterm birth (< 37 weeks). Secondary outcomes were preeclampsia, small for gestational age (SGA), low 5-min Apgar score (< 7), fetal or infant loss, cesarean section, and gestational diabetes. Results We found that IgAN was associated with an increased risk of preterm birth (13.1% vs 5.6%; aOR = 2.69; 95% confidence interval [CI] = 1.52–4.77), preeclampsia (13.8% vs 4.2%; aOR = 4.29; 95%CI = 2.42–7.62), SGA birth (16.0% vs 11.1%; aOR = 1.84; 95%CI = 1.17–2.88), and cesarean section (23.9% vs 16.2%; aOR = 1.74, 95%CI = 1.14–2.65). Absolute risks were low for intrauterine (0.6%) or neonatal (0%) death and for low 5-min Apgar score (1.5%), and did not differ from the reference population. Sibling comparisons suggested increased risks of preterm birth, preeclampsia, and SGA in IgAN, but not of cesarean section. Conclusion We conclude that although most women with IgAN will have a favorable pregnancy outcome, they are at higher risk of preterm birth, preeclampsia and SGA. Intensified supervision during pregnancy is warranted.

scholarly journals Impact of Inherited Bleeding Disorders on Maternal Bleeding and Other Pregnancy Outcomes: A Population-Based Cohort Study

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 493-493
Author(s):  
Arafat Ul Alam ◽  
Cynthia M. Wu ◽  
Venu Jain ◽  
Haowei Linda Sun
Keyword(s):  
Cohort Study ◽  
Pregnancy Outcomes ◽  
Research Funding ◽  
Population Based ◽  
Diagnostic Code ◽  
Bleeding Disorders ◽  
Live Births ◽  
Increased Risk ◽  
Significant Change

Abstract Introduction: Increasing rate of postpartum hemorrhage (PPH) has been observed between 2003 and 2010 in Canada. Given that bleeding disorders contribute to the risk of PPH, it is important to identify the current trend in PPH in the last decade and assess the impact of inherited bleeding disorders on maternal bleeding and other pregnancy outcomes. Methods: This is a retrospective population-based cohort study using the Alberta Pregnancy Birth Cohort. The creation of this cohort using multiple linked administrative databases has been previously described. Number of deliveries per year in Alberta, Canada was determined by Vital Statistics birth registry from 2010 to 2018 and was linked with Discharge Abstract Database (DAD) to identify cases of PPH and other pregnancy outcomes. PPH was defined as a blood loss of ≥500 ml following vaginal delivery or ≥1000 ml following Caesarean section, or as a diagnosis noted by a health care provider. All diagnoses and procedures were identified by International Classification of Diseases (ICD)-10 codes and Canadian Classification of Interventions (CCI) codes, respectively. Previous validation study of diagnostic code for PPH in DAD showed high sensitivity and specificity. Inherited bleeding disorders including von Willebrand disease, hemophilia carriers, platelet function disorder, and hereditary deficiencies of other coagulation factors were identified by presence of at least two ICD codes. All analyses were restricted to hospitalized deliveries with live births. Temporal trend of PPH rate was assessed by Mann-Kendall test. Univariate logistic regression analyses were used to compute odds of pregnancy outcomes among women with inherited bleeding disorders compared with those without at their index pregnancies during the study period. Results: Between 2010 to 2018, 311,657 women had a total of 452,846 pregnancies with live births. The mean age of the study cohort was 29 years. Most (90%) of them reached term pregnancies. The total number of PPH was 47,602 (10.5 per 100 deliveries). The rate of PPH did not have any significant change from 10.3 in 2010 (95% confidence interval [CI] 10.0-10.6) to 10.8 (95% CI 10.6 -11.1) in 2018 (P for trend =0.28) [Figure 1]. Among 311,657 women, 345 (0.1%) had a diagnosis of inherited bleeding disorders [Table 1]. Women with bleeding disorders were more likely to experience PPH (odds ratio [OR] 1.4; 95% CI 1.1-1.9), antepartum hemorrhage (OR 4.3; 95% CI 2.9-6.4) and had a 3-fold increased risk of undergoing hysterectomy (OR 3.1; 95% CI 1.8-5.2). The bleeding cohort had 3.8 (95% CI: 2.4-6.0) times greater risk of being transfused with blood products. We observed a trend towards higher odds of caesarean delivery in women with bleeding disorders compared with those without (OR 1.2, 95% CI 0.9-1.5), albeit not statistically significant. However, there was no significant difference in prolonged labor, obstetric hematoma, low birth weight baby and induced labour. Conclusion: Despite a rise in the rate of PPH between 2003-2010, we observed no significant change in the rate of PPH in Alberta between 2010-2018. Women with inherited bleeding disorders are at an increased risk of bleeding events during pregnancy and childbirth. Further investigation into quality of care among this patient population is ongoing to identify areas for improvement. Figure 1 Figure 1. Disclosures Wu: BMS-Pfizer: Honoraria, Research Funding; Leo Pharma: Honoraria; Pfizer: Honoraria; Servier: Honoraria; Bayer: Research Funding; Daiichi-Sankyo: Research Funding. Sun: Pfizer: Consultancy; Novo Nordisk: Consultancy; Bayer: Consultancy; Octapharma: Consultancy, Research Funding; Shire: Consultancy.

scholarly journals Adverse pregnancy outcomes in women with diabetes-related microvascular disease and risks of disease progression in pregnancy: A systematic review and meta-analysis

PLoS Medicine ◽  
2021 ◽  
Vol 18 (11) ◽  
pp. e1003856
Author(s):  
Sophie Relph ◽  
Trusha Patel ◽  
Louisa Delaney ◽  
Soha Sobhy ◽  
Shakila Thangaratinam
Keyword(s):  
Risk Factors ◽  
Systematic Review ◽  
Preterm Birth ◽  
Pregnant Women ◽  
Pregnancy Outcomes ◽  
Meta Analysis ◽  
Microvascular Disease ◽  
Adverse Pregnancy ◽  
In Pregnancy

Background The rise in the global prevalence of diabetes, particularly among younger people, has led to an increase in the number of pregnant women with preexisting diabetes, many of whom have diabetes-related microvascular complications. We aimed to estimate the magnitude of the risks of adverse pregnancy outcomes or disease progression in this population. Methods and findings We undertook a systematic review and meta-analysis on maternal and perinatal complications in women with type 1 or 2 diabetic microvascular disease and the risk factors for worsening of microvascular disease in pregnancy using a prospective protocol (PROSPERO CRD42017076647). We searched major databases (January 1990 to July 2021) for relevant cohort studies. Study quality was assessed using the Newcastle–Ottawa Scale. We summarized the findings as odds ratios (ORs) with 95% confidence intervals (CIs) using random effects meta-analysis. We included 56 cohort studies involving 12,819 pregnant women with diabetes; 40 from Europe and 9 from North America. Pregnant women with diabetic nephropathy were at greater risk of preeclampsia (OR 10.76, CI 6.43 to 17.99, p < 0.001), early (<34 weeks) (OR 6.90, 95% CI 3.38 to 14.06, p < 0.001) and any preterm birth (OR 4.48, CI 3.40 to 5.92, p < 0.001), and cesarean section (OR 3.04, CI 1.24 to 7.47, p = 0.015); their babies were at increased risk of perinatal death (OR 2.26, CI 1.07 to 4.75, p = 0.032), congenital abnormality (OR 2.71, CI 1.58 to 4.66, p < 0.001), small for gestational age (OR 16.89, CI 7.07 to 40.37, p < 0.001), and admission to neonatal unit (OR 2.59, CI 1.72 to 3.90, p < 0.001) than those without nephropathy. Diabetic retinopathy was associated with any preterm birth (OR 1.67, CI 1.27 to 2.20, p < 0.001) and preeclampsia (OR 2.20, CI 1.57 to 3.10, p < 0.001) but not other complications. The risks of onset or worsening of retinopathy were increased in women who were nulliparous (OR 1.75, 95% CI 1.28 to 2.40, p < 0.001), smokers (OR 2.31, 95% CI 1.25 to 4.27, p = 0.008), with existing proliferative disease (OR 2.12, 95% CI 1.11 to 4.04, p = 0.022), and longer duration of diabetes (weighted mean difference: 4.51 years, 95% CI 2.26 to 6.76, p < 0.001) than those without the risk factors. The main limitations of this analysis are the heterogeneity of definition of retinopathy and nephropathy and the inclusion of women both with type 1 and type 2 diabetes. Conclusions In pregnant women with diabetes, presence of nephropathy and/or retinopathy appear to further increase the risks of maternal complications.

scholarly journals Cohort profile: molecular signature in pregnancy (MSP): longitudinal high-frequency sampling to characterise cross-omic trajectories in pregnancy in a resource-constrained setting

BMJ Open ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. e041631
Author(s):  
Tobias Brummaier ◽  
Basirudeen Syed Ahamed Kabeer ◽  
Pornpimon Wilaisrisak ◽  
Mupawjay Pimanpanarak ◽  
Aye Kyi Win ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Pregnant Women ◽  
Pregnancy Outcomes ◽  
High Frequency ◽  
Molecular Signature ◽  
Resource Constrained ◽  
Targeted Interventions ◽  
Frequency Sampling ◽  
High Frequency Sampling ◽  
In Pregnancy

PurposeA successful pregnancy relies on the interplay of various biological systems. Deviations from the norm within a system or intersystemic interactions may result in pregnancy-associated complications and adverse pregnancy outcomes. Systems biology approaches provide an avenue of unbiased, in-depth phenotyping in health and disease. The molecular signature in pregnancy (MSP) cohort was established to characterise longitudinal, cross-omic trajectories in pregnant women from a resource constrained setting. Downstream analysis will focus on characterising physiological perturbations in uneventful pregnancies, pregnancy-associated complications and adverse outcomes.ParticipantsFirst trimester pregnant women of Karen or Burman ethnicity were followed prospectively throughout pregnancy, at delivery and until 3 months post partum. Serial high-frequency sampling to assess whole blood transcriptomics and microbiome composition of the gut, vagina and oral cavity, in conjunction with assessment of gene expression and microbial colonisation of gestational tissue, was done for all cohort participants.Findings to date381 women with live born singletons averaged 16 (IQR 15–18) antenatal visits (13 094 biological samples were collected). At 5% (19/381) the preterm birth rate was low. Other adverse events such as maternal febrile illness 7.1% (27/381), gestational diabetes 13.1% (50/381), maternal anaemia 16.3% (62/381), maternal underweight 19.2% (73/381) and a neonate born small for gestational age 20.2% (77/381) were more often observed than preterm birth.Future plansResults from the MSP cohort will enable in-depth characterisation of cross-omic molecular trajectories in pregnancies from a population in a resource-constrained setting. Moreover, pregnancy-associated complications and unfavourable pregnancy outcomes will be investigated at the same granular level, with a particular focus on population relevant needs such as effect of tropical infections on pregnancy. More detailed knowledge on multiomic perturbations will ideally result in the development of diagnostic tools and ultimately lead to targeted interventions that may disproportionally benefit pregnant women from this resource-limited population.Trial registration numberNCT02797327.

scholarly journals Warning of Immortal Time Bias When Studying Drug Safety in Pregnancy: Application to Late Use of Antibiotics and Preterm Delivery

2020 ◽  
Vol 17 (18) ◽  
pp. 6465
Author(s):  
Giovanni Corrao ◽  
Federico Rea ◽  
Matteo Franchi ◽  
Benedetta Beccalli ◽  
Anna Locatelli ◽  
...  
Keyword(s):  
Birth Weight ◽  
Preterm Birth ◽  
Low Birth Weight ◽  
Preterm Delivery ◽  
Apgar Score ◽  
Time Varying ◽  
Immortal Time Bias ◽  
Increased Risk ◽  
In Pregnancy

This study aimed to illustrate and account for immortal time bias in pregnancy observational investigations, using the relationship between late use of antibiotics and risk of preterm birth as an example. We conducted a population-based cohort study including 549,082 deliveries between 2007 and 2017 in Lombardy, Italy. We evaluated the risk of preterm births, low birth weight, small for gestational age, and low Apgar score associated with antibiotic dispensing during the third trimester of pregnancy. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) of the outcomes, considering the use of antibiotics as time-fixed (with biased classification of exposure person-time) and time-varying (with proper classification of exposure person-time) exposure. There were 23,638 (4.3%) premature deliveries. There was no association between time-fixed exposure to antibiotics and preterm delivery (adjusted HR 0.96; 95% CI 0.92 to 1.01) but an increased risk of preterm birth when time-varying exposure to antibiotics was considered (1.27; 1.21 to 1.34). The same trend was found for low birth weight and low Apgar score. Immortal time bias is a common and sneaky trap in observational studies involving exposure in late pregnancy. This bias could be easily avoided with suitable design and analysis.

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