Correlación entre la medición ecográfica del cordón umbilical y la edad gestacional,su relación con la biometría fetal y los resultados perinatales

Aim

(a) To evaluate the umbilical cord in normal pregnancies using ultrasonography in the third trimester with a view to obtaining gestational age values according to reference tables. (b) To compare umbilical cord measurements with fetal biometry, length, weight and perinatal outcomes to determine whether this type of correlation exists in our population and whether it could be used to establish values of normality that would help to diagnose abnormalities.

Material and methods

From Juny 2001 to June 2002 we studied 48 pregnat women that have been controlled by ultrasound from week 28 to 38 of gestation. We just included patients with normal and controlled pregnancies, without any associated pathology. We obtain biparietal diameter, abdominal circumference, femoral long measurement, and umbilical cord diameter through a transversal cut of the umbilical area. Gestational age was obtain by last menstruation and by ultrasound according with biometry. measurement of the umbilical cord was compared with a nomogram of the gestational age (GA) performed by the Obstetric and Gynaecology Department of the Insubria University in Italy.We registered the type of birth the GA at birth, APGAR score length, weight, cephalic diameter, and eventually complications. For calculate the normal umbilical cord area according to the gestational age by last menstruation we use the Raio et al equations to construct the corresponding nomogram. It was apply statistics methods with an alfa of 5%.

Results

LMP-based gestational age was highly correlated with ultrasound measurements. Theoretical UCA was not correlated with observed UCA. Only 54.2% of UCAs were found to be within the 5th and 95th percentiles (P =0.001), and consequently only two-thirds of the patients were within the parameters of normality. No correlation was found between UCA and gestational age, when attempting to construct a nomogram for our population (P=.99). No association was found between UCA and fetal biometry parameters. No significant correlation was found with weight, length, head circumference or gestational age at delivery. Apgar score was favorable and stable in all neonates; Apgar score was thus considered a constant and was not correlated with UCA. UCA was significantly lower in women who underwent cesarean section than in those with normal deliveries (P<.05).

Conclusion

UCA was not correlated with gestational age, fetal biometry or perinatal outcomes. Values in our population cannot be extrapolated to existing nomograms.