healthcare Article
Increasing Incidence Rate of Cervical Cerclage in Pregnancy in Australia: A Population-Based Study Corrine Lu 1, *, Boon Lim 1,2 and Stephen J. Robson 1,2 1 2
*
Centenary Hospital for Women and Children, Canberra Hospital, Garran ACT 2605, Australia; [email protected] (B.L.); [email protected] (S.J.R.) Australian National University Medical School, Canberra Hospital Campus, Garran ACT 2605, Australia Correspondence: [email protected]
Academic Editor: Sampath Parthasarathy Received: 16 June 2016; Accepted: 30 August 2016; Published: 12 September 2016
Abstract: Objective: Data published from the United States have demonstrated that the use of cervical cerclage has fallen in the period 1998–2013. This is in contrast to recommendations in Australia. We examined this trend using data from the Australian Institute of Health and Welfare (AIHW). Study design: Retrospective population-based study. Methods: Data from the Australian Institute of Health and Welfare procedural database were used to determine the total number of cervical cerclage sutures inserted during the period 2004 to 2013. Population datasets were used to calculate age-stratified incidence rates of cerclage. Findings: There was a significant increase in the rate of cervical cerclage in women aged 25 to 34 years and in the 35 years and older age group. The incidence of preterm birth was stable for gestations of 32 to 36 weeks, but slightly increased in the 20 to 27 week and 28 to 31 week gestational age groups. Further research into cervical cerclage and the use of vaginal progesterone for the prevention of preterm birth would be valuable. Keywords: cerclage; preterm; pregnancy; birth; population; incidence
1. Introduction Preterm birth is the leading cause of perinatal death, complicating more than 10% of births internationally [1,2]. In addition to perinatal death, preterm birth is also the cause of both short- and long-term morbidity and disability. Despite a concerted international commitment to reducing the incidence of preterm birth, there is little evidence of any decrease: preterm birth rates may in fact have increased [3]. One strategy employed to reduce the risk of preterm delivery is the placement of a cervical cerclage suture (cerclage), in an attempt to prevent cervical dilatation and subsequent preterm birth. The first description of this procedure was published 60 years ago [4] and although it has undergone modifications [5] since that then, the technique for placement in pregnancy has changed little. Typically it is employed in three circumstances: where there is a history of sequential mid-trimester losses; when a diagnosis of cervical shortening is made on ultrasound examination during pregnancy; and, when cervical shortening, dilatation, or both are found on examination [6]. There is evidence that cerclage is superior to no treatment in the prevention of preterm birth and that its use might be associated with a reduction in the risk of perinatal death [6]. However there are higher rates of febrile and infectious morbidity and an increased rate of caesarean delivery in pregnancies managed with the use of cerclage. An evolving evidence base for the use of progesterone supplementation for the prevention of preterm birth has made the place of cerclage in pregnancy less clear. At the time of writing, there are no published studies of direct comparison of progesterone with cerclage in the setting of cervical shortening. Indirect comparisons made by meta-analysis have not shown one method to be superior [7]. Despite this continuing uncertainty, recent data from the United States have suggested that cerclage use has fallen by more than half over that last 16 years [8]. Healthcare 2016, 4, 68; doi:10.3390/healthcare4030068
www.mdpi.com/journal/healthcare
Healthcare 2016, 4, 68 Healthcare 2016, 4, x
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The Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) has over athat last 16 years [8]. Royal Australian and New Zealand College and endorsed recommendation forThe consideration of cerclage since 2008 [9], thus, of weObstetricians set out to determine Gynaecologists (RANZCOG) has endorsed a recommendation for consideration of cerclage since whether a similar trend in the use of cerclage was evident at a national level in Australia. 2008 [9], thus, we set out to determine whether a similar trend in the use of cerclage was evident at a national level in Australia. 2. Methods
2. Methods Data regarding pregnancy-associated cervical cerclage were obtained from the Australian Institute of Health Data and Welfare (AIHW) national procedural dataset, collected through from the Australian National regarding pregnancy-associated cervical cerclage were obtained the Australian Health Information Agreement under the auspice of the Australian Health Ministers’ Advisory Institute of Health and Welfare (AIHW) national procedural dataset, collected through Council the (AHMAC). This National is specified in theInformation National Minimum Setsthe relating to of hospitals and dayHealth procedure Australian Health AgreementData under auspice the Australian Ministers’ Advisory Council Thisby is Australian specified in state the National Minimum Data Sets facilities, and comprises pooled (AHMAC). data supplied and territory health authorities. relating to hospitals andprocedures day procedure facilities, and comprises data supplied by It provides information about performed on admitted patientspooled in hospitals and day surgery Australian state and territory health authorities. It provides information about procedures facilities. To ensure no pre-pregnancy (interval) cerclage data were included (either laparoscopic or performeddata on admitted patients in hospitals day surgery facilities. To ensure no pre-pregnancy transvaginal), was extracted based on the and ICD-10-AM (Australian Modification) in the procedure (interval) cerclage data were included (either laparoscopic or transvaginal), data was extracted chapter XIII, using the ICD specific codes 16511-00 (insertion of cervical suture). The data was based on the ICD-10-AM (Australian Modification) in the procedure chapter XIII, using the ICD collected in age bands and extracted to an Excel™ spreadsheet for analysis. To obtain denominators, specific codes 16511-00 (insertion of cervical suture). The data was collected in age bands and the total numbers term and preterm for births for each year ofdenominators, the study were fromofthe AIHW extracted to anofExcel™ spreadsheet analysis. To obtain the obtained total numbers term Australia’s Mothers and series [10]. Linear were to calculate R and and preterm births forBabies each year of the study wereregressions obtained from theperformed AIHW Australia’s Mothers 2 (aR2 ) values, and p-values. This study received prospective approval from the 2Australian adjusted and RBabies series [10]. Linear regressions were performed to calculate R and adjusted R (aR2) values, and p-values. This study received prospective(protocol approval2015/347). from the Australian National National University Human Research Ethics Committee University Human Research Ethics Committee (protocol 2015/347).
3. Results 3. Results
Data were obtained for the period from July 2004 to June 2013. Over that period, there was a were obtained forin the period from July to June 2013.inOver was group a slight butData significant increase the percentage of2004 preterm births boththat theperiod, 20 to there 27 week slight but significant increase in the percentage of preterm births in both the 20 to 27 week group (R 2 = 0.48; p = 0.02), but no (R = 0.68; aR2 = 0.47; p = 0.03) and the 28 to 31 week group (R = 0.73; aR = 0.68; aR2 = 0.47; p = 0.03) and the 28 to 31 week group (R = 0.73; aR2 = 0.48; p = 0.02), but no 2 observed change in the 32–36 week group (R = 0.52; aR 2 = 0.18; p = 0.12) (Figure 1). The incidence observed change in the 32–36 week group (R = 0.52; aR = 0.18; p = 0.12) (Figure 1). The incidence rate ofrate cerclage (procedures perper 1000 births) fromjust just over 3/1000 births of cerclage (procedures 1000 births)increased increased significantly, significantly, from over 3/1000 births to to 2 3.8/1000 birthsbirths (R = (R 0.895; aR =aR 0.776; p < 0.005) over the periodperiod (Figure 2). When the incidence 2 = 0.776; 3.8/1000 = 0.895; p < 0.005) overstudy the study (Figure 2). When the rates incidence of cerclage were stratified by maternal age, we found no increase for women aged less than rates of cerclage were stratified by maternal age, we found no increase for women aged 2 = 0.11; less(R than 25 years = 0.46;p aR p =after 0.19),2007 but,(coincident after 2007 (coincident with publication of the 25 years = 0.46; aR2 (R = 0.11; = 0.19), but, with publication of the RANZCOG 2 RANZCOG guidance), there were significant in theage 25 group to 34 year group = 0.84;p aR guidance), there were significant increases in theincreases 25 to 34 year (R =age 0.84; aR2(R = 0.67; = 0.002) 2 2 = 0.67; p = 0.002) theage 35 years and ageaR group (R = 0.99; aR = 0.96; p < 0.005) and the 35 years andand older group (Rolder = 0.99; = 0.96; p < 0.005) (Figure 3). (Figure 3).
32-36 weeks
20-27 weeks
28-31 weeks
Year
Figure 1. Preterm births a percentageofofall allbirths births in in Australia, 2013. There havehave beenbeen Figure 1. Preterm births as as a percentage Australia,2004 2004toto 2013. There slight but significant increases in the percentage of preterm births in the 20–27 week group (R = 0.68; slight but significant increases in the percentage of preterm births in the 20–27 week group (R = 0.68; aR2 = 0.47; p = 0.03) and 28–31 week group (R = 0.73; aR2 = 0.48; p = 0.02) but no change in the 32–36 week group (R = 0.52; aR2 = 0.18; p = 0.12). From AIHW Australia’s Mothers and Babies series.
Healthcare 2016, 4, x
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aR2 = 0.47; p = 0.03) and 28–31 week group (R = 0.73; aR2 = 0.48; p = 0.02) but no change in the 32–36 3 of 5 week group (R = 0.52; aR2 = 0.18; p = 0.12). From AIHW Australia’s Mothers and Babies series.
Healthcare 2016, 4, 68
R = 0.895 aR2 = 0.776 p < 0.005
Year Figure 2. 2. Overall Overall incidence incidence rate rate of of cervical cervical cerclage cerclage (procedures (procedures per per 1000 1000 births) births) in in Australia Australia for for the the Figure period 2004 2004 until until 2013. 2013. period
> 34 years
25 – 34 years
< 25 years
Year Figure 3. 3. Maternal Maternal age-stratified age-stratified incidence incidence rates rates for cervical cerclage 1000 births) births) in in for cervical cerclage (procedures (procedures per per 1000 Figure Australia for forthe theperiod period2004 2004 until 2013. There no increase inrate the of rate of cerclage age Australia until 2013. There waswas no increase in the cerclage in the in agethe group 2 == 0.11; 2 = 0.11; p = 0.19), but significant group less than 25 years the study 0.46;p aR less than 25 years across theacross study period (R =period 0.46; aR(R = 0.19), but significant increases since 2 2 increases in age the 25 to 34 age (Rp==0.84; aRand = 0.67; = 0.002) theage 35group years 2007 in thesince 25 to 2007 34 year group (Ryear = 0.84; aRgroup = 0.67; 0.002) the 35p years andand older 2 =group and olderaR age 0.99; aR2 = 0.96; p < 0.005). (R = 0.99; 0.96; p(R
Increasing Incidence Rate of Cervical Cerclage in Pregnancy in Australia: A Population-Based Study Corrine Lu 1, *, Boon Lim 1,2 and Stephen J. Robson 1,2 1 2
*
Centenary Hospital for Women and Children, Canberra Hospital, Garran ACT 2605, Australia; [email protected] (B.L.); [email protected] (S.J.R.) Australian National University Medical School, Canberra Hospital Campus, Garran ACT 2605, Australia Correspondence: [email protected]
Academic Editor: Sampath Parthasarathy Received: 16 June 2016; Accepted: 30 August 2016; Published: 12 September 2016
Abstract: Objective: Data published from the United States have demonstrated that the use of cervical cerclage has fallen in the period 1998–2013. This is in contrast to recommendations in Australia. We examined this trend using data from the Australian Institute of Health and Welfare (AIHW). Study design: Retrospective population-based study. Methods: Data from the Australian Institute of Health and Welfare procedural database were used to determine the total number of cervical cerclage sutures inserted during the period 2004 to 2013. Population datasets were used to calculate age-stratified incidence rates of cerclage. Findings: There was a significant increase in the rate of cervical cerclage in women aged 25 to 34 years and in the 35 years and older age group. The incidence of preterm birth was stable for gestations of 32 to 36 weeks, but slightly increased in the 20 to 27 week and 28 to 31 week gestational age groups. Further research into cervical cerclage and the use of vaginal progesterone for the prevention of preterm birth would be valuable. Keywords: cerclage; preterm; pregnancy; birth; population; incidence
1. Introduction Preterm birth is the leading cause of perinatal death, complicating more than 10% of births internationally [1,2]. In addition to perinatal death, preterm birth is also the cause of both short- and long-term morbidity and disability. Despite a concerted international commitment to reducing the incidence of preterm birth, there is little evidence of any decrease: preterm birth rates may in fact have increased [3]. One strategy employed to reduce the risk of preterm delivery is the placement of a cervical cerclage suture (cerclage), in an attempt to prevent cervical dilatation and subsequent preterm birth. The first description of this procedure was published 60 years ago [4] and although it has undergone modifications [5] since that then, the technique for placement in pregnancy has changed little. Typically it is employed in three circumstances: where there is a history of sequential mid-trimester losses; when a diagnosis of cervical shortening is made on ultrasound examination during pregnancy; and, when cervical shortening, dilatation, or both are found on examination [6]. There is evidence that cerclage is superior to no treatment in the prevention of preterm birth and that its use might be associated with a reduction in the risk of perinatal death [6]. However there are higher rates of febrile and infectious morbidity and an increased rate of caesarean delivery in pregnancies managed with the use of cerclage. An evolving evidence base for the use of progesterone supplementation for the prevention of preterm birth has made the place of cerclage in pregnancy less clear. At the time of writing, there are no published studies of direct comparison of progesterone with cerclage in the setting of cervical shortening. Indirect comparisons made by meta-analysis have not shown one method to be superior [7]. Despite this continuing uncertainty, recent data from the United States have suggested that cerclage use has fallen by more than half over that last 16 years [8]. Healthcare 2016, 4, 68; doi:10.3390/healthcare4030068
www.mdpi.com/journal/healthcare
Healthcare 2016, 4, 68 Healthcare 2016, 4, x
2 of 5 2 of 5
The Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) has over athat last 16 years [8]. Royal Australian and New Zealand College and endorsed recommendation forThe consideration of cerclage since 2008 [9], thus, of weObstetricians set out to determine Gynaecologists (RANZCOG) has endorsed a recommendation for consideration of cerclage since whether a similar trend in the use of cerclage was evident at a national level in Australia. 2008 [9], thus, we set out to determine whether a similar trend in the use of cerclage was evident at a national level in Australia. 2. Methods
2. Methods Data regarding pregnancy-associated cervical cerclage were obtained from the Australian Institute of Health Data and Welfare (AIHW) national procedural dataset, collected through from the Australian National regarding pregnancy-associated cervical cerclage were obtained the Australian Health Information Agreement under the auspice of the Australian Health Ministers’ Advisory Institute of Health and Welfare (AIHW) national procedural dataset, collected through Council the (AHMAC). This National is specified in theInformation National Minimum Setsthe relating to of hospitals and dayHealth procedure Australian Health AgreementData under auspice the Australian Ministers’ Advisory Council Thisby is Australian specified in state the National Minimum Data Sets facilities, and comprises pooled (AHMAC). data supplied and territory health authorities. relating to hospitals andprocedures day procedure facilities, and comprises data supplied by It provides information about performed on admitted patientspooled in hospitals and day surgery Australian state and territory health authorities. It provides information about procedures facilities. To ensure no pre-pregnancy (interval) cerclage data were included (either laparoscopic or performeddata on admitted patients in hospitals day surgery facilities. To ensure no pre-pregnancy transvaginal), was extracted based on the and ICD-10-AM (Australian Modification) in the procedure (interval) cerclage data were included (either laparoscopic or transvaginal), data was extracted chapter XIII, using the ICD specific codes 16511-00 (insertion of cervical suture). The data was based on the ICD-10-AM (Australian Modification) in the procedure chapter XIII, using the ICD collected in age bands and extracted to an Excel™ spreadsheet for analysis. To obtain denominators, specific codes 16511-00 (insertion of cervical suture). The data was collected in age bands and the total numbers term and preterm for births for each year ofdenominators, the study were fromofthe AIHW extracted to anofExcel™ spreadsheet analysis. To obtain the obtained total numbers term Australia’s Mothers and series [10]. Linear were to calculate R and and preterm births forBabies each year of the study wereregressions obtained from theperformed AIHW Australia’s Mothers 2 (aR2 ) values, and p-values. This study received prospective approval from the 2Australian adjusted and RBabies series [10]. Linear regressions were performed to calculate R and adjusted R (aR2) values, and p-values. This study received prospective(protocol approval2015/347). from the Australian National National University Human Research Ethics Committee University Human Research Ethics Committee (protocol 2015/347).
3. Results 3. Results
Data were obtained for the period from July 2004 to June 2013. Over that period, there was a were obtained forin the period from July to June 2013.inOver was group a slight butData significant increase the percentage of2004 preterm births boththat theperiod, 20 to there 27 week slight but significant increase in the percentage of preterm births in both the 20 to 27 week group (R 2 = 0.48; p = 0.02), but no (R = 0.68; aR2 = 0.47; p = 0.03) and the 28 to 31 week group (R = 0.73; aR = 0.68; aR2 = 0.47; p = 0.03) and the 28 to 31 week group (R = 0.73; aR2 = 0.48; p = 0.02), but no 2 observed change in the 32–36 week group (R = 0.52; aR 2 = 0.18; p = 0.12) (Figure 1). The incidence observed change in the 32–36 week group (R = 0.52; aR = 0.18; p = 0.12) (Figure 1). The incidence rate ofrate cerclage (procedures perper 1000 births) fromjust just over 3/1000 births of cerclage (procedures 1000 births)increased increased significantly, significantly, from over 3/1000 births to to 2 3.8/1000 birthsbirths (R = (R 0.895; aR =aR 0.776; p < 0.005) over the periodperiod (Figure 2). When the incidence 2 = 0.776; 3.8/1000 = 0.895; p < 0.005) overstudy the study (Figure 2). When the rates incidence of cerclage were stratified by maternal age, we found no increase for women aged less than rates of cerclage were stratified by maternal age, we found no increase for women aged 2 = 0.11; less(R than 25 years = 0.46;p aR p =after 0.19),2007 but,(coincident after 2007 (coincident with publication of the 25 years = 0.46; aR2 (R = 0.11; = 0.19), but, with publication of the RANZCOG 2 RANZCOG guidance), there were significant in theage 25 group to 34 year group = 0.84;p aR guidance), there were significant increases in theincreases 25 to 34 year (R =age 0.84; aR2(R = 0.67; = 0.002) 2 2 = 0.67; p = 0.002) theage 35 years and ageaR group (R = 0.99; aR = 0.96; p < 0.005) and the 35 years andand older group (Rolder = 0.99; = 0.96; p < 0.005) (Figure 3). (Figure 3).
32-36 weeks
20-27 weeks
28-31 weeks
Year
Figure 1. Preterm births a percentageofofall allbirths births in in Australia, 2013. There havehave beenbeen Figure 1. Preterm births as as a percentage Australia,2004 2004toto 2013. There slight but significant increases in the percentage of preterm births in the 20–27 week group (R = 0.68; slight but significant increases in the percentage of preterm births in the 20–27 week group (R = 0.68; aR2 = 0.47; p = 0.03) and 28–31 week group (R = 0.73; aR2 = 0.48; p = 0.02) but no change in the 32–36 week group (R = 0.52; aR2 = 0.18; p = 0.12). From AIHW Australia’s Mothers and Babies series.
Healthcare 2016, 4, x
3 of 5
aR2 = 0.47; p = 0.03) and 28–31 week group (R = 0.73; aR2 = 0.48; p = 0.02) but no change in the 32–36 3 of 5 week group (R = 0.52; aR2 = 0.18; p = 0.12). From AIHW Australia’s Mothers and Babies series.
Healthcare 2016, 4, 68
R = 0.895 aR2 = 0.776 p < 0.005
Year Figure 2. 2. Overall Overall incidence incidence rate rate of of cervical cervical cerclage cerclage (procedures (procedures per per 1000 1000 births) births) in in Australia Australia for for the the Figure period 2004 2004 until until 2013. 2013. period
> 34 years
25 – 34 years
< 25 years
Year Figure 3. 3. Maternal Maternal age-stratified age-stratified incidence incidence rates rates for cervical cerclage 1000 births) births) in in for cervical cerclage (procedures (procedures per per 1000 Figure Australia for forthe theperiod period2004 2004 until 2013. There no increase inrate the of rate of cerclage age Australia until 2013. There waswas no increase in the cerclage in the in agethe group 2 == 0.11; 2 = 0.11; p = 0.19), but significant group less than 25 years the study 0.46;p aR less than 25 years across theacross study period (R =period 0.46; aR(R = 0.19), but significant increases since 2 2 increases in age the 25 to 34 age (Rp==0.84; aRand = 0.67; = 0.002) theage 35group years 2007 in thesince 25 to 2007 34 year group (Ryear = 0.84; aRgroup = 0.67; 0.002) the 35p years andand older 2 =group and olderaR age 0.99; aR2 = 0.96; p < 0.005). (R = 0.99; 0.96; p(R
