Approximately 1 in Every _____ Babies Born in the United States Has a Low Birth Weight
Vaccine. 2017 Dec 4; 35(48Part A): 6492–6500.
Low nascency weight: Case definition & guidelines for information collection, analysis, and presentation of maternal immunization safe data
Clare L. Cutland
aMedical Research Quango: Respiratory and Meningeal Pathogens Research Unit, Johannesburg, Due south Africa
bDepartment of Science and Technology National Enquiry Foundation, Vaccine Preventable Diseases, South Africa
cFaculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
Eve M. Lackritz
dGlobal Alliance to Prevent Prematurity and Stillbirth (GAPPS), Seattle Children'south Research Plant, Seattle, WA, USA
Tamala Mallett-Moore
eSanofi Pasteur Inc., Swiftwater, PA, USA
Azucena Bardají
fISGlobal, Barcelona Ctr. Int. Wellness Res. (CRESIB), Infirmary Clínic – University of Barcelona, Barcelona, Spain
Ravichandran Chandrasekaran
grandMadras Medical College, Bharat
Chandrakant Lahariya
hDepartment of Community Medicine, GR Medical College and Associated Hospitals, Gwalior, MP, India
Muhammed Imran Nisar
iDepartment of Pediatrics and Kid Wellness, Aga Khan University, Karachi, Pakistan
Milagritos D. Tapia
jAcademy of Maryland Schoolhouse of Medicine, Center for Vaccine Development, Doc, United states
Jayani Pathirana
aMedical Research Quango: Respiratory and Meningeal Pathogens Enquiry Unit, Johannesburg, S Africa
bDepartment of Science and Technology National Research Foundation, Vaccine Preventable Diseases, Due south Africa
cFaculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
Sonali Kochhar
kGlobal Healthcare Consulting, Republic of india
thousandErasmus University Medical Center, Rotterdam, Holland
Flor One thousand. Muñoz
lBaylor College of Medicine, Departments of Pediatrics, Molecular Virology and Microbiology, Houston, TX, USA
Keywords: Low birth weight, Agin event, Immunization, Guidelines, Case definition
one. Preamble
1.1. Demand for developing instance definitions and guidelines for data collection, assay, and presentation for low birth weight as an agin upshot following maternal immunization
The nascency weight of an infant is the first weight recorded later on birth, ideally measured within the first hours subsequently birth, before significant postnatal weight loss has occurred. Low nascence weight (LBW) is defined as a birth weight of less than 2500 m (up to and including 2499 g), as per the World Health Organization (WHO) [1]. This definition of LBW has been in beingness for many decades. In 1976, the 29th World Health Associates agreed on the currently used definition. Prior to this, the definition of LBW was '2500 m or less'. Depression birth weight is farther categorized into very depression birth weight (VLBW, <1500 1000) and extremely low nativity weight (ELBW, <1000 g) [i]. Depression birth weight is a upshot of preterm nascence (PTB, curt gestation <37 completed weeks), intrauterine growth restriction (IUGR, likewise known equally fetal growth restriction), or both.
The term low birth weight refers to an accented weight of <2500 chiliad regardless of gestational age. Pocket-sized for gestational historic period (SGA) refers to newborns whose nascency weight is less than the tenth percentile for gestational age. This study volition focus specifically on nativity weight <2500 g. Further details related to case definitions for PTB [2], IUGR and SGA are included in dissever GAIA reports.
Globally, information technology is estimated that fifteen–20% of all births, or >20 million newborns annually, are depression nativity weight infants. Low- and center-income countries account for a disproportionate burden of LBW; over 95% of the world's LBW infants are born in LMICs. There are marked global and regional variations in LBW rates. An estimated 6% of infants are born LBW in East Asia and the Pacific, 13% in Sub-Saharan Africa, and upwardly to 28% in South Asia [3]. Upward to one-half of all LBW infants are born in s Asia [4]. Loftier-income regions written report lower LBW rates, including 6.nine% from United kingdom [5]. Of business organisation is the estimated increase in LBW rates in certain middle-income countries such as Sultanate of oman, where the LBW charge per unit went from iv% in 1980 to 8.one% in 2000 [6].
One of the major challenges in monitoring the incidence of LBW is that more than half of infants in the LMICs are not weighed [7]. Population-based survey data often rely on modeled estimates, with statistical methods to accommodate for underreporting and misreporting of nascence weight. In the context of vaccine safe monitoring, accurate ascertainment of birth weight in LMICs volition continue to crave attention and investment to improve accuracy and reporting of this of import health indicator.
1.i.1. Why are we concerned about low birth weight?
Low birth weight is a valuable public health indicator of maternal health, nutrition, healthcare commitment, and poverty. Neonates with low birth weight accept a >xx times greater risk of dying than neonates with birth weight of >2500 thou [8], [9]. Additionally, low nascence weight is associated with long-term neurologic disability, impaired language evolution [ten], impaired academic achievement, and increased risk of chronic diseases including cardiovascular disease and diabetes. Preterm infants acquit additional risk due to immaturity of multiple organ systems, including intracranial hemorrhage, respiratory distress, sepsis, blindness, and gastrointestinal disorders. Preterm nascency is the leading cause of all under-v child mortality worldwide [11].
In addition, economical studies in low-income settings have demonstrated that reducing the burden of low birth weight would have important toll savings both to the health organization and to households [12].
1.1.ii. What leads to depression birth weight?
The underlying causes of both PTB and IUGR are multifactorial, and the biological pathways and preventive strategies for these two conditions are quite dissimilar [thirteen], [xiv], [15]. The exact cause of PTB may exist unknown in many cases, however numerous maternal, fetal and placental factors may contribute to PTB [13]. Significant maternal weather include extra-uterine infection, chorioamnionitis, trauma and disease (east.g. pre-eclampsia/eclampsia). Significant fetal conditions include IUGR, fetal infection, death and anomalies. Placental pathologic weather include placental abruption and placenta praevia [13].
In full general, the causes of IUGR can exist due to maternal, fetal, and placental factors. Although the etiologies are different, they often have the final common pathway of bereft uterine-placental perfusion and fetal diet.
IUGR can be asymmetrical IUGR (where babies have features of malnutrition), symmetrical IUGR (hypoplastic small for dates) or mixed IUGR. Asymmetrical IUGR is the most common (lxx–80%) form of IUGR, resulting from an insult (frequently utero-placental insufficiency) later in pregnancy, which results in affected babies having normal length and caput circumference (encephalon sparing), but reduced weight. Symmetrical IUGR on the other hand arises from an insult (ofttimes genetic, structural or infectious) occurring earlier in pregnancy leading to a reduction in all anthropometric parameters in fetus/newborn [xv].
Bereft perfusion, through abnormal placentation, aberrant placental vascularization, maternal hypertensive disorders, and tobacco use, all result in IUGR. Multiple gestation (i.eastward., twins, triplets) is associated with increased risk of both IUGR and PTB [16]. Infectious diseases, including intrauterine infections, HIV, and malaria, issue in LBW due to both growth restriction and short gestation. Multiple maternal characteristics, risk behaviors, and social determinants are associated with both IUGR and PTB; these include maternal short stature, maternal malnutrition, low torso mass index, poverty, black race, narrow kid spacing, low maternal didactics, poor antenatal care, substance abuse, and emotional and physical stress [5], [17], [eighteen], [19]. How these factors are mediated biologically remains poorly understood.
Preterm nativity may be spontaneous or medically-indicated, such as induction or cesarean department for maternal complications such every bit pre-eclampsia. Infectious and inflammatory processes are associated with increased take a chance for PTB, including chorioamnionitis, bacterial vaginosis, bacteriuria, and systemic or remote site infection such as sepsis and periodontal illness.
one.1.3. The importance of short gestation on immune role and vaccine efficacy
Transplacental antibody transfer is an agile process mediated past Fc receptors in the placental syncytiotrophoblast [twenty], which increases from thirty weeks gestation. Pocket-size molecular weight particles (<600 Da) cross the placenta by passive mechanism including improvidence, however, larger molecular weight particles (>1000 Da) are transported across the placenta by and active receptor-mediated process [21]. Fetal IgG levels are approximately 50% of maternal antibody level at 32 weeks gestation and rises chop-chop through the third trimester [22]. Preterm newborns have significantly lower antibody levels than term newborns [22]. LBW term newborns have significantly lower antibody concentrations to Canker simplex virus type 1, respiratory syncytial virus ad varicella zoster virus than term newborns with birth weight >2500 g [23].
Maternal antibody levels, receptor density and functionality, ardor, antigen nature, and gestational age make up one's mind the efficiency of placental antibody transfer [24]. Diseases that are highly prevalent in some areas, such as malaria and human immunodeficiency virus (HIV), are known to cause placental damage, particularly placental malaria [25], [26]. Maternal HIV infection has been consistently associated with reduced placental passage of antibodies against several mutual viral and bacterial antigens [27], [28]. Placental malaria has been associated with maternal hypergammaglobulinemia and reduced transfer of antibodies against measles virus, Clostridium tetani, Streptococcus pneumonia, and varicella-zoster virus in some studies [20], [29], [30], [31]. The transfer during pregnancy of maternal antibodies to the fetus minimizes deficiencies in antibody product in the fetus and provides short-term passive amnesty [32], conditioning the success of vaccination in newborns [33] which is especially important in preterm and IUGR newborns. Multiple comorbidities are associated with both LBW and immune suppression, such as malnutrition and infection, thereby further exacerbating macerated allowed function in the compromised newborn.
1.ane.4. Maternal immunization and birth weight
Maternal infections, including flu, have been associated with increased risk of low nascency weight newborns [34]. Every bit a corollary, prevention of certain infections during pregnancy might have a protective issue against LBW. This has been observed in a maternal immunization trial conducted in Bangladesh [35], in which the mean birth weight of infants built-in to mothers who received an inactivated flu vaccine during pregnancy was higher than of infants built-in to mothers who received a pneumococcal polysaccharide vaccine (3178 thousand vs. 2978 g, p = 0.02). This trend has not been observed in other maternal influenza immunization trials [36].
The field of immunization of significant women has highlighted the importance of knowing background rates of adverse pregnancy events, including LBW, PTB, SGA, IUGR, stillbirths, and neonatal death, which can vary markedly betwixt and within regions. The greatest bear on of disease prevention from maternal immunization is expected to be observed in LMIC, where the brunt of disease is greatest and access to wellness care services is well-nigh limited. For this reason, particular attending is being given to advancing maternal immunization trials in LMICs. Unfortunately, reliable, accurate, and timely reports of vital statistics and demographic data are oftentimes limited in these settings.
Data Condom Monitoring Boards are established to review clinical trial data, including regular assessment or review of adverse event rates in trial participants. Without accurate information on background rates of low birthweight and other agin pregnancy outcomes, information technology will exist impossible to discover an increment in adverse events post-obit immunization. Evolution of standardized methods to collect and report LBW and other essential outcomes will be essential to advancing maternal immunization programs worldwide.
Nascence weight is commonly included under demographics of trial participant infants, and the differences in nativity weights betwixt participants enrolled in active and placebo or control arms of interventional trials in pregnancy are normally assessed.
The LBW Working Group recommends use of traditional case definitions of LBW equally defined by the Globe Health Organization. This report therefore focuses on delineating data quality related to methods used to estimate nascence weight in LMICs, and summarizes some surrogate measurements that are under investigation to assess nativity weight and approximate population-level groundwork LBW rates.
1.2. Methods for the review of the case definition and guidelines for data collection, analysis, and presentation for low birth weight in clinical trial and population settings
Following the process described in the overview paper [21] as well as on the Brighton Collaboration Website http://www.brightoncollaboration.org/cyberspace/en/index/process.html, the Brighton Collaboration Depression birth weight Working Grouping was formed in 2016 and included 16 members of varied backgrounds including clinical, academic, public health and industry. The composition of the working and reference group every bit well equally results of the web-based survey completed by the reference group with subsequent discussions in the working group can be viewed at: http://www.brightoncollaboration.org/cyberspace/en/alphabetize/working_groups.html.
To guide the decision-making for the guidelines, a literature search was performed using Medline/PubMed, Embase, ClinicalKey (ebooks), ScienceDirect (eBooks), eBrary (eBooks) and the Cochrane Libraries, including the terms: 'pregnancy, vaccines and low nascence weight', and restricted to English language publications since 2005. The search resulted in the identification of 41 references. All abstracts were screened for possible reports of Low nascence weight following immunization. 30-2 articles with potentially relevant material were reviewed in more detail, in club to identify studies using case definitions or, in their absence, providing clinical descriptions of the case material. This review resulted in a detailed summary of 19 articles, including information on the written report type, the vaccine, the diagnostic criteria or instance definition put forth, the time interval since time of immunization, and any other symptoms. Multiple general medical, pediatric and communicable diseases book chapters were also searched.
The definition of low nascency weight used was consistent across all literature reviewed.
A second literature search using the search terms 'nativity weight and tools' was performed using Pubmed, to identify other measurements used equally proxies for nascence weight. The search, unrestricted for linguistic communication and yr of publication, identified in 235 results. Titles were screened and 10 manufactures were identified for farther review.
1.3. Rationale for selected decisions about the case definition of low birth weight equally an adverse result following maternal immunization
1.3.1. The term low birth weight
'Low birth weight' (LBW) has been defined as offset weight recorded within hours of nascency of <2500 k. Very low birth weight (VLBW) is accepted every bit <1500 g and extremely low birth weight (ELBW) is <yard chiliad [i].
Inside the definition context, however, the three diagnostic levels must not exist misunderstood as reflecting unlike grades of clinical severity. They instead reverberate diagnostic certainty.
The levels of certainty take been formulated such that the Level 1 definition is highly specific for the condition. 2 additional diagnostic levels accept been included in the definition, offering a stepwise loss of precision and accuracy from Level One down to Level Iii, while retaining an approach to aggrandize utilization of available data. In this way it is hoped that information on low birth weight can exist captured more broadly at the population level.
1.3.2. Timing of birth weight assessment
The birth weight is described equally the commencement weight measured, all the same, in settings with low rates of facility-based deliveries, a newborn may not exist assessed by a health care worker until several days onetime. Nativity weight should exist assessed inside hours of birth, prior to significant weight loss [37]. Term neonates lose betwixt iii.5% and 6.6% of their birth weight inside the showtime 2.5–2.7 days of life. Exclusively breastfed neonates have a greater weight loss (Median six.6%, 95%CI 6.3–half dozen.9%) than formula-fed (Median 3.5%, 95%CI 3.0–3.9%) or mixed fed (5.9%, 95%CI 4.8–6.nine%) neonates respectively, and take longer to regain their birth weight (8.3 vs. 6.5 vs. 7.9 days) [37].
The LBW working group decided to restrict 'birth weight' to a weight measured in the first 48 h of life. In the absence of a weight measured within the outset 48 h of life, a weight measured during the first week of life, could exist classified as an 'early neonatal weight' but non 'birth weight'.
In a clinical trial scenario, measurement of weight within starting time 48 h of life should be doable, as the clinical trial would procure adequate equipment, employ and train staff to assess nascency weight in a timely manner, and enroll participants who reside in areas which are relatively easily accessed by trial or health care staff.
Many newborns globally are not weighed within hours of birth, mainly due to difficulty in accessing health intendance personnel, facilities, and essential equipment. Specific time frames for onset of symptoms following immunization are not included for the following main reasons:
We postulate that a definition designed to be a suitable tool for testing causal relationships requires ascertainment of the upshot (eastward.thou. low nascency weight) contained from the exposure (e.thousand. immunizations). Therefore, to avoid selection bias, a restrictive fourth dimension interval from immunization to nascency of a LBW newborn should not exist an integral part of such a definition. Instead, where feasible, details of this interval should be assessed and reported as described in the data collection guidelines.
Further, measurement of birth weight ofttimes occurs outside the controlled setting of a clinical trial or infirmary. In some settings it may exist impossible to obtain a clear timeline of the assessment of a nascency weight, peculiarly in less developed or rural settings. In order to avoid selecting against such cases, the Brighton Collaboration instance definition avoids setting capricious fourth dimension frames. The fourth dimension between delivery and measurement of nascence weight should be recorded and accounted for in the analysis.
ane.four. Guidelines for data collection, analysis and presentation
As mentioned in the overview newspaper [38], the case definition is accompanied by guidelines which are structured co-ordinate to the steps of conducting a clinical trial, i.e. data drove, analysis and presentation. Neither case definition nor guidelines are intended to guide or institute criteria for management of sick infants, children, or adults. Both were developed to meliorate standardization of example definitions and data comparability.
one.5. Periodic review
Like to all Brighton Collaboration case definitions and guidelines, review of the definition with its guidelines is planned on a regular basis (i.due east. every three to 5 years) or more than frequently if needed.
two. Case definition of depression nascence weightiii
Level i of diagnostic certainty
| Newborn baby weighed within 24 h of nascency | AND |
| Utilise electronic calibration which is graduated to 10 k | AND |
| Scale is calibrated at least once a year | AND |
| Calibration placed on level, difficult surface | AND |
| Calibration tared to zero grams | AND |
| Weight recorded as <2500 m | OR |
| Birth weight recorded equally <2500 one thousand | AND |
| Nascence weight assessed every bit per wellness care facility'due south standard operating process, which fulfills criteria 1 to five of LOC1 |
Level two of diagnostic certainty
| Newborn infant weighed within 24 h of birth | AND |
| Scale (electronic/bound) is graduated to at least 50 g | AND |
| Scale is calibrated at least once a twelvemonth, or more than frequently if moved | AND |
| Scale tared to aught grams or 0.00 kg | AND |
| Weight recorded as <2500 k | OR |
| Nativity weight recorded as <2500 1000 | AND |
| Nascence weight assessed as per health intendance facility's standard operating process, which fulfills criteria one to 4 of LOC2 |
Scale used: could be electronic or leap scale, including color-coded scale.
Level 3 of diagnostic certainty
| Newborn infant weighed on day 1 or 2 of life (starting time 48 h of life) | AND |
| Weight measured using dial/leap/color-coded scale | AND |
| Weight assessed every bit <2500 grand |
Level 4 of diagnostic certainty
| Newborn infant 'weight' assessed on day ane or 2 of life (commencement 48 h of life) | AND |
| Proxy measure of nativity weight used | AND |
| Weight CATEGORY assessed every bit <2500 g |
In many settings, including high-income countries, birth weight is assessed by a health care provider who is bellboy during/soon after delivery, and non the vaccine trialist/researcher. The details of fourth dimension of nascence weight assessment, and details of scale used and calibration details are unremarkably not recorded in newborn cess medical notes.
The newborn weight assessment is presumed to be assessed accurately as per health care middle's standard operating procedures. In many instances, trialists need to rely on the attending medical staff at wellness care facility for birth weight assessment. Strengthening grooming and oversight of birth weight measurement would be expected to strengthen data both in clinical trials and post-marketing surveillance.
2.1. Other tools under investigation to estimate birth weight in individuals and populations
Upwards to threescore million infants are born at home annually [39], and up to 48% of infants worldwide are not weighed at nativity [3]. Lack of access to health care facilities or health care workers hampers accurate assessment of low nativity weight rates in many regions. In club to identify pocket-size newborns, who could be preterm, IUGR, or both, who require boosted intendance, cheap tools are required which can be utilized in the field.
The lack of data available has encouraged the development of a mathematical model to calculate the expected number of adverse events, including neonatal and maternal deaths, SGA, preterm birth and major built malformations [twoscore].
Several anthropometric measurements, including chest circumference, foot length and mid-upper arm circumference, have been assessed as proxies for birth weight [41], [42], [43], [44]. Tabular array 1 summarizes these tools and their validity for identifying low birth weight newborns. These tools at this betoken are considered investigational and have been included in level four definition merely, which indicates that evidence is inadequate to meet the definition, withal, may be useful for population background LBW estimates.
Table 1
Validated tools used equally proxy measures of nativity weight.
| Measurement | Method of assessment | Cut-off values used | Comments | |
|---|---|---|---|---|
| Newborn human foot length [41], [42], [43], [46] | Foot length from eye of heel pad to tip of large toe in millimeters | Hard plastic ruler pressed vertically against sole of pes (highest AUC) | 7.ii cm for 2000 g | Weakest correlation with LBW of all anthropometric measurements [47], [48] |
| Sole of human foot placed on solid board with measuring tape | 7.viii cm for preterm [41] | |||
| ⩽seven.4 cm (seven.3–7.4 cm) for 2500 g [43] | AUC 0.94, 95%CI 0.92–0.96 [43] | |||
| For <2500 g | ||||
| Footprint fabricated on White paper, and tip of big toe and heel marked with pencil | 7.2 cm (Europe) | <8 cm at birth was 87% sensitive for LBW [46] | ||
| vi.3–vii.85 cm (Asia) | ||||
| 7.4–eight cm (Africa) | ||||
| Chest circumference [42], [43] | Chest circumference at level of nipples in centimeters | Non-rubberband, flexible measuring tape graduated to nearest 0.1 cm, measured during expiration | ⩽thirty.iv cm (xxx.0–thirty.iv cm) [43] | Highly predictive of LBW if measured at <24 h of age (AUC 0.98, 95%CI 0.96–0.99) [43] |
| In meta-assay, best anthropometric measurement to predict LBW [47] | ||||
| Risk of hypothermia | ||||
| Mid upper arm circumference [43] | Mid-point between tip of acromion process and olecranon procedure in centimeters | Non-elastic, flexible measuring record graduated to nearest 0.i cm | ⩽nine.0 cm (viii.seven–nine.0 cm) [43] | Highly predictive of LBW if measured at <24 h of age (AUC 0.98, 95%CI 0.96–0.99) [43] |
In improver to these measurements, other tools are utilized in some communities to assess birth weight, including divergence between adult weight with and without newborn in artillery (see Fig. 1).
Tools used to measure birth weight (See to a higher place-mentioned references for further data.).
three. Guidelines for data drove, analysis and presentation of depression birth weight
It was the consensus of the Brighton Collaboration Working Group for Low birth weight to recommend the following guidelines to enable meaningful and standardized collection, analysis, and presentation of information about low birth weight. Nevertheless, implementation of all guidelines might not be possible in all settings. The availability and quality of information may vary depending upon resources, geographical region, and whether the source of information is a prospective clinical trial, epidemiological study, postal service-marketing surveillance, or an private report. As well, equally explained in more particular in the overview paper [38], these guidelines have been developed by this working grouping for guidance only, and are not to be considered a mandatory requirement for data collection, analysis, or presentation.
3.1. Data collection
These guidelines stand for a desirable standard for the collection of data on availability post-obit immunization to allow for comparability of data, and are recommended equally an add-on to data collected for the specific study question and setting. The guidelines are not intended to guide the primary reporting of depression birth weight to a surveillance organisation or study monitor. Investigators developing a data collection tool based on these data collection guidelines also need to refer to the criteria in the case definition, which are not repeated in these guidelines.
Guidelines numbers below have been developed to accost data elements for the collection of adverse event information as specified in general drug safe guidelines by the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human being Use [49], and the class for reporting of drug adverse events past the Council for International Organizations of Medical Sciences [fifty]. These data elements include an identifiable reporter and patient, one or more than prior immunizations, and a detailed clarification of the adverse consequence, in this case, of low nascency weight following immunization. The additional guidelines take been developed as guidance for the drove of boosted information to permit for a more comprehensive understanding of low nativity weight post-obit maternal immunization.
3.1.1. Source of data/reporter
For all cases and/or all written report participants, as appropriate, the following data should be recorded:
-
(1)
Date of report.
-
(2)
Name and contact data of person reporting4 and/or diagnosing depression birth weight as specified by land-specific data protection law.
-
(3)
Name and contact information of the investigator responsible for the subject field, as applicable.
-
(4)
Relation to the patient (east.g., healthcare provider, immunizer, customs health worker, family member [indicate relationship], other).
3.ane.2. Vaccinee/control
3.i.2.1. Demographics
For all cases and/or all report participants, as appropriate, the post-obit information should be recorded:
-
(5)
Case/report participant identifiers for female parent and newborn (e.thousand. first name initial followed by final proper noun initial) or code (i.east. infirmary identifier or in accordance with country-specific information protection laws). Each newborn should have a unique identifier, ideally linked to female parent's identifier (eastward.g. participant code could be same for mother and baby(ies), with an added prefix/suffix to place mother/baby).
-
(half dozen)
Maternal date of nascency, or if not available, maternal age.
-
(7)
For each babe: Appointment and time of delivery, unmarried or multiple, live birth vs. fetal death (fresh or diminished), estimated gestational age, method of determination of gestational historic period (LMP, fundal height, outset trimester ultrasound) and birth weight.
- • For collection of birth weight, ideally record timeline of weight measurement (e.yard. time of delivery to fourth dimension of weight), type of calibration used (e.g. surface-mounted leap) and place where birth weight was measured (e.k. health intendance facility, mobile health worker visiting home).
three.1.2.ii. Clinical and immunization history
For all cases and/or all study participants, every bit appropriate, the following information should be recorded:
-
(viii)
Maternal past medical history, including hospitalizations, gravidity and parity, underlying diseases/disorders; complications of pregnancy, labor, or delivery; pre-immunization signs and symptoms including identification of indicators for, or the absence of, a history of allergy to vaccines, vaccine components or medications; food allergy; allergic rhinitis; eczema; asthma.
-
(9)
Any medication history (other than treatment for the event described) prior to, during, and after immunization including prescription and non-prescription medication equally well as medication or treatment with long half-life or long term effect. (E.1000. immunoglobulins, claret transfusion and immunosuppressants).
-
(10)
Immunization history (i.e. previous immunizations and any agin event following immunization (AEFI)), in particular occurrence of low birth weight afterwards a previous maternal immunization.
3.i.iii. Details of the immunization
For all cases and/or all study participants, equally appropriate, the following data should exist recorded:
-
(xi)
Date and time of maternal immunization(due south).
-
(12)
Clarification of vaccine(s) (proper noun of vaccine, manufacturer, lot number, dose (e.g. 0.25 mL, 0.five mL), vaccine diluent (composition and lot number) and number of dose if function of a series of immunizations against the same disease).
-
(13)
The anatomical sites (including left or correct side) of all immunizations (e.1000. vaccine A in proximal left lateral thigh, vaccine B in left deltoid).
-
(xiv)
Route and method of administration (e.g. intramuscular, intradermal, subcutaneous, and needle-gratuitous (including type and size), other injection devices).
-
(15)
Needle length and gauge.
3.1.iv. The agin event
-
(xvi)
For all cases at any level of diagnostic certainty and for reported events with insufficient evidence, the criteria fulfilled to meet the case definition should be recorded.
Specifically document:
-
(17)
Severity of Low birth weight (LBW, VLBW or ELBW), and if there was medical confirmation of the LBW (i.eastward. patient seen by doc/other health care worker).
-
(18)
Date/time of observation,5 and diagnosis.6
-
(nineteen)
Concurrent signs, symptoms, and diseases, including prematurity.
-
(20)
Measurement/testing.
- • Values and units of routinely measured parameters (grams for nascency weight);
- • Method of measurement (eastward.g. type of scale.);
- • Weight should be recorded with minimal or ideally no vesture;
-
(21)
Objective clinical bear witness supporting classification of the outcome equally "serious".7
-
(22)
Exposures other than the immunization 24 h before and after immunization (e.chiliad. infection, environmental) considered potentially relevant to the reported event.8
three.1.5. Miscellaneous/general
-
(23)
The duration of surveillance for low birth weight should exist from 0 to 48 h of life. Any weight measured afterward 48 h of age should not be considered a 'nascency weight'.9
-
(24)
Methods of data drove should exist consistent within and between study groups, if applicable.ten
-
(25)
Investigators of patients with low birth weight should provide guidance to reporters to optimize the quality and completeness of information provided.
iii.2. Data analysis
The following guidelines represent a desirable standard for analysis of information on depression nativity weight to allow for comparability of data, and are recommended as an addition to data analyzed for the specific study question and setting.
-
(26)
Reported events should exist classified in one of the following v categories including the 3 levels of diagnostic certainty. Events that meet the instance definition should exist classified co-ordinate to the levels of diagnostic certainty every bit specified in the case definition. Events that practice non meet the case definition should exist classified in the additional categories for analysis.
Event nomenclature in 5 categories
Event meets case definition
-
(one)
Level 1: Criteria as specified in the Low nativity weight example definition
-
(2)
Level ii: Criteria equally specified in the Low nascence weight example definition
-
(3)
Level 3: Criteria as specified in the Depression birth weight instance definition
Outcome does non meet case definition
Additional categories for analysis
-
(four)
Reported Low birth weight with insufficient evidence to meet the case definition.7
-
(5)
Birth weight not assessed, therefore data unavailable.
-
(27)
The interval betwixt immunization and reported Low nativity weight could be defined as the date/fourth dimension of immunization to the appointment/time of cess4 of nativity weight. If few cases are reported, the physical time course could be analyzed for each; for a large number of cases, data tin be analyzed in the following increments.
-
(28)
If birth weight is assessed by more than than one method, the value recorded which fulfills the highest level of certainty should be used equally the basis for assay.
-
(29)
The distribution of birth weight data could be analyzed in predefined increments (e.thousand. LBW < 2500 g, VLBW < 1500 g, ELBW < one thousand 1000). Increments specified above should be used. When just a small number of cases are presented, the respective values can be presented individually.
-
(30)
Data on Low nativity weight obtained from participants whose mothers received a vaccine should be compared with those obtained from an appropriately selected and documented control group to assess groundwork rates of LBW in non-exposed populations, and should be analyzed by report arm and dose where possible, due east.one thousand. in prospective clinical trials.
3.3. Data presentation
These guidelines represent a desirable standard for the presentation and publication of data on Low birth weight post-obit immunization to allow for comparability of data, and are recommended as an addition to data presented for the specific report question and setting. Additionally, information technology is recommended to refer to existing general guidelines for the presentation and publication of randomized controlled trials, systematic reviews, and meta-analyses of observational studies in epidemiology (e.yard. statements of Consolidated Standards of Reporting Trials (CONSORT) [51], of Improving the quality of reports of meta-analyses of randomized controlled trials (QUORUM) [52], and of meta-analysis Of Observational Studies in Epidemiology (MOOSE) [53], respectively).
-
(31)
All reported events of Low birth weight should be presented according to the categories listed in guideline 31.
-
(32)
Information on Low birth weight events should be presented in accord with data collection guidelines ane–25 and data assay guidelines 26–xxx.
-
(33)
Information should be presented as rates with a numerator and denominator (due north/N) (and not just in percentages), with confidence intervals around the point estimates.
Although immunization safety surveillance systems denominator data are usually not readily bachelor, attempts should be made to place judge denominators. The source of the denominator data should be reported and calculations of estimates be described (eastward.g. manufacturer data like total doses distributed, reporting through Ministry of Health, coverage/population based information, etc.).
-
(34)
The incidence of cases in the report population should be presented and clearly identified as such in the text.
-
(35)
If the distribution of birth weight data is skewed, median and range are usually the more appropriate statistical descriptors than a mean. However, the mean and standard deviation should too exist provided.
-
(36)
Whatsoever publication of data on Low birth weight should include a detailed description of the methods used for information collection and analysis as possible. It is essential to specify:
- • The written report design;
- • The method, frequency and duration of monitoring for Low nascency weight;
- • The trial contour, indicating participant flow during a report including drop-outs and withdrawals to betoken the size and nature of the respective groups nether investigation;
- • The type of surveillance (e.g. passive or active surveillance);
- • The characteristics of the surveillance system (east.yard. population served, mode of report solicitation);
- • The search strategy in surveillance databases;
- • Comparison group(s), if used for analysis;
- • The instrument of information collection (due east.grand. standardized questionnaire, diary card, report form);
- • Whether the 24-hour interval of immunization was considered "day ane" or "twenty-four hour period zero" in the analysis;
- • Whether the appointment of onset4 and/or the appointment of starting time ascertainment5 and/or the engagement of diagnosisvi was used for analysis; and
- • Use of this case definition for Low birth weight, in the abstract or methods section of a publication.11
Disclaimer
The findings, opinions and assertions contained in this consensus document are those of the private scientific professional members of the working group. They practise not necessarily represent the official positions of each participant's organisation (e.chiliad., government, university, or corporation). Specifically, the findings and conclusions in this newspaper are those of the authors and do not necessarily stand for the views of their respective institutions.
Acknowledgements
The authors are grateful for the support and helpful comments provided by the Brighton Collaboration Steering Committee and Reference group, as well as other experts consulted every bit office of the process. The authors would like to give thanks the following working grouping members for their contribution: Trésor Bodjick, Brian Magowan, Jeffrey Murray. The authors are grateful to Karalee Sheaffer of the Scientific Intelligence group at Sanofi Pasteur for the "pregnancy, vaccines and low birth weight" literature search. The authors are as well grateful to Jan Bonhoeffer, Jorgen Bauwens of the Brighton Collaboration Secretariat and Sonali Kochhar of Global Healthcare Consulting for final revisions of the final document.
Footnotes
3The instance definition should be applied when at that place is no clear alternative diagnosis for the reported outcome to account for the combination of symptoms.
4If the reporting center is unlike from the vaccinating center, appropriate and timely communication of the adverse event should occur.
5The date and/or time of observation is divers as the time postal service immunization, when the Low birth weight was recorded.
viThe date of diagnosis of an episode is the twenty-four hours postal service immunization when the event met the example definition at any level.
7An AEFI is defined every bit serious by international standards if it meets one or more of the following criteria: (one) it results in decease, (2) is life-threatening, (3) it requires inpatient hospitalization or results in prolongation of existing hospitalization, (4) results in persistent or pregnant disability/incapacity, (five) is a congenital bibelot/nativity defect, (6) is a medically important event or reaction.
eightTo determine the appropriate category, the user should outset establish, whether a reported issue meets the criteria for the everyman applicable level of diagnostic certainty, e.one thousand. Level iii. If the lowest applicable level of diagnostic certainty of the definition is met, and there is evidence that the criteria of the next college level of diagnostic certainty are met, the consequence should be classified in the next category. This approach should exist connected until the highest level of diagnostic certainty for a given outcome could be determined. Major criteria can be used to satisfy the requirement of minor criteria. If the lowest level of the case definition is not met, it should be ruled out that any of the college levels of diagnostic certainty are met and the event should be classified in additional categories four or five.
ixIf the evidence available for an effect is insufficient because information is missing, such an consequence should exist categorized every bit "Reported Low birth weight with insufficient bear witness to meet the example definition".
xAn result does not see the example definition if investigation reveals a negative finding of a necessary benchmark (necessary condition) for diagnosis. Such an effect should be rejected and classified as "Non a case of Low birth weight".
11Use of this document should preferably exist referenced by referring to the corresponding link on the Brighton Collaboration website (http://www.brightoncollaboration.org).
Appendix ASupplementary data associated with this commodity tin can be institute, in the online version, at https://doi.org/ten.1016/j.vaccine.2017.01.049.
Appendix A. Supplementary material
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Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5710991/
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