The terms "Intrauterine growth retardation" or "fetal growth retardation" refer to fetuses whose growth measurements or birth weights are abnormal, and presumably below standards established for a given population. A fetus with abnormal growth patterns may be more vulnerable to brain damage due to asphyxia. It is more difficult for these fetuses to combat hypoxia due to low or non-existent reserves.
The most chronically and severely deprived fetuses will show reduced growth in all parameters and be underweight. An important measurement is head circumference, which does not always follow the same pattern as weight or length. This is known as asymmetrical growth retardation.
The selection of the growth chart and data upon which a specific child's growth or weight is measured will affect the outcome of the analysis. Each set of data has built-in biases which are characteristic of the population studied. Perhaps the more difficult cases involve infants who are borderline normal, or are within one, as opposed to two, standard deviations from the mean.
Gestational Age Must Be Calculated Accurately
A critical component of any analysis of fetal growth is an accurate determination of gestational age. It is a rare case in which gestational age can be determined with precise certainty. The oldest method for the clinical measurement of gestational age and the establishment of the estimated date of confinement is the mother's last menstrual period. This estimate is prone to miscalculation and clinicians recognized that any estimate based on LMP is off by 2 weeks. Advances in ultrasonography have made the determination of gestational age less dependent on estimates of the date of the last menstrual period and based on measurement of the biparietal diameter, between 16 and 20 weeks. Since it is impossible to weigh the fetus at intervals during gestation, management decisions are based on clinical estimate of gestational age.
The Key Points To Remember!
One must carefully distinguish between the potential adverse effects of impaired growth during pregnancy and their actual diagnostic significance. Many babies who fall in the 10% or below of normal growth parameters have normal outcomes. One should look for clinical signs suggesting that the fetus was exposed to recent episodes of hypoxia, as opposed to conditions lasting days or weeks, that caused uteroplacental conditions that impeded fetal growth and nutrition.
Determining normal growth and weight during pregnancy is also necessary to assess placental function. Sometimes placental insufficiency becomes a potential problem due to hypertension, preeclampsia or other maternal complications that impair normal blood flow to the placenta. The clinician needs to know if this has occurred, since he or she may have to remove the fetus from this hostile environment and consider earlier delivery.
Please Note:
This web site is not intended as legal advice on cerebral palsy, and is not a substitute for obtaining guidance from your own legal counsel about cerebral palsy litigation. It provides general educational information about the standards of care and causation issues that can arise in obstetrical malpractice and cerebral palsy litigation. Readers of the articles contained within this web site should not act upon the cerebral palsy information without first consulting with a lawyer who is experienced in evaluating and litigating cerebral palsy and obstetrical malpractice cases. Mr. Apfel is admitted to practice law in Maryland and the District of Columbia. When Mr. Apfel is asked to participate in cerebral palsy
litigation filed in other states, he will associate with, and act as co-counsel with, an attorney licensed in that state who is familiar with the local laws and procedures.
