What is the average size of a baby born in America? Would you guess 7 pounds? Maybe 7 and a half? Eight pounds. Eight pounds is the average size of babies born in America. That means some (lots!) of babies are bigger than that – and many babies are smaller than that. Genetics and mom’s lifestyle, among other things, play a huge role in how big you grow your babies. I’ve seen babies born vaginally that weighed over 10 pounds! I’ve heard stories of babies just as large born vaginally with no pain medication! It’s certainly not impossible. (Maybe not necessarily the most pleasant thought… but not impossible!) Do you know how much amniotic fluid is adding to your weight? Well, not much honestly, but if you’re around 34 weeks, you have now reached the peak amount of amniotic fluid at about 800 mL. From 34 weeks on, amniotic fluid levels will gradually decline. Read on to learn why this matters.
Some doctors suggest an induction for “big baby” because they believe it decreases the chance of a shoulder dystocia (difficulty delivering the shoulders) or the need for a cesarean due to the baby being too large to fit through the pelvis. However, research shows this is simply not true. The risk of shoulder dystocia is relatively small – and it’s impossible to predict who will have a shoulder dystocia. Furthermore, for a doctor to suggest a woman to induce for this reason, the doctor must assume the ultrasound is accurately assessing the size of the baby. Next time a late-pregnancy ultrasound is recommended to you to assess fetal size during your pregnancy, ask your doctor or the sonographer how accurate it is. If they tell you the baby “might” weigh about 8 pounds, please know they can be off by as much as 2 pounds either direction. There is a HUGE difference between a 6 pound baby, an 8 pound baby, and a 10 pound baby. I have seen elective c-sections performed on first-time mothers due to “possible macrosomia” (big baby), only to discover the baby weighed LESS than 8 pounds.
I often tell people that things in labor and delivery can be very dynamic. The more I think about it, the more I realize how true that statement is in so many ways. No two pregnancies are the same (even within the same body), no two labors are the same; there are so many factors that play into a pregnancy and her subsequent labor and birth. Another dynamic aspect of pregnancy? Amniotic fluid. As I mentioned above, the amount of amniotic fluid peaks at about 34 weeks, reaching around 800 mL, and gradually declines to around 600 mL by 40 weeks. However, there are many factors that can play into these numbers. The baby, the mother, and the sonographer measuring the amniotic fluid can all affect the actual or perceived level of fluid.
The baby constantly circulates the fluid by inhaling it, swallowing it, and then releasing it through the urinary tract. Near term, the baby swallows more and urinates less often, thereby holding more fluid at any given time. Other baby-driven factors include: post-term (past 42-weeks), birth defect, or problems with the kidneys or urinary tract.
If you are dehydrated, such as in the coming summer months especially, if your water is broken, or if the placenta is no longer functioning properly, you may be diagnosed with low amniotic fluid. Some things you may try to increase amniotic fluid levels include drinking more water (at least 2-3 liters a day) and laying on your left side during an ultrasound when measuring fluid levels. Other factors that can play into an inaccurate reading include too much pressure on the ultrasound transducer, floating particles in the fluid, and an obese mother. Yes, “low amniotic fluid” could be a sign of a health issue and can be a medical reason for induction, but ask your doctor what their specific concern is before agreeing to induction simply for “low amniotic fluid.” Furthermore, you may wish to have a reevaluation in a couple days. Drink lots and lots of water, and when you return for another ultrasound (hopefully by the same sonographer!), if the fluid level is still low, or has decreased further, then you may wish to discuss the next step with your provider. If it has increased, then you might have saved yourself from an unnecessary induction! For a brand new diagnosis of “low fluid” without any other known cause, you may be better off to wait.
"What I have heard, and what I suspect it ultimately boils down to, is for one thing, doctors are human." - tweet this!
So, knowing all of this, why do doctors recommend things that are not backed by research or ACOG? My honest answer is: I don’t know. What I have heard, and what I suspect it ultimately boils down to, is that for one thing, doctors are human. Meaning: doctors want convenience and easy and predictable and good ratings. What? Good ratings? Exactly. Doctors and hospitals have a business to run. They have to keep their patients happy to keep them coming back for subsequent care! And businesses are consumer-driven. How many times have you heard that you can’t treat a viral infection with antibiotics? And yet, when a patient goes into a doctor’s office, demanding something to be done about their illness, they just might walk out with an antibiotic prescription in hand. Same thing with inductions. When a patient begs, pleads, whines, and complains about all the aches and pains, and difficulties of pregnancy, their doctor wants to appease them. No, not all doctors act this way, but the ones that do are the ones contributing to the problem and making it “okay” for other doctors to do the same. Although, I have to say – it’s not ALL the doctors’ faults. We, as women, as mothers, as consumers are just as much to blame. If I walk into my doctor’s office, demanding an induction – all the while, knowing all the risks of doing such – my doctor doesn’t want to lose me as a customer, so he agrees.
You Have More Power Than You Know
On the flip side, if more women – more consumers – are asking their doctors to allow their bodies to go into labor naturally, they will stop suggesting and allowing for non-medical inductions. If more women are getting educated on their options and on the pros and cons of such procedures, and refusing inductions for the sake of convenience, doctors will follow suit. Ultimately, they want to make their customers happy.
"Amniotic fluid peaks at 34 weeks, reaching around 800 mL, and gradually declines to around 600 mL by 40 weeks." - tweet this!