Perinatal outcomes after sonographic detection of isolated short femur in the second trimester.
OBJECTIVE
To determine the association of fetal isolated short femur in the second-trimester ultrasound (US) examination with perinatal outcomes such as small-for-gestational age (SGA) and low-birth weight (LBW) neonates.


METHODS
This is a retrospective cohort study in fetuses routinely assessed by US examination at 18 to 24 weeks during 2006-2009. A fetal isolated short femur was defined as femur length below the 5th percentile and with no chromosomal or structural abnormalities. Fetuses with abdominal circumference below the 5th percentile at the time of US examination were excluded. Each case of short femur was matched with three controls according to gestational age at the time of the US examination.


RESULTS
Sixty-one fetuses met the inclusion criteria. Both the group of women carrying a fetus with isolated short femur and that of women carrying a fetus with normal femur length had similar general and obstetric characteristics. Women carrying a fetus with isolated short femur were significantly more likely to deliver a SGA neonate (19.7% versus 8.7%, p < 0.05) and a LBW neonate (19.7% versus 7.1%, p < 0.05) than women carrying a fetus with normal femur length. Logistic regression analysis found odds ratios for SGA and LBW of 2.6 (95% confidence interval, 1.1-5.9) and 2.9 (95% confidence interval, 1.2-7.1), respectively.


CONCLUSIONS
Isolated short femur in the second-trimester US examination is associated with a subsequent delivery of SGA and LBW neonates.
Fetal Medicine Unit, Instituto Nacional Materno Perinatal, Lima, Peru.
Walter
W
Ventura
Johnny
J
Huaman
Conny Elizabeth
CE
Nazario
Jaime
J
Ingar
Erasmo
E
Huertas
Oscar
O
Antonio Limay
D000328:Adult; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging*; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging*; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D016015:Logistic Models; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D016216:Ultrasonography, Prenatal / Q000379:methods*