Fetal macrosomia can result in maternal and fetal morbidity and mortality. A variety of maternal risk factors have been associated with a high neonatal birth weight.


Definition of fetal macrosomia from the American College of Obstetricians and Gynecologists is an absolute weight > 4,500 grams irrespective of gestational age or other variables.


Infants with macrosomia can be graded based on weight. This correlates with complications during and after delivery.

Fetal Weight in Grams


4, 001 to 4,500


4,501 to 5,000


>= 5,001



Risk factors associated with fetal macrosomia include:

(1) diabetes mellitus (including gestational diabetes)

(2) previous infant with macrosomia

(3) obesity prior to pregnancy (tend to have higher rate of diabetes)

(4) nonsmoking (infants from smoking mothers tend to be smaller and have other complications)


Other risk factors:

(1) older maternal age (>= 35 years)

(2) married

(3) parity >= 3 (multiparous)

(4) hypertension during pregnancy

(5) male infants

(6) low caffeine intake

(7) 10 or more years of education (this could correlate with higher age)

(8) previous pregnancy loss

(9) White race

(10) gestational age > 42 weeks



• As pointed out by Sacks and Chen, the presence of multiple risk factors may not be predictive fetal macrosomia.


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