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CLINICAL REPORT
Effect of Maternal Psoriasis on Pregnancy and Birth Outcomes: A
Population-based Cohort Study from Denmark and Sweden
Gabriella BRÖMS 1,2 *, Ann HAERSKJOLD 3 *, Fredrik GRANATH 1 , Helle KIELER 1 , Lars PEDERSEN 4 and Ingegärd A. BERGLIND 1
1
Centre for Pharmacoepidemiology, Karolinska Institutet, 2 Division of Internal Medicine, Danderyd Hospital, Stockholm, 3 Department of
Dermatology and Venereology, Bispebjerg University Hospital, Copenhagen, and 4 Department of Clinical Epidemiology, Aarhus University
Hospital, Aarhus, Denmark
*These authors contributed equally.
Studies on pregnancy and birth outcomes in women
with psoriasis are scarce and the findings inconsistent.
The effect of maternal psoriasis and its severity on the
risk of adverse pregnancy and birth outcomes was exa-
mined. A cross-national population-based cohort study
was performed using prospectively collected data from
Denmark and Sweden. Singleton births in women with
psoriasis were identified in the national health regis-
ters between April 2007 and December 2012 and clas-
sified according to disease severity. Lifestyle factors,
co-morbidity, pregnancy and birth outcomes were eva-
luated. A total of 8,097 births were identified in 6,103
women with psoriasis and 964 births in 753 women
with psoriatic arthritis. Increased risk of gestational
diabetes, gestational hypertension, pre-eclampsia,
elective and emergency caesarean delivery was found
in women with psoriasis. The risks were higher for wo-
men with severe psoriasis, who also had an increased
risk of preterm birth and low birth weight. Pre-concep-
tion counselling to improve maternal, pregnancy and
birth outcome is encouraged.
Key words: psoriasis; adverse pregnancy and birth events; ob-
servational study.
Accepted Mar 15, 2018; Epub ahead of print Mar 15, 2018
Acta Derm Venereol 2018; 98: 728–734.
Corr: Ann Haerskjold, Department of Dermatology and Venereology,
Bispebjerg University Hospital, Bispebjergbakke 23, DK-2400 Copenha-
gen, Denmark. E-mail: [email protected]
P
soriasis is a complex chronic inflammatory disease.
Its pathophysiology is not fully understood, but
involves genetic, immunological, environmental, and
lifestyle-related factors. The prevalence of psoriasis in
women of reproductive age is approximately 1% (1).
A substantial proportion of patients with psoriasis de-
velop obesity, hypertension, diabetes mellitus, depression
and other chronic inflammatory diseases, such as inflam-
matory bowel disease (IBD) and rheumatoid arthritis
(RA) (2, 3), all of which have been associated with ad-
verse pregnancy and birth outcomes. Joint symptoms are
common among patients with psoriasis and 6–30% de-
velop psoriatic arthritis (PsA) (3). Furthermore, patients
with psoriasis are more prone to a generally unhealthy
doi: 10.2340/00015555-2923
Acta Derm Venereol 2018; 98: 728–734
SIGNIFICANCE
Psoriasis is a common chronic inflammatory disorder with
significant physical and psychological sequelae. This study
evaluated pregnancy and birth outcomes in Danish and
Swedish women with psoriasis. Increased risk of gesta-
tional diabetes, gestational hypertension, pre-eclampsia,
elective and emergency caesarean delivery was found in
women with psoriasis. The risks were higher for women
with severe psoriasis, who also had an increased risk of
preterm birth and low birth weight. Pre-conception coun-
selling to improve maternal, pregnancy and birth outcome
is encouraged.
lifestyle, including smoking, which is also associated
with adverse pregnancy and birth outcomes (4, 5).
Large population-based studies on pregnancy and
birth outcomes in women with psoriasis are scarce, and
the results of previous studies are inconsistent (6–10).
The aim of this study was to assess the effect of mater-
nal psoriasis and its severity on adverse pregnancy and
birth outcomes using a population-based register data in
Sweden and Denmark.
METHODS
Data collection
This observational population-based cohort study used data from
the national birth registers (11), the national patient registers, and
the national prescribed drug registers (12–15) in Denmark and
Sweden. The national birth registers include data on maternal
characteristics (age at delivery, parity, smoking habits, body mass
index (BMI)) and on pregnancy, delivery and the neonatal period.
The patient registers contain information on all hospitalizations
and outpatient visits to specialist care, including primary and
secondary diagnoses. Diagnoses are recorded according to the
International Classification of Diseases, version 10 (ICD-10) and
data are available from 1998 onwards in Sweden and Denmark.
The prescribed drug registers include data on the formulations and
date of all dispensed prescriptions. Drugs are categorized accor-
ding to the WHO Anatomical Therapeutic Chemical classification
(ATC codes). In Denmark, data on prescribed drugs have been
available since 1999 and in Sweden since July 2005. Individual
record linkage between the registers in each country is possible
through the unique p