A 38-week Gestation, 2500-gram Infant Is Placed On Your Service. How Would She Be Described?

Vaccine. 2017 December 4; 35(48Part A): 6492–6500.

Low birth weight: Case definition & guidelines for data collection, assay, and presentation of maternal immunization safety data

Clare L. Cutland,^a, ^b, ^c, ^⁎ Eve M. Lackritz,^d Tamala Mallett-Moore,^e Azucena Bardají,^f Ravichandran Chandrasekaran,^thou Chandrakant Lahariya,^h Muhammed Imran Nisar,ⁱ Milagritos D. Tapia,^j Jayani Pathirana,^a, ^b, ^c Sonali Kochhar,^k, ^m, ^ane Flor M. Muñoz,^l and The Brighton Collaboration Low Nativity Weight Working Group²

Clare L. Cutland

^aMedical Research Council: Respiratory and Meningeal Pathogens Research Unit, Johannesburg, Due south Africa

^bDepartment of Science and Technology National Research Foundation, Vaccine Preventable Diseases, S Africa

^cFaculty of Wellness Sciences, Academy of the Witwatersrand, Johannesburg, South Africa

Eve M. Lackritz

^dGlobal Alliance to Prevent Prematurity and Stillbirth (GAPPS), Seattle Children's Inquiry Found, Seattle, WA, U.s.a.

Tamala Mallett-Moore

^{due east}Sanofi Pasteur Inc., Swiftwater, PA, USA

Azucena Bardají

^fISGlobal, Barcelona Ctr. Int. Wellness Res. (CRESIB), Hospital Clínic – University of Barcelona, Barcelona, Spain

Ravichandran Chandrasekaran

^gMadras Medical College, Republic of india

Chandrakant Lahariya

^hDepartment of Community Medicine, GR Medical College and Associated Hospitals, Gwalior, MP, India

Muhammed Imran Nisar

ⁱSection of Pediatrics and Kid Health, Aga Khan Academy, Karachi, Pakistan

Milagritos D. Tapia

^jUniversity of Maryland Schoolhouse of Medicine, Center for Vaccine Development, Medico, USA

Jayani Pathirana

^aMedical Inquiry Council: Respiratory and Meningeal Pathogens Enquiry Unit, Johannesburg, South Africa

^bDepartment of Scientific discipline and Technology National Enquiry Foundation, Vaccine Preventable Diseases, South Africa

^cFaculty of Wellness Sciences, Academy of the Witwatersrand, Johannesburg, Due south Africa

Sonali Kochhar

^mGlobal Healthcare Consulting, India

^gErasmus University Medical Center, Rotterdam, The Netherlands

Flor M. Muñoz

^lBaylor College of Medicine, Departments of Pediatrics, Molecular Virology and Microbiology, Houston, TX, United states

Keywords: Low birth weight, Agin consequence, Immunization, Guidelines, Case definition

1. Preamble

one.1. Need for developing case definitions and guidelines for data collection, analysis, and presentation for low birth weight as an adverse result following maternal immunization

The birth weight of an infant is the first weight recorded after birth, ideally measured inside the commencement hours after birth, earlier significant postnatal weight loss has occurred. Low birth weight (LBW) is divers every bit a nativity weight of less than 2500 g (upward to and including 2499 g), as per the World Health System (WHO) [1]. This definition of LBW has been in existence for many decades. In 1976, the 29th World Health Assembly agreed on the currently used definition. Prior to this, the definition of LBW was '2500 g or less'. Low birth weight is further categorized into very low birth weight (VLBW, <1500 g) and extremely low birth weight (ELBW, <1000 one thousand) [1]. Low nascence weight is a result of preterm birth (PTB, short gestation <37 completed weeks), intrauterine growth brake (IUGR, besides known as fetal growth restriction), or both.

The term low birth weight refers to an absolute weight of <2500 thousand regardless of gestational age. Pocket-size for gestational age (SGA) refers to newborns whose nascency weight is less than the 10th percentile for gestational age. This report will focus specifically on birth weight <2500 g. Further details related to case definitions for PTB [2], IUGR and SGA are included in separate GAIA reports.

Globally, it is estimated that 15–20% of all births, or >20 1000000 newborns annually, are low birth weight infants. Depression- and middle-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 Eastern asia and the Pacific, xiii% in Sub-Saharan Africa, and upward to 28% in South asia [iii]. Upward to half of all LBW infants are born in south asia [4]. Loftier-income regions study lower LBW rates, including half-dozen.9% from Great britain [5]. Of concern is the estimated increase in LBW rates in certain middle-income countries such as Oman, where the LBW rate went from 4% in 1980 to 8.ane% in 2000 [6].

One of the major challenges in monitoring the incidence of LBW is that more than than half of infants in the LMICs are not weighed [seven]. Population-based survey data ofttimes rely on modeled estimates, with statistical methods to adapt for underreporting and misreporting of birth weight. In the context of vaccine safety monitoring, accurate ascertainment of nativity weight in LMICs volition continue to require attention and investment to improve accuracy and reporting of this of import wellness indicator.

ane.1.1. Why are we concerned about low birth weight?

Low nativity weight is a valuable public health indicator of maternal health, nutrition, healthcare delivery, and poverty. Neonates with low birth weight have a >20 times greater take a chance of dying than neonates with birth weight of >2500 k [8], [nine]. Additionally, low nascence weight is associated with long-term neurologic disability, impaired language development [ten], impaired bookish achievement, and increased chance of chronic diseases including cardiovascular disease and diabetes. Preterm infants carry boosted take chances due to immaturity of multiple organ systems, including intracranial hemorrhage, respiratory distress, sepsis, blindness, and gastrointestinal disorders. Preterm birth is the leading cause of all under-v child mortality worldwide [11].

In add-on, economic studies in low-income settings have demonstrated that reducing the burden of low birth weight would have important cost savings both to the wellness system and to households [12].

1.1.2. 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 different [13], [14], [15]. The verbal cause of PTB may exist unknown in many cases, however numerous maternal, fetal and placental factors may contribute to PTB [13]. Significant maternal conditions include extra-uterine infection, chorioamnionitis, trauma and illness (east.g. pre-eclampsia/eclampsia). Significant fetal conditions include IUGR, fetal infection, death and anomalies. Placental pathologic conditions include placental abruption and placenta praevia [xiii].

In general, the causes of IUGR can be due to maternal, fetal, and placental factors. Although the etiologies are different, they often have the final common pathway of insufficient uterine-placental perfusion and fetal diet.

IUGR can be asymmetrical IUGR (where babies take features of malnutrition), symmetrical IUGR (hypoplastic small for dates) or mixed IUGR. Asymmetrical IUGR is the near mutual (seventy–80%) form of IUGR, resulting from an insult (often utero-placental insufficiency) later in pregnancy, which results in affected babies having normal length and caput circumference (brain sparing), but reduced weight. Symmetrical IUGR on the other hand arises from an insult (often genetic, structural or infectious) occurring earlier in pregnancy leading to a reduction in all anthropometric parameters in fetus/newborn [15].

Bereft perfusion, through abnormal placentation, aberrant placental vascularization, maternal hypertensive disorders, and tobacco use, all issue in IUGR. Multiple gestation (i.e., twins, triplets) is associated with increased risk of both IUGR and PTB [sixteen]. Infectious diseases, including intrauterine infections, HIV, and malaria, result in LBW due to both growth brake 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 child spacing, depression maternal education, poor antenatal intendance, substance abuse, and emotional and physical stress [5], [17], [eighteen], [nineteen]. How these factors are mediated biologically remains poorly understood.

Preterm birth may be spontaneous or medically-indicated, such every bit induction or cesarean department for maternal complications such as pre-eclampsia. Infectious and inflammatory processes are associated with increased risk for PTB, including chorioamnionitis, bacterial vaginosis, bacteriuria, and systemic or remote site infection such as sepsis and periodontal affliction.

1.1.3. The importance of brusque gestation on immune function and vaccine efficacy

Transplacental antibiotic transfer is an active process mediated by Fc receptors in the placental syncytiotrophoblast [twenty], which increases from 30 weeks gestation. Pocket-sized molecular weight particles (<600 Da) cross the placenta past passive mechanism including diffusion, however, larger molecular weight particles (>1000 Da) are transported beyond the placenta by and active receptor-mediated process [21]. Fetal IgG levels are approximately l% of maternal antibody level at 32 weeks gestation and rises rapidly through the third trimester [22]. Preterm newborns accept significantly lower antibody levels than term newborns [22]. LBW term newborns have significantly lower antibody concentrations to Herpes 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 determine the efficiency of placental antibody transfer [24]. Diseases that are highly prevalent in some areas, such equally malaria and man immunodeficiency virus (HIV), are known to cause placental damage, specially placental malaria [25], [26]. Maternal HIV infection has been consistently associated with reduced placental passage of antibodies against several common 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 production in the fetus and provides brusque-term passive immunity [32], conditioning the success of vaccination in newborns [33] which is especially of import in preterm and IUGR newborns. Multiple comorbidities are associated with both LBW and immune suppression, such as malnutrition and infection, thereby further exacerbating diminished immune function in the compromised newborn.

1.one.four. Maternal immunization and birth weight

Maternal infections, including influenza, have been associated with increased hazard of low birth weight newborns [34]. As a corollary, prevention of certain infections during pregnancy might have a protective effect against LBW. This has been observed in a maternal immunization trial conducted in Bangladesh [35], in which the mean birth weight of infants born to mothers who received an inactivated influenza vaccine during pregnancy was college than of infants built-in to mothers who received a pneumococcal polysaccharide vaccine (3178 thousand vs. 2978 1000, p = 0.02). This trend has not been observed in other maternal influenza immunization trials [36].

The field of immunization of pregnant women has highlighted the importance of knowing background rates of adverse pregnancy events, including LBW, PTB, SGA, IUGR, stillbirths, and neonatal death, which tin vary markedly between and within regions. The greatest impact of affliction prevention from maternal immunization is expected to be observed in LMIC, where the burden of disease is greatest and access to health care services is most 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 information are frequently express in these settings.

Information Safety Monitoring Boards are established to review clinical trial data, including regular assessment or review of adverse event rates in trial participants. Without authentic data on groundwork rates of low birthweight and other adverse pregnancy outcomes, information technology will be incommunicable to detect an increase in adverse events following immunization. Development of standardized methods to collect and report LBW and other essential outcomes will be essential to advancing maternal immunization programs worldwide.

Birth weight is usually included under demographics of trial participant infants, and the differences in birth weights between participants enrolled in agile and placebo or command arms of interventional trials in pregnancy are usually assessed.

The LBW Working Group recommends use of traditional case definitions of LBW as defined by the World Wellness Arrangement. This report therefore focuses on delineating data quality related to methods used to estimate nativity weight in LMICs, and summarizes some surrogate measurements that are under investigation to assess nativity weight and estimate population-level background LBW rates.

1.ii. Methods for the review of the case definition and guidelines for information collection, analysis, and presentation for low nascence weight in clinical trial and population settings

Following the process described in the overview newspaper [21] every bit well every bit on the Brighton Collaboration Website http://www.brightoncollaboration.org/cyberspace/en/index/procedure.html, the Brighton Collaboration Low nascence weight Working Group 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 equally well as results of the spider web-based survey completed by the reference group with subsequent discussions in the working group tin be viewed at: http://www.brightoncollaboration.org/cyberspace/en/index/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 birth weight', and restricted to English language language publications since 2005. The search resulted in the identification of 41 references. All abstracts were screened for possible reports of Depression nascency weight following immunization. Thirty-ii articles with potentially relevant fabric were reviewed in more than particular, in order 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 xix articles, including information on the report type, the vaccine, the diagnostic criteria or case definition put forth, the time interval since time of immunization, and whatsoever other symptoms. Multiple general medical, pediatric and communicable diseases volume capacity were also searched.

The definition of low birth weight used was consistent beyond all literature reviewed.

A second literature search using the search terms 'nascency weight and tools' was performed using Pubmed, to identify other measurements used as proxies for nativity weight. The search, unrestricted for language and year of publication, identified in 235 results. Titles were screened and x articles were identified for further review.

1.iii. Rationale for selected decisions about the case definition of low nascency weight as an adverse event post-obit maternal immunization

1.3.1. The term depression birth weight

'Low nascency weight' (LBW) has been defined as start weight recorded within hours of nativity of <2500 g. Very low birth weight (VLBW) is accepted as <1500 yard and extremely low birth weight (ELBW) is <chiliad g [1].

Within the definition context, nevertheless, the three diagnostic levels must non exist misunderstood as reflecting different grades of clinical severity. They instead reflect diagnostic certainty.

The levels of certainty have been formulated such that the Level one definition is highly specific for the condition. Two additional diagnostic levels take been included in the definition, offering a stepwise loss of precision and accuracy from Level One down to Level 3, while retaining an approach to expand utilization of available data. In this way information technology is hoped that data on low birth weight can be captured more broadly at the population level.

one.3.2. Timing of nativity weight assessment

The birth weight is described equally the first weight measured, however, in settings with low rates of facility-based deliveries, a newborn may not exist assessed by a health intendance worker until several days one-time. Nascence weight should be assessed within hours of birth, prior to meaning weight loss [37]. Term neonates lose between iii.5% and 6.6% of their birth weight within the commencement 2.v–2.7 days of life. Exclusively breastfed neonates have a greater weight loss (Median 6.6%, 95%CI 6.three–6.9%) than formula-fed (Median 3.5%, 95%CI 3.0–3.9%) or mixed fed (five.ix%, 95%CI 4.8–half-dozen.ix%) 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 outset 48 h of life. In the absenteeism of a weight measured within the first 48 h of life, a weight measured during the outset week of life, could be classified equally an 'early neonatal weight' only non 'birth weight'.

In a clinical trial scenario, measurement of weight within offset 48 h of life should be doable, as the clinical trial would procure adequate equipment, employ and railroad train staff to assess nascency weight in a timely manner, and enroll participants who reside in areas which are relatively easily accessed past trial or health intendance staff.

Many newborns globally are not weighed inside hours of nascency, mainly due to difficulty in accessing health care personnel, facilities, and essential equipment. Specific time frames for onset of symptoms post-obit immunization are not included for the following master reasons:

We postulate that a definition designed to be a suitable tool for testing causal relationships requires ascertainment of the outcome (e.one thousand. low nascence weight) independent from the exposure (e.g. immunizations). Therefore, to avoid selection bias, a restrictive time interval from immunization to birth of a LBW newborn should non be an integral part of such a definition. Instead, where viable, details of this interval should be assessed and reported as described in the data drove guidelines.

Further, measurement of birth weight often occurs exterior the controlled setting of a clinical trial or hospital. In some settings it may be incommunicable to obtain a articulate timeline of the assessment of a birth weight, particularly in less developed or rural settings. In club to avert selecting against such cases, the Brighton Collaboration case definition avoids setting capricious time frames. The fourth dimension between delivery and measurement of nascence weight should be recorded and accounted for in the assay.

1.4. Guidelines for data collection, analysis and presentation

As mentioned in the overview paper [38], the case definition is accompanied past guidelines which are structured according to the steps of conducting a clinical trial, i.eastward. data collection, assay and presentation. Neither instance definition nor guidelines are intended to guide or establish criteria for direction of ill infants, children, or adults. Both were developed to amend standardization of instance definitions and data comparability.

ane.5. Periodic review

Similar to all Brighton Collaboration case definitions and guidelines, review of the definition with its guidelines is planned on a regular footing (i.e. every three to five years) or more ofttimes if needed.

2. Instance definition of low birth weightⁱⁱⁱ

Level i of diagnostic certainty

Newborn infant weighed within 24 h of birth	AND
Use electronic scale which is graduated to 10 g	AND
Scale is calibrated at least once a year	AND
Scale placed on level, hard surface	AND
Scale tared to zero grams	AND
Weight recorded as <2500 g	OR
Birth weight recorded as <2500 yard	AND
Birth weight assessed every bit per wellness care facility's standard operating procedure, which fulfills criteria ane to 5 of LOC1

Level ii of diagnostic certainty

Newborn babe weighed within 24 h of nascence	AND
Calibration (electronic/spring) is graduated to at least 50 yard	AND
Scale is calibrated at least once a year, or more often if moved	AND
Scale tared to zero grams or 0.00 kg	AND
Weight recorded as <2500 g	OR
Nativity weight recorded as <2500 g	AND
Nascency weight assessed as per wellness care facility's standard operating procedure, which fulfills criteria 1 to four 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 (first 48 h of life)	AND
Weight measured using dial/spring/colour-coded calibration	AND
Weight assessed as <2500 g

Level 4 of diagnostic certainty

Newborn infant 'weight' assessed on 24-hour interval 1 or ii of life (first 48 h of life)	AND
Proxy mensurate of nascence weight used	AND
Weight CATEGORY assessed as <2500 g

In many settings, including loftier-income countries, nascency weight is assessed by a health intendance provider who is bellboy during/soon afterwards delivery, and not the vaccine trialist/researcher. The details of time of birth weight assessment, and details of scale used and calibration details are normally not recorded in newborn assessment medical notes.

The newborn weight assessment is presumed to be assessed accurately as per wellness care eye's standard operating procedures. In many instances, trialists need to rely on the attending medical staff at health care facility for birth weight assessment. Strengthening preparation and oversight of nascence weight measurement would be expected to strengthen data both in clinical trials and mail-marketing surveillance.

2.1. Other tools under investigation to estimate birth weight in individuals and populations

Up to 60 one thousand thousand infants are born at habitation annually [39], and up to 48% of infants worldwide are not weighed at nativity [3]. Lack of access to health care facilities or health intendance workers hampers accurate assessment of low nascence weight rates in many regions. In society to identify small newborns, who could be preterm, IUGR, or both, who require additional intendance, inexpensive 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 congenital malformations [40].

Several anthropometric measurements, including chest circumference, pes length and mid-upper arm circumference, have been assessed as proxies for nascence weight [41], [42], [43], [44]. Table 1 summarizes these tools and their validity for identifying low birth weight newborns. These tools at this signal are considered investigational and take been included in level four definition only, which indicates that prove is inadequate to meet the definition, however, may exist useful for population background LBW estimates.

Table 1

Validated tools used as proxy measures of birth weight.

	Measurement	Method of assessment	Cut-off values used	Comments
Newborn pes length [41], [42], [43], [46]	Foot length from center of heel pad to tip of big toe in millimeters	Hard plastic ruler pressed vertically against sole of foot (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	vii.8 cm for preterm [41]
			⩽vii.four cm (7.3–7.4 cm) for 2500 g [43]	AUC 0.94, 95%CI 0.92–0.96 [43]
			For <2500 g
		Footprint made on White paper, and tip of big toe and heel marked with pencil	vii.ii cm (Europe)	<eight cm at birth was 87% sensitive for LBW [46]
			6.3–vii.85 cm (Asia)
			7.iv–8 cm (Africa)
Chest circumference [42], [43]	Chest circumference at level of nipples in centimeters	Not-rubberband, flexible measuring tape graduated to nearest 0.ane cm, measured during expiration	⩽30.4 cm (30.0–30.4 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-analysis, all-time anthropometric measurement to predict LBW [47]
				Hazard of hypothermia
Mid upper arm circumference [43]	Mid-point betwixt tip of acromion process and olecranon process in centimeters	Not-elastic, flexible measuring record graduated to nearest 0.1 cm	⩽9.0 cm (8.vii–9.0 cm) [43]	Highly predictive of LBW if measured at <24 h of age (AUC 0.98, 95%CI 0.96–0.99) [43]

In add-on to these measurements, other tools are utilized in some communities to assess nascence weight, including departure between adult weight with and without newborn in artillery (see Fig. 1).

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Tools used to measure birth weight (Run across above-mentioned references for further information.).

3. Guidelines for data collection, analysis and presentation of depression nascency weight

It was the consensus of the Brighton Collaboration Working Group for Low birth weight to recommend the post-obit guidelines to enable meaningful and standardized collection, assay, and presentation of information well-nigh low nativity weight. Withal, implementation of all guidelines might non exist 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, mail-marketing surveillance, or an individual report. Also, as explained in more than detail in the overview paper [38], these guidelines accept been developed past this working grouping for guidance merely, and are not to be considered a mandatory requirement for data collection, analysis, or presentation.

iii.ane. Information collection

These guidelines represent a desirable standard for the drove of data on availability post-obit immunization to allow for comparability of data, and are recommended as an add-on to information collected for the specific study question and setting. The guidelines are not intended to guide the primary reporting of low birth weight to a surveillance organization or written report monitor. Investigators developing a data collection tool based on these data collection guidelines also need to refer to the criteria in the example definition, which are not repeated in these guidelines.

Guidelines numbers below have been developed to address data elements for the drove of adverse event information every bit specified in full general drug safety guidelines by the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Employ [49], and the form for reporting of drug agin events past the Council for International Organizations of Medical Sciences [50]. These information elements include an identifiable reporter and patient, 1 or more prior immunizations, and a detailed description of the adverse event, in this case, of low birth weight post-obit immunization. The boosted guidelines have been adult equally guidance for the collection of additional information to allow for a more comprehensive understanding of low nascence weight following maternal immunization.

iii.1.1. Source of data/reporter

For all cases and/or all study participants, as appropriate, the following information should be recorded:

(1)

Date of report.
(two)

Name and contact data of person reporting^iv and/or diagnosing low birth weight as specified past land-specific information protection law.
(3)

Name and contact information of the investigator responsible for the subject field, as applicable.
(4)

Relation to the patient (east.k., healthcare provider, immunizer, community health worker, family unit member [point relationship], other).

3.ane.two. Vaccinee/control

3.1.ii.1. Demographics

For all cases and/or all study participants, as appropriate, the following information should be recorded:

(5)

Case/study participant identifiers for mother and newborn (due east.grand. first name initial followed past last name initial) or code (i.e. hospital identifier or in accordance with land-specific information protection laws). Each newborn should accept a unique identifier, ideally linked to mother's identifier (due east.yard. participant lawmaking could be same for female parent and babe(ies), with an added prefix/suffix to place mother/baby).
(six)

Maternal date of birth, or if not bachelor, maternal historic period.
(7)
For each infant: Date and time of delivery, unmarried or multiple, live birth vs. fetal decease (fresh or macerated), estimated gestational age, method of determination of gestational age (LMP, fundal superlative, kickoff trimester ultrasound) and nascence weight.
- •
  
  For collection of birth weight, ideally record timeline of weight measurement (e.one thousand. time of delivery to time of weight), blazon of scale used (e.chiliad. surface-mounted spring) and place where nascence weight was measured (e.g. health care facility, mobile health worker visiting home).

3.1.ii.2. Clinical and immunization history

For all cases and/or all study participants, every bit appropriate, the following information should be recorded:

(8)

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; nutrient 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 handling with long one-half-life or long term effect. (E.g. immunoglobulins, blood transfusion and immunosuppressants).
(10)

Immunization history (i.e. previous immunizations and whatever adverse consequence following immunization (AEFI)), in particular occurrence of depression birth weight afterwards a previous maternal immunization.

three.1.three. Details of the immunization

For all cases and/or all written report participants, every bit advisable, the following information should exist recorded:

(11)

Engagement and time of maternal immunization(s).
(12)

Description of vaccine(due south) (name of vaccine, manufacturer, lot number, dose (e.thou. 0.25 mL, 0.5 mL), vaccine diluent (limerick and lot number) and number of dose if function of a serial of immunizations confronting the aforementioned disease).
(13)

The anatomical sites (including left or right side) of all immunizations (e.g. vaccine A in proximal left lateral thigh, vaccine B in left deltoid).
(14)

Road and method of administration (e.k. intramuscular, intradermal, subcutaneous, and needle-free (including blazon and size), other injection devices).
(15)

Needle length and approximate.

3.one.four. The adverse 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 exist recorded.

Specifically document:

(17)

Severity of Depression nascence weight (LBW, VLBW or ELBW), and if there was medical confirmation of the LBW (i.eastward. patient seen by physician/other health care worker).
(18)

Appointment/time of observation,^v and diagnosis.⁶
(xix)

Concurrent signs, symptoms, and diseases, including prematurity.
(xx)
Measurement/testing.
- •
  
  Values and units of routinely measured parameters (grams for birth weight);
- •
  
  Method of measurement (e.g. blazon of scale.);
- •
  
  Weight should be recorded with minimal or ideally no clothing;
(21)

Objective clinical evidence supporting classification of the event as "serious".^seven
(22)

Exposures other than the immunization 24 h earlier and after immunization (e.g. infection, environmental) considered potentially relevant to the reported upshot.⁸

iii.1.5. Miscellaneous/general

(23)

The duration of surveillance for low nativity weight should exist from 0 to 48 h of life. Any weight measured after 48 h of age should not exist considered a 'birth weight'.⁹
(24)

Methods of data collection should exist consistent inside and betwixt study groups, if applicable.¹⁰
(25)

Investigators of patients with low birth weight should provide guidance to reporters to optimize the quality and completeness of data provided.

3.2. Data analysis

The following guidelines represent a desirable standard for analysis of data on low birth weight to allow for comparability of data, and are recommended as an addition to data analyzed for the specific report question and setting.

(26)

Reported events should be classified in one of the following five categories including the three levels of diagnostic certainty. Events that see the case definition should be classified co-ordinate to the levels of diagnostic certainty equally specified in the instance definition. Events that exercise not run into the case definition should be classified in the additional categories for assay.

Event classification in 5 categories

Event meets case definition

(1)

Level 1: Criteria as specified in the Depression nascence weight case definition
(two)

Level 2: Criteria as specified in the Low nascence weight case definition
(3)

Level 3: Criteria as specified in the Low birth weight case definition

Upshot does not run into instance definition

Additional categories for analysis

(4)

Reported Low birth weight with insufficient evidence to run across the example definition.⁷
(five)

Birth weight not assessed, therefore data unavailable.
(27)

The interval between immunization and reported Low nascency weight could be defined as the date/time of immunization to the date/time of assessment⁴ of birth weight. If few cases are reported, the physical fourth dimension course could be analyzed for each; for a large number of cases, information can be analyzed in the following increments.
(28)

If nativity weight is assessed past more 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.thou. LBW < 2500 thousand, VLBW < 1500 one thousand, ELBW < 1000 g). Increments specified to a higher place should be used. When simply a minor number of cases are presented, the respective values can be presented individually.
(30)

Information on Low birth weight obtained from participants whose mothers received a vaccine should exist compared with those obtained from an appropriately selected and documented command grouping to appraise background rates of LBW in not-exposed populations, and should exist analyzed by study arm and dose where possible, east.grand. in prospective clinical trials.

iii.3. Data presentation

These guidelines represent a desirable standard for the presentation and publication of data on Low birth weight following immunization to allow for comparability of data, and are recommended as an improver to information presented for the specific study question and setting. Additionally, it 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 (due east.g. 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 Depression birth weight should be presented co-ordinate to the categories listed in guideline 31.
(32)

Data on Depression birth weight events should be presented in accordance with information collection guidelines 1–25 and data assay guidelines 26–xxx.
(33)

Data should be presented as rates with a numerator and denominator (n/Due north) (and not only in percentages), with confidence intervals around the indicate estimates.

Although immunization safety surveillance systems denominator data are commonly not readily available, attempts should be fabricated to identify approximate denominators. The source of the denominator data should be reported and calculations of estimates exist described (e.g. manufacturer information like total doses distributed, reporting through Ministry building of Health, coverage/population based data, etc.).

(34)

The incidence of cases in the study population should be presented and conspicuously identified every bit such in the text.
(35)

If the distribution of birth weight data is skewed, median and range are usually the more than appropriate statistical descriptors than a mean. However, the mean and standard deviation should as well be provided.
(36)
Any publication of data on Low birth weight should include a detailed description of the methods used for information collection and analysis every bit possible. It is essential to specify:
- •
  
  The study design;
- •
  
  The method, frequency and duration of monitoring for Low birth weight;
- •
  
  The trial contour, indicating participant flow during a study including driblet-outs and withdrawals to signal the size and nature of the respective groups under investigation;
- •
  
  The blazon of surveillance (e.g. passive or agile surveillance);
- •
  
  The characteristics of the surveillance system (east.yard. population served, mode of report solicitation);
- •
  
  The search strategy in surveillance databases;
- •
  
  Comparison grouping(s), if used for analysis;
- •
  
  The instrument of data collection (due east.g. standardized questionnaire, diary bill of fare, report class);
- •
  
  Whether the day of immunization was considered "day 1" or "day zero" in the assay;
- •
  
  Whether the date of onset⁴ and/or the date of first observation⁵ and/or the date of diagnosis⁶ was used for assay; and
- •
  
  Utilize of this case definition for Depression birth weight, in the abstruse or methods section of a publication.^eleven

Disclaimer

The findings, opinions and assertions independent in this consensus document are those of the individual scientific professional members of the working grouping. They practice not necessarily represent the official positions of each participant's organization (e.g., authorities, university, or corporation). Specifically, the findings and conclusions in this paper are those of the authors and do non necessarily stand for the views of their respective institutions.

Acknowledgements

The authors are grateful for the back up and helpful comments provided by the Brighton Collaboration Steering Committee and Reference group, also every bit other experts consulted as part of the procedure. The authors would like to thank the following working group 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 also grateful to Jan Bonhoeffer, Jorgen Bauwens of the Brighton Collaboration Secretariat and Sonali Kochhar of Global Healthcare Consulting for final revisions of the terminal document.

Footnotes

³The case definition should exist applied when there is no clear alternative diagnosis for the reported event to account for the combination of symptoms.

^ivIf the reporting middle is dissimilar from the vaccinating center, appropriate and timely communication of the agin outcome should occur.

^fiveThe date and/or time of observation is defined as the time post immunization, when the Low nativity weight was recorded.

^viThe date of diagnosis of an episode is the day mail immunization when the effect met the case definition at any level.

^viiAn AEFI is defined as serious by international standards if information technology meets i or more of the following criteria: (1) it results in death, (two) is life-threatening, (3) information technology requires inpatient hospitalization or results in prolongation of existing hospitalization, (four) results in persistent or meaning disability/incapacity, (5) is a built anomaly/birth defect, (6) is a medically of import event or reaction.

⁸To determine the appropriate category, the user should get-go constitute, whether a reported event meets the criteria for the everyman applicable level of diagnostic certainty, eastward.g. Level three. If the everyman applicable level of diagnostic certainty of the definition is met, and at that place is evidence that the criteria of the next higher level of diagnostic certainty are met, the result should exist classified in the adjacent category. This arroyo should exist connected until the highest level of diagnostic certainty for a given consequence could be adamant. Major criteria tin can be used to satisfy the requirement of pocket-size criteria. If the lowest level of the case definition is non met, it should be ruled out that any of the higher levels of diagnostic certainty are met and the event should exist classified in boosted categories four or 5.

⁹If the evidence available for an upshot is bereft because information is missing, such an event should be categorized equally "Reported Low birth weight with insufficient evidence to meet the case definition".

¹⁰An event does non meet the case definition if investigation reveals a negative finding of a necessary criterion (necessary condition) for diagnosis. Such an event should exist rejected and classified as "Not a case of Low birth weight".

^elevenUse of this certificate should preferably be referenced by referring to the respective link on the Brighton Collaboration website (http://www.brightoncollaboration.org).

^{Appendix A}Supplementary data associated with this commodity tin can be establish, in the online version, at https://doi.org/10.1016/j.vaccine.2017.01.049.

Appendix A. Supplementary material

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