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We consecutively-recruited 97.9% (19,144/19,563) wife/husband pregnancy planners who were eligible for the study, with a high participation rate across the districts; 96.4% (15,615/16,201) eligible women were recruited consecutively at early pregnancy (Figure 1).
The socio-demographic and lifestyle characteristics of the participants are presented in Table 1. The mean (SD) age was 29.9 (3.9) years, 31.4 (4.5) years, and 29.9 (4.0) years of female and male pregnancy planners and women at early pregnancy, respectively. The majority of the participants were of Han ethnicity, educated to college level or above, and employed. About half of the sample lived in suburban districts. Smoking was uncommon among women but common among men. Further, 1 in 3 women consumed alcohol before conception but only 1 in 10, during pregnancy; alcohol consumption was more common among men than women. Half of the women in early pregnancy were primigra-vidae.
Table 1. Characteristics of pregnancy planners and women in early pregnancy
Characteristics Couples completed questionnaires (a)
at pre-pregnancy examination clinics visit
(female = 11,099, male = 8,045)Pregnant women completed
questionnaires (b) at first antenatal
clinic visit (n = 15,615)Wife-pregnancy
planners, n (%)Husband-pregnancy
planners, n (%)Women in early
pregnancy, n (%)Age, years < 30 6,527 (58.8) 3,517 (43.7) 8,587 (55.0) ≥ 30 4,572 (41.2) 4,528 (56.3) 7,028 (45.0) Ethnicity Han 10,773 (97.1) 7,843 (97.5) 15,245 (97.6) Others 259 (2.3) 158 (2.0) 342 (2.2) Missing 67 (0.6) 44 (0.5) 28 (0.2) Educational level High school or less 947 (8.5) 613 (7.6) 2,117 (13.6) College or above 10,041 (90.5) 7,383 (91.7) 13,436 (86.0) Missing 111 (1.0) 49 (0.6) 62 (0.4) Occupation Blue collar 2,698 (24.3) 3,540 (44.0) 2,650 (17.0) White collar 3,499 (31.5) 2,413 (30.0) 2,403 (15.4) Others 4,661 (42.0) 1,954 (24.3) 5,366 (34.4) Missing 241 (2.2) 138 (1.7) 163 (1.0) Residencea Suburban districts 4,728 (42.6) 4,473 (55.6) 7,481 (47.9) Urban districts 6,371 (57.4) 3,572 (44.4) 8,134 (52.1) Smokingb No 10,816 (97.5) 5,501 (68.4) 15,410 (98.7) Yes 248 (2.2) 2,517 (31.3) 161 (1.0) Missing 35 (0.3) 27 (0.3) 44 (0.3) Alcohol consumptionc No 7,532 (67.9) 3,043 (37.8) 13,976 (89.5) Yes 3,374 (30.4) 4,840 (60.2) 1,599 (10.2) Missing 193 (1.7) 162 (2.0) 40 (0.3) Attending pre-pregnancy examination NA NA No 11,622 (74.4) Yes 3,374 (21.6) Missing 619 (4.0) Gravidity (times) NA NA < 2 7,804 (50.0) ≥ 2 7,782 (49.8) Missing 29 (0.2) Note. a Residence was classified according to administrative division of the Shanghai government. Suburban districts in this study were ‘rural areas’, where the national FA programme has been implemented since 2009.
bParticipants with a history of smoking.
cAlcohol consumption within three months.
FA, folic acid; NA, not applicable. -
In Table 2, among the pregnancy planners, 42.4% (4,710/11,099) of the wives and 17.1% (1,377/8,045) of the husbands reported current FA supplement use. The prevalence of FA supplementation in suburban districts was 40.6% (1,921/4,728) in the wives and 15.4% (688/4,473) in the husbands compared with 43.8% (2,789/6,371) and 19.3% (689/3,572), respectively, in the urban districts that were not included in the programme. Among women at early pregnancy, 93.4% (14,585/15,615) reported FA supplementation after their last menstrual period.
Table 2. Prevalence and dose of FA supplement use before and at early pregnancy
Description Before pregnancy At early pregnancy Female Male Early pregnant women Total prevalence of FA supplementation, n/N (%) 4,710/11,099 (42.4) 1,377/8,045 (17.1) 14,585/15,615 (93.4) Prevalence of FA supplementation in suburban districts, n/N (%) 1,921/4,728 (40.6) 688/4,473 (15.4) 6,951/7,481 (92.9) Prevalence of FA supplementation in urban districts, n/N (%) 2,789/6,371 (43.8) 689/3,572 (19.3) 7,634/8,134 (93.9) Respondent, n (%)a 2,866 (60.8) 648 (47.1) 10,033 (68.8) The percentage of single FA, n (%) 203 (7.1) 22 (3.3) 751 (7.5) The percentage of multi-vitamin, n (%) 2,663 (92.9) 626 (96.7) 9,282 (92.5) Dose of daily FA supplement (μg/d), n (%)b 2,781 (59.0) 614 (44.6) 10,033 (68.8) < 400, n (%) 613 (22.0) 135 (22.0) 1,072 (10.7) 400–1,000, n (%) 2,038 (73.3) 466 (75.9) 7,950 (79.2) > 1,000, n (%) 130 (4.7) 13 (2.1) 1,011 (10.1) Note. aNumber of participants who responded to ‘brand of product’; bNumber of participants who responded to both ‘brand of product’ and frequency of use. FA, folic acid. Based on the information on FA products, FA dose was calculated for 3,395 pregnancy planners (n = 614 husbands; n = 2,781 wives) and 10,033 women at early pregnancy. Insufficient FA intake (< 400 μg/d) was reported in 22.0% (613/2,781) of the wives, while 4.7% (130/2,781) of the wives went over the recommended TUL of 1,000 μg/d. At early pregnancy, 10.7% (1,072/14,585) of the women took a low dose of FA (< 400 μg/d), and 10.1% (1,011/14,585) exceeded the TUL.
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In the multivariable log-binomial model analysis, factors that were statistically significantly associated with high FA supplement use in both male and female pregnancy planners were older age, high education level, and residence in an urban district. FA supplement use was lower in female pregnancy planners who consumed alcohol. High education level was also associated with high FA supplement use in early pregnancy women. In contrast to pregnancy planners, FA supplement use decreased in older early pregnant women. FA supplement use was low in pregnant women in multigravida. FA supplement use was high in early pregnant women who had attended a pre-pregnancy examination. The detailed results are presented in Table 3.
Table 3. Analyses of factors relate to FA supplement use among pregnancy planners and women in early pregnancy
Characteristics Female pregnancy plannersa Male pregnancy plannersb Early pregnancy womenc RR (95% CI) P RR (95% CI) P RR (95% CI) P Age (years) < 30 1 1 1 ≥ 30 1.13 (1.08–1.18) < 0.001 1.22 (1.11–1.35) < 0.001 0.99 (0.98–0.99) 0.003 Ethnicity Han 1 1 1 Others 1.04 (0.90–1.20) 0.585 0.92 (0.65–1.31) 0.653 1.01 (0.99–1.03) 0.340 Education High school or less 1 1 1 College or above 1.71 (1.53–1.92) < 0.001 2.06 (1.55–2.75) < 0.001 1.04 (1.03–1.06) < 0.001 Occupation Blue collar 1 1 1 White collar 0.97 (0.92–1.02) 0.258 1.07 (0.95-1.21) 0.288 1.01 (0.99–1.02) 0.054 Other 1.02 (0.96–1.08) 0.473 1.03 (0.92–1.15) 0.634 1.00 (0.98–1.01) 0.697 Residing- districts Suburban districts 1 1 1 Urban districts 1.06 (1.01–1.11) 0.011 1.25 (1.11–1.41) < 0.001 1.00 (0.99–1.01) 0.828 Smoking No 1 1 1 Yes 0.94 (0.79–1.11) 0.444 0.91 (0.81–1.01) 0.081 0.95 (0.89–1.01) 0.101 Alcohol consumption No 1 1 1 Yes 0.95 (0.90–0.99) 0.035 0.98 (0.89–1.09) 0.719 0.99 (0.98–1.01) 0.291 Attending pre-pregnancy examination NA NA No Yes 1.02 (1.01–1.03) < 0.001 Gravidity (times) NA NAd < 2 ≥ 2 0.97 (0.96–0.98) < 0.001 Note. Multivariable log-binomial model was used. Missing data have not been included in the analysis. aModel performance: N = 10,612, Log likelihood = −7161.4269; bModel performance: N = 7,714, Log likelihood = −3511.2040; cModel performance: N = 14,769, Log likelihood = −3488.4899; dLacking of information due to the design limitation in questionnaires (a). RR, Risk ratio; FA, folic acid; 95% CI, 95% confidence interval; NA, not applicable.
doi: 10.3967/bes2020.074
Folic Acid Supplementation in Chinese Peri-conceptional Population: Results from the SPCC Study
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Abstract:
Objective To determine the prevalence and determinants of folic acid (FA) supplementation in Chinese couples planning for pregnancy and in women during early pregnancy. Methods This was a cross-sectional study based on the Shanghai PreConception Cohort (SPCC) study. Data on FA supplementation and socio-demographic features were collected using questionnaires. Couples visiting clinics for pre-pregnancy examination and pregnant women at < 14 gestational weeks were recruited in Shanghai, China, between March 2016 and September 2018. Results Among the pregnancy planners, 42.4% (4,710/11,099) women and 17.1% (1,377/8,045) men used FA supplements, while 93.4% (14,585/15,615) of the pregnant women used FA supplements. FA supplement use was higher in female pregnancy planners who were older (RR: 1.13, 95% CI: 1.08–1.18), had higher education (RR: 1.71, 95% CI: 1.53–1.92), and were residing in urban districts (RR: 1.06, 95% CI: 1.01–1.11) of FA supplementation; female pregnancy planners with alcohol consumption (RR: 0.95, 95% CI: 0.90–0.99) had lower odds of FA supplementation. In early pregnancy, women with higher educational level (RR: 1.04, 95% CI: 1.03–1.06), who underwent pre-pregnancy examination (RR: 1.02, 95% CI: 1.01–1.03) had higher odds of using an FA supplement; older aged (RR: 0.99, 95% CI: 0.98–0.99), and multigravida (RR: 0.97, 95% CI: 0.96–0.98) had lower odds of FA supplementation. Conclusion Although the majority of pregnant women took FA supplements, more than half of the women planning for pregnancy did not. Urgent strategies are needed to improve pre-conception FA supplementation. -
Key words:
- Folic acid supplementation /
- Peri-conception /
- Birth defects /
- China /
- Pregnancy
&Members of Shanghai PreConception Cohort Group are listed at the end of manuscript
注释: -
S1. Map of the districts in Shanghai engaged in the study.
19,144 pregnancy planners attending pre-pregnancy examination clinics at 19 maternity and child health institutions in 9 districts (Minhang, Huangpu, Xuhui, Changning, Jing’an, Yangpu, Pudong, Songjiang, and Qingpu) in Shanghai and 15,615 women attending antenatal care clinics at 8 maternity and child health institutions in 5 districts (Minhang, Huangpu, Xuhui, Songjiang, and Yangpu) were recruited.
Figure 1. Flowchart of study population.
Couples visiting pre-pregnancy examination clinics (‘pregnancy planners’) at 19 community-based maternity and child health care centres and pregnant women attending their first antenatal exam at 10 maternity hospitals in Shanghai were recruited. At the pre-pregnancy clinics, 98.5% (19,260/19,563) eligible pregnancy planners were recruited. At the antenatal healthcare clinics, 96.4% (15,615/16,201) eligible pregnant women were recruited in this study.
Table 1. Characteristics of pregnancy planners and women in early pregnancy
Characteristics Couples completed questionnaires (a)
at pre-pregnancy examination clinics visit
(female = 11,099, male = 8,045)Pregnant women completed
questionnaires (b) at first antenatal
clinic visit (n = 15,615)Wife-pregnancy
planners, n (%)Husband-pregnancy
planners, n (%)Women in early
pregnancy, n (%)Age, years < 30 6,527 (58.8) 3,517 (43.7) 8,587 (55.0) ≥ 30 4,572 (41.2) 4,528 (56.3) 7,028 (45.0) Ethnicity Han 10,773 (97.1) 7,843 (97.5) 15,245 (97.6) Others 259 (2.3) 158 (2.0) 342 (2.2) Missing 67 (0.6) 44 (0.5) 28 (0.2) Educational level High school or less 947 (8.5) 613 (7.6) 2,117 (13.6) College or above 10,041 (90.5) 7,383 (91.7) 13,436 (86.0) Missing 111 (1.0) 49 (0.6) 62 (0.4) Occupation Blue collar 2,698 (24.3) 3,540 (44.0) 2,650 (17.0) White collar 3,499 (31.5) 2,413 (30.0) 2,403 (15.4) Others 4,661 (42.0) 1,954 (24.3) 5,366 (34.4) Missing 241 (2.2) 138 (1.7) 163 (1.0) Residencea Suburban districts 4,728 (42.6) 4,473 (55.6) 7,481 (47.9) Urban districts 6,371 (57.4) 3,572 (44.4) 8,134 (52.1) Smokingb No 10,816 (97.5) 5,501 (68.4) 15,410 (98.7) Yes 248 (2.2) 2,517 (31.3) 161 (1.0) Missing 35 (0.3) 27 (0.3) 44 (0.3) Alcohol consumptionc No 7,532 (67.9) 3,043 (37.8) 13,976 (89.5) Yes 3,374 (30.4) 4,840 (60.2) 1,599 (10.2) Missing 193 (1.7) 162 (2.0) 40 (0.3) Attending pre-pregnancy examination NA NA No 11,622 (74.4) Yes 3,374 (21.6) Missing 619 (4.0) Gravidity (times) NA NA < 2 7,804 (50.0) ≥ 2 7,782 (49.8) Missing 29 (0.2) Note. a Residence was classified according to administrative division of the Shanghai government. Suburban districts in this study were ‘rural areas’, where the national FA programme has been implemented since 2009.
bParticipants with a history of smoking.
cAlcohol consumption within three months.
FA, folic acid; NA, not applicable.Table 2. Prevalence and dose of FA supplement use before and at early pregnancy
Description Before pregnancy At early pregnancy Female Male Early pregnant women Total prevalence of FA supplementation, n/N (%) 4,710/11,099 (42.4) 1,377/8,045 (17.1) 14,585/15,615 (93.4) Prevalence of FA supplementation in suburban districts, n/N (%) 1,921/4,728 (40.6) 688/4,473 (15.4) 6,951/7,481 (92.9) Prevalence of FA supplementation in urban districts, n/N (%) 2,789/6,371 (43.8) 689/3,572 (19.3) 7,634/8,134 (93.9) Respondent, n (%)a 2,866 (60.8) 648 (47.1) 10,033 (68.8) The percentage of single FA, n (%) 203 (7.1) 22 (3.3) 751 (7.5) The percentage of multi-vitamin, n (%) 2,663 (92.9) 626 (96.7) 9,282 (92.5) Dose of daily FA supplement (μg/d), n (%)b 2,781 (59.0) 614 (44.6) 10,033 (68.8) < 400, n (%) 613 (22.0) 135 (22.0) 1,072 (10.7) 400–1,000, n (%) 2,038 (73.3) 466 (75.9) 7,950 (79.2) > 1,000, n (%) 130 (4.7) 13 (2.1) 1,011 (10.1) Note. aNumber of participants who responded to ‘brand of product’; bNumber of participants who responded to both ‘brand of product’ and frequency of use. FA, folic acid. Table 3. Analyses of factors relate to FA supplement use among pregnancy planners and women in early pregnancy
Characteristics Female pregnancy plannersa Male pregnancy plannersb Early pregnancy womenc RR (95% CI) P RR (95% CI) P RR (95% CI) P Age (years) < 30 1 1 1 ≥ 30 1.13 (1.08–1.18) < 0.001 1.22 (1.11–1.35) < 0.001 0.99 (0.98–0.99) 0.003 Ethnicity Han 1 1 1 Others 1.04 (0.90–1.20) 0.585 0.92 (0.65–1.31) 0.653 1.01 (0.99–1.03) 0.340 Education High school or less 1 1 1 College or above 1.71 (1.53–1.92) < 0.001 2.06 (1.55–2.75) < 0.001 1.04 (1.03–1.06) < 0.001 Occupation Blue collar 1 1 1 White collar 0.97 (0.92–1.02) 0.258 1.07 (0.95-1.21) 0.288 1.01 (0.99–1.02) 0.054 Other 1.02 (0.96–1.08) 0.473 1.03 (0.92–1.15) 0.634 1.00 (0.98–1.01) 0.697 Residing- districts Suburban districts 1 1 1 Urban districts 1.06 (1.01–1.11) 0.011 1.25 (1.11–1.41) < 0.001 1.00 (0.99–1.01) 0.828 Smoking No 1 1 1 Yes 0.94 (0.79–1.11) 0.444 0.91 (0.81–1.01) 0.081 0.95 (0.89–1.01) 0.101 Alcohol consumption No 1 1 1 Yes 0.95 (0.90–0.99) 0.035 0.98 (0.89–1.09) 0.719 0.99 (0.98–1.01) 0.291 Attending pre-pregnancy examination NA NA No Yes 1.02 (1.01–1.03) < 0.001 Gravidity (times) NA NAd < 2 ≥ 2 0.97 (0.96–0.98) < 0.001 Note. Multivariable log-binomial model was used. Missing data have not been included in the analysis. aModel performance: N = 10,612, Log likelihood = −7161.4269; bModel performance: N = 7,714, Log likelihood = −3511.2040; cModel performance: N = 14,769, Log likelihood = −3488.4899; dLacking of information due to the design limitation in questionnaires (a). RR, Risk ratio; FA, folic acid; 95% CI, 95% confidence interval; NA, not applicable. -
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