The research implications of the selection of a gestational age estimation method

Paediatric and Perinatal Epidemiology - Tập 21 Số s2 - Trang 86-96 - 2007
Courtney D. Lynch1, Jun Zhang1
1Epidemiology Branch, Division of Epidemiology, Statistics, and Prevention Research, National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA.

Tóm tắt

SummaryThere are three primary methods of gestational age estimation: dating based on last menstrual period (LMP), ultrasound‐based dating and neonatal estimates. We review the strengths and limitations of each method as well as their implications for research. Dating based on LMP is a simple, low‐cost method of estimating gestational age. Limitations associated with the use of menstrual‐based dating include reporting problems such as uncertainty regarding the LMP date, possibly due to bleeding not associated with menses, as well as concerns about the incidence of delayed ovulation, which can result in invalid estimates of gestation, even for women with certain LMP dates. Given that most women in the US have at least one ultrasound during pregnancy, it is becoming increasingly common for clinicians to verify menstrual dates using early ultrasound. To calculate gestational age with the use of ultrasound, fetal measurements are compared with a gestational age‐specific reference. The primary limitation of this method is the fact that the gestational age estimates of symmetrically large or small fetuses will be biased. Further, given that ultrasound references were developed using pregnancies that were dated according to reliable LMP dates, they are potentially biased in the same direction as dates calculated according to LMP. Neonatal estimates of gestational age have been shown to be the least precise dating method. To highlight the research implications of the choice of a gestational dating method, we used data from the Routine Antenatal Diagnostic Imaging with Ultrasound Study to identify risk factors for post‐term delivery. Risk factors for post‐term delivery are shown to vary according to the choice of a gestational dating method, suggesting that some findings are an artefact of the choice of a method rather than evidence of causality.

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Tài liệu tham khảo

10.1016/0140-6736(91)91653-C

10.2307/2991522

10.1111/j.1471-0528.1985.tb01347.x

10.1136/jech.38.1.79

10.1016/0002-9378(74)90152-5

10.1046/j.1365-3016.2000.00275.x

10.1016/0002-9378(80)90133-7

10.1016/0002-9378(72)90525-X

10.1093/oxfordjournals.aje.a115930

10.1016/j.earlhumdev.2005.06.004

10.1097/00001648-199509000-00015

10.3109/00016349009028681

10.2307/2532929

10.2307/2530453

10.1002/sim.716

10.1093/humrep/13.2.394

10.2105/AJPH.89.2.213

10.1097/00001648-199509000-00012

Horger EO, 1989, Ultrasound and the prenatal diagnosis of congenital anomalies: a medicolegal perspective, Obstetrics and Gynecology, 74, 617

10.1056/NEJM199309163291201

10.1016/S0140-6736(84)90492-6

10.1016/S0140-6736(88)90636-8

Ewigman B, 1990, A randomized trial of routine prenatal ultrasound, Obstetrics and Gynecology, 76, 189

10.1111/j.1471-0528.1996.tb09796.x

ACOG Committee on Practice Bulletins – Obstetrics., 2004, American College of Obstetrics and Gynecology Practice Bulletin. Clinical management guidelines for obstetricians‐gynecologists. Number 55, September 2004 (replaces practice pattern number 6, October 1997). Management of Postterm Pregnancy, Obstetrics and Gynecology, 104, 639

Stebbins B, 1999, Textbook of Fetal Ultrasound., 47

10.1097/00006250-200412000-00045

10.1148/radiology.152.2.6739822

10.1016/S0002-9378(98)70477-6

10.1046/j.1469-0705.1997.08060397.x

10.1093/humrep/15.8.1819

10.1016/S0022-3476(70)80038-5

10.1016/S0022-3476(79)80734-9

10.1016/S0022-3476(05)82056-6

10.1016/0002-9378(92)91357-G

Sanders M, 1991, Gestational age assessment in preterm neonates weighing less than 1500 grams, Pediatrics, 88, 542

10.1111/j.1365-3016.1992.tb00786.x

Rossavik IK, 1989, Conceptional age, menstrual age, and ultrasound age: a second‐trimester comparison of pregnancies of known conception date with pregnancies dated from the last menstrual period, Obstetrics and Gynecology, 73, 243

10.1001/jama.1988.03410220090034

10.3109/00016349409013412

Campbell S, 1985, Routine ultrasound screening for the prediction of gestational age, Obstetrics and Gynecology, 65, 613

10.1016/S0002-9378(96)70408-8

10.1046/j.1469-0705.1996.08030178.x

Waldenstrom U, 1990, A comparison of the ability of a sonographically measured biparietal diameter and the last menstrual period to predict the spontaneous onset of labor, Obstetrics and Gynecology, 76, 336

10.3109/00016349309021110

10.1016/0895-4356(94)00162-J

10.1067/mob.2002.127601

10.1046/j.1469-0705.2002.00855.x

10.1111/j.1471-0528.2000.tb11694.x

10.1111/j.1471-0528.2004.00311.x

10.1001/jama.1968.03140060001001

10.1097/00001648-200211000-00011

10.1016/S0301-2115(03)00154-4

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Paediatric and Perinatal Epidemiology

Tập 21 Số s2

86-96

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