Fertility rates and pregnancy outcomes in women with psoriasis and psoriatic arthritis: a population-based cohort study

Study type
Protocol
Date of Approval
Study reference ID
20_197
Lay Summary

Psoriasis is an immune-mediated, chronic inflammatory skin condition which often presents with red patches of skin with surrounding silvery scales, and psoriatic arthritis is a long-term painful inflammatory arthritis that occurs in people with psoriasis. Almost half of adults affected with psoriasis, or psoriatic arthritis (PsA) are women in whom the average age of diagnosis is usually during the reproductive years. This may pose specific challenges and may potentially impact on their fertility.

Psoriasis and PsA are known to impact on personal relationships and sexual functioning. Furthermore, studies have reported that people with these conditions smoke and drink alcohol more often than those without the condition. In addition, psoriasis and PsA frequently occur along with other medical conditions such as depression, high blood pressure, diabetes, cardiovascular disease and inflammatory bowel disease, all of which have been linked with a higher risk of developing complications during pregnancy. Despite this, little is known regarding the impact psoriasis or PsA may have on pregnancy and its outcomes. Studies on pregnancy and pregnancy outcomes in women with psoriasis or PsA are few, typically of small size, and have reported conflicting findings.

Therefore, we aim to investigate the pregnancy rate and the relationship between psoriasis and PsA and serious pregnancy outcomes, including maternal death, development of high blood pressure and diabetes during pregnancy, still birth, low birth weight, and premature birth.

Technical Summary

Psoriasis and psoriatic arthritis (PsA) are chronic inflammatory disorders that are associated with a number of co-morbidities including obesity, metabolic syndrome, cardiovascular disease, psychiatric diseases and other inflammatory diseases, such as inflammatory bowel disorders. Psoriasis and PsA are known to have a considerable psychosocial impact which may affect personal relationships and social interactions as well as result in maladaptive coping mechanisms and unhealthy lifestyle behaviours including smoking and alcohol excess.

Almost 50% of patients affected with psoriasis and PsA are women in whom the average age of onset of the disease is before 40 years of age, coinciding with the peak reproductive years. This overlap may pose specific challenges. Specifically, psoriasis and PsA have been negatively associated with sexual function, which may affect the fertility rate in women affected with these conditions. Furthermore, the comorbidities and the unhealthy lifestyle behaviours associated with psoriasis and PsA have been associated with adverse pregnancy and birth outcomes.

Despite this, studies examining fertility rate, pregnancy and birth outcomes in women with psoriasis and PsA are scarce, typically of small size including less than 100 women, and have reported conflicting results. Therefore, this study aims to generate evidence relating to trends in the fertility rate and risk of adverse pregnancy and birth outcomes in mothers with psoriasis or PsA compared to those without the diseases using data obtained from CPRD GOLD. Fertility rate ratios and odds ratios for adverse pregnancy and birth outcomes among women with psoriasis or PsA will be estimated from logistic regression models by comparing to women without the diseases. Findings from this study will add to the limited existing knowledge, thus, providing patients and clinicians, including general practitioners, dermatologists, rheumatologists and obstetricians, with guidance to ensure these patients and their offspring achieve optimal outcomes.

Health Outcomes to be Measured

Outcome 1 – Fertility rates per year
• Pregnancy rates (live births, still births and miscarriages)
• Live birth rates

Outcome 2 – Pregnancy outcomes
• Gestational diabetes
• Antenatal haemorrhage
• Venous thromboembolism during pregnancy
• Preeclampsia or evidence of preeclampsia (e.g. gestational hypertension)

Outcome 3 – Birth outcomes
• Maternal death
• Post-natal mental illness (e.g. depression or psychosis)
• Pre-term birth (<37 weeks vs. ?37 weeks of gestation)
? Moderate pre-term (32-36 weeks of gestation)
? Very pre-term (<32 weeks of gestation)
• Live births, still birth and miscarriages
• Low birth weight (<2500g vs. ?2500g)
• Mode of delivery (elective or emergency caesarean section compared to normal delivery)
• Neonatal death

Collaborators

Darren Ashcroft - Chief Investigator - University of Manchester
Teng-Chou Chen - Corresponding Applicant - University of Manchester
Christopher Griffiths - Collaborator - University of Manchester
Elise Kleyn - Collaborator - University of Manchester
Ireny Iskandar - Collaborator - University of Manchester
Matthias Pierce - Collaborator - University of Manchester
Rosa Parisi - Collaborator - University of Manchester

Linkages

CPRD Mother-Baby Link;HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation;Pregnancy Register