At 35 weeks and 6 days pregnant I have a painful pressure. What complications could occur if my baby were born between 36-37 weeks instead of full term?
In pregnancy the female body does a remarkable job in cramming two people into the space of one. Unfortunately, when there's push and shove, the baby usually wins, leaving for you what I like to call "The terminal miseries of pregnancy." By this I mean that the pregnancy has reached a "critical mass" enough to really take a toll on the mother-to-be. Luckily, the terminal miseries of pregnancy are also for the most part harmless. You question is one that all women ask when just close enough to wonder whether a delivery just a few weeks early can be harmless for the baby and take a major load off of you.
The best way to answer you is to consider that we are a species that has perfected the reproduction process. A baby has a way, the full extent still uncertain, of signaling the host (you) when to go into labor. There are many things that have to synchronize right to have this come to be--including ovarian, endocrine, and even thyroid and adrenal hormones. Such a complex scenario is best left alone to proceed naturally. However...
What's the harm in having a delivery just a few weeks early? Certainly this happens all of the time--and naturally, too. But there's a big difference in allowing it to happen and causing it to happen. Most babies achieve lung maturity between the 36th and 37th week (37-42 weeks is term). But the 36th week is the center of a bell curve, meaning that half will achieve lung maturity before this time, but half after. I've even seen a 39 week baby go on a ventilator. If you were to go into labor spontaneously before 37 weeks, that's one thing. But to cause labor by induction, or delivery by C-section just because you're miserable is not a good enough reason.
This is not meant to sound unsympathetic.
But it's only fair to the baby to allow maturation to continue without interference. Since "the terminal miseries of pregnancy" are mostly harmless, but immature lungs of a baby are not, common sense should prevail here.
Besides lung, the liver is maturing as well. Sure, even term babies need to be put under a bili-light, but a pre-term baby will have that much more of a fight. Also, arbitrary prematurity can affect feeding, which can have nutritional and neurological consequences in the long run. Basically, a 36-37 week baby would probably be a great baby from the first cry, but no one can guarantee that, and you can't rely on it as a prudent mother.
But let's say the pain is ridiculously tortuous. Everyone feels pregnancy differently, and in some cases intervention can be for the patient's well being. Can anything be done?
If your willing to accept the very small risks of infection, premature rupture of membranes, or the very pre-term labor you're trying to prove safe, then an amniocentesis can be done to test the amniotic fluid for lung maturity. And if the test confirms lung maturity, then you will next have to accept that an induction may not "take" on a cervix that isn't ready to yield (dilation and effacement). That means that at the end of a long day, if not delivered, your doctor may offer you either a second (or third) day of trial of induction, a C-section, or the equally uncomfortable choice of going home undelivered. So the lung maturity aspect is only half the problem. The cervix has to be a "gimme." If it isn't, you're more than tripling your chances of ending up with a C-section, and most doctors will decline.
In my practice, I will stop aggressively premature labors before 35 weeks; attempt to stop labors WITHOUT heroism between 35-37 weeks, and allow labor to ensue unimpeded after 37 weeks. If a mother feels tortured and I feel that the benefit to her outweighs the risk of an amniocentesis, I will offer that. (If the test comes back indicating that lungs ARE NOT mature, then I will have all the reason to champion non-delivery and have a reason to back it up. Pain becomes a lot easier to forgive if a mother knows that continued pregnancy is proven necessary.) Otherwise, I follow the usual guidelines for elective induction--acceptable at 39 weeks if the cervix is actually inducible.
One other added note: Labor before 37 weeks can happen for a reason--possibly related to infection (like Group B beta-Strep) or problems with the placenta. These concerns need to be addressed before seeing labor as just a natural phenomenon. Also, any pain in the lower abdomen may represent a bladder infection, which also has to be ruled out. A previous C-section scar on the uterus can stretch, causing severe pain. Also, premature separation of the placenta can cause severe pain, but this complication usually makes itself obvious in short time.