The data for these four cohorts were collected prospectively during 2003-2008 using a common protocol and included a wide range of maternal and fetal characteristics (e.g., objective measures of
gestational age by ultrasound examination), biological samples, and environmental measurements (e.g., air pollution) (Guxens et al.
Variables related to
gestational age are shown in Table 3.
The main uses of ultrasonography are determination of
gestational age and assessment of foetal size.
(1.) Lohr PA, Reeves MF and Creinin MD, A comparison of transabdominal and transvaginal ultrasonography for determination of
gestational age and clinical outcomes in women undergoing early medical abortion, Contraception, 2010, 81(3):240-244.
There was no correlation between
gestational age and kisspeptin concentration in amniotic fluid (P = 0.56; Fig.
A detailed tabulation of the BPD at various
gestational age is given at results and discussion section.
To see what effect distribution of births by
gestational age might have on a nation's infant mortality rate, the NCHS applied our gestational-age specific infant mortality rate to Sweden's distribution of births by
gestational age and found that in 2004 our infant mortality rate could have been reduced to 3.9, or by 33%, if we had Sweden's
gestational age distribution; that is, if we had fewer preterm births, we'd have less infant mortality.
Results: The total mean birth weight was 1105 g ([+ or -] 223 g), the mean
gestational age was 30 weeks ([+ or -] 2.7 weeks), and the mean weight gain rate was 13.4 g/kg/d ([+ or -] 6.8 g/kg/d).
Premature birth, low birthweight, and small size for
gestational age are all risk factors for poor health in infancy and can lead to complications later in life.
Those with a lower
gestational age also faced a higher risk of being placed on the register.
Fetuses that are small for
gestational age (SGA) are at increased risk of stillbirth.
National estimates of newborn feeding practices by
gestational age have not been available previously.