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BMC Pregnancy and Childbirth
Published in: BMC Pregnancy and Childbirth 1/2004

Open Access 01-12-2004 | Research article

A parsimonious explanation for intersecting perinatal mortality curves: understanding the effects of race and of maternal smoking

Authors: K S Joseph, Kitaw Demissie, Robert W Platt, Cande V Ananth, Brian J McCarthy, Michael S Kramer

Published in: BMC Pregnancy and Childbirth | Issue 1/2004

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Abstract

Background

Neonatal mortality rates among black infants are lower than neonatal mortality rates among white infants at birth weights <3000 g, whereas white infants have a survival advantage at higher birth weights. This finding is also observed when birth weight-specific neonatal mortality rates are compared between infants of smokers and non-smokers. We provide a parsimonious explanation for this paradoxical phenomenon.

Methods

We used data on births in the United States in 1997 after excluding those with a birth weight <500 g or a gestational age <22 weeks. Birth weight- and gestational age-specific perinatal mortality rates were calculated per convention (using total live births at each birth weight/gestational age as the denominator) and also using the fetuses at risk of death at each gestational age.

Results

Perinatal mortality rates (calculated per convention) were lower among blacks than whites at lower birth weights and at preterm gestational ages, while blacks had higher mortality rates at higher birth weights and later gestational ages. With the fetuses-at-risk approach, mortality curves did not intersect; blacks had higher mortality rates at all gestational ages. Increases in birth rates and (especially) growth-restriction rates presaged gestational age-dependent increases in perinatal mortality. Similar findings were obtained in comparisons of smokers versus nonsmokers.

Conclusions

Formulating perinatal risk based on the fetuses-at-risk approach solves the intersecting perinatal mortality curves paradox; blacks have higher perinatal mortality rates than whites and smokers have higher perinatal mortality rates than nonsmokers at all gestational ages and birth weights.
Appendix
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Literature
1.
Yerushalmy J: The relationship of parents' cigarette smoking to outcome of pregnancy – implications as to the problem of inferring causation from observed associations. Am J Epidemiol. 1971, 93: 443-56.PubMed
2.
Wilcox AJ, Russell IT: Why small black infant have lower mortality than small white infants: the case for population-specific standards for birth weight. J Pediatr. 1990, 116: 7-10.CrossRefPubMed
3.
Hertz-Picciotto I, Din-Dzietham R: Comparisons of infant mortality using a percentile- based method of standardization for birthweight or gestational age. Epidemiol. 1998, 9: 61-7.CrossRef
4.
Meyer MB, Comstock GW: Maternal cigarette smoking and perinatal mortality. Am J Epidemiol. 1972, 96: 1-10.PubMed
5.
Lie RT: Invited commentary: Intersecting perinatal mortality curves by gestational age – are appearances deceiving?. Am J Epidemiol. 2000, 152: 1117-9. 10.1093/aje/152.12.1117.CrossRefPubMed
6.
Wilcox AJ, Russell IT: Birthweight and perinatal mortality: III. Towards a new method of analysis. Int J Epidemiol. 1986, 15: 188-96.CrossRefPubMed
7.
English PB, Eskenazi B: Reinterpreting the effects of maternal smoking on infant birthweight and perinatal mortality: a multivariate approach to birth weight standardization. Int J Epidemiol. 1992, 21: 1097-1105.CrossRefPubMed
8.
9.
Wilcox AJ: Birth weight and perinatal mortality: the effect of maternal smoking. Am J Epidemiol. 1993, 137: 1098-1104.PubMed
10.
Buekens P, Wilcox A: Why do small twins have a lower mortality than small singletons?. Am J Obstet Gynecol. 1993, 168: 937-41.CrossRefPubMed
11.
Wilcox AJ, Skjœrven R, Buekens P, Kiely J: Birth weight and perinatal mortality: A comparison of the United States and Norway. JAMA. 1995, 272: 709-11.CrossRef
12.
Cheung YB, Yip P, Karlberg J: Mortality of twins and singletons by gestational age: a varying-coefficient approach. Am J Epidemiol. 2000, 152: 1107-16. 10.1093/aje/152.12.1107.CrossRefPubMed
13.
Wilcox AJ: On the importance – and the unimportance – of birthweight. Int J Epidemiol. 2001, 30: 1233-41. 10.1093/ije/30.6.1233.CrossRefPubMed
14.
Mittendorf R, Williams MA, Kennedy JL, Berry RE, Herschel M, Aronson MP, Davidson KM: A hypothesis to explain paradoxical racial differences in neonatal mortality. Am J Prev Med. 1993, 9: 327-330.PubMed
15.
Platt RW, Yang H, Kramer MS, Joseph KS: Maturity, growth and infant mortality: a new approach [abstract]. Paediatric Perinat Epidemiol. 2000, 14: A25-
16.
Joseph KS, Liu S, Demissie K, Wen SW, Platt RW, Ananth CV, Dzakpasu S, Sauve R, Allen AC, Kramer MS, for the Fetal and Infant Health Study Group of the Canadian Perinatal Surveillance System: A parsimonious explanation for intersecting perinatal mortality curves: understanding the effects of plurality and parity. BMC Pregnancy Childbirth. 2003, 3: 3-10.1186/1471-2393-3-3.CrossRefPubMedPubMedCentral
17.
Joseph KS: Incidence-based measures of birth, growth-restriction and death can free perinatal epidemiology from erroneous concepts of risk. J Clin Epidemiol. 2004.
18.
Taffel S, Johnson D, Heuse R: A method of imputing length of gestation on birth certificates. Vital Health Stat 2. 1982, 93: 1-11.PubMed
19.
MacDorman MF, Atkinson JO: Infant mortality statistics from the linked birth/infant death data set – 1991–95 period data. Monthly Vital Statistics Report. 1998, Hyattsville, MD: National Center for Health Statistics, 46 (Suppl 2):
20.
Joseph KS, Allen AC, Lutfi S, Murphy-Kaulbeck L, Vincer MJ, Wood E: Does the risk of cerebral palsy increase or decrease with increasing gestational age?. BMC Pregnancy Childbirth. 2003, 3: 8-10.1186/1471-2393-3-8.CrossRefPubMedPubMedCentral
21.
Rothman KJ, Greenland S: Modern epidemiology. 1998, Lippincott-Raven Publishers. Philadelphia, p 287-89. Second
22.
Alexander G, Himes J, Kaufman R, Mor J, Kogan M: A United States national reference for fetal growth. Obstet Gynecol. 1996, 87: 163-8. 10.1016/0029-7844(95)00386-X.CrossRefPubMed
23.
Ventura SJ, Martin JA, Curtin SC, Mathews TJ: Births: Final data for 1997. National vital statistics reports. 1999, Hyattsville, Maryland: National Center for Health Statistics, 47 (18):
24.
Kramer MS: Birthweight and infant mortality: perceptions and pitfalls. Paediatr Perinat Epidemiol. 1990, 4: 381-90.CrossRefPubMed
25.
Adams MM: The continuing challenge of preterm delivery. JAMA. 1995, 272: 739-40.CrossRef
26.
27.
Yudkin PL, Wood L, Redman CWG: Risk of unexplained stillbirth at different gestational ages. Lancet. 1987, 1: 1192-4.PubMed
28.
Ferguson R, Myers SA: Population study of the risk of fetal death and its relationship to birth weight, gestational age, and race. Am J Perinatol. 1994, 11: 267-72.CrossRefPubMed
29.
Hilder L, Costeloe K, Thilaganathan B: Prolonged pregnancy: evaluating gestation- specific risks of fetal and infant mortality. Br J Obstet Gynaecol. 1998, 105: 169-73.CrossRefPubMed
30.
Liu S, Joseph KS, Wen SW, Kramer MS, Marcoux S, Ohlsson A, Sauve R: Changing patterns of fetal and infant death due to congenital anomalies in Canada. Am J Med Genetics. 2001, 104: 7-13. 10.1002/1096-8628(20011115)104:1<7::AID-AJMG10023>3.3.CO;2-2.CrossRef
31.
Joseph KS, Marcoux S, Ohlsson A, Liu S, Allen AC, Kramer MS, Wen SW: Changes in stillbirth and infant mortality associated with increases in preterm birth among twins. Pediatrics. 2001, 108: 1055-61.CrossRefPubMed
32.
Kramer MS, Liu S, Luo Z, Yuan H, Platt RW, Joseph KS: Analysis of perinatal mortality and its components: time for a change?. Am J Epidemiol. 2002, 156: 493-7. 10.1093/aje/kwf077.CrossRefPubMed
33.
Joseph KS, Demissie K, Kramer MS: Trends in obstetric intervention, stillbirth and preterm birth. Semin Perinatol. 2002, 26: 250-9.CrossRefPubMed
34.
Sairam S, Costeloe K, Thilaganathan B: Prospective risk of stillbirth in multiple-gestation pregnancies: a population-based analysis. Obstet Gynecol. 2002, 100: 638-41. 10.1016/S0029-7844(02)02174-9.PubMed
35.
Liu S, Joseph KS, Wen SW: Trends in fetal and infant deaths due to congenital anamalies. Semin Perinatol. 2002, 26: 268-276.CrossRefPubMed
36.
Smith GC, Pell JP, Dobbie R: Caesarean section and risk of unexplained stillbirth in subsequent pregnancy. Lancet. 2003, 362: 779-84.
37.
Kahn B, Lumey LH, Zybert PA, Lorenz JM, Cleary-Goldman J, D'Alton ME, Robinson JN: Prospective risk of fetal death in singleton, twin, and triplet gestations: implications for practice. Obstet Gynecol. 2003, 102: 685-92. 10.1016/S0029-7844(03)00616-1.PubMed
38.
Caughey AB, Musci TJ: Complications of term pregnancies beyond 37 weeks of gestation. Obstet Gynecol. 2004, 103: 57-62.CrossRefPubMed
39.
Yawn BP, Wollan P, McKeon K, Field CS: Temporal changes in rates and reasons for medical induction of term labor, 1980–1996. Am J Obstet Gynecol. 2001, 184: 611-9. 10.1067/mob.2001.110292.CrossRefPubMed
40.
Rayburn WF, Zhang J: Rising rates of labor induction: present concerns and future strategies. Obstet Gynecol. 2002, 100: 164-7. 10.1016/S0029-7844(02)02047-1.PubMed
41.
Zhang J, Yancey MK, Henderson CE: U.S. national trends in labor induction, 1989–1998. J Reprod Med. 2002, 47: 120-4.PubMed
42.
Joseph KS, Wilkins R, Dodds L, Allen VM, Ohlsson A, Marcoux S, Liston R: Gestational age-specific fetal growth-restriction and perinatal mortality among males and females and among whites and blacks (Abstract B44). Annual meeting of the Society for Pediatric and Perinatal Epidemiologic Research. Atlanta. 2003, [http://​www.​sper.​org/​2003posterB.​pdf]
43.
Platt RW, Joseph KS, Ananth CV, Grondines J, Abrahamowicz M, Kramer MS: A proportional hazards model with time-dependent covariates and time-varying effects for analysis of fetal and infant death. Am J Epidemiol. 2004.
44.
Scott DT, Tyson JE: Follow up of infants discharged from newborn intensive care. In: Oski's pediatrics – principles and practice. Edited by: McMillan JA, DeAngelis CD, Feigin RD, Warshaw JB. 1999, Lippincott Williams & Wilkins. New York, 209-14.
45.
Dietz PM, Adams MM, Kendrick JS, Mathis MP, the PRAMS Working Group: Completeness of ascertainment of prenatal smoking using birth certificates and confidential questionnaires: variations by maternal attributes and infant birth weight. Am J Epidemiol. 1998, 148: 1048-54.CrossRefPubMed
Metadata
Title
A parsimonious explanation for intersecting perinatal mortality curves: understanding the effects of race and of maternal smoking
Authors
K S Joseph
Kitaw Demissie
Robert W Platt
Cande V Ananth
Brian J McCarthy
Michael S Kramer
Publication date
01-12-2004
Publisher
BioMed Central
Published in
BMC Pregnancy and Childbirth / Issue 1/2004
Electronic ISSN: 1471-2393
DOI
https://doi.org/10.1186/1471-2393-4-7

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