Birth weight for gestational age patterns by ethnicity, gender, and parity in an urban population.To the Editor: Current standards for assessing birth weight rely on data that may not approximate specific populations. (1,2) The objective of this study was 1) to develop a regional reference of birth weight for gestational age ges·ta·tion·al age n. See estimated gestational age. Gestational age The estimated age of a fetus expressed in weeks, calculated from the first day of the last normal menstrual period. curves for an urban population of African Americans and Hispanics at sea level; 2) to assess the effects of ethnicity, gender, and parity on birthweight and 3) to compare our results with well-known published birth weights for gestational nomograms. This study was a retrospective review retrospective review, a posttreatment assessment of services on a case-by-case or aggregate basis after the services have been performed. of deliveries performed at a single institution, King Drew Medical Center, Los Angeles from January 1, 1982 to December 31, 2001. Institutional Review Board approval was obtained. The database contained 90,767 cases. All cases with incomplete records, implausible birth weight/gestational age combinations, major congenital anomalies, stillbirths, birth weights <500 g, diabetes, hypertension disorders, and multiple pregnancies were excluded. The population was low income and indigent indigent 1) n. a person so poor and needy that he/she cannot provide the necessities of life (food, clothing, decent shelter) for himself/herself. 2) n. one without sufficient income to afford a lawyer for defense in a criminal case. . A total of 72,600 mother/infant pairs between 25 to 44 weeks' gestation were analyzed. The study was restricted to African Americans (10,417 [14.3%]) and Hispanics (62,183 [85.7%]). Unweighted fourth degree polynomial polynomial, mathematical expression which is a finite sum, each term being a constant times a product of one or more variables raised to powers. With only one variable the general form of a polynomial is a0xn+a equations which provided the best fit for these data were derived and birth weight values at each week of gestation were extrapolated from smooth curves. Data were analyzed as indicated. Birthweight curves were compared with those of published nomograms (Table). The study population consisted of 37,123 (51.1%) male infants and 35,477 (48.9%) female infants. Mean maternal age was 25.23 (0.02); approximately 30% of mothers were primiparous pri·mip·a·ra n. pl. pri·mip·a·ras or pri·mip·a·rae 1. A woman who is pregnant for the first time. 2. A woman who has given birth to only one child. . The mean birth weight for Hispanic newborns was 3406.93 ([+ or -]2.17) grams, and 2953.91 ([+ or -]6.51) grams for African-American newborns. Hispanic newborns weighed approximately 453.02 g, (P = 0.000, 95% CI = 440, 467) more than African-American newborns at birth. Hispanic newborns tended to be larger than African-American newborns at all gestational ages, but this difference only became significant from 33 weeks to 44 weeks. Female neonates weighed an average of 3290.93 ([+ or -]3) grams and male infants weighed an average of 3390.7 ([+ or -]3.1) grams. Thus, male neonates weighed approximately 99.73 g (P = 0.000, 95% CI = 91, 108) more than female neonates at birth. This difference only became significant from 35 weeks to 44 weeks. The mean birth weight of babies of primiparous women was 3253.8 ([+ or -]3.63) grams and 3381 ([+ or -]2.65) grams for babies of multiparous mul·tip·a·rous adj. 1. Relating to a multipara. 2. Giving birth to more than one offspring at a time. women. Babies of multiparous women weighed approximately 127 g, (P = 0.000, 95% CI = 118,136) more than primiparous babies at birth; again this difference only became significant from 35 weeks to 44 weeks. Statistical analysis did not show any significant difference with year of delivery. Comparison with published nomograms showed that Denver/Lubchenco (1) and Cleveland/Brenner (2) curves underestimated low birth weight (LBW LBW Low birth weight, see there ) and overestimated large for gestational age large for gestational age Neonatology adjective Referring to a fetus weighing ≥ 4.0 kg, 9lbs or ≥ 90 percentile for weight (LGA LGA abbr. large for gestational age LGA Large for gestational age, see there ). California/Williams, (3) Alexander/national (4) and St. Louis/Ott (5) curves underestimated LBW until 33 to 36 weeks, and overestimated LBW thereafter. The present nomograms provide regional reference data for neonates born to Hispanic and African-American mothers. Using the Brenner/Cleveland and Lubchenco/Denver curves would consistently miss 4 to 9% of the intrauterine intrauterine /in·tra·uter·ine/ (-u´ter-in) within the uterus. in·tra·u·ter·ine adj. Within the uterus. Intrauterine Situated or occuring in the uterus. growth rate (IUGR IUGR intrauterine growth retardation (or restriction). IUGR abbr. intrauterine growth retardation IUGR Intrauterine growth retardation, see there ) in our population, while there was no consistent relationship with the Ott/St. Louis, Alexander/national and the Williams/Californian nomograms. Some of these differences were due to ethnic and geographic variations; for example the Alexander and Brenner curves were composed of all races; while the Los Angeles study was performed at sea level, and the Lubchenco/Denver study was performed at one mile above sea level. It is interesting to note that the differences in birthweight due to parity, gender and ethnicity only became significant in the third trimester. This suggests the contribution of social, environmental, nutritional and economic factors. Our data shows that ethnicity, gender and parity affects birthweight. Given differences in demographics, altitude, and study methodology, this data supports the development or use of appropriate birth weight standards for specific populations. Dotun Ogunyemi, MD Brandye Manigat-Wilson, MD Mohsen Bazargan, PhD Deyu Pan, PhD King Drew Medical Center Charles Drew University of Medicine & Science David Geffen School of Medicine at UCLA UCLA School of Medicine or David Geffen School of Medicine at UCLA is an accredited allopathic medical school located in Los Angeles, California, United States. The school was named in honor of media mogul David Geffen who donated $200 million in unrestricted funds to the Los Angeles, CA References 1. Lubchenco L, Hansman C, Dressler M, et al. Intrauterine growth as estimated from liveborn birth-weight data at 24 to 42 weeks of gestation. Pediatrics 1963;32:793-800. 2. Brenner W, Edelman D, Hendricks CH. A standard of fetal growth for the United States of America UNITED STATES OF AMERICA. The name of this country. The United States, now thirty-one in number, are Alabama, Arkansas, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Mississippi, Missouri, New Hampshire, . Am J Obstet Gynecol 1976;126:555-564. 3. Williams RL, Creasy RK, Cunningham GC, et al. Fetal growth and perinatal viability in California. Obstet Gynecol 1982;59:624-632. 4. Alexander G, Himes J, Kaufman R, et al. A United States national reference for fetal growth. Obstet Gynecol 1996;87:163-168. 5. Ott W. Intrauterine growth retardation Intrauterine Growth Retardation Definition Intrauterine growth retardation (IUGR) occurs when the unborn baby is at or below the 10th weight percentile for his or her age (in weeks). and preterm preterm /pre·term/ (-term´) before completion of the full term; said of pregnancy or of an infant. pre·term adj. delivery. Am J Obstet Gynecol 1993;168:1710-1717. Presented at the American College of Obstetricians and Gynecologists' 52nd Annual Clinical Meeting (ACM (Association for Computing Machinery, New York, www.acm.org) A membership organization founded in 1947 dedicated to advancing the arts and sciences of information processing. In addition to awards and publications, ACM also maintains special interest groups (SIGs) in the computer field. ) in San Francisco, California “San Francisco” redirects here. For other uses, see San Francisco (disambiguation). The City and County of San Francisco (EN IPA: [sænfrənˈsɪskoʊ] . Table. Number of subjects and inclusion criteria (a) Gestational Hispanic African-American Lower cutoff Upper cutoff age (wk) (%) (%) point (g) point (g) (b) 25 55 (52) 50 (48) 500 1250 26 53 (41) 78 (59) 500 1450 27 79 (54) 68 (46) 500 1650 28 98 (48) 106 (52) 500 1900 29 90 (50) 90 (50) 750 2150 30 143 (48) 152 (52) 750 2400 31 208 (57) 160 (43) 750 2600 32 333 (57) 249 (43) 750 2800 33 440 (63) 257 (37) 1000 3100 34 804 (67) 399 (33) 1000 3300 35 1186 (69) 522 (31) 1000 3600 36 2495 (75) 820 (25) 1000 37 4393 (81) 1042 (19) 1500 38 8576 (85) 1510 (15) 1500 39 13632 (88) 1881 (12) 1500 40 18145 (88) 2405 (12) 1500 41 8357 (91) 857 (9) 1500 42 5208 (91) 504 (9) 1500 43 1653 (91) 170 (9) 1500 44 736 (89) 91 (11) 1500 Totals 66684 11411 N before inclusions = 90,767. N after exclusions = 78,095. (a) Abbreviated table. Please contact Dr. D. Ogunyemi for more complete information at Dotun.Ogunyemi@cshs.org. (b) Methods used to obtain upper cutoff points are described in Zhang and Bowes. |
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