The Effect of Birth Order on Neonatal Morbidity and Mortality in Very Preterm Twins
18 October 2016
05 January 2017
23 February 2017 (online)
Objective This retrospective cohort study examined the effect of birth order on neonatal morbidity and mortality in very preterm twins.
Study Design Using 2005 to 2012 data from the Canadian Neonatal Network, very preterm twins born between 24 0/7 and 32 6/7 weeks of gestation were included. Odds of morbidity and mortality of second-born cotwins compared with first-born cotwins were examined by matched-pair analysis. Outcomes were neonatal death, severe brain injury (intraventricular hemorrhage grade 3 or 4 or persistent periventricular echogenicity), bronchopulmonary dysplasia, severe retinopathy of prematurity (ROP) (> stage 2), necrotizing enterocolitis (≥ stage 2), and respiratory distress syndrome (RDS). Multivariable analysis was performed adjusting for confounders.
Result There were 6,636 twins (3,318 pairs) included with a mean gestational age (GA) of 28.9 weeks. A higher rate of small for GA occurred in second-born twins (10 vs. 6%). Mortality was significantly lower for second-born twins (4.3 vs. 5.3%; adjusted odds ratio: 0.75; 95% confidence interval [CI]: 0.59–0.95). RDS (66 vs. 60%; adjusted odds ratio: 1.40; 95% CI: 1.29–1.52) and severe retinopathy (9 vs. 7%; adjusted odds ratio: 1.46; 95% CI: 1.07–2.01) were significantly higher in second-born twins.
Conclusion Thus, while second-born twins had reduced odds of mortality, they also had increased odds of RDS and ROP.
List of CNN Site Investigators: Prakesh S. Shah, MD, MSc (Director, Canadian Neonatal Network and site investigator), Mount Sinai Hospital, Toronto, Ontario; Adele Harrison, MD, MBChB, Victoria General Hospital, Victoria, British Columbia; Anne Synnes, MDCM, MHSC, British Columbia Children's Hospital, Vancouver, British Columbia; Todd Sokoran, MD, Royal Columbian Hospital, New Westminster, British Columbia and Surrey Memorial Hospital, Surrey, British Columbia; Wendy Yee, MD, Foothills Medical Centre, Calgary, Alberta; Khalid Aziz, MBBS, MA, MEd, Royal Alexandra Hospital, Edmonton, Alberta; Zarin Kalapesi, MD, Regina General Hospital, Regina, Saskatchewan; Koravangattu Sankaran, MD, MBBS, Royal University Hospital, Saskatoon, Saskatchewan; Mary Seshia, MBChB, Winnipeg Health Sciences Centre, Winnipeg, Manitoba; Ruben Alvaro, MD, St. Boniface General Hospital, Winnipeg, Manitoba; Sandesh Shivananda, MBBS, MD, DM, Hamilton Health Sciences Centre, Hamilton, Ontario; Orlando Da Silva, MD, MSc, London Health Sciences Centre, London, Ontario; Chuks Nwaesei, MD, Windsor Regional Hospital, Windsor, Ontario; Kyong-Soon Lee, MD, MSc, Hospital for Sick Children, Toronto, Ontario; Michael Dunn, MD, Sunnybrook Health Sciences Centre, Toronto, Ontario; Nicole Rouvinez-Bouali, MD, Children's Hospital of Eastern Ontario and Ottawa General Hospital, Ottawa, Ontario; Kimberly Dow, MD, Kingston General Hospital, Kingston, Ontario; Ermelinda Pelausa, MD, Jewish General Hospital, Montréal, Québec; Keith Barrington, MBChB, Hôpital Sainte-Justine, Montréal, Québec; Christine Drolet, MD, Centre Hospitalier Universitaire de Québec, Sainte Foy Québec; Patricia Riley, MD, MDCM, BSc, Montréal Children's Hospital, Montréal, Québec and Royal Victoria Hospital, Montréal, Québec; Valerie Bertelle, MD, Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Québec; Rody Canning, MD, Moncton Hospital, Moncton, New Brunswick; Barbara Bulleid, MD, Dr. Everett Chalmers Hospital, Fredericton, New Brunswick; Cecil Ojah, MBBS, and Luis Monterrosa, MD, Saint John Regional Hospital, Saint John, New Brunswick; Akhil Deshpandey, MD, MBBS, Janeway Children's Health and Rehabilitation Centre, St. John's, Newfoundland; Jehier Afifi, MB BCh, MSc, IWK Health Centre, Halifax, Nova Scotia; Andrzej Kajetanowicz, MD, Cape Breton Regional Hospital, Sydney, Nova Scotia; Shoo K. Lee, MBBS, PhD (chairman, Canadian Neonatal Network), Mount Sinai Hospital, Toronto, Ontario.
- 1 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 (7593): 576 . Doi: 10.1136/bmj.39118.483819.55
- 2 Smith GC, Pell JP, Dobbie R. Birth order, gestational age, and risk of delivery related perinatal death in twins: retrospective cohort study. BMJ 2002; 325 (7371): 1004 . Doi: 10.1136/bmj.325.7371.1004
- 3 Armson BA, O'Connell C, Persad V, Joseph KS, Young DC, Baskett TF. Determinants of perinatal mortality and serious neonatal morbidity in the second twin. Obstet Gynecol 2006; 108 (3 Pt 1): 556-564
- 4 Wen SW, Fung Kee Fung K, Oppenheimer L, Demissie K, Yang Q, Walker M. Neonatal mortality in second twin according to cause of death, gestational age, and mode of delivery. Am J Obstet Gynecol 2004; 191 (03) 778-783
- 5 Sheay W, Ananth CV, Kinzler WL. Perinatal mortality in first- and second-born twins in the United States. Obstet Gynecol 2004; 103 (01) 63-70
- 6 The Canadian Neonatal Network TM Abstractor's Manual. CNN v1.3.4. 2011 . Available at http://www.canadianneonatalnetwork.org
- 7 Papile LA, Burstein J, Burstein R, Koffler H. Incidence and evolution of subependymal and intraventricular hemorrhage: a study of infants with birth weights less than 1,500 gm. J Pediatr 1978; 92 (04) 529-534
- 8 Shennan AT, Dunn MS, Ohlsson A, Lennox K, Hoskins EM. Abnormal pulmonary outcomes in premature infants: prediction from oxygen requirement in the neonatal period. Pediatrics 1988; 82 (04) 527-532
- 9 International Committee for the Classification of Retinopathy of Prematurity. The International classification of retinopathy of prematurity revisited. Arch Ophthalmol 2005; 123 (07) 991-999
- 10 Bell MJ, Ternberg JL, Feigin RD. , et al. Neonatal necrotizing enterocolitis. Therapeutic decisions based upon clinical staging. Ann Surg 1978; 187 (01) 1-7
- 11 Richardson DK, Corcoran JD, Escobar GJ, Lee SK. SNAP-II and SNAPPE-II: simplified newborn illness severity and mortality risk scores. J Pediatr 2001; 138 (01) 92-100
- 12 Wong LF, Holmgren CM, Silver RM, Varner MW, Manuck TA. Outcomes of expectantly managed pregnancies with multiple gestations and preterm premature rupture of membranes prior to 26 weeks. Am J Obstet Gynecol 2015; 212 (02) 215.e1-215.e9
- 13 Pakrashi T, Defranco EA. The relative proportion of preterm births complicated by premature rupture of membranes in multifetal gestations: a population-based study. Am J Perinatol 2013; 30 (01) 69-74
- 14 Cohen A, Skornick-Rapaport A, Cohen Y, Mandel D, Rimon E. The influence of prolonged preterm premature rupture of the membranes on neonatal outcome of the presenting and non-presenting twin. Eur J Obstet Gynecol Reprod Biol 2014; 181: 28-31
- 15 Luo ZC, Ouyang F, Zhang J, Klebanoff M. Perinatal mortality in second- vs firstborn twins: a matter of birth size or birth order?. Am J Obstet Gynecol 2014; 211 (02) 153.e1-153.e8
- 16 Grantz KL, Grewal J, Albert PS. , et al. Dichorionic twin trajectories: the NICHD Fetal Growth Studies. Am J Obstet Gynecol 2016; 215 (02) 221.e1-221.e16
- 17 Viteri OA, Blackwell SC, Chauhan SP. , et al. Antenatal corticosteroids for the prevention of respiratory distress syndrome in premature twins. Obstet Gynecol 2016; 128 (03) 583-591
- 18 Boghossian NS, McDonald SA, Bell EF. , et al; Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Association of antenatal corticosteroids with mortality, morbidity, and neurodevelopmental outcomes in extremely preterm multiple gestation infants. JAMA Pediatr 2016; 170 (06) 593-601