Abstract
Objectives: To assess whether the observed vs. expected lung-to-head ratio (o/e LHR) corrects for the dependence of the LHR on gestational age. Study design: Published data on right lung area (LA) and LHR were used to plot the 50th percentile and different fixed values of the o/e LHR (e.g. 30%) against gestational age from 16-32 weeks. The Z-scores for various fixed o/e LHR values and similar percent value of LA were calculated. The effect of using a fixed LHR or a fixed o/e LHR was tested against gestational age. The o/e LHR-equivalent to a fixed LHR of 1.0 was assessed against gestational age. Results: The LHR and the o/e LHR both increase with gestational age. The Z-score of a given fixed value of the o/e LHR (e.g. 30%) is not similar to the Z-score of the same percent (e.g., 30%) of the expected LA, and thus identifies different proportions of subjects. A fixed o/e LHR (e.g. 30%) results in different populations, depending on the gestational age. The o/e LHR equivalent to an LHR value of 1.0 decreases from 80% at 16 weeks to 30% at 32 weeks. Conclusions: The o/e LHR is not independent of gestational age. Studies using this parameter should be interpreted with caution.
| Original language | English |
|---|---|
| Pages (from-to) | 552-557 |
| Number of pages | 6 |
| Journal | Journal of Maternal-Fetal and Neonatal Medicine |
| Volume | 26 |
| Issue number | 6 |
| DOIs | |
| State | Published - Apr 1 2013 |
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Keywords
- Congenital diaphragmatic hernia
- Lung-to-head ratio
- Observed vs. expected lung-to-head ratio
- Ultrasound
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Obstetrics and Gynecology
Cite this
The observed vs. expected lung-to-head ratio does not correct for the effect of gestational age on the lung-to-head ratio. / Quintero, Rubén A.; Kontopoulos, Eftichia V.; Quintero, Luis F.; Landy, David C.; Gonzalez, Reinaldo; Chmait, Ramen H.
In: Journal of Maternal-Fetal and Neonatal Medicine, Vol. 26, No. 6, 01.04.2013, p. 552-557.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The observed vs. expected lung-to-head ratio does not correct for the effect of gestational age on the lung-to-head ratio
AU - Quintero, Rubén A.
AU - Kontopoulos, Eftichia V.
AU - Quintero, Luis F.
AU - Landy, David C.
AU - Gonzalez, Reinaldo
AU - Chmait, Ramen H.
PY - 2013/4/1
Y1 - 2013/4/1
N2 - Objectives: To assess whether the observed vs. expected lung-to-head ratio (o/e LHR) corrects for the dependence of the LHR on gestational age. Study design: Published data on right lung area (LA) and LHR were used to plot the 50th percentile and different fixed values of the o/e LHR (e.g. 30%) against gestational age from 16-32 weeks. The Z-scores for various fixed o/e LHR values and similar percent value of LA were calculated. The effect of using a fixed LHR or a fixed o/e LHR was tested against gestational age. The o/e LHR-equivalent to a fixed LHR of 1.0 was assessed against gestational age. Results: The LHR and the o/e LHR both increase with gestational age. The Z-score of a given fixed value of the o/e LHR (e.g. 30%) is not similar to the Z-score of the same percent (e.g., 30%) of the expected LA, and thus identifies different proportions of subjects. A fixed o/e LHR (e.g. 30%) results in different populations, depending on the gestational age. The o/e LHR equivalent to an LHR value of 1.0 decreases from 80% at 16 weeks to 30% at 32 weeks. Conclusions: The o/e LHR is not independent of gestational age. Studies using this parameter should be interpreted with caution.
AB - Objectives: To assess whether the observed vs. expected lung-to-head ratio (o/e LHR) corrects for the dependence of the LHR on gestational age. Study design: Published data on right lung area (LA) and LHR were used to plot the 50th percentile and different fixed values of the o/e LHR (e.g. 30%) against gestational age from 16-32 weeks. The Z-scores for various fixed o/e LHR values and similar percent value of LA were calculated. The effect of using a fixed LHR or a fixed o/e LHR was tested against gestational age. The o/e LHR-equivalent to a fixed LHR of 1.0 was assessed against gestational age. Results: The LHR and the o/e LHR both increase with gestational age. The Z-score of a given fixed value of the o/e LHR (e.g. 30%) is not similar to the Z-score of the same percent (e.g., 30%) of the expected LA, and thus identifies different proportions of subjects. A fixed o/e LHR (e.g. 30%) results in different populations, depending on the gestational age. The o/e LHR equivalent to an LHR value of 1.0 decreases from 80% at 16 weeks to 30% at 32 weeks. Conclusions: The o/e LHR is not independent of gestational age. Studies using this parameter should be interpreted with caution.
KW - Congenital diaphragmatic hernia
KW - Lung-to-head ratio
KW - Observed vs. expected lung-to-head ratio
KW - Ultrasound
UR - http://www.scopus.com/inward/record.url?scp=84875404792&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84875404792&partnerID=8YFLogxK
U2 - 10.3109/14767058.2012.736000
DO - 10.3109/14767058.2012.736000
M3 - Article
C2 - 23046345
AN - SCOPUS:84875404792
VL - 26
SP - 552
EP - 557
JO - Journal of Maternal-Fetal and Neonatal Medicine
JF - Journal of Maternal-Fetal and Neonatal Medicine
SN - 1476-7058
IS - 6
ER -