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Prematurity and Maternal Conditions Affecting the Newborn

Prematurity is still a huge problem in the United States. It affects about 40,000 infants a year. They have respiratory distress syndrome. Surfactants have been in wide use most of this decade in most hospitals. It doesn’t help the tiniest babies, the 24, 25, 26 weekers, and prevention is still the key. Antenatal steroids have been in use for some 50 years almost - 40 years I guess - but only a few years ago it was about 20%. There was an NIH consensus council that put out a statement that reiterated that it’s the best thing to do. Again, it doesn’t always help those tiny babies. It’s usually given for 24 to 34 weeks gestation.

There are some problems, and the OB is going to quote this with the moms, it’s very rare but they can have pulmonary edema that’s used along with tocolytics. Diabetes is hard to control. Anytime you give steroids to anyone who has a problem with insulin resistance. Infection risk may be greater. There is preterm prolonged rupture of membranes, but no long term adverse side effects. So there will be an occasional mom who is not a candidate for getting preterm steroids. This is important to know in your prenatal history, when you are going to be looking at these kids.

We are going to go through some diseases that are listed here, that can have specific effects on the babies and things that you may be asked on the Boards, and I’ll try to point out the associations on these. Systemic lupus; you’ll probably remember from medical school, you can get congenital heart block in the babies and that’s the first thing you should think of, even if the mother is diagnosed. The 25% is the thing you want to remember, 1:4. If the mom is known to have lupus there is a 25% chance the infant will have congenital heart block. If the infant is born with congenital heart block, there is a 25% chance.

Myasthenia gravis; we don’t come across very often but can have effects on the baby. Very rarely there is arthroproposis. Only about 10-20% of the infants will end up with neonatal myasthenia. It usually happens 12-48 hours after birth,.

Hyperthyroidism, you are much more likely to come across in infants if the mothers have had that. The thyrotoxicosis is obviously dangerous to moms and babies. One percent of neonates born to hyperthyroid mothers are thyrotoxic. So it’s rare but it does happen. And Graves disease is the most common reason for the mother to have hyperthyroidism.

Hypothyroidism; also uncommon but you will still come across it, and you may be asked about these things. Iodine deficiency is rare but if that happens, there is a high fetal loss. That’s a real important element needed in the growth and development of the fetus. There can be congenital anomalies. Goiter is probably the most common thing.

Maternal phenylketonuria; again, it’s not very common but the effects on the babies can be devastating. It’s only the last probably 20 years that we have seen the second generation that mothers with phenylketonuria have been managed well, have been diagnosed at birth by the newborn screening exams, treated. Unfortunately as many young adults and teenagers do the diet is pretty restrictive and they decide, as folks with diabetes do, that they really don’t need to do this anymore.

Diabetes; you’ll come across this nearly every week of your practice, no matter what you do, in pediatrics. It’s a huge problem, both gestational and adult onset, juvenile onset. Whatever the mother has, it has pretty much the same effect on the baby. It’s not good. Pre-natally we see increased fetal loss, hyper-insulinemia and hyperglycemia. In the obstetric period there are increased stillborns. Birth injury; if the mother is not well controlled the babies can be large and there can be forceps delivery, perinatal asphyxia for the same reason, prematurity - their uterus can only handle so much volume and as with multiple births.

Neonatal hypoglycemia; there are a lot of definitions. These ten I have here tend to be the ones that are most commonly followed and the ones that, if they are on the Board, you would expected to know. If you have a screening level glucose and screening level One-Step, dextra-stick, whatever your nursery uses, of less than 30, IV glucose is what to give.

Hypertension is another one of those common things that you come across in mothers. It affects the babies. If can either be chronic - so they’ve had it before the pregnancy commenced - or pregnancy induced.

HELLP syndrome is a specific form of pregnancy-induced hypertension. It’s more severe and has some implications for the baby. It includes hypertension, elevated liver enzymes, low platelets. The fetal effects are IUGR. The baby may have low platelets. So if you have a small undergrown baby with low platelets there are a variety of things you need to think about, such as congenital infections. But always knowing the history on the mom, so if you should get a baby transferred in.

IUGR baby. They are scrawny looking. Their head can either be too big for their body or it can be very proportionate, and that has different meanings. 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. That’s 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. It usually happens early in gestation, so the whole body is affected. Because the baby is growing pretty symmetrically at that point.