1. Martin JA, Hamilton BE, Osterman MJK. Births in the United States, 2016. NCHS Data Brief. 2017; 1–8.
2. Korean Statistical Information Service. Birth data for 2016, Korea. Daejeon: Korean Statistical Information Service;2017.
3. Lee GH, Song HJ, Lee KS, Choi YM. Current status of assisted reproductive technology in Korea, 2010. Clin Exp Reprod Med. 2015; 42:8–13. PMID:
25874168.
Article
4. Aduloju OP, Olofinbiyi B, Olagbuji BN, Ade-Ojo IP, Akintayo A. Obstetric outcome of twin gestations in a tertiary hospital South-western Nigeria. J Matern Fetal Neonatal Med. 2015; 28:900–904. PMID:
25030878.
Article
5. Luke B, Keith LG. The contribution of singletons, twins and triplets to low birth weight, infant mortality and handicap in the United States. J Reprod Med. 1992; 37:661–666. PMID:
1432978.
6. Ananth CV, Joseph KS, Demissie K, Vintzileos AM. Trends in twin preterm birth subtypes in the United States, 1989 through 2000: impact on perinatal mortality. Am J Obstet Gynecol. 2005; 193:1076–1082. PMID:
16157115.
Article
7. Yoo EH, Chun D, Kim MJ, Cha HH, Seong WJ. Comparison of perinatal outcomes in late preterm birth between singleton and twin pregnancies. Obstet Gynecol Sci. 2017; 60:421–426. PMID:
28989917.
Article
8. Black M, Bhattacharya S. Epidemiology of multiple pregnancy and the effect of assisted conception. Semin Fetal Neonatal Med. 2010; 15:306–312. PMID:
20630816.
Article
9. Masheer S, Maheen H, Munim S. Perinatal outcome of twin pregnancies according to chorionicity: an observational study from tertiary care hospital. J Matern Fetal Neonatal Med. 2015; 28:23–25. PMID:
24605797.
Article
10. Doss AE, Mancuso MS, Cliver SP, Jauk VC, Jenkins SM. Gestational age at delivery and perinatal outcomes of twin gestations. Am J Obstet Gynecol. 2012; 207:410.e1–410.e6. PMID:
22959832.
Article
11. Acosta-Rojas R, Becker J, Munoz-Abellana B, Ruiz C, Carreras E, Gratacos E, et al. Twin chorionicity and the risk of adverse perinatal outcome. Int J Gynaecol Obstet. 2007; 96:98–102. PMID:
17250837.
Article
12. Hansen M, Kurinczuk JJ, Milne E, de Klerk N, Bower C. Assisted reproductive technology and birth defects: a systematic review and meta-analysis. Hum Reprod Update. 2013; 19:330–353. PMID:
23449641.
Article
13. Wen J, Jiang J, Ding C, Dai J, Liu Y, Xia Y, et al. Birth defects in children conceived by
in vitro fertilization and intracytoplasmic sperm injection: a meta-analysis. Fertil Steril. 2012; 97:1331–1337.e1-4. PMID:
22480819.
14. Tararbit K, Lelong N, Jouannic JM, Goffinet F, Khoshnood B; EPICARD Study Group. Is the probability of prenatal diagnosis or termination of pregnancy different for fetuses with congenital anomalies conceived following assisted reproductive techniques? A population-based evaluation of fetuses with congenital heart defects. BJOG. 2015; 122:924–931. PMID:
25752912.
15. Moses XJ, Torres T, Rasmussen A, George C. Congenital anomalies identified at birth among infants born following assisted reproductive technology in Colorado. Birth Defects Res A Clin Mol Teratol. 2014; 100:92–99. PMID:
24532453.
Article
16. Reefhuis J, Honein MA. Maternal age and non-chromosomal birth defects, Atlanta--1968–2000: teenager or thirty-something, who is at risk? Birth Defects Res A Clin Mol Teratol. 2004; 70:572–579. PMID:
15368555.
Article
17. Cleary-Goldman J, Malone FD, Vidaver J, Ball RH, Nyberg DA, Comstock CH, et al. Impact of maternal age on obstetric outcome. Obstet Gynecol. 2005; 105:983–990. PMID:
15863534.
Article
18. Goldenberg RL, Culhane JF, Iams JD, Romero R. Epidemiology and causes of preterm birth. Lancet. 2008; 371:75–84. PMID:
18177778.
Article
19. Rafael TJ, Berghella V, Alfirevic Z. Cervical stitch (cerclage) for preventing preterm birth in multiple pregnancy. Cochrane Database Syst Rev. 2014; CD009166. PMID:
25208049.
Article
20. Nam SH, Lee JE, Choi SJ, Oh SY, Kim JH, Roh CR. Pregnancy outcome of cervical incompetence in twin versus singleton pregnancies. Korean J Perinatol. 2007; 18:149–153.
21. Meath AJ, Ramsey PS, Mulholland TA, Rosenquist RG, Lesnick T, Ramin KD. Comparative longitudinal study of cervical length and induced shortening changes among singleton, twin, and triplet pregnancies. Am J Obstet Gynecol. 2005; 192:1410–1415. PMID:
15902123.
Article
22. Kahn B, Lumey LH, Zybert PA, Lorenz JM, Cleary-Goldman J, D'Alton ME, et al. Prospective risk of fetal death in singleton, twin, and triplet gestations: implications for practice. Obstet Gynecol. 2003; 102:685–692. PMID:
14550996.
Article
23. Cheung YB, Yip P, Karlberg J. Mortality of twins and singletons by gestational age: a varying-coefficient approach. Am J Epidemiol. 2000; 152:1107–1116. PMID:
11130615.
Article
24. Lewi L, Van Schoubroeck D, Gratacós E, Witters I, Timmerman D, Deprest J. Monochorionic diamniotic twins: complications and management options. Curr Opin Obstet Gynecol. 2003; 15:177–194. PMID:
12634610.
Article
25. Van Mieghem T, De Heus R, Lewi L, Klaritsch P, Kollmann M, Baud D, et al. Prenatal management of monoamniotic twin pregnancies. Obstet Gynecol. 2014; 124:498–506. PMID:
25162249.
Article
26. Vergani P, Russo FM, Follesa I, Cozzolino S, Fedeli T, Ventura L, et al. Perinatal complications in twin pregnancies after 34 weeks: effects of gestational age at delivery and chorionicity. Am J Perinatol. 2013; 30:545–550. PMID:
23096054.
Article
27. Newman RB, Unal ER. Multiple gestations: timing of indicated late preterm and early-term births in uncomplicated dichorionic, monochorionic, and monoamniotic twins. Semin Perinatol. 2011; 35:277–285. PMID:
21962627.
Article
28. Spong CY, Mercer BM, D'alton M, Kilpatrick S, Blackwell S, Saade G. Timing of indicated late-preterm and early-term birth. Obstet Gynecol. 2011; 118:323–333. PMID:
21775849.
Article
29. National Institute for Health and Clinical Excellence. Antenatal management of multiple gestations: NICE clinical guideline 129 [Internet]. London: National Institute for Health and Care Excellence;c2011. cited 2015 Mar 20. Available from:
http://guidance.nice.org.uk/CG129.
30. Lee HJ, Kim SH, Chang KH, Sung JH, Choi SJ, Oh SY, et al. Gestational age at delivery and neonatal outcome in uncomplicated twin pregnancies: what is the optimal gestational age for delivery according to chorionicity? Obstet Gynecol Sci. 2016; 59:9–16. PMID:
26866030.
Article
31. Sung JH, Kim SH, Kim YM, Kim JH, Kim MN, Lee HR, et al. Neonatal outcomes of twin pregnancies delivered at late-preterm versus term gestation based on chorionicity and indication for delivery. J Perinat Med. 2016; 44:903–911. PMID:
27149198.
Article
32. Lee YM, Cleary-Goldman J, D'Alton ME. The impact of multiple gestations on late preterm (near-term) births. Clin Perinatol. 2006; 33:777–792. PMID:
17148004.
Article
33. Smith GC, Shah I, White IR, Pell JP, Dobbie R. Mode of delivery and the risk of delivery-related perinatal death among twins at term: a retrospective cohort study of 8073 births. BJOG. 2005; 112:1139–1144. PMID:
16045531.
Article
34. Smith GC, Fleming KM, White IR. Birth order of twins and risk of perinatal death related to delivery in England, Northern Ireland, and Wales, 1994–2003: retrospective cohort study. BMJ. 2007; 334:576. PMID:
17337456.
Article
35. Barrett JF, Hannah ME, Hutton EK, Willan AR, Allen AC, Armson BA, et al. A randomized trial of planned cesarean or vaginal delivery for twin pregnancy. N Engl J Med. 2013; 369:1295–1305. PMID:
24088091.
Article
36. Schmitz T, Carnavalet CC, Azria E, Lopez E, Cabrol D, Goffinet F. Neonatal outcomes of twin pregnancy according to the planned mode of delivery. Obstet Gynecol. 2008; 111:695–703. PMID:
18310373.
Article
37. Rossi AC, Mullin PM, Chmait RH. Neonatal outcomes of twins according to birth order, presentation and mode of delivery: a systematic review and meta-analysis. BJOG. 2011; 118:523–532. PMID:
21291505.
Article
38. Yamashita A, Ishii K, Taguchi T, Mabuchi A, Ota S, Sasahara J, et al. Adverse perinatal outcomes related to the delivery mode in women with monochorionic diamniotic twin pregnancies. J Perinat Med. 2014; 42:769–775. PMID:
24728848.
Article
39. Lim JS, Lim SW, Ahn JH, Song BS, Shim KS, Hwang IT. New Korean reference for birth weight by gestational age and sex: data from the Korean Statistical Information Service (2008–2012). Ann Pediatr Endocrinol Metab. 2014; 19:146–153. PMID:
25346919.
Article