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Questions raised over Iraq congenital birth defects study

The release of a study on congenital birth defects in Iraq has been met with controversy, with

some experts questioning its methodology and peer review. Paul C Webster reports.

WHO officials have stepped in to

defend an unsigned and sharply

criticised report released by the

Iraqi Ministry of Health (MOH) on

congenital birth defects in areas where

US-led coalition forces used toxin-

laced munitions.

Although several recent studies

from Iraq reported worrying ratesof congenital birth defects in areas

where highly toxic munitions such as

depleted uranium shells were used by

British, US, and other coalition forces,

the new study, which was cofunded

by the Iraqi Government and WHO,

found no clear evidence to suggest

an unusually high rate of congenital

birth defects in Iraq. After initially

referring questions about the study

to Iraqi offi cials, Jaffar Hussain, WHOs

Head of Mission in Iraq, told the

The Lancet last week that the report isbased on survey techniques that are

renowned worldwide and on the

work of international experts who peer

reviewed the data extensively.

The study, which is based on a

2012 survey of mothers in 10 800

households from 18 Iraqi districts,

relies largely on mothers memories

of the details of spontaneous

abortions, stillbirths, and births with

congenital defects since the 1980s

(43 387 pregnancies). Citing a lack of

medical records for older events, theIraqi Government interviewers were

able to view medical files for only 32%

of the total reported cases.

Although warning that the surveyed

mothers recollections might not

be accurate, the report does note a

three-fold increase in reported birth

defects between 198892 (76 per

1000 births) and 200307 (262 per

1000 births). Nonetheless, it asserts

the rates for spontaneous abortion,

stillbirths and congenital birth defects

found in the study are consistent

with or even lower than international

estimates. The reported stillbirth rate

for 200812 is considerably lower

than WHO-established norms, the

study indicates, leading it to suggest

possible underreporting of stillbirths,

or that stillbirth rates in Iraq are lower

than estimated elsewhere.

WHO says that since the issueof associating birth defects with

exposure to depleted uranium has

not been included in the scope of

this particular study, establishing alink between the [congenital birth

defects] prevalence and exposure to

depleted uranium would require further

research. According to Jaffar, there is

still further room for more detailed

analysis and WHO is discussing

producing a more detailed report with

the Iraqi MOH.

The study notes that WHO offered

technical services to the Ministry,

and that WHO convened an expert

peer review meeting on the study

in late July with six experts from theLondon School of Hygiene and Tropical

Medicine (LSHTM), University College

London (UCL), the US Centers for

Disease Control and Prevention (CDC),

and the Norway-based Fafo Research

Foundation. WHO says this meeting

was organised after it was determined

the work should also undergo the

scientific standard of peer review.

That may not have been fully

achieved, however. Simon Cousens,

professor of epidemiology and

statistics at LSHTM, who was among

those invited by WHO to review the

study, says he attended a relatively

brief meeting of around one and a half

hours, so just gave some comments

on an early presentation of the results.

I wouldnt classify that as thorough

peer review.

At the CDC in Atlanta, Georgia,

spokeswoman Belsie Gonzalez confirm-ed that CDC officials did participate

in the peer review meeting at the

invitation of the WHO Regional Offi ce

for the Eastern Mediterranean. CDC did

not participate in any aspects of the

study. We provided data interpretation

advice on the report.

Several of WHOs expert reviewers

raise methodological concerns about

the study. Its main limitation is that

it is largely based on what people

reported, without any medical

examination, says Cousens. Atthe Fafo Foundation in Oslo, social

anthropologist John Pedersen adds

that the studys limited geographical

scope (Iraq has more than 100 districts)

sharply reduces its relevance in

understanding the national pattern

and prevalence of birth defects in Iraq.

I wouldnt necessarily have designed

the study in the same way as it was

designed, explains Pedersen, who

Children who were born with birth defects in Fallujah (pictured November, 2009)

The study...relies largely on

mothers memories of the

details of spontaneous

abortions, stillbirths, and births

with congenital defects since

the 1980s...

GettyImages

Published Online

October 1, 2013

http://dx.doi.org/10.1016/

S0140-6736(13)61812-7

For thereport on congenital

birth defects by the Iraqi

Government see http://www.

emro.who.int/images/stories/

iraq/documents/Congenital_

birth_defects_report.pdf

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notes that lower rates of birth defects

could be expected from mothersrecollections than if doctors had been

asked to report them.

I agree with Jon Pedersen that

there are limitations in the study

design, says Bernadette Modell,

emeritus professor of community

genetics at UCL. However, it is really

difficult to conduct epidemiological

studies of congenital disorders

outside a high-income setting,

because many congenital disorders

are difficult to diagnose without

sophisticated clinical and laboratoryfacilities and a relatively high

proportion of those that occur in

lower-income settings may be due to

environmental causes.

Taking these limitations into account,

Modell adds, I think the Iraq study was

pretty good, and as objective as was

feasible. I was particularly impressed

with the efficient organisation of

data-collection when the study was

underway. The reviewers all agreed

that the data provide no evidence

to support claims of an epidemic ofcongenital anomalies either nationally,

or in any particular area. However, the

study amassed a very large amount

of data, which needs further analysis,

ideally with expert assistance.

Keith Baverstock, author of a

2004 UN report that highlighted the

potential seriousness of Iraqs legacy

of intensive exposure to depleted

uranium ordinance employed by

British and American troops both

during the First Gulf War of 1991,

and after the US-led occupation in2003, says the reports reliance on the

term peer review does not conform

with conventional usage. Its really

misleading, he charges. I have to

question what the role of WHO is in

this study as a whole, Baverstock adds

after noting that the study names no

authors from WHO or the Iraqi MOH

although a WHO website does explain

it did provide technical assistance

on study design, methodology, data

collection, data analysis and report

writing. For his part, WHOs Jaffar

confirms that the ownership of study

and the authorship of the report iswith the MOH from the outset.

Researchers in Iraq, the UK, and the

USA who have probed congenital birth

defects and have published recent peer-

reviewed studies also express concerns

about the methodology employed by

the Iraqi MOH and WHO.

Although WHO says that at this

point no effort to neither substantiate

nor negate the findings of other studies

can be employed because the study is

not aiming to establish cause-effect

associations between [congenital birthdefects] prevalence and environmental

risk factors, the study issued by the

Iraqi Government states that in recent

years there have been several anecdotal

reports of geographical regions with

an unusually high prevalence ofcongenital birth defects in Iraq. Most

of the reports did not meet the norms

for an objective study of birth defects,

and a review of the published literature

could find no clear evidence to support

their findings.

Samira Alaani, a paediatrician

in Fallujah, Iraq, who copublished

a 2011 study utilising hospital

records to conclude that congenital

malformations accounted for 15% of

all births in Fallujah since 2003, says

the new study cofunded by WHO andthe Iraqi Government should have

employed hospital records more

comprehensively.

Muhsin Al-Sabbak of the Basrah

Medical School in Basrah, Iraq, who

copublished a 2012 study reporting

a 17-fold increase in birth defects in

the Al Basrah Maternity Hospital since

1994, warns that the data from Basrah

in the new study does not match local

hospital records.

Alison Alborz is a specialist on

learning disabilities in children at

the University of Manchester, UK,

who published a 2013 study present-ing data from a 2010 survey of

6032 households in four Iraqi govern-

ates including data for more than

10 000 children and young people

showing a prevalence of congenital

birth defects more than 25 times

higher than reported in the Iraqi

Government study. She says the new

report gives little information about

sampling and does not offer any

discussion of whether the districts

chosen for analysis reflect the charac-

teristics of the governorate as a whole.Mozhgan Savabieasfahani, a toxic-

ologist based in Michigan, USA, who

coauthored the Alaani and Al-Sabbak

studies, agrees with Alborz that the

selection criteria determined by the

MOH are not sufficiently explained.

Based on information available

in this report, we cannot rule out

selection bias issues, she warns.

She also questions the decision not

to employ hospital records more

comprehensively, and notes that the

report suffers from a lack of detailregarding which areas were exposed

to bombardment or heavy fighting

and which areas were not. The exposed

and unexposed populations remain

unidentified throughout.

Tariq Al-Hadithi of the Hawler

Medical University in Erbil, Iraq, who

undertook the literature review cited

by the Iraqi Government in describ-

ing the work of Alaani, Al Sabbak,

Alborz, and Savabieasfahani as not

meeting objective norms, reached a

conclusion that was far more tenta-tive than the Iraqi Government

suggests. As not enough data

on pre-1991 Gulf War prevalence

of birth defects are available,

Al-Hadithi stresses, the ranges of

birth defects reported in the reviewed

studies from Iraq most probably do

not provide a clear indication of a

possible environmental exposure

including [depleted uranium] or other

teratogenic agents.

Paul C Webster

...it is really diffi cult to conduct

epidemiological studies of

congenital disorders outside

a high-income setting...

For thepaper by Samira Alaani

and colleaguesseeInt J Environ Res Public Health

2011;8:8996

For the paper by

Muhsin Al-Sabbak and

colleaguessee

Bull Environ Contam Toxicol2012;

89:93744

For the paper by Alison Alborz

and colleaguessee

Med Confl Surviv2013; 29:2644