Maternal and neonatal pregnancy outcomes in ankylosing spondylitis
Authors: Krichevskaya O. A. , Gandaloeva Z. M. , Klimenchenko N. I. , Dyomina A. B. , Dubinina T. V. 
Published: September 2020

Objective: To evaluate maternal and neonatal pregnancy outcomes in ankylosing spondylitis (AS) patients.

Subjects and methods. The prospective study included 36 pregnant women with AS (modified New York AS criteria, 1984), all participants were followed. Mean patients’ age was 31.6±4.8 years, age at disease onset – 21.8±10.9 years, duration of the disease – 134,9±89.3 months. Stage II-III sacroiliitis was diagnosed in 88.9% of women, stage IV – in 11.1%. AS activity levels measured by mean BASDAI score in I, II and III trimesters were 2,8±1,7 – 3,2±1,9 – 3,3±2,1, respectively.

Results. 34 pregnancies resulted in live births at median 39 [38; 40] weeks of gestation. Adverse pregnancy outcomes were documented in 2 cases (5.6%): a missed miscarriage at 18 weeks of gestation in a woman with burdened maternal obstetric history and moderate AS activity; and medical abortion at 23d week of gestation because of fetal critical condition owing to persistent high AS activity with severe axial and extra-articular manifestations of the disease. Most common pregnancy complications included threatened early miscarriage (11.1%), threatened premature labor (11.8%), infectious and inflammatory conditions (pyelonephritis in pregnancy, acute respiratory viral infections – 36,1%), iron-deficiency anemia (19,4%), gestational hypothyroidism (11,1%). Preterm birth was documented in 5,9% patients. No association was found between disease activity, therapy, and preterm birth. There were no cases of preeclampsia. 52.9% of the patients had vaginal delivery, and 47.1% had a caesarean section (CS), which was elective in 87.5% of all CS cases. Indications for elective CS included severe hip joints involvement with altered function, and scar on the uterus. Emergency C-section was performed in cases of uterine inertia and preterm discharge of amniotic fluid. Average birthweight of newborns was 3384.4±382.0 g, and length –51.5±2.0 cm, Apgar score was 8.0±0.4/8.9±0.4. Early neonatal complications were documented in 14,3% newborns, Congenital abnormalities were registered in 3 (8.6%) newborns: a slit-like defect of the atrial septum, a defect of the interventricular septum, and unilateral hydronephrosis.

Conclusion. Pregnancy outcomes in AS patients practically do not differ from those in general population, except for higher rates of elective C-sections, being generally favorable given AS activity is adequately controlled and gestation &delivery are thoroughly monitored. AS is not associated with higher rates of severe pregnancy complications and preterm birth. AS seemed to have no negative impact on newborn anthropometric data and health condition in general. No severe neonatal complications occurred. Considering the small sample size, it is impossible to draw definite conclusions about occurrence of various malformations in newborn to mothers with AS at this particular stage of the research. Interdisciplinary consensus is necessary in place to optimize pregnancy and birth management in AS patients