scholarly journals Dengue during pregnancy and live birth outcomes: a cohort of linked data from Brazil

BMJ Open ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. e023529 ◽  
Author(s):  
Enny S Paixão ◽  
Oona M Campbell ◽  
Maria Gloria Teixeira ◽  
Maria CN Costa ◽  
Katie Harron ◽  
...  

ObjectivesDengue is the most common viral mosquito-borne disease, and women of reproductive age who live in or travel to endemic areas are at risk. Little is known about the effects of dengue during pregnancy on birth outcomes. The objective of this study is to examine the effect of maternal dengue severity on live birth outcomes.Design and settingWe conducted a population-based cohort study using routinely collected Brazilian data from 2006 to 2012.ParticipatingWe linked birth registration records and dengue registration records to identify women with and without dengue during pregnancy. Using multinomial logistic regression and Firth method, we estimated risk and ORs for preterm birth (<37 weeks’ gestation), low birth weight (<2500 g) and small for gestational age (<10thcentile). We also investigated the effect of time between the onset of the disease and each outcome.ResultsWe included 16 738 000 live births. Dengue haemorrhagic fever was associated with preterm birth (OR=2.4; 95% CI 1.3 to 4.4) and low birth weight (OR=2.1; 95% CI 1.1 to 4.0), but there was no evidence of effect for small for gestational age (OR=2.1; 95% CI 0.4 to 12.2). The magnitude of the effects was higher in the acute disease period.ConclusionThis study showed an increased risk of adverse birth outcomes in women with severe dengue during pregnancy. Medical intervention to mitigate maternal risk during severe acute dengue episodes may improve outcomes for infants born to exposed mothers.

BMJ Open ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. e023879 ◽  
Author(s):  
Filip Norlén ◽  
Per Gustavsson ◽  
Pernilla Wiebert ◽  
Lars Rylander ◽  
Maria Albin ◽  
...  

ObjectivesThe aim of this study was to investigate if occupational exposure to inorganic particles or welding fumes during pregnancy is associated with negative birth outcomes.DesignA prospective national cohort study.SettingAll single births from 1994 to 2012 in Sweden. Information on birth weight, preterm birth, small for gestational age, smoking habits, nationality, age, occupation, absence from work and education was obtained from nationwide registers. Exposure to inorganic particles (mg/m3) was assessed from a job exposure matrix.ParticipantsThis study included all single births by occupationally active mothers (995 843).Outcome measuresAssociations between occupational exposures and negative birth outcomes in the form of low birth weight, preterm birth and small for gestational age.ResultsMothers who had high exposure to inorganic particles and had less than 50 days (median) of absence from work during pregnancy showed an increased risk of preterm birth (OR 1.18; 95% CI 1.07 to 1.30), low birth weight (OR 1.32; 95% CI 1.18 to 1.48) as well as small for gestational age (OR 1.20; 95% CI 1.04 to 1.39). The increased risks were driven by exposure to iron particles. No increased risks were found in association with exposure to stone and concrete particles. High exposure to welding fumes was associated with an increased risk of low birth weight (OR 1.22; 95% CI 1.02 to 1.45) and preterm birth (OR 1.24; 95% CI 1.07 to 1.42).ConclusionsThe results indicate that pregnant women should not be exposed to high levels of iron particles or welding fumes.


BMJ Open ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. e027344
Author(s):  
Yohannes Ejigu ◽  
Jeanette H Magnus ◽  
Johanne Sundby ◽  
Maria C Magnus

ObjectiveThe objective of the study was to compare pregnancy outcomes according to maternal antiretroviral treatment (ART) regimens.DesignA retrospective cohort study.Participants and settingsClinical data was extracted from ART exposed pregnancies of HIV-infected Ethiopian women attending antenatal care follow-up in public health facilities in Addis Ababa between February 2010 and October 2016.OutcomesThe primary outcomes evaluated were preterm birth, low birth weight and small-for-gestational-age.ResultsA total 1663 of pregnancies exposed to ART were included in the analyses. Of these pregnancies, 17% resulted in a preterm birth, 19% in low birth weight and 32% in a small-for-gestational-age baby. Compared with highly active antiretroviral therapy (HAART) initiated during pregnancy, zidovudine monotherapy was less likely to result in preterm birth (adjusted OR 0.35, 95% CI 0.19 to 0.64) and low birth weight (adjusted OR 0.48, 95% CI 0.24 to 0.94). We observed no differential risk of preterm birth, low birth weight and small-for-gestational-age, when comparing women who initiated HAART during pregnancy to women who initiated HAART before conception. The risk for preterm birth was higher in pregnancies exposed to nevirapine-based HAART (adjusted OR 1.44, 95% CI 1.06 to 1.96) compared with pregnancies exposed to efavirenz-based HAART. Comparing nevirapine-based HAART with efavirenz-based HAART indicated no strong evidence of increased risk of low birth weight or small-for-gestational-age.ConclusionsWe observed a higher risk of preterm birth among women who initiated HAART during pregnancy compared with zidovudine monotherapy. Pregnancies exposed to nevirapine-based HAART also had a greater risk of preterm births compared with efavirenz-based HAART.


2019 ◽  
Vol 76 (8) ◽  
pp. 537-544 ◽  
Author(s):  
Filip Norlén ◽  
Per Gustavsson ◽  
Pernilla Wiebert ◽  
Lars Rylander ◽  
Magnus Westgren ◽  
...  

ObjectiveTo study if children of women exposed to organic particles and combustion products at work during pregnancy, have an increased risk of low birth weight, preterm birth or small for gestational age.MethodsA nationwide cohort of all occupationally active mothers and their children from single births during 1994 to the end of 2012 (1 182 138 observations) was formed. Information on birth outcome was obtained from the medical birth register. Information on absence from work, education, occupation, age, nationality and smoking habits was obtained from national registers. A job exposure matrix (FINJEM) was used to assess the exposure.ResultsPregnant women with low absence from work and high (>50th percentile) exposure to organic particles had an increased risk of giving birth to children with low birth weight (OR=1.19; 95% CI: 1.07 to 1.32), small for gestational age (OR=1.22; 95% CI: 1.07 to 1.38) or preterm birth (OR=1.17; 95% CI: 1.08 to 1.27). Subgroup analyses showed an increased risk of small for gestational age in association with exposure to oil mist. Exposure to oil mist and cooking fumes was associated with low birth weight. Paper and other organic dust was associated with preterm birth. Exposure to combustion products showed an increased risk of small for gestational age (OR=1.40; 95% CI: 1.15 to 1.71).ConclusionsThe results indicate that occupational exposure to organic particles or combustion products during pregnancy is associated with restriction of fetal growth and preterm birth. More studies are needed to confirm a casual association.


Author(s):  
Ane Bungum Kofoed ◽  
Laura Deen ◽  
Karin Sørig Hougaard ◽  
Kajsa Ugelvig Petersen ◽  
Harald William Meyer ◽  
...  

AbstractHuman health effects of airborne lower-chlorinated polychlorinated biphenyls (LC-PCBs) are largely unexplored. Since PCBs may cross the placenta, maternal exposure could potentially have negative consequences for fetal development. We aimed to determine if exposure to airborne PCB during pregnancy was associated with adverse birth outcomes. In this cohort study, exposed women had lived in PCB contaminated apartments at least one year during the 3.6 years before conception or the entire first trimester of pregnancy. The women and their children were followed for birth outcomes in Danish health registers. Logistic regression was performed to estimate odds ratios (OR) for changes in secondary sex ratio, preterm birth, major congenital malformations, cryptorchidism, and being born small for gestational age. We performed linear regression to estimate difference in birth weight among children of exposed and unexposed mothers. All models were adjusted for maternal age, educational level, ethnicity, and calendar time. We identified 885 exposed pregnancies and 3327 unexposed pregnancies. Relative to unexposed women, exposed women had OR 0.97 (95% CI 0.82, 1.15) for secondary sex ratio, OR 1.13 (95% CI 0.76, 1.67) for preterm birth, OR 1.28 (95% CI 0.81, 2.01) for having a child with major malformations, OR 1.73 (95% CI 1.01, 2.95) for cryptorchidism and OR 1.23 (95% CI 0.88, 1.72) for giving birth to a child born small for gestational age. The difference in birth weight for children of exposed compared to unexposed women was − 32 g (95% CI—79, 14). We observed an increased risk of cryptorchidism among boys after maternal airborne LC-PCB exposure, but due to the proxy measure of exposure, inability to perform dose–response analyses, and the lack of comparable literature, larger cohort studies with direct measures of exposure are needed to investigate the safety of airborne LC-PCB exposure during pregnancy


2021 ◽  
Vol 10 (4) ◽  
pp. 643
Author(s):  
Veronica Giorgione ◽  
Corey Briffa ◽  
Carolina Di Fabrizio ◽  
Rohan Bhate ◽  
Asma Khalil

Twin pregnancies are commonly assessed using singleton growth and birth weight reference charts. This practice has led to a significant number of twins labelled as small for gestational age (SGA), causing unnecessary interventions and increased risk of iatrogenic preterm birth. However, the use of twin-specific charts remains controversial. This study aims to assess whether twin-specific estimated fetal weight (EFW) and birth weight (BW) charts are more predictive of adverse outcomes compared to singleton charts. Centiles of EFW and BW were calculated using previously published singleton and twin charts. Categorical data were compared using Chi-square or McNemar tests. The study included 1740 twin pregnancies, with the following perinatal adverse outcomes recorded: perinatal death, preterm birth <34 weeks, hypertensive disorders of pregnancy (HDP) and admissions to the neonatal unit (NNU). Twin-specific charts identified prenatally and postnatally a smaller proportion of infants as SGA compared to singleton charts. However, twin charts showed a higher percentage of adverse neonatal outcomes in SGA infants than singleton charts. For example, perinatal death (SGA 7.2% vs. appropriate for gestational age (AGA) 2%, p < 0.0001), preterm birth <34 weeks (SGA 42.1% vs. AGA 16.4%, p < 0.0001), HDP (SGA 21.2% vs. AGA 13.5%, p = 0.015) and NNU admissions (SGA 69% vs. AGA 24%, p < 0.0001), when compared to singleton charts (perinatal death: SGA 2% vs. AGA 1%, p = 0.029), preterm birth <34 weeks: (SGA 20.6% vs. AGA 17.4%, p = 0.020), NNU admission: (SGA 34.5% vs. AGA 23.9%, p < 0.000). There was no significant association between HDP and SGA using the singleton charts (p = 0.696). In SGA infants, according to the twin charts, the incidence of abnormal umbilical artery Doppler was significantly more common than in SGA using the singleton chart (27.0% vs. 8.1%, p < 0.001). In conclusion, singleton charts misclassify a large number of twins as at risk of fetal growth restriction. The evidence suggests that the following twin-specific charts could reduce unnecessary medical interventions prenatally and postnatally.


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