A Comparison of Risk Factors for Twin Preterm Birth in the United States Between 1981–82 and 1996–97
Tóm tắt
Objective: This paper examines risk factors for twin preterm birth in 1981–82 and 1996–97 in the United States in order to see if they have changed over time. Methods: We studied all U.S. twin births for the years examined (N = 346,567). Since the gestational age distributions for twins differs from singletons, the risk of preterm birth was examined at <33, 33–34, and 35–36 weeks. Logistic regression was used to examine the contributions of sociodemographic and obstetric factors at each period. Results: While the <33 week twin preterm rate rose 7% from 1981–82 to 1996–97, the 33–34-week rate rose 31%, and the 35–36-week rate rose 51%. Women with less education, teenagers, unmarried women, primiparas, and blacks were more likely to deliver preterm across all three preterm birth levels. However, the effect of these low socioeconomic status markers diminished over the study period. Additionally, the odds of preterm birth among blacks increased with earlier gestational ages. Women who had intensive prenatal care utilization as compared with less than adequate utilization were more likely to deliver preterm (35–36 weeks) in 1996–97 (odds ratio (OR) = 2.05) compared with 1981–82 (OR = 1.44). Smaller increases were noted for <33 and 33–34 weeks. Conclusions: Obstetric factors appear to be playing a greater role in the rise of twin preterm births at 35–36 weeks gestation. Temporal sociodemographic changes do not explain the rise in the preterm rate. Changing clinical practices may be having unintended consequences on the public health goals of reducing preterm and low birthweight rates in the United States.
Tài liệu tham khảo
Medearis AL, Jonas HS, Stockbauer JW, Danke HR. Perinatal deaths in twin pregnancy. Am J Obstet Gynecol 1979;134:413–21.
McCarthy BJ, Sachs BP, Layde PM, Burton A, Terry JS, Rochat R. The epidemiology of neonatal death in twins. Am J Obstet Gynecol 1981;141:252–6.
Gardner MO, Goldenberg RL, Cliver SP, Tucker JM, Nelson KG, Copper RL.The origin and outcome of preterm twin pregnancies. Obstet Gynecol 1995;85:553–7.
Kogan MD, Alexander GR, Kotelchuck M, MacDorman MF, Buekens P, Martin J, Papiernik E. Trends in twin birth outcomes and prenatal care utilization in the United States, 1981–1997. JAMA 2000;284(3):335–41.
Nageotte MP. Prevention and treatment of preterm labor in twin gestation. Clin Obstet Gynecol 1990;33(1):61–8.
Vergani P, Ghidini A, Bozzo G, Sirtori M. Prenatal management of twin gestation. Experience with a new protocol. J Reprod Med 1991;36(9):667–71.
Heffner LJ, Sherman CB, Spiezer FE, Weiss ST. Clinical and environmental predictors of preterm labor. Obstet Gynecol 1993;81(5, Part 1):750–7.
Powers WF, Kiely JL. The risks confronting twins: A national perspective. Am J Obstet Gynecol 1994;170(2):456–61.
Newman RB, Ellings JM. Antepartum management of the multiple gestation: The case for specialized care. Semin Perinatol 1995;19(5):387–403.
Edwards CF, Chazotte C, Freda MC, Shah L, Girz B, Damus K, Merkatz IR. Impact of an inner-city, hospital-based preterm prevention program on preterm births in twin gestation. J Assoc Acad Minor Phys 1995;6(2):78–81.
Ventura SJ, Martin JA, Curtin SC, Mathews TJ. Births: Final Data for 1997. Natl Vital Stat Rep 1999;47(18):1–93.
Alexander GR, Korenbrot C. The role of prenatal care in preventing low birth weight. Future Child 1995;5(1):103–20.
Ventura SJ, Martin JA, Curtin SC, Mathews TJ. Report of final natality statistics, 1996. Mon Vital Stat Rep 1998;46(11, Suppl):1–99.
National Center for Health Statistics. Instruction Manual Part 12, Computer Edits for Natality Data, Effective 1993. Hyattsville, MD: Public Health Service, 1995:1–59.
Taffel S, Johnson D, Heuser R. Amethod of imputing length of gestation on birth certificates. Vital and Health Statistics,Vol. 93, Series 2 (DHHS Publication No. PHS 82–1367). Washington, DC: U.S. Government Printing Office, May 1982:1–11.
Alexander GR, Kogan MD, Martin JA, Papiernik E. What are the fetal growth patterns of singletons, twins, and triplets in the United States? Clin Obstet Gynecol 1998;41(1):115–23.
Cooperstock MS, Bakewell J, Herman A, Schramm WF. Effects of fetal sex and race on risk of very preterm birth in twins. Am J Obstet Gynecol 1998;179(3, Part 1):762–5.
Cooperstock MS, Bakewell J, Herman A, Schramm WF. Association of sociodemographic variables with risk for very preterm birth in twins. Obstet Gynecol 1998;92(1):53–6.
Wennerholm UB, Holm B, Mattsby-Baltzer I, Nielsen T, Platz-Christensen J, Sundell G, Hosseini N, Hagberg H. Fetal fi-bronectin, endotoxin, bacterial vaginosis and cervical length as predictors of preterm birth and neonatal morbidity in twins. Br J Obstet Gynecol 1997;104(12):1398–1404.
Hong S, Berkowitz G, Wang W, Stone J, Ainbender E. Unexplained elevated maternal alpha-fetoprotein levels and pregnancy outcome in twins. Obstet Gynecol 1996;88(3):337–42.
Goldenberg RL, Iams JD, Miodovnik M, Van Dorsten JP, Thurnau G, Bottoms S, Mercerc BM, Meis PJ, Moawad AH, Das A, Caritis SN, McNellis D. The preterm prediction study: Risk factors in twin gestations. AmJ Obstet Gynecol 1996;175:1047–53.
Alexander GR, Kotelchuck M. Quantifying the adequacy of prenatal care: A comparison of indices. Public Health Rep 1996;111:408–18.
Joseph KS, Kramer MS, Marcoux S, Ohlsson A, Wen SW, Allen A, Platt R. Determinants of preterm birth in Canada from 1981 through 1983 and from 1992 through 1994. N Engl J Med 1998;339:1434–9.
Joseph KS, Allen AC, Dodds L, Vincer MJ, Armson BA. Causes and consequences of recent increases in preterm birth among twins. Obstet Gynecol 2001;98:57–64.
Friedman SA, Schiff E, Kao L, Kuint J, Sibai BM.Dotwins mature earlier than singletons? Results from a matched control study. Am J Obstet Gynecol 1997;176:1193–9.
Wilcox LS, Kiely JL, Melvin CL, Martin MC. Assisted reproductive technologies: Estimates of their contribution to multiple births and newborn hospital days in the United States. Fert Steril 1996;65(2):351–6.
Emery ES, Eaton A, Grether JK, Nelson KB. Assessment of gestational age using birth certificate data compared with medical record data. Paediatr Perinat Epidemiol 1997;11:313–21.
Alexander GR, Allen MC. Conceptualization, measurement, and use of gestational age I. Clinical and public health practice. J Perinatol 1996;16:53–9.
Cooperstock M. Gestational age-specific birthweight of twins in vital records. Paediatr Perinat Epidemiol 1998;12:347–51.
Bernasko J, Lynch L, Lapinski R, Berkowitz RL. Twin pregnancies conceived by assisted reproductive techniques: Maternal and neonatal outcomes. Obstet Gynecol 1997;89(3):368–72.
U.S. Department of Health and Human Services. Healthy People 2010, 2nd ed. Washington, DC: U.S. Government Printing Office, 2000. With Understanding and Improving Health and Objectives for Improving Health, 2 vols.