Large, chubby babies are adorable. All parents love those chubby cheeks and chunky limbs, which always make for a great like-worthy photograph on Facebook! When it comes to an unborn baby, however, it may not be the best.
Babies that are unusually large may have a condition known as macrosomia. Literally “big body,” this condition may bring with it a number of risks to both the mother and the baby upon childbirth. The trouble with it is that it can be extremely tricky to diagnose. In addition, even in macrosomic babies the complications are so rare that it’s difficult to tell where the complications will pop up. As such, recommending drastic treatment such as a C-section with every single baby with suspected macrosomia isn’t ideal.
When it comes to large babies, there’s quite a lot that the expectant mother needs to understand. First of all, it’s important to screen for the risk factors of macrosomia to know whether the luck of the draw is in favor of the mom-to-be in this respect. It’s equally important to know just how macrosomia can be detected and diagnosed early. Finally, the mom-to-be must also understand the different possibilities that may arise during childbirth involving the larger baby.
To address all that, we’ve whipped out this list of fifteen things that all moms need to know when delivering a baby that’s larger than usual. While some of the possible complications may seem rather grim, do remember that these are unlikely worst case scenarios and there are still plenty that the family and the medical team can do to ensure that the big baby is a safe baby.
There are several things that can increase the mom-to-be’s risk of having a large baby. For instance, it’s far more common in moms with diabetes regardless of whether it came up before or during the pregnancy. This is especially if blood sugar levels remained uncontrolled, which stimulates increase in fetal size and the buildup of body fat. Macrosomia is also more likely with moms who are obese or gain too much weight through the course of the pregnancy.
But it’s important to note, also, that sometimes macrosomia just happens without any known cause and investigation continues to find the reasons. Perhaps some babies just grow faster than others, or there are other things we haven’t found yet that affect the baby’s size. Or perhaps it’s just luck of the draw. What is fairly clear, however, that moms who have given birth to a baby with macrosomia will be more likely to have large babies in the future.
A macrosomic baby is one that is about 4 kilograms, nine pounds, or more. For reference, that’s about as heavy as very large honeydew melon. Some guidelines, however, say that macrosomia starts at 4.5 kilograms. Most of the risks associated with giving birth to a large baby, however, involve one that is 5 kilograms are more.
Prior to birth, it may be possible to get an idea of just how big the baby is. This can be done through an ultrasound and an equation that considers uterus size, the mom’s weight and height and how much weight was gained during the third trimester. The sex of the baby may also be plugged into the equation as newborn boys tend to be bigger than girls. But considering all the factors that come into play during pregnancy, the absolute diagnosis of whether a baby is macrosomic or not can only be made once it is born.
Despite the fact that the actual macrosomia diagnosis can only be made after birth, there are a few things that can tip the mom-to-be and the doctors off that the little one may be quite large. For one thing, the fundal height, or the distance between the pubic bone and the tip of the uterus, is a fairly good indicator of how far on the pregnancy is. Starting at around twelve or fifteen weeks, this measurement often matches with the gestational age of the fetus. There are times, of course, when the measurement will be off by a centimeter or two. With macrosomia, however, the fundal height will be significantly larger than the gestational age.
Another clue is if there is too much amniotic fluid. This can be indirectly determined through taking measurements during an ultrasound. This happens because part of the amniotic fluid is actually fetal urine and bigger babies urinate more than smaller ones.
Many moms think that a large baby automatically means a C-section. But this isn’t quite the case. Sure, there is a higher risk for a C-section with a suspected macrosomic baby, but many are still born through a normal, vaginal birth. There are, however, several problems that are more common with a vaginal birth of a macrosomic baby. We’ll cover these later, but it’s still important to know that, while increased, the overall risks are still pretty low.
In many cases, it’s still mom’s call as to what sort of delivery she’d like, unless there are other serious risks such as diabetes or severe polyhydramnios (too much amniotic fluid). The mom-to-be might opt for an elective C-section or, perhaps, have labor induced before she reaches 40 weeks to prevent the baby from growing even larger. But since, as we’ve talked about earlier, fetal macrosomia can be so hard to diagnose and that absolute risks aren’t that high, many doctors will simply recommend a vaginal delivery.
One of the reasons why fetal macrosomia might occur is when the little one is overdue. This is because babies continue to grow in the womb even after the due date. As a result, the baby might grow too large during the few extra weeks she’s in there. In some cases, she’ll even grow too big to fit through the birth canal, especially if the mom’s pelvis is small to begin with.
There is more leeway, however, in moms who have normal-sized pelvises. In most cases, a big baby will still manage to fit through the birth canal. However, being overdue comes with other risks. A placenta calcifies or matures over time. A placenta that is over-mature may not be able to support the baby for very long and increases the risk of a stillbirth. It’s therefore best to discuss the problem of being over term separately with macrosomia during the doctor’s appointment.
Moms with macrosomia may take more time in the labor room than those with average-sized babies. This is pretty intuitive. Given its large size relative to the birth canal, a big baby will take more time to descend through the birth canal. The birth canal, in turn, will have to stretch much wider than it typically would to get a large baby out.
But perhaps the most important factor that can make a difference between a vaginal and a caesarian birth is the size of the baby’s head and shoulders. When the baby’s mass is evenly distributed, the birth canal won’t have to stretch as far. If the baby’s head, the presenting part, and shoulders, the largest part of the baby to pass through the birth canal, are disproportionately large in size, the baby might take more time to get out and may even get stuck. This situation is far more common in diabetic women.
A large baby also increases mom’s risk of getting perineal tears and lacerations. These can range from small, superficial tears on the skin to larger ones that reach down to the muscle. Some tears will require stitching so that they heal properly. In rare cases, the doctor may have to perform an episiotomy, a surgical cut to make the baby’s exit point bigger, to prevent too many tears from developing.
Most moms will be so immersed into the childbirth experience that these tears are unlikely to be too painful initially. They’re more of a problem postpartum, when the adrenaline rush has subsided and mom has nothing else to think about than her sore lady parts! This perineal pain can be managed through a combination of ice compresses and heat pads or sitz baths. If these don’t relieve the pain, the doctor might prescribe an oral painkiller or an anesthetic spray.
Perineal tears are pretty common, but one rare complication that may arise with a big baby is tailbone injury. In mild cases, parts of it will only be bruised or get swollen from the pressure of childbirth. This can usually be managed easily with pain medications and time. More serious cases, however, might result in dislocation or fracture. These, however, are extremely rare.
Often neither the mom nor the doctor will know that the tailbone has been injured during childbirth. After birth, however, mom might feel really intense soreness around that region. It’s often worse when sitting, as this position applies the most pressure to that area. To diagnose this, a doctor may have to do an assessment, which may require an x-ray. In most cases, tailbone injuries heal on their own with time and rest. However, mom may also need physical therapy or, in the most severe of cases, surgery.
Because it’s more difficult for a large baby to pass through the birth canal, in rare cases a baby might get stuck during her descent. With macrosomic babies of diabetic moms, this is usually though shoulder dystocia. In this case, the baby’s head is delivered successfully but the shoulders, the largest length that will pass through the birth canal, gets stuck in the pelvis. A qualified medical team handling the delivery in this case will perform a series of maneuvers to help get the baby out. This situation can be risky for both mother and baby. The longer it takes to get the baby out, the lower the chances of survival.
One of the injuries that may occur with shoulder dystocia is damage to the nerves of the brachial plexus. This is because during childbirth, these nerves may stretch out and get injured. In most cases, babies with nerve damage recover with time. However, if the nerve is under so much pressure that it tears, the damage may be more permanent.
Because of the high risk of injury resulting from the extreme stretching of the birth canal and, also, the uterus, there’s also a greater risk that mom will bleed too much after the birth of a large baby. This phenomenon, called postpartum hemorrhage, is when mom loses more than half a litre of blood commonly within the first day after childbirth. Because of the abrupt decrease in blood volume, mom might not have enough fluid to maintain adequate blood volume. In rare cases where the uterus does not contract well, this can even happen for up to a month or so after childbirth.
It’s best to monitor the amount and quality of discharge after childbirth to detect postpartum hemorrhage early. By the fourth day, discharge should no longer be bright red in color. A woman experiencing postpartum hemorrhage might also have low blood pressure and feel cold and clammy. Some women will become restless and even faint due to the decreased blood supply in the brain.
It’s not just the nerves that are at risk when delivering a large baby, however. The baby’s bones are also prone to damage. The collar bones are the ones that are most prone to fractures, although other bones around the shoulder area may also get injured. Often, the medical team may not be able to detect fractures immediately after childbirth. Instead, these are usually an hour or so afterward when swelling begins to develop over the broken bone. The baby may also avoid moving the injured side, resulting in an unusual asymmetry of movement. In some cases, the affected side may even seem flaccid and limp.
When a fracture is detected, the baby may have to get a splint or a medical procedure known as closed reduction, where the broken bone is repositioned without having to use surgery. Actual surgery will only be necessary in the most severe of cases.
Most of injuries following the delivery of a macrosomic baby involve the shoulders. In a few cases, however, the head may also receive a considerable amount of injury which may sometimes result in brain damage. This is especially if the baby’s head retreats and comes down several times through labor, making it hit the pelvic bone repeatedly. But this isn’t the only mechanism in which the brain can be damaged. If the labor goes on for way too long and the baby suffers some form of oxygen deprivation through the process, brain cells may also die.
This can result in cerebral palsy, autism or other long-term intellectual disabilities. It can be difficult to predict just how severe the disability will be following childbirth-related brain damage, or even if there is any at all. What is important is that, following such injury, the baby receives immediate treatment and, once out of the hospital, the parents continue to monitor her condition.
Fetal macrosomia can be particularly difficult for moms who have not yet given birth vaginally. It’s already well-known that moms who give birth for the first time are likely to have longer labors and that subsequent pregnancies are likely to be easier. This is because prior to the first childbirth, the pelvis and the birth canal will not have been stretched out yet. During childbirth, the two hip bones will literally separate at the symphysis pubis to allow the birth canal to widen enough for the baby to pass through.
After childbirth, the hips return to their pre-pregnancy state. However, the cartilage in between them will have loosened enough that future pregnancies will be much easier and will take much less time. Because of this, a mom who happens to have a macrosomic baby during her first pregnancy is more likely to experience complications than another mom, also with a macrosomic baby, who has delivered before.
We’ve already covered that moms with diabetes, especially if uncontrolled, have a greater chance of having a baby with macrosomia. It’s important to note, however, that macrosomic babies born to moms with diabetes also have separate risks that might not be found in a large baby born to a mom without macrosomia. For one thing, they tend to have higher mortality rates.
In addition, babies born to diabetic moms may have to have blood sugar monitoring following childbirth. This is because their systems are so used to having an increased amount of blood sugar that they naturally produce too much insulin. When the source of the high blood sugar, i.e. mom, is no longer connected to the little one via placenta, it may take time for the baby’s pancreas to figure this out and decrease insulin supply. The baby may therefore experience fetal hypoglycemia, a dangerous condition that requires immediate medical intervention.
Because of all these considerations, it’s especially vital that the mom-to-be who is at high risk of having a macrosomic baby must have a comprehensive childbirth plan. For one thing, it’s important to consider that absolute risks are pretty low and most moms with macrosomic babies are able to deliver them vaginally with minimal medical guidance. However, as they say, when it rains it pours and so when things go wrong, it can get serious really quick.
As such, it may be necessary for a mom with these risk factors to opt for childbirth at a hospital rather than one at home or at a birthing center. If a birthing center is the preferable option, it’s best to get one that is within reasonable distance of a more advanced health care facility. Again, it’s extremely important to talk to the doctor or the midwife so that there’s a plan B in case things do go wrong.