Limits...
An adjustable fetal weight standard for twins: a statistical modeling study.

Zhang J, Mikolajczyk R, Lei X, Sun L, Yu H, Cheng W - BMC Med (2015)

Bottom Line: The adjustable fetal weight standard has an excellent match with the observed birthweight data in non-Hispanic White, non-Hispanic Black, Hispanics, and Asian from 24 to 38 weeks gestation.It also had a very good fit with cross-sectional data from Australia and Norway, and a longitudinal standard from Brazil.The adjustable fetal weight standard for twins is a flexible tool and can be used in different populations.

View Article: PubMed Central - PubMed

Affiliation: MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kong Jiang Road, Shanghai, 200092, China. junjimzhang@gmail.com.

ABSTRACT

Background: It is a common practice to use a singleton fetal growth standard to assess twin growth. We aim to create a twin fetal weight standard which is also adjustable for race/ethnicity and other factors.

Methods: Over half a million twin births of low risk pregnancies in the US, from 1995 to 2004, were used to construct a fetal weight standard. We used the Hadlock's fetal growth standard and the proportionality principle to make the standard adjustable for other factors such as race/ethnicity. We validated the standard in different race/ethnicities in the US and against previously published curves from around the world.

Results: The adjustable fetal weight standard has an excellent match with the observed birthweight data in non-Hispanic White, non-Hispanic Black, Hispanics, and Asian from 24 to 38 weeks gestation. It also had a very good fit with cross-sectional data from Australia and Norway, and a longitudinal standard from Brazil. However, our model-based 10th and 90th percentiles differed substantially from studies in Japan and US that used the last menstrual period for estimate of gestational age.

Conclusion: The adjustable fetal weight standard for twins is a flexible tool and can be used in different populations.

Show MeSH

Related in: MedlinePlus

Observed 10th, 50th, and 90th percentiles of birthweight for gestational week (dashed lines) by race/ethnicity in a US twin population, 1995–2004, in comparison to the corresponding adjusted fetal weight standard (solid lines)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4491250&req=5

Fig3: Observed 10th, 50th, and 90th percentiles of birthweight for gestational week (dashed lines) by race/ethnicity in a US twin population, 1995–2004, in comparison to the corresponding adjusted fetal weight standard (solid lines)

Mentions: Table 1 presents the mean birthweight at 37 weeks gestation by different race/ethnic groups in the US – Black and Asian twins had mean birthweights approximately 100 and 150 g lower than White twins at 37 weeks gestation. We then compared the observed birthweight by gestational week with the adjusted standard in White, Black, Hispanic, and Asian twin births. Figure 3 shows that the adjustable standard at the 50th percentile matched the mean observed birthweight curves very well for all races/ethnicities in the US from 24 to 38 weeks gestation. However, the adjustable standard tended to have a narrower range at the 10th and 90th percentiles than the observed data.Fig. 3


An adjustable fetal weight standard for twins: a statistical modeling study.

Zhang J, Mikolajczyk R, Lei X, Sun L, Yu H, Cheng W - BMC Med (2015)

Observed 10th, 50th, and 90th percentiles of birthweight for gestational week (dashed lines) by race/ethnicity in a US twin population, 1995–2004, in comparison to the corresponding adjusted fetal weight standard (solid lines)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4491250&req=5

Fig3: Observed 10th, 50th, and 90th percentiles of birthweight for gestational week (dashed lines) by race/ethnicity in a US twin population, 1995–2004, in comparison to the corresponding adjusted fetal weight standard (solid lines)
Mentions: Table 1 presents the mean birthweight at 37 weeks gestation by different race/ethnic groups in the US – Black and Asian twins had mean birthweights approximately 100 and 150 g lower than White twins at 37 weeks gestation. We then compared the observed birthweight by gestational week with the adjusted standard in White, Black, Hispanic, and Asian twin births. Figure 3 shows that the adjustable standard at the 50th percentile matched the mean observed birthweight curves very well for all races/ethnicities in the US from 24 to 38 weeks gestation. However, the adjustable standard tended to have a narrower range at the 10th and 90th percentiles than the observed data.Fig. 3

Bottom Line: The adjustable fetal weight standard has an excellent match with the observed birthweight data in non-Hispanic White, non-Hispanic Black, Hispanics, and Asian from 24 to 38 weeks gestation.It also had a very good fit with cross-sectional data from Australia and Norway, and a longitudinal standard from Brazil.The adjustable fetal weight standard for twins is a flexible tool and can be used in different populations.

View Article: PubMed Central - PubMed

Affiliation: MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kong Jiang Road, Shanghai, 200092, China. junjimzhang@gmail.com.

ABSTRACT

Background: It is a common practice to use a singleton fetal growth standard to assess twin growth. We aim to create a twin fetal weight standard which is also adjustable for race/ethnicity and other factors.

Methods: Over half a million twin births of low risk pregnancies in the US, from 1995 to 2004, were used to construct a fetal weight standard. We used the Hadlock's fetal growth standard and the proportionality principle to make the standard adjustable for other factors such as race/ethnicity. We validated the standard in different race/ethnicities in the US and against previously published curves from around the world.

Results: The adjustable fetal weight standard has an excellent match with the observed birthweight data in non-Hispanic White, non-Hispanic Black, Hispanics, and Asian from 24 to 38 weeks gestation. It also had a very good fit with cross-sectional data from Australia and Norway, and a longitudinal standard from Brazil. However, our model-based 10th and 90th percentiles differed substantially from studies in Japan and US that used the last menstrual period for estimate of gestational age.

Conclusion: The adjustable fetal weight standard for twins is a flexible tool and can be used in different populations.

Show MeSH
Related in: MedlinePlus