What's The Big Deal About 'Big' Babies?
EXPERT ADVICE: Remember the bedtime story of Goldilocks? Goldilocks tried three chairs – one was too big, one was too small and one was just right. Well, what is the ‘just right’ sized baby? Midwife and eumom pregnancy & birth expert Tracy Donegan is regularly asked this and now addresses the issue. Let’s look at the evidence and experiences in Ireland. Several times a month I’m contacted by women who have had a recent scan and have been told that their baby is measuring too big or too small, so it's time to look at this issue from an evidence standpoint – as a midwife and as a mother who gave birth to a 10lb 7oz baby boy at home with only a slight graze. Going for an ultrasound scan is generally an exciting time as you get to take a peek at your baby in his little world. But in the back of every mom’s mind is the worry that something unexpected may show up on the scan. You’re caught between watching the strange shapes on the screen and watching the sonographer's facial expressions, looking for clues that something’s not quite right. You probably even forget to breathe if you have a particularly quiet sonographer as she clicks and concentrates.
What’s the big deal about big babies?
I’ve found that although there is an international definition for ‘big’ babies, sometimes the prediction of a ‘big’ baby is in the eye of the beholder (your OB) if you’re not particularly tall. The research suggests that a baby is considered to be big when it weighs more than 4,000 grams (8 pounds 13 ounces) at birth, and others say a baby is big if it weighs more than 4,500 grams (9 pounds 15 ounces).
Although there is an international definition for ‘big’ babies, sometimes the prediction is in the eye of the beholder
Big babies are more likely to experience problems with their shoulders being born (i.e. shoulder dystocia), but around half of all babies who have this problem are of ‘normal’ weight. Epidurals and instrumental births add to this problem. Babies need lots of room to manoeuver through the pelvis and if your pelvis is closed (i.e. you’re flat on your back – it makes it harder for baby).
An ‘open’ pelvis is an upright pelvis or at least side lying. Instrumental births are a risk factor for shoulder dystocia in all babies – big or small. Shoulder dystocia is a medical emergency, but in most cases it can be resolved by changing mom's position to facilitate opening the pelvis more. A 2009 study reported that your caregiver’s suspicion of a big baby is in fact more dangerous than the baby itself! Moms who were suspected of having a big baby (and actually ended up having one) had three times the induction rate; more than triple the C-section rate, and a quadrupling of complications for mom compared to women whose obstetricians didn’t think their baby was big but ended up having a surprise big baby in the end. Scans are notoriously inaccurate, especially late in your pregnancy. “Throughout my pregnancy I had been measuring average and no one even mentioned the words 'big baby'," says mom Amanda. "In the end, my daughter Katie was born weighing 9lb 9oz! I got through it with just gas and air and a Tens machine, and the midwife was brilliant too advising to pause when baby's head was emerging.”
Inductions come along with a long list of potential problems for you and your baby, and there is no evidence to support inducing early to ‘stop baby getting any bigger’. Induction increases the likelihood of complications instead of reducing them.
A 2009 study reported that your caregiver’s suspicion of a big baby is in fact more dangerous than the baby itself
I can only imagine how stressful it can be to be told your baby is measuring large at 35 weeks, knowing you have potentially another 5+ weeks to go. After my son Jack was born weighing 8lbs 15oz, I was expecting a bigger baby but never dreamed Cooper would be over the 10lb mark (and I was not diabetic). Babies born to moms with uncontrolled diabetes tend to be on the larger size due to the extra sugar in mom's bloodstream. If your diabetes is well controlled and your sugars have been stable, this is not something for you to be worried about. I’m quite sure the last few weeks of my pregnancy would have been very different if I’d had a late scan, and no doubt the worry would have impacted my labour which would probably have become a self-fulfilling prophecy.
“My first baby was exactly 9lbs," says mom Aoife. "In all scans he had measured on the bigger side, but no one made any comments until at 38 weeks one midwife asked me what I was eating, as the baby was big. I was devastated as I thought it was all my fault and I wouldn't be able to have a home birth with the community midwives. A week later, a different midwife said I was fine and the baby wasn't that big. I delivered my 9lb baby with just gas and air – it turned out he was long, not fat, and as his dad is 6ft 4 I wasn't surprised! He continued to grow and grow, and was off the charts at his last developmental check. My baby was the perfect size for my body. Yes it stung pushing him out, but I was absolutely fine and don't think a smaller baby would have felt much different.”
Is smaller better?
We know that scans are rarely accurate and that goes for predicting small but healthy babies too. As a precaution we’re always going to monitor your baby’s weight gain and blood flow through the placenta more thoroughly if we think your baby’s growth has slowed down significantly. We’ll also consider your lifestyle (smoking/stress) and your diet. A sick baby is definitely better off on the outside receiving medical care than on the inside if he’s not growing.
Babies born to moms with uncontrolled diabetes tend to be on the larger size due to the extra sugar in mom's bloodstream
Up until recently it was thought that a baby that was in the tenth centile of growth (meaning 90 per cent of other babies are likely to be larger) needed to be born, but new Irish and international guidelines suggest that most of these babies are perfectly healthy, just small. Chances are mom has had small healthy babies in the past, or if this is her first we find the parents are usually small-framed themselves and were probably smaller babies at birth too. Only the babies that fall into the third centile (if all else is well) require additional monitoring and perhaps an early birth.
Things you can do
Big or small, all babies do better when mom has a healthy balanced diet during her pregnancy, is getting some exercise, reducing stress and avoiding cigarettes. Talk to your caregiver about the evidence against induction and Caesarean for suspected big or small babies based on international best practice. Irish guidelines can take years to be implemented into our maternity units, so it’s up to parents to inform themselves and initiate the discussion if you’re unsure about induction for your health and your baby’s.
Guidelines can take years to be implemented into our maternity units, so it’s up to parents to inform themselves and initiate the discussion
Remain upright as much as possible in active labour and avoid the epidural so your mobility is not restricted and your pelvis can move around your baby with the help of gravity. Give birth in the position of your choosing. Leave the waters intact to facilitate an easier journey through the pelvis for your baby. If you have an epidural, change position often (from side to side), and if you have some feeling in your legs move to an upright position over the back of the bed, with the help of your partner, for the second stage of labour. Do you have a pregnancy or birth-related question for Tracy?