A C TA Obstetricia et Gynecologica
AOGS M A I N R E SE A RC H A R TI C LE
Maternal folic acid supplementation trends 2009–2013 AOIFE MCKEATING1, MARIA FARREN1, SHONA CAWLEY2, NIAMH DALY1, DANIEL MCCARTNEY2 & MICHAEL J. TURNER1 1
UCD Centre for Human Reproduction, Coombe Women and Infants University Hospital, Dublin, and 2School of Biological Sciences, Dublin Institute of Technology, Dublin, Ireland
Key words Folic acid, supplementation, neural tube defects, vitamins, antenatal care Correspondence Aoife McKeating, UCD Centre for Human Reproduction, Coombe Women and Infants University Hospital, Dublin, Ireland. E-mail: [email protected] Conflict of interest All authors have completed the ICMJE uniform disclosure form at http:// www.icmje.org/coi_disclosure.pdf and declare: no support from any organization for the submitted work; no financial relationships with any organizations that might have an interest in the submitted work in the previous 3 years; no other relations or activities that could appear to have influenced the submitted work. Please cite this article as: McKeating A, Farren M, Cawley S, Daly N, McCartney D, Turner MJ. Maternal folic acid supplementation trends 2009–2013. Acta Obstet Gynecol Scand 2015; 94: 727–733. Received: 4 December 2014 Accepted: 8 April 2015 DOI: 10.1111/aogs.12656
Abstract Objective. We analyzed trends in folic acid supplementation among women booking for antenatal care between 2009 and 2013. Design. Prospective observational study. Setting. Large university teaching hospital. Population. We included all women who delivered an infant ≥500 g from 1 January 2009 to 31 December 2013. Methods. Body mass index was calculated using early pregnancy weight and height measured at first antenatal visits. Sociodemographic and clinical data were gathered prospectively. Multivariate logistic regression analyses were applied to determine the correlates of periconceptional folic acid supplementation. Main outcome measures. Rates and correlates of folic acid supplementation. Results. Of 42 362 women, 99.2% (n = 42 042) were suitable for analysis. The mean age was 30.7 years and mean body mass index was 25.6 kg/m2, 40.7% (n = 17 054) were primigravidas and 70.6% (n = 29 741) were Irish-born. Overall, 43.9% (n = 18 473) took periconceptional (preconceptional and postconceptional) folic acid, 49.4% (n = 20 782) took postconceptional folic acid only, and 6.6% (n = 2787) took no folic acid. The women most likely to take folic acid were those who planned their pregnancy and were >30 years old, non-obese, Irish-born and employed professionally. The periconceptional folic acid rate decreased from 45.1% in 2009 to 43.1% in 2013 (p = 0.01). Over five years, periconceptional folic acid supplementation decreased among women who were multiparous (43.8–41.6%, p = 0.02), aged 30–39 years (58.9–55.0%, p < 0.001), Irish-born (50.1–47.1%, p < 0.001) and obese (38.6–36.9%, p = 0.02). Conclusion. Overall, the rate of periconceptional folic acid supplementation decreased in the five years 2009–2013, particularly among women who were multiparous, aged 30–39 years, Irish-born and obese. BMI, body mass index; CI, confidence interval; EU, European Union; FA, folic acid; NTD, neural tube defects; OR, odds ratio.
Abbreviations:
Introduction Neural tube defects (NTDs) are a group of serious congenital neurodevelopmental malformations associated with failure of closure of the neural tube during early embryonic development (1). The reported worldwide prevalence of NTDs varies from 0.05 to 6.0 per thousand births with regional and population-specific variations (1). Even within Europe, these variations are marked (2). NTDs constitute an important public health problem in
Key Message The rate of periconceptional folic acid supplementation among women booking for antenatal care in Ireland is decreasing. This is concerning in light of recently reported increases in neural tube defects nationally and as folic acid food fortification remains voluntary and is not mandatory in Europe.
ª 2015 Nordic Federation of Societies of Obstetrics and Gynecology, Acta Obstetricia et Gynecologica Scandinavica 94 (2015) 727–733
727
Folic acid supplementation trends 2009–2013
A. McKeating et al.
terms of mortality, morbidity, social cost and human suffering (3). In 1991 the results of the Medical Research Council Vitamin study were published. This randomized controlled trial showed that preconceptional folic acid (FA) reduced the risk of NTD by approximately 72% (4). Efforts to improve women’s dietary habits so that they consume more folaterich foods or daily vitamin supplements have had little success in improving NTD rates because they require behavior change, improved accessibility, affordability or sustainability (5). Increased intake of foods naturally rich in folate has also been shown to be relatively ineffective compared with equivalent intakes of FA-fortified food or FA supplements due to the decreased bioavailability of these naturally occurring folates (6). Mandatory food fortification has been introduced in over 70 countries worldwide, including the USA, Canada and Australia (7). Despite evidence that such fortification is effective, however, over 120 countries, including all countries in the European Union (EU), have not introduced mandatory food fortification (8–10). Thus, most women of child-bearing age need to take preconceptional FA to reduce their risk of an NTD-affected pregnancy. A recent comprehensive national audit of births for the triennium 2009–2011 identified 236 NTDs among 226 000 births in Ireland (11). This represented a significant increase in the incidence of NTDs in Ireland from 0.92 per thousand births reported in 2005–2006 to 1.04 per thousand in 2009–2011 (11,12). Information on periconceptional FA was available in only 52.5% (n = 124) of cases, and only 13.7% (n = 17) of these reported periconceptional FA supplementation. The aim of this prospective observational study was to analyze recent trends in FA supplementation among women booking for antenatal care in a large university maternity hospital in Ireland.
Material and methods The data were examined for all women who delivered an infant weighing ≥500 g between 1 January 2009 and 31
December 2013 inclusive. The Hospital provides one of the largest women’s healthcare hospital services in Europe (13,14). Approximately one in eight women nationally deliver in the Hospital and it accepts women from all socioeconomic groups across the urban–rural divide, including those with private health insurance. The study was granted ethical approval by the Hospital’s Research Ethics Committee (ref. 004-013) and as this study involved collection of anonymized data only, it did not require patient consent by Hospital Research Ethics Committee consensus. Direct measurements of maternal height and weight were recorded at the first antenatal clinic appointment by trained midwives before the body mass index (BMI) was calculated. Maternal BMI was classified according to the World Health Organization categorization. Clinical and sociodemographic details were also computerized at this visit. Interpreters were available for women with difficulty understanding English. Information on pregnancy intention was recorded as part of the electronic medical record using a computerized questionnaire at the woman’s first antenatal visit. Women were asked whether this was a planned pregnancy. After delivery, the clinical details of the pregnancy and delivery were again computerized for subsequent analysis and publication in the Annual Clinical Report (13). Clinical and sociodemographic details recorded included maternal age, parity, BMI, place of birth, FA supplementation and maternal occupation. FA supplementation was classified as periconception (both pre- and postconception), postconception only, and no FA supplementation. In cases where an FA supplement was used, the reported brand name and FA dose contained (either the standard 0.4 mg or high-dose 5 mg) was recorded according to the manufacturer. Country of birth was classified as Ireland, EU 14 (women born in the 14 other countries in the EU before 2004), EU 13 (women born in the 13 Accession countries that joined the EU following enlargement in 2004), or elsewhere (women born outside the EU). Self-described occupation was used to categorize the women into the following socioeconomic groups:
Table 1. Characteristics of the study population.
Mean age (years) (SD) Mean BMI (kg/m2) (SD) Nulliparous (%) Smokers (%) Unemployed (%) Irish-born (%)
2009 (n = 8576)
2010 (n = 8711)
2011 (n = 8458)
2012 (n = 8344)
2013 (n = 7953)
Total (n = 42 042)
30.6 5.8 25.8 4.9 41.5 16.6 7.9 71.8
30.5 5.7 25.5 5.0 42.4 15.4 7.9 69.8
30.6 5.6 25.7 5.1 40.5 14.9 9.4 70.6
30.9 5.6 25.5 5.1 40.1 14.4 10.3 69.9
31.2 5.5 25.6 5.1 38.7 12.6 10.1 70.6
30.7 5.6 25.6 5.0 40.7 14.8 9.1 70.6
BMI, body mass index.
728
ª 2015 Nordic Federation of Societies of Obstetrics and Gynecology, Acta Obstetricia et Gynecologica Scandinavica 94 (2015) 727–733
A. McKeating et al.
Folic acid supplementation trends 2009–2013
Table 2. Folic acid supplementation usage in 2009–2013.
FA
2009 (n = 8576)
2010 (n = 8711)
2011 (n = 8458)
2012 (n = 8344)
2013 (n = 7953)
Total (n = 42 042)
p-valuea
Periconception (%) Postconception only (%) None (%)
45.1 47.3 7.6
43.1 49.6 7.3
43.0 50.4 6.6
45.0 49.1 5.9
43.1 51.1 5.8
43.9 49.4 6.6
0.01
AOGS M A I N R E SE A RC H A R TI C LE
Maternal folic acid supplementation trends 2009–2013 AOIFE MCKEATING1, MARIA FARREN1, SHONA CAWLEY2, NIAMH DALY1, DANIEL MCCARTNEY2 & MICHAEL J. TURNER1 1
UCD Centre for Human Reproduction, Coombe Women and Infants University Hospital, Dublin, and 2School of Biological Sciences, Dublin Institute of Technology, Dublin, Ireland
Key words Folic acid, supplementation, neural tube defects, vitamins, antenatal care Correspondence Aoife McKeating, UCD Centre for Human Reproduction, Coombe Women and Infants University Hospital, Dublin, Ireland. E-mail: [email protected] Conflict of interest All authors have completed the ICMJE uniform disclosure form at http:// www.icmje.org/coi_disclosure.pdf and declare: no support from any organization for the submitted work; no financial relationships with any organizations that might have an interest in the submitted work in the previous 3 years; no other relations or activities that could appear to have influenced the submitted work. Please cite this article as: McKeating A, Farren M, Cawley S, Daly N, McCartney D, Turner MJ. Maternal folic acid supplementation trends 2009–2013. Acta Obstet Gynecol Scand 2015; 94: 727–733. Received: 4 December 2014 Accepted: 8 April 2015 DOI: 10.1111/aogs.12656
Abstract Objective. We analyzed trends in folic acid supplementation among women booking for antenatal care between 2009 and 2013. Design. Prospective observational study. Setting. Large university teaching hospital. Population. We included all women who delivered an infant ≥500 g from 1 January 2009 to 31 December 2013. Methods. Body mass index was calculated using early pregnancy weight and height measured at first antenatal visits. Sociodemographic and clinical data were gathered prospectively. Multivariate logistic regression analyses were applied to determine the correlates of periconceptional folic acid supplementation. Main outcome measures. Rates and correlates of folic acid supplementation. Results. Of 42 362 women, 99.2% (n = 42 042) were suitable for analysis. The mean age was 30.7 years and mean body mass index was 25.6 kg/m2, 40.7% (n = 17 054) were primigravidas and 70.6% (n = 29 741) were Irish-born. Overall, 43.9% (n = 18 473) took periconceptional (preconceptional and postconceptional) folic acid, 49.4% (n = 20 782) took postconceptional folic acid only, and 6.6% (n = 2787) took no folic acid. The women most likely to take folic acid were those who planned their pregnancy and were >30 years old, non-obese, Irish-born and employed professionally. The periconceptional folic acid rate decreased from 45.1% in 2009 to 43.1% in 2013 (p = 0.01). Over five years, periconceptional folic acid supplementation decreased among women who were multiparous (43.8–41.6%, p = 0.02), aged 30–39 years (58.9–55.0%, p < 0.001), Irish-born (50.1–47.1%, p < 0.001) and obese (38.6–36.9%, p = 0.02). Conclusion. Overall, the rate of periconceptional folic acid supplementation decreased in the five years 2009–2013, particularly among women who were multiparous, aged 30–39 years, Irish-born and obese. BMI, body mass index; CI, confidence interval; EU, European Union; FA, folic acid; NTD, neural tube defects; OR, odds ratio.
Abbreviations:
Introduction Neural tube defects (NTDs) are a group of serious congenital neurodevelopmental malformations associated with failure of closure of the neural tube during early embryonic development (1). The reported worldwide prevalence of NTDs varies from 0.05 to 6.0 per thousand births with regional and population-specific variations (1). Even within Europe, these variations are marked (2). NTDs constitute an important public health problem in
Key Message The rate of periconceptional folic acid supplementation among women booking for antenatal care in Ireland is decreasing. This is concerning in light of recently reported increases in neural tube defects nationally and as folic acid food fortification remains voluntary and is not mandatory in Europe.
ª 2015 Nordic Federation of Societies of Obstetrics and Gynecology, Acta Obstetricia et Gynecologica Scandinavica 94 (2015) 727–733
727
Folic acid supplementation trends 2009–2013
A. McKeating et al.
terms of mortality, morbidity, social cost and human suffering (3). In 1991 the results of the Medical Research Council Vitamin study were published. This randomized controlled trial showed that preconceptional folic acid (FA) reduced the risk of NTD by approximately 72% (4). Efforts to improve women’s dietary habits so that they consume more folaterich foods or daily vitamin supplements have had little success in improving NTD rates because they require behavior change, improved accessibility, affordability or sustainability (5). Increased intake of foods naturally rich in folate has also been shown to be relatively ineffective compared with equivalent intakes of FA-fortified food or FA supplements due to the decreased bioavailability of these naturally occurring folates (6). Mandatory food fortification has been introduced in over 70 countries worldwide, including the USA, Canada and Australia (7). Despite evidence that such fortification is effective, however, over 120 countries, including all countries in the European Union (EU), have not introduced mandatory food fortification (8–10). Thus, most women of child-bearing age need to take preconceptional FA to reduce their risk of an NTD-affected pregnancy. A recent comprehensive national audit of births for the triennium 2009–2011 identified 236 NTDs among 226 000 births in Ireland (11). This represented a significant increase in the incidence of NTDs in Ireland from 0.92 per thousand births reported in 2005–2006 to 1.04 per thousand in 2009–2011 (11,12). Information on periconceptional FA was available in only 52.5% (n = 124) of cases, and only 13.7% (n = 17) of these reported periconceptional FA supplementation. The aim of this prospective observational study was to analyze recent trends in FA supplementation among women booking for antenatal care in a large university maternity hospital in Ireland.
Material and methods The data were examined for all women who delivered an infant weighing ≥500 g between 1 January 2009 and 31
December 2013 inclusive. The Hospital provides one of the largest women’s healthcare hospital services in Europe (13,14). Approximately one in eight women nationally deliver in the Hospital and it accepts women from all socioeconomic groups across the urban–rural divide, including those with private health insurance. The study was granted ethical approval by the Hospital’s Research Ethics Committee (ref. 004-013) and as this study involved collection of anonymized data only, it did not require patient consent by Hospital Research Ethics Committee consensus. Direct measurements of maternal height and weight were recorded at the first antenatal clinic appointment by trained midwives before the body mass index (BMI) was calculated. Maternal BMI was classified according to the World Health Organization categorization. Clinical and sociodemographic details were also computerized at this visit. Interpreters were available for women with difficulty understanding English. Information on pregnancy intention was recorded as part of the electronic medical record using a computerized questionnaire at the woman’s first antenatal visit. Women were asked whether this was a planned pregnancy. After delivery, the clinical details of the pregnancy and delivery were again computerized for subsequent analysis and publication in the Annual Clinical Report (13). Clinical and sociodemographic details recorded included maternal age, parity, BMI, place of birth, FA supplementation and maternal occupation. FA supplementation was classified as periconception (both pre- and postconception), postconception only, and no FA supplementation. In cases where an FA supplement was used, the reported brand name and FA dose contained (either the standard 0.4 mg or high-dose 5 mg) was recorded according to the manufacturer. Country of birth was classified as Ireland, EU 14 (women born in the 14 other countries in the EU before 2004), EU 13 (women born in the 13 Accession countries that joined the EU following enlargement in 2004), or elsewhere (women born outside the EU). Self-described occupation was used to categorize the women into the following socioeconomic groups:
Table 1. Characteristics of the study population.
Mean age (years) (SD) Mean BMI (kg/m2) (SD) Nulliparous (%) Smokers (%) Unemployed (%) Irish-born (%)
2009 (n = 8576)
2010 (n = 8711)
2011 (n = 8458)
2012 (n = 8344)
2013 (n = 7953)
Total (n = 42 042)
30.6 5.8 25.8 4.9 41.5 16.6 7.9 71.8
30.5 5.7 25.5 5.0 42.4 15.4 7.9 69.8
30.6 5.6 25.7 5.1 40.5 14.9 9.4 70.6
30.9 5.6 25.5 5.1 40.1 14.4 10.3 69.9
31.2 5.5 25.6 5.1 38.7 12.6 10.1 70.6
30.7 5.6 25.6 5.0 40.7 14.8 9.1 70.6
BMI, body mass index.
728
ª 2015 Nordic Federation of Societies of Obstetrics and Gynecology, Acta Obstetricia et Gynecologica Scandinavica 94 (2015) 727–733
A. McKeating et al.
Folic acid supplementation trends 2009–2013
Table 2. Folic acid supplementation usage in 2009–2013.
FA
2009 (n = 8576)
2010 (n = 8711)
2011 (n = 8458)
2012 (n = 8344)
2013 (n = 7953)
Total (n = 42 042)
p-valuea
Periconception (%) Postconception only (%) None (%)
45.1 47.3 7.6
43.1 49.6 7.3
43.0 50.4 6.6
45.0 49.1 5.9
43.1 51.1 5.8
43.9 49.4 6.6
0.01
