References
1. DaVanzo J, Hale L, Razzaque A, Rahman M. Effects of interpregnancy
interval and outcome of the preceding pregnancy on pregnancy outcomes in
Matlab, Bangladesh. BJOG. 2007;114(9):1079-87.
2. Conde-Agudelo A, Rosas-Bermudez A, Castano F, Norton MH. Effects of
birth spacing on maternal, perinatal, infant, and child health: a
systematic review of causal mechanisms. Stud Fam Plann.
2012;43(2):93-114.
3. Cleland J, Bernstein S, Ezeh A, Faundes A, Glasier A, Innis J. Family
planning: the unfinished agenda. Lancet. 2006;368(9549):1810-27.
4. World Health Organization, USAID, Mathernal and Child Health
Integrated Program. Programming Strategies for Postpartum Family
Planning. Geneva: World Health Organization; 2013.
5. White K, Teal SB, Potter JE. Contraception after delivery and short
interpregnancy intervals among women in the United States. Obstet
Gynecol. 2015;125(6):1471-7.
6. Dev R, Kohler P, Feder M, Unger JA, Woods NF, Drake AL. A systematic
review and meta-analysis of postpartum contraceptive use among women in
low- and middle-income countries. Reprod Health. 2019;16(1):154.
7. Huang YM, Merkatz R, Kang JZ, Roberts K, Hu XY, Di Donato F, et al.
Postpartum unintended pregnancy and contraception practice among
rural-to-urban migrant women in Shanghai. Contraception.
2012;86(6):731-8.
8. Huang YM, Kang J, Hu X, Chen R, Cheng L. Study on unintended
pregnancy and risk factors among postnatal women in Shanghai.
Reproduction and Contraception. 2008;28(5):286-90.
9. Kang C, Li P, Liu X, Ding Y, Wang X, Zhou H. Use of contraceptives
and uptake of long-acting reversible contraception among postpartum
women in rural China. BMJ sexual & reproductive health. 2018.
10. Singh S, Reme L, Sedg G, Kwok L, Onda T. Abortion worldwide
2017:uneven progress and uneuqal access. New York: Guttmacher Institute;
2018.
11. Ahrens KA, Thoma ME, Copen CE, Frederiksen BN, Decker EJ, Moskosky
S. Unintended pregnancy and interpregnancy interval by maternal age,
National Survey of Family Growth. Contraception. 2018;98(1):52-5.
12. Moore Z, Pfitzer A, Gubin R, Charurat E, Elliott L, Croft T. Missed
opportunities for family planning: an analysis of pregnancy risk and
contraceptive method use among postpartum women in 21 low- and
middle-income countries. Contraception. 2015;92(1):31-9.
13. Xiao H, Qin C, Yan H, Li S, Xu D. Prevalence and related reasons of
unintended pregnancy in the first year of delivery among married women
in Enshi. Chinese Journal of Disease Control & Prevention.
2014;18(9):876-9.
14. National Health Commission. China’s Health Statistics Yearbook 2018.
Beijing: Peking union medical college press; 2019.
15. Donner A, Birkett N, Buck C. Randomization by cluster. Sample size
requirements and analysis. American journal of epidemiology.
1981;114(6):906-14.
16. Hayes RJ, Bennett S. Simple sample size calculation for
cluster-randomized trials. Int J Epidemiol. 1999;28(2):319-26.
17. Whiteman M, Curtis K, Hillis S, Zapata L, D’Angelo D, SL Farr, et
al. Contraceptive Use Among Postpartum Women — 12 States and New York
City, 2004–2006. MMWR weekly. 2009;58(30):821-6.
18. Wilopo SA, Setyawan A, Pinandari AW, Prihyugiarto T, Juliaan F,
Magnani RJ. Levels, trends and correlates of unmet need for family
planning among postpartum women in Indonesia: 2007-2015. BMC Womens
Health. 2017;17(1):120.
19. Mehata S, Paudel YR, RanjuMehta, Dariang M, Poudel P, Barnett4 S.
Unmet Need for Family Planning in Nepal during the First Two Years
Postpartum. BioMed Research International [Internet]. 2014;
2014:[1-9 pp.].
20. (WHO/RHR); WHODoRHaR, (CCP); JHBSoPHCfCP, Project. KfH. Family
Planning: A Global Handbook for Providers (2018 update). Baltimore and
Geneva: CCP and WHO; 2018.
21. Ruo L, Zhang J, Luo J. An investigation of the unintended pregnancy
and induced abortion in Pengshan District of Meishai City. Journal of
Hainan Medicine. 2018;29(9):1305-8.
22. National Bureau of Statistics. In 2017, the State economic operation
was stable, positive and better than expected: National Bureau of
Statistics,; 2018 [cited 2020 June 6]. Available from:
http://www.stats.gov.cn/tjsj/zxfb/201801/t20180118_1574917.html.
Table 1. Cumulative 6-, 12-, and 24-month rates of pregnancy, unintended
pregnancy and induced abortion, by geographic regions