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Intrauterine Growth Restriction

Intrauterine growth restricted babies appear underdeveloped. Their head can either be too big for their body or it can be very proportionate, and that has different meanings intrauterine growth restriction, intrauterine growth retardation, intrauterine growth delay. But they look like little old men. They are just kind of wizened. These are surely things you will be asked about; symmetric versus asymmetric IUGR. Different causes, different prognosis. Different problems early versus late. Thatís important for you to know just for your general management, and what to do in the DR and what to expect in the nursery when you get one of these babies. The symmetric IUGR makes sense if you think about it.

Chronic maternal disorders; if the mom has very severe diabetes with renal problems she is not going to have a big old baby, just from not controlling her glucose. Sheís going to have a little, scrawny, probably symmetric IUGR baby. Chronic hypertension, chronic renal disease due to anything, thatís what you tend to get. The prognosis, short term, is pretty good. These babies have been living in this environment. Their lungs tend to be mature. You donít see a lot of respiratory distress in the newborn period. So itís mostly that they need a good steady supply of glucose.

On the other hand, the asymmetric IUGR spares the brain. Thatís the big thing to remember and itís important for the long term follow up for these babies. It happens later in gestation, so the brain growth has occurred, all the organs have developed, and itís not the somatic growth thatís affected. Maternal hypertension, but later in the pregnancy, chronic fetal stress, again maybe later in the pregnancy, malnutrition in the mom that doesnít happen early on. The prognosis short term is worse. These kids tend to be asphyxiated, then tend to be sick, they tend to have lung disease. So your management in the DR is more intense than with the symmetric IUGR. But their long term outlook is good and they have a fair amount of catch-up growth. Once you get them into an environment where you can give them as many calories as they need they catch up.

All right, now the transitional period; you all know the airway, breathing and circulation by now. Thatís CPR and itís getting babies through the transition once the placenta has been disconnected from them. Apgar scores; Iím not going to go over but you should review those and know what the five things are that make it up. Itís in your syllabus. The Apgar score is sort of what the environment theyíve immediately come out of. Whatís happened right before birth.

Very low prognostic value. Youíll notice my reference here is 1981. Thatís almost 20 years ago. Thereís no better reference, no further research, no further retrospective looks, prospective looks, or anything else has come up with any information.

Intraventricular hemorrhages; they are getting away from calling them grade I, II, III and IV, but thatís still most likely what you will see on the test. But grade I is a general matrix bleed inside the ventricle. There is no extension, no hydrocephalus. Grade II there is blood in the ventricle, but they are not filled with blood so there is no hydrocephalus. So grade I and II are considered mild bleeds. Grade III and IV are the severe bleeds that have consequences to the babies.

Patent ductus arteriosus. If you have a birth weight of less than 1000 gm you have about a 40% chance of having a ductus. Not necessarily a symptomatic one, but of having a ductus that remains open after the first three days when youíd expect the pulmonary vascular resistance to drop. One thousand or fifteen hundred, 20% and by the time you are over 1500 gm it keeps dropping to about 7%. So the tiniest preemies. May or may not hear a murmur. If itís present itís usually harsh and is an ejection murmur. It often is not holosystolic. Bounding pulses; I find that more helpful in the premature.

Contraindications are these; a high BUN, high creatinine, urine output is low - because when you give the indomethacin it not only constricts the ductus, it constricts the renal arteries and other blood vessels. So if you already have impaired renal function, thatís a contraindication, giving Indocin. And if the platelet count is low because Indocin affects platelet adhesion.

This air leak, this is the one that shows it the best. I donít think anyone would miss that. Thereís the outline of the lung, the mediastinum is kind of squished there and the flag sign, the air has lifted the lobe of the thymus sac. You may get asked about that. Thatís pathognomonic for air leak.

Okay, long term sequelae; bronchopulmonary dysplasia in up to 30% of the survivors, retinopathy prematurity because the retinal vessels are susceptible to hyperoxia, but again how much of this is the RDS and how much is the prematurity is hard to separate out. Neurologic impairments. The sicker the infant the more likely these complications will happen.

Okay, we are going to do a little case study. Iím not going to have you call out answers, I just want you to think about this as this goes along because this is the sort of thing you may see on the Boards, differentiating causes of respiratory distress depending on how it presents and when it presents. So, you are called to the newborn nursery to look at a three-hour-old infant male who is grunting and cyanotic. The nurses has already place an Oxy-hood, and what do you do next? Well, you want to know about the history as you examine the baby or ask the nurse whatís going on.