Since getting pregnant, you’ve probably learnt enough new phrases to fill a whole book.
And just as you might have learnt the words “Braxton Hicks”, “linea nigra", and “ventouse” during the weird and wonderful journey that is pregnancy, once you get closer to the finish line, you’ll be wondering what it means when your baby’s head is engaged.
We’ve summed up everything you need to know…
What happens when my baby's head is engaged?
When your midwife or doctor talks about your baby's head engaging (or bottom if your baby is sitting in the breech position), she or he means how far into your pelvis the head has moved down.
“You might be told that baby is ‘at the brim’, which means that the baby's brow is just into your pelvis and the head can't wiggle and look around quite so much anymore,” says Rachel Fitz-Desorgher, a midwife with 30 years’ experience in infant feeding, active births and working with parents.
If the widest part of the baby’s head can get into the pelvis, there is a better chance that your new arrival will come out the other side at birth without too much difficulty.
“Week by week, you might learn that that the head is 1/5th, 2/5ths, 3/5ths - and so on - into your pelvis as the head goes in deeper and deeper. Ask your midwife or GP if he or she is telling you how many fifths are already in your pelvis or how many can still be felt out - 3/5ths out is, of course, 2/5ths in! When 3/5ths are down into your pelvis, then the widest part of the head has got in and the baby is said to be engaged.”
But why is this measured? The answer is that if the widest part of the baby’s head can get into the pelvis, there is a better chance that your new arrival will come out the other side at birth without too much difficulty.
When does it happen?
The time when a baby’s head engages varies from mother to mother, according to Fitz-Desorgher.
There are several different factors that can affect the speed at which the head will drop in and engage, from the size and shape of your pelvis to whether you’re having your first baby or not. The way that your baby is facing can also have an impact.
“With a first baby, the head generally starts to move down into the pelvis from about 36 weeks but some babies get moving downwards well before that,” she says. “Then, week by week, until you go into labour, the head moves down until it is engaged. Sometimes the engagement process is quick and sometimes it is slow. With a second or third (or umpteenth) baby, it is not uncommon for the baby to stay out of the pelvis, or just a little way in, until you get into labour. Then the baby goes into, through and out of the pelvis in one fell swoop in labour!”
What are the symptoms?
The symptoms for each mother and baby vary, with some mums not getting any symptoms at all when their baby goes into their pelvis.
However, Fitz-Desorgher says, some mums could notice several different symptoms: having a bit more space under their ribs, a need to urinate more often, aching and stiffness in their back and front bone and sometimes all around their pelvis, changes in bowel habits, more Braxton Hicks contractions, and the baby’s wriggles and kicks feeling less furious but more like shifting about.
“Always tell your midwife or GP what you are experiencing so that you can be properly checked to make sure that all is well and that your symptoms are simply the baby going downwards,” she adds.
Once my baby has engaged, how long will it be until I go into labour?
There’s no one-size-fits-all answer to the questions of how long it takes to go into labour once your baby has engaged.
Women vary enormously in their experience of labour, and the time it takes for engagement to happen can be extremely different, even with the same woman with different babies.
“People will tell you that once the head is engaged, you will go into labour soon,” says Fitz-Desorgher. “This is not true, nor is it true that you won't go into labour if the head hasn't engaged. However, with a first baby, the head going down (even if it doesn't fully engage) is a good sign that your pelvis is a good size for birth.
“Don't panic, though, if this is your first baby and the head hasn't gone down by term - it might simply be that baby needs to wiggle into a better position as labour gets going and then will get down into and through your pelvis quite nicely.Your midwife or GP is the best person to advise you, not your mates on Facebook!”
Can I encourage my baby to engage?
There’s all sorts of advice for women about how to encourage their babies to engage, but according to Fitz-Desorgher, it’s debatable whether these recommendations actually work.
“Many people will tell you to lie on your left hand side in bed and to be careful not to sit too far back in your sofa, but good evidence for this is a little thin on the ground and many women start to fret and feel guilty when they do ‘all the right things’ and the baby hasn't dropped,” she says.
“Your body is beautifully evolved for growing and birthing your baby, so relax, stay as comfortable as you can in bed at night and when sitting at work or at home, and your baby will go into and through your pelvis all in good time. Remember that your midwife and GP are experts in understanding your pregnant body and how a baby grows and moves down. So write down all your worries and questions day by day and share them with her or him at every visit.”
Rachel Fitz-Desorgher’s first book Your Baby Skin to Skin: Learn to Trust your Baby's Instincts in the First Year is out now. (£12.99 White Ladder Press)