I’m sure there’s a simple answer to this, but I can’t find it. I realize a pregnancy is supposed to be about 40 weeks, and that pregnancies of shorter terms can produce children that live. What is the shortest term for a pregnancy where the child born has the best chance to live?
I know I’m not really phrasing this right – I guess my question is better put this way: how long before we’re out of the woods and know that the baby could survive pretty well if the mother could no longer maintain the pregnancy?
There are some landmarks to remember:
37-40 weeks is a term pregnancy. By 32 weeks, all that is left is lung maturation and for the fetus to grow, and outcomes of fetuses delivereed after 32 weeks are basically the same as normal. Survivability takes a sharp turn upwards at 25-26 weeks. The lower limit of viability is 22-23 weeks as indicated in the chart, although anything before 25 weeks is very rocky.
My nephew was born (20 years ago) about 10-11 weeks premature.
He was in an infant intensive care unit for quite a while. I remember asking how long he would be there, and the doctor saying that babies needed 9 months to develop, and since he was 2-1/2 months premature, he would likely stay there for 2-1/2 months until he could go home.
In my ER we take just about any pregnant female 20 weeks or more straight to OB for eval because that’s the theoretical limit. We’d keep them for a stubbed toe or a gunshot wound to the chest, and anyone under 20 weeks. That’s probably a conservative date to ward off lawyers.
Keep in mind that these are time frames for survival only. There are still tremendous risks involved with infections, heart and lung disorders, brain hemorrhaging, blindness, etc. Additonally, it also depends on the condition the baby is in while in the womb.
–Mother to a former 26-week gestation micropreemie (now a healthy 4-year old)
To neonatal docs, weight is even more important than gestational age. A 1000 gram 24 weeker has a much better chance than a 500 gram 26 weeker.
There is a huge difference between the beginning of 23 weeks and the end of 23 weeks. WhyBaby, at 23 weeks and 6 days, was given a 50% chance - much better than the 30% of a 23 week, 0 days, but not as good as a 24 week, 6 days - which is 70%! Those two weeks are the critical weeks right now. This will change as technology changes. Prior to 1980 and the invention of surfactant, there was simply no way to save a baby before 30 weeks - their lungs would simply crack due to a lack of slipperiness. History of Surfactant use.
In addition to GFactor’s nationwide averages, it’s important to know that there are different levels of neonatal intensive care available at different hospitals. Some hositals are equiped for and routinely see 24 weekers with a good survival rate. (Our hospital has a 70% survival rate for those babies born at the end of 24 weeks - one of the highest rates in the nation.) Others, due to equipment and personnel restrictions, aren’t equiped to handle anything but resuscitation and stabalizing a sick newborn for tranfer to another hospital.
NICUs used to be called “Level I, Level II or Level III”, with Level III handling the sickest, youngest babies. The terminology changed relatively recently - recently enough that a lot of nurses and doctors still use the old terms. The new terms are “Basic, Specialty and Subspecialty”) The breakdown of what they can do follows (from here) :