A C TA Obstetricia et Gynecologica
AOGS M A I N R E SE A RC H A R TI C LE
Rheumatoid arthritis and outcomes in first and subsequent births based on data from a national birth registry MARIANNE WALLENIUS1,2, KJELL A. SALVESEN3,4, ANNE K. DALTVEIT5,6 & JOHAN F. SKOMSVOLL1,2 1
National Service for Pregnancy and Rheumatic Diseases, Department of Rheumatology, Trondheim University Hospital, Trondheim, Norway, 2Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway, 3Department of Obstetrics and Gynecology, Clinical Sciences, Lund University, Lund, Sweden, 4Department of Laboratory Medicine, Women’s and Child Health, Norwegian University of Science and Technology, Trondheim, Norway, 5 Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway, and 6Medical Birth Registry of Norway, Division of Epidemiology, Norwegian Institute of Public Health, Bergen, Norway
Key words Birth registry, pregnancy outcomes, rheumatoid arthritis, first birth, subsequent births Correspondence Marianne Wallenius, National Service for Pregnancy and Rheumatic Diseases, Department of Rheumatology, St Olav’s Hospital (Trondheim University Hospital), Bevegelsessenteret, 7006 Trondheim, Norway. E-mail: [email protected] Conflicts of interest The authors have stated explicitly that there are no conflicts of interest in connection with this article. Please cite this article as: Wallenius M, Salvesen K A, Daltveit AK, Skomsvoll JF. Rheumatoid arthritis and outcomes in first and subsequent births based on data from a national birth registry. Acta Obstet Gynecol Scand 2014; 93:302–307. Received: 29 May 2013 Accepted: 13 December 2013 DOI: 10.1111/aogs.12324
Abstract Objective. To examine associations between rheumatoid arthritis (RA) and pregnancy outcomes in first and subsequent births. Design. Cohort study. Setting. Study based on data registered in the Medical Birth Registry of Norway from the period 1 December 1998 to 31 December 2009. Population. Singleton births in women recorded with RA (n = 1496) and reference deliveries from the general population (n = 625 642). Methods. Outcomes of first and subsequent births were analyzed separately. First birth was defined as the first delivery of nulliparous women. Associations between RA and maternal and perinatal outcomes were assessed in logistic regression analyses and adjusted for maternal age at delivery, gestational age, smoking habits and for previous cesarean section when relevant. Main outcome measures. Maternal and perinatal outcomes. Results. Vaginal bleeding was observed more often among women with RA both in first pregnancy [adjusted odds ratio (aOR) 1.8, 95% CI 1.3– 2.4] and in subsequent pregnancies (aOR 1.4, 95% CI 1.1–1.9). Elective cesarean section was more common among women with RA both in the first birth (aOR 2.0, 95% CI 1.4–2.8) and in subsequent births (aOR 1.5, 95% CI 1.2– 2.0). Preterm delivery was more frequent among women with RA than the reference population in first pregnancy (aOR 1.5, 95% CI 1.1–2.0) and in subsequent pregnancies (aOR 1.5, 95% CI 1.1–1.9). Conclusion. Complications and poor pregnancy outcomes were more often observed in women with RA and the greatest differences were observed in the first pregnancy. aOR, adjusted odds ratios; CI, confidence interval; CIJD, chronic inflammatory joint diseases; CS, cesarean section; MBRN, Medical Birth Registry of Norway; NSAIDs, non-steroidal anti-inflammatory drugs; RA, rheumatoid arthritis.
Abbreviations:
Introduction
Key Message
Rheumatoid arthritis (RA) is a chronic, autoimmune disease characterized by destructive synovitis and may also affect the internal organs. The estimated prevalence of RA is about 0.5–1.0% in European and North American adults (1). In a Norwegian patient register, the female: male ratio was >4 in people of premenopausal age (2). Chronic inflammatory joint diseases (CIJD) include RA,
Women with rheumatoid arthritis (RA) had pregnancy complications and poor outcomes more often than women without the disease, both in the first and subsequent pregnancies. Major malformations or perinatal death were not observed more frequently among the women with rheumatoid arthritis.
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ª 2013 Nordic Federation of Societies of Obstetrics and Gynecology, Acta Obstetricia et Gynecologica Scandinavica 93 (2014) 302–307
M. Wallenius et al.
psoriatic arthritis, ankylosing spondylitis, and juvenile idiopathic arthritis. Several studies have addressed effects of CIJD combined or RA specifically on pregnancy and delivery (3–8). Specific studies of RA and pregnancy outcomes are necessary because the effects of pregnancy may differ between RA and other CIJD. New classification criteria for RA (9) and for other CIJD (10,11), the treat-to-target principle (12), and the introduction of biological diseasemodifying anti-rheumatic drugs have changed the patient populations, and probably also the course of the disease in pregnancy. Pregnancy and delivery complications are more frequent in the first pregnancy and delivery (13–15). The risk of cesarean section (CS) in nulliparous women with spontaneous start of labor and the fetus in a cephalic presentation has been reported to be 2.5 times higher than for comparable parous women without a previous CS (16). The causes for this increased risk are not fully understood, although it has been known for more than 40 years (17,18). In only one previous study of women with CIJD have outcomes of first and subsequent births been analyzed separately, and the study showed that the first birth was associated with the highest risks (8). Separate analyses of outcomes in first and subsequent births in women diagnosed with RA have not been previously published. The aim of this study was to examine pregnancy outcomes in first and subsequent births in women diagnosed with RA compared with reference women from the general population with focus on mode of delivery, smallfor-gestational age, preterm birth, perinatal death and congenital malformations.
Material and methods The Medical Birth Registry of Norway (MBRN) was established in 1967 and comprises more than 2.2 million births (19). The birth notification forms are completed by birth attendants and sent to the MBRN within 1 week of delivery. The information in the forms is based on three elements: (i) a standardized form used during pregnancy by the woman’s physician, (ii) oral information given by the woman when admitted to the hospital, and (iii) information from the doctor and the midwife about the actual delivery and the newborn. The MBRN used one notification form from 1967 to 1998, but a more detailed form was introduced from 1 December 1998. This new form includes all births (spontaneous abortions, live births and stillbirths) after 12 weeks of gestation, and data on complications, maternal disease and mode of delivery are entered in textboxes and/or as free text (19). Data from the MBRN are routinely linked to the Cause of Death
Rheumatoid arthritis and pregnancy outcome
Registry by a national, unique identification number to obtain information on infant mortality. The MBRN includes data on the mother’s health at birth, before and during pregnancy and characteristics of the newborn within the first week after delivery. After 1 December 1998, all women diagnosed with RA were registered by specific coding according to the International Classification of Diseases 10th revision (ICD-10) systems. The diagnosis is based on information from the woman’s physician and information in the patient records at the hospital. In the present study we have used data from women diagnosed with RA giving birth in the period 1 December 1998 to 31 December 2009. The study was carried out in compliance with the Helsinki Declaration and was approved by the Regional Ethics Committee of Central Norway (2011/127-3). Women diagnosed with RA in the MBRN registry (ICD-10 codes M05.0, M05.1, M05.2, M05.8, M05.9, M06.0, M06.8, M06.9) were compared with all other deliveries from 1 December 1998 to 31 December 2009 where the mother did not have CIJD. Anonymized births were stratified in first and subsequent births. Only data for single births were analyzed. Data on maternal characteristics, smoking habits, chronic hypertension (hypertension diagnosed before pregnancy), assisted reproduction (all methods combined), preeclampsia, induction of labor (amniotomy, oxytocin, prostaglandin), preterm delivery (
AOGS M A I N R E SE A RC H A R TI C LE
Rheumatoid arthritis and outcomes in first and subsequent births based on data from a national birth registry MARIANNE WALLENIUS1,2, KJELL A. SALVESEN3,4, ANNE K. DALTVEIT5,6 & JOHAN F. SKOMSVOLL1,2 1
National Service for Pregnancy and Rheumatic Diseases, Department of Rheumatology, Trondheim University Hospital, Trondheim, Norway, 2Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway, 3Department of Obstetrics and Gynecology, Clinical Sciences, Lund University, Lund, Sweden, 4Department of Laboratory Medicine, Women’s and Child Health, Norwegian University of Science and Technology, Trondheim, Norway, 5 Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway, and 6Medical Birth Registry of Norway, Division of Epidemiology, Norwegian Institute of Public Health, Bergen, Norway
Key words Birth registry, pregnancy outcomes, rheumatoid arthritis, first birth, subsequent births Correspondence Marianne Wallenius, National Service for Pregnancy and Rheumatic Diseases, Department of Rheumatology, St Olav’s Hospital (Trondheim University Hospital), Bevegelsessenteret, 7006 Trondheim, Norway. E-mail: [email protected] Conflicts of interest The authors have stated explicitly that there are no conflicts of interest in connection with this article. Please cite this article as: Wallenius M, Salvesen K A, Daltveit AK, Skomsvoll JF. Rheumatoid arthritis and outcomes in first and subsequent births based on data from a national birth registry. Acta Obstet Gynecol Scand 2014; 93:302–307. Received: 29 May 2013 Accepted: 13 December 2013 DOI: 10.1111/aogs.12324
Abstract Objective. To examine associations between rheumatoid arthritis (RA) and pregnancy outcomes in first and subsequent births. Design. Cohort study. Setting. Study based on data registered in the Medical Birth Registry of Norway from the period 1 December 1998 to 31 December 2009. Population. Singleton births in women recorded with RA (n = 1496) and reference deliveries from the general population (n = 625 642). Methods. Outcomes of first and subsequent births were analyzed separately. First birth was defined as the first delivery of nulliparous women. Associations between RA and maternal and perinatal outcomes were assessed in logistic regression analyses and adjusted for maternal age at delivery, gestational age, smoking habits and for previous cesarean section when relevant. Main outcome measures. Maternal and perinatal outcomes. Results. Vaginal bleeding was observed more often among women with RA both in first pregnancy [adjusted odds ratio (aOR) 1.8, 95% CI 1.3– 2.4] and in subsequent pregnancies (aOR 1.4, 95% CI 1.1–1.9). Elective cesarean section was more common among women with RA both in the first birth (aOR 2.0, 95% CI 1.4–2.8) and in subsequent births (aOR 1.5, 95% CI 1.2– 2.0). Preterm delivery was more frequent among women with RA than the reference population in first pregnancy (aOR 1.5, 95% CI 1.1–2.0) and in subsequent pregnancies (aOR 1.5, 95% CI 1.1–1.9). Conclusion. Complications and poor pregnancy outcomes were more often observed in women with RA and the greatest differences were observed in the first pregnancy. aOR, adjusted odds ratios; CI, confidence interval; CIJD, chronic inflammatory joint diseases; CS, cesarean section; MBRN, Medical Birth Registry of Norway; NSAIDs, non-steroidal anti-inflammatory drugs; RA, rheumatoid arthritis.
Abbreviations:
Introduction
Key Message
Rheumatoid arthritis (RA) is a chronic, autoimmune disease characterized by destructive synovitis and may also affect the internal organs. The estimated prevalence of RA is about 0.5–1.0% in European and North American adults (1). In a Norwegian patient register, the female: male ratio was >4 in people of premenopausal age (2). Chronic inflammatory joint diseases (CIJD) include RA,
Women with rheumatoid arthritis (RA) had pregnancy complications and poor outcomes more often than women without the disease, both in the first and subsequent pregnancies. Major malformations or perinatal death were not observed more frequently among the women with rheumatoid arthritis.
302
ª 2013 Nordic Federation of Societies of Obstetrics and Gynecology, Acta Obstetricia et Gynecologica Scandinavica 93 (2014) 302–307
M. Wallenius et al.
psoriatic arthritis, ankylosing spondylitis, and juvenile idiopathic arthritis. Several studies have addressed effects of CIJD combined or RA specifically on pregnancy and delivery (3–8). Specific studies of RA and pregnancy outcomes are necessary because the effects of pregnancy may differ between RA and other CIJD. New classification criteria for RA (9) and for other CIJD (10,11), the treat-to-target principle (12), and the introduction of biological diseasemodifying anti-rheumatic drugs have changed the patient populations, and probably also the course of the disease in pregnancy. Pregnancy and delivery complications are more frequent in the first pregnancy and delivery (13–15). The risk of cesarean section (CS) in nulliparous women with spontaneous start of labor and the fetus in a cephalic presentation has been reported to be 2.5 times higher than for comparable parous women without a previous CS (16). The causes for this increased risk are not fully understood, although it has been known for more than 40 years (17,18). In only one previous study of women with CIJD have outcomes of first and subsequent births been analyzed separately, and the study showed that the first birth was associated with the highest risks (8). Separate analyses of outcomes in first and subsequent births in women diagnosed with RA have not been previously published. The aim of this study was to examine pregnancy outcomes in first and subsequent births in women diagnosed with RA compared with reference women from the general population with focus on mode of delivery, smallfor-gestational age, preterm birth, perinatal death and congenital malformations.
Material and methods The Medical Birth Registry of Norway (MBRN) was established in 1967 and comprises more than 2.2 million births (19). The birth notification forms are completed by birth attendants and sent to the MBRN within 1 week of delivery. The information in the forms is based on three elements: (i) a standardized form used during pregnancy by the woman’s physician, (ii) oral information given by the woman when admitted to the hospital, and (iii) information from the doctor and the midwife about the actual delivery and the newborn. The MBRN used one notification form from 1967 to 1998, but a more detailed form was introduced from 1 December 1998. This new form includes all births (spontaneous abortions, live births and stillbirths) after 12 weeks of gestation, and data on complications, maternal disease and mode of delivery are entered in textboxes and/or as free text (19). Data from the MBRN are routinely linked to the Cause of Death
Rheumatoid arthritis and pregnancy outcome
Registry by a national, unique identification number to obtain information on infant mortality. The MBRN includes data on the mother’s health at birth, before and during pregnancy and characteristics of the newborn within the first week after delivery. After 1 December 1998, all women diagnosed with RA were registered by specific coding according to the International Classification of Diseases 10th revision (ICD-10) systems. The diagnosis is based on information from the woman’s physician and information in the patient records at the hospital. In the present study we have used data from women diagnosed with RA giving birth in the period 1 December 1998 to 31 December 2009. The study was carried out in compliance with the Helsinki Declaration and was approved by the Regional Ethics Committee of Central Norway (2011/127-3). Women diagnosed with RA in the MBRN registry (ICD-10 codes M05.0, M05.1, M05.2, M05.8, M05.9, M06.0, M06.8, M06.9) were compared with all other deliveries from 1 December 1998 to 31 December 2009 where the mother did not have CIJD. Anonymized births were stratified in first and subsequent births. Only data for single births were analyzed. Data on maternal characteristics, smoking habits, chronic hypertension (hypertension diagnosed before pregnancy), assisted reproduction (all methods combined), preeclampsia, induction of labor (amniotomy, oxytocin, prostaglandin), preterm delivery (
