This prospective cohort study involved 48 pregnant women with psoriatic arthritis and ankylosing spondylitis attending the inpatient and outpatient clinics of Rheumatology & Rehabilitation and Obstetrics & Gynecology Departments, Faculty of Medicine, Zagazig University Hospital in Egypt and 30 apparently healthy age- and sex-matched pregnant women between January 12,018, and December 31, 2019.
All patients enrolled in this study provided informed consent before joining our study and all had the right to take away from the study without any interruption of their treatment plan and rights. All personal data of our enrolled patients were preserved and kept away from data retrieving personnel. A detailed flowchart (Fig. 1) was made for study demonstration.
The study group patients were diagnosed using modified New York criteria for ankylosing spondylitis [9] and classification for psoriatic arthritis (CASPAR) criteria [10].
Information was gathered in advance preconception (3 months to 1 year), throughout the 1st trimester (8–12 weeks), 2nd trimester (16–24 weeks) and 3rd trimester (28–34 weeks of pregnancy).
All pregnant women who consented to participate were enrolled at the 4 time points:
Complete medical history, medication exposures during pregnancy, obstetric history including maternal age, expected date of delivery, gravity, parity, gestational age at enrollment and at labour, pregnancy by ICSI, and previous preterm delivery or intrauterine growth retardation., family history, preconception body mass index (BMI), and socioeconomic status. Medication included start and end dates, indications, variations in dose and frequency, use of caffeine, nutritional supplements, folic acid intakes, infections, or antenatal investigation or other medical intervention. Any woman with other autoimmune diseases or other chronic diseases was excluded from the study.
General and local musculoskeletal examination.
Laboratory investigations.
The erythrocyte sedimentation rate (ESR) was determined by the Westergren method, the C-reactive protein (CRP) level was determined by the latex agglutination test, and HLA B27 (ELISA Kit) was estimated by collecting blood samples which stored at − 20 °C until tested for human HLA B27 using the Sunlong Biotech kit, China (catalog number: SL1056Hu).
IL-17A ELISA: ELISA is an enzyme-linked immunosorbent assay for the quantitative detection of human IL-17A. The kit was supplied by IBL International GmbH (Flughafenstr. 52A, 22,335 Hamburg, Germany).
Disease activity.
Using patient-reported assessments, including the Health Assessment Questionnaire (HAQ) [11] on a scale from 0 to 3, as well as pain score and patient global disease activity assessment on a scale from 0 to 100, the study group was evaluated at the same obstetric evaluation time points (pre-conceptional, first trimester, and third trimester). Next, the total pain score was divided by 10 for a range of 0–10, and the patient global assessment was performed in the same way. Cumulative Routine Assessment of Patient Index Data 3 (RAPID3) had three markers of disease activity and each marker was combined to yield a RAPID3 score ranging from 1 to 30, with active disease defined as a RAPID3 score ≥ 7 [12]. Active disease was defined as a HAQ score greater than 0.5.
Measures of pregnancy outcomes:
Premature birth (delivery before 37 weeks of gestation), small for gestational age (SGA—fetal weight is projected to be smaller than the 10th percentile for the child’s gestational age and sex), and delivery methods (vaginal or cesarean).
Inclusion criteria included a singleton pregnancy aged ≥18 years, with diagnosis of AS or PsA for at least 6 months, without major fetal anomalies, known chromosomal abnormalities or other autoimmune diseases, and gestational age of 28–40 weeks. Patients with a history of preterm labour, or any medical disorder were excluded from the study.
Ultrasound biometry measurements such as the biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL) were taken on each fetus. Hadlock’s formula gives the estimated fetal weight (EFW). William’s tables were used to obtain the overall EFW percentile. The tables determine the birth weight percentile by gestational age and sex, and they are from a large population-based study with a sample size large enough to calculate the percentile in question [13, 14].
Statistical analysis
Data collected throughout history, basic clinical examination, laboratory investigations and outcome measures were coded, entered and analyzed using Microsoft Excel software. The data collected were tabulated and analyzed by SPSS (statistical package for social science) version 25 (IBM, Armonk, NY, USA) on an IBM compatible computer.
Descriptive statistics were calculated for the data in the form of the mean and standard deviation± SD for quantitative data, and the frequency and distribution for qualitative data.
Regarding analytical statistics, in the statistical comparison between the different groups, the significance of differences was tested using one of the following tests after establishing their non normality by the Shapiro–Wilk test of normality: (1) Student’s t-test was used to compare the mean of two groups of quantitative data of parametric data. (2) the Mann-Whitney test (U test) was used to assess the statistical significance of the difference of a nonparametric variable between two study groups. (3) Intergroup comparison of categorical data was performed by using the chi square test (X2-value) and Fisher’s exact test (FET), and (4) Poisson regression yielded adjusted odds ratios with 95% confidence intervals. Poisson regression is used to predict a count outcome. These tests (Shapiro–Wilk test, Student’s t-test, and the Mann-Whitney test) help in demonstration of increased maternal and fetal risk in late pregnancy with increased disease activity and high IL-17 levels. A P value < 0.05 was considered statistically significant and > 0.05 statistically insignificant, while a P value < 0.01 was considered highly significant in all analyses.
