Optimal Fetal Positioning, or OFP, describes movements and positions that you can do during pregnancy and labor to encourage your baby to enter into a favorable position in the pelvis. While most babies can navigate their way through most pelvises regardless of position, there are certain positions that are “optimal” and make labor shorter and less painful. Before we look at what positions are most optimal and why, let’s talk about your pelvis and how we describe the baby’s position inside your body.
This is a model of a human pelvis. The parts that you may recognize right away include the hip bones on the sides, the sacrum and coccyx in the back, and the pubic bone in the front. But the inside of the pelvis is actually what’s most important to our discussion of labor and birth.
The pelvis has three main planes or areas that the baby must pass through in order to be born.
- The pelvic inlet is the top part, also called the brim. It has the largest diameter and is usually oval shaped.
- The midplane is the middle part and has the smallest diameter of the pelvis. This is where the baby has the least room to pass through.
- The pelvic outlet is the lower rim of the pelvis and is bounded in front by the pubic bone and in back by the sacrum and coccyx. It is usually diamond shaped and will stretch due to cartilage in the pubic bone to allow the baby to pass through. The coccyx is also mobile and can slide out of the way as the baby is passing through.
In order to understand why optimal fetal positioning is important, you need to understand the various different positions the baby can be in during pregnancy and labor. The medical terminology for describing the baby’s position in the uterus uses a 2- or 3-letter acronym. For all the descriptions, we are always talking about the back of the baby—either the back of the head or the back of the body.
The first letter in the 3-letter acronym stands for which side the baby is on, so this letter is L for left or R for right. The L or R refers to which side of the parent the baby’s back is towards. If the baby is directly in the middle, there would be no first letter L or R.
The second letter, or the first if there is no L or R, is which part of the baby is presenting first in the pelvis. O is for occiput or head down. S is for sacrum or butt down, and describes a breech baby.
The third letter describes whether the baby is facing front, back, or to the side. It can be a little confusing, but the reference point is the baby’s back. So if the baby’s back is towards the parent’s front, that is anterior or the letter A. If the baby’s back is toward the parent’s back, that is posterior or the letter P. If the baby’s back is directly to the side, that is transverse, or the letter T. Any position with the baby’s back towards the parent’s front is called anterior, any position with the baby’s back towards the parent’s back is called posterior.
Putting all these positions and letters together, we get a total of eight possible positions when the baby is head down. Starting on the parent’s left, you have left occiput transverse, or LOT, which is when the baby is directly sideways, back facing towards the left. Moving clockwise, the next possibility is left occiput anterior, LOA, with the baby’s back towards the parent’s front but on the left side. Occiput anterior, OA, is when the baby’s back is directly facing the parent’s front. Then you have ROA and ROT with the baby’s back towards the right. The positions on the top half from ROP over to LOP are posterior positions, with the baby’s back towards the parent’s back.
You may wonder why all this is important. You may have heard or think that as long as the baby is head down birth will happen just fine. But head down is only part of the equation. The other elements of the baby’s position that are extremely important include having their chin tucked down onto their chest and having their back turned towards your front.
The most favorable positions for the start of labor are with the baby’s back facing your front or in an anterior position. It’s important to remember that it’s not a straight shot down and out. Babies have to basically spiral their way out as they move through each plane of the pelvis. So the position that they start off in is important in determining how the rest of labor goes.
At the start of labor, most babies will enter the pelvic inlet or brim either facing directly to the side or facing obliquely to the left or right. This is the way that the baby’s head fits best into the pelvic inlet opening. Once past the inlet, most babies will turn so that they are directly facing front or back. Because the midplane is the tightest squeeze the baby has to turn directly front or back to fit through. In the anterior position, babies will usually tuck their chins to navigate the midplane. This presents the smallest diameter of the baby’s head into this tight area of the pelvis. This part of the head also provides solid, even pressure onto the cervix leading to strong, effective contractions.
This is the main reason why optimal fetal positioning is important, and all efforts to get the baby in a good position before labor begins are aimed at getting the baby to descend through the midplane anteriorly with a tucked chin.
In the posterior position, the top of the head comes down first because the neck is usually extended. This part of the head is larger and makes it more difficult for the head to navigate the pelvis. Also this part of the head doesn’t put as much concentrated, targeted pressure on the cervix as does an anterior head with a tucked chin, so contractions tend to be more erratic and less effective in opening the cervix. In addition to a longer, more difficult labor, when the baby is posterior the back of their head rubs against the laboring person’s sacrum as it passes through the pelvis causing lower back pain and what is called “back labor.” Usually, back labor is more painful, pain is felt even in between contractions, and the overall length of labor is longer than with an anterior baby.
One of the single most important things you can do to encourage the baby turning anterior is to pay attention to your posture. Modern lifestyles encourage us to slouch and be lazy. In these images you can see several ways that we slouch in chairs rather than sit upright. Rather than walking or riding a bike we sit in cars. Rather than squat or stand, we slouch back into overstuffed chairs or at our desks. These backward leaning positions encourage your baby to settle into your pelvis in a posterior position (with their back towards your back). This is because when you lean back gravity pulls the baby’s back (which is heavier than the front) around towards your back. When you are upright or leaning forward, the reverse happens—gravity pulls the baby’s back towards your front.
The most important thing to remember about posture is to keep yourself upright with a straight back, and when you’re sitting or lying down, lean forward more than you lean backward. When you are standing, remember to pull your shoulders and hips back. Don’t allow your lower back to sway forward. This upright standing posture will also prevent back and hip pain as well as promote OFP. When you are sitting or resting, remember the following:
- Keep your knees lower than or level with your hips. This means no slouching back into soft couches or chairs that are close to the floor.
- Sit on an exercise ball whenever possible. You’re almost forced to have good posture when you’re on a ball. Instead of straight-backed chairs or desk chairs, use an exercise ball at your desk, at the kitchen table, or while watching TV or reading.
- Another good option is to sit cross legged on the floor or squat whenever you can. When you’re folding laundry, playing with older children, reading a book, watching TV—try to be in these forward leaning, upright positions that help open the pelvis and hips.
- If you need to sit in a straight-backed chair, turn the chair around and sit on it backwards. This keeps you more upright and forward leaning, and prevents you from slouching back.
- When you are sitting on soft armchairs or couches, keep an upright back by sitting on the front of your sitz bones not back on your sacrum. Put a small pillow behind your lower back to keep you more upright.
- Rest is important, so don’t feel like you can never lie back and rest on a couch or bed. Just minimize the time you spend semi-reclining on your back. If you want to rest on a couch or bed, lie on your side with a pillow between your knees.
Sitting on an exercise ball is a great way to be upright. You’re almost forced to have good posture while you’re on a ball. Use it at the kitchen table, at your desk, and while you’re doing thinGs like watching tv, reading, or folding laundry. Sit on the ball so that your feet are flat and apart. Your feet and the center of the ball should make a tripod when you sit down. The ball should be firm and big enough for your height so that your hips are equal or higher than your knees. Just sitting here is great, but you can also do wide figure-eights or circles with your hips while sitting on the ball to increase balance and flexibility. This also helps open the pelvis and hips and allow baby more room to get into a good position.
Pelvic rocking helps relieve back pain, strengthens and relaxes pelvic floor muscles, and encourages OFP by allowing gravity to rotate the baby anteriorly. Remember in forward leaning positions like this, gravity helps pull the baby’s back around towards your front.
To start, come onto hands and knees on a mat or folded blanket. Your hands are under your shoulders with straight arms. Your fingers are pointing forward and your knees are under your hips. If your wrists or forearms are uncomfortable like this, you can curl your hands into fists and rest on your knuckles instead. Relax the shoulders. Your back should be straight with a slightly lifted chin. To begin the movement, exhale, and tuck your tailbone under (like a dog tucking its tail between its legs), round your back, and bring your chin toward your chest. Pause here for a moment. Then, as you inhale, gently come back to a neutral straight back while you slightly lift your chin and extend your neck. This is a great exercise to repeat gently for about 5-10 minutes once or twice daily.
Bird Dog will help strengthen your back and core muscles, relieves back pain, and encourages OFP.
Start the same as you would for pelvic rocking. Get onto your hands and knees and remember to keep your hands under your shoulders with straight arms. Your fingers are pointing forward and your knees are under your hips. Again, you can come onto your knuckles if that’s more comfortable for you. Relax the shoulders. Your back should be straight with a slightly lifted chin. Engage your abdominal muscles, then lift right leg straight behind you, keeping the hips level. When you’re ready, lift the left arm straight in front of you. Stretch the body out long as if there was a cord running from your left hand through the arm, all the way through your body, through the right leg, and out the right foot. This cord is parallel to the floor and nice and straight. Keep the back of your neck in line with your spine. Hold this position for a few seconds and breathe deeply before returning to your starting position. Repeat with the left leg and right arm. Take your time and move slowly as you switch sides. Keep your core and your glutes tight, and your shoulders relaxed.
Active squatting strengthens your legs, glutes, core, and pelvic floor muscles. Also it helps build stamina and endurance for labor and birth.
Start by standing with your feet shoulder-width apart and your toes turned slightly out. Activate your core and glutes while lowering your body as if you were going to sit in a chair. Keep knees over ankles so that your shins are parallel to floor. Keep your heels flat on floor. Reach your arms out in front of you for stability as you squat down if you prefer. Pause at bottom, breathing deeply. Keep your glutes contracted as you press up through heels and return slowly to starting position.
Static deep squatting is excellent birth preparation as it opens up the mobility of your hips and pelvis, increases blood supply to the entire pelvic area, and relaxes and stretches the pelvic floor muscles. Getting into a deep low squat also encourages OFP because it allows the baby more space to navigate the pelvic opening.
Start by standing with your feet shoulder-width apart and your toes turned slightly out. Activate your core and glutes while lowering your body as if you were going to sit in a chair. Once you squat down as far as you can, pause and breathe deeply. Rest your arms on top of your thighs or place your elbows inside your knees with the palms of your hands together. Lift the chest bones away from the pubic bone. Keep the spine long, rather than rounded. Keep your heels flat on floor. If this position is difficult for you, or you have trouble keeping your heels flat on the floor, use a wall to support your back. Gradually increase the time you spend in this position until you can maintain it for five minutes at a time. Spend some time in a deep static squat at least once a day.
Lunging opens up the hips and pelvis, relaxes and stretches the pelvic floor muscles, and promotes OFP. To do this exercise, you will need to stand by a chair, coffee table, or other sturdy piece of furniture that is about the height of your knee. Put one foot up on the chair or table and before you lunge, make sure that your body is making an L. The foot on the table should be pointing to the side and the foot on the floor should be pointing towards the front of the body. So your two feet are making a right angle. Lunge into the foot up on the chair or table by leaning in to that side. Keep your knee above your ankle, don’t let that knee extend past the ankle. If needed, adjust your foot on the floor either closer to or further away from the chair or table so that when you lunge to the side your knee stays over the ankle. Remember to lunge to the side. Don’t face the chair or table, make sure you are facing to the side and lunging to the side. Come back to a neutral position, then repeat 5-10 times. Switch sides to the other leg.
FORWARD LEANING INVERSION
The forward leaning inversion helps release and relax the ligaments around the uterus. After the stretch, when you stand up, the baby has more room to get into a good position.
Make sure you have a helper near you the first couple of times you try this position in case you become dizzy or unbalanced. Start off by kneeling on the edge of a couch, bed, or chair. Carefully lower your hands to the floor and then lower yourself onto your forearms. Your elbows are out, and your hands are close together. Use a stool or step, if you like, to help walk your hands down. Go slowly if you’re unused to doing something like this. Once your forearms are on the floor, let your head hang freely with a tucked chin. Don’t rest your head on the floor. Keep your knees close to the edge of the couch or bed. While you’re here, you can tilt or sway your hips, if you like. Take three deep, slow breaths in this position and stay here for about 30 seconds. After 30 seconds or so, come back up onto your hands, then lift yourself up to a kneeling position again. Stay here for a moment and breathe deeply before standing or walking. You may notice that your head pounds the first few times you get into this position. That’s ok. Just come up a little sooner if you want. Your body will adjust after a few times and you won’t feel it anymore. There’s a few situations where you should not do forward leaning inversions. Don’t do this position if you have high blood pressure, severe heartburn, or possible placental abruption.
Child’s Pose is great anytime you want to rest and stretch your back, shoulders, and arms. The forward leaning position encourages OFP.
To start, come onto your hands and knees on a mat or folded blanket. Spread your knees wide apart while keeping your big toes touching. Now lower your upper body to the floor with your chest, head, and arms resting on the floor. You can put a pillow under your upper body if you like. To get a good stretch in your arms, keep your arms long and extended in front of you, palms facing down. Or you can rest them alongside your thighs, palms facing up. Stay in this position for as long as you like.
While all of these techniques can help get a baby rotated and into an optimal fetal position, it is important to remember that pelvises and babies’ heads are still amazing at adapting. Babies can still be born in posterior positions, with brow and face presentations, and in other “non-optimal” positions. It may take a little more time, and a lot more effort, but your body is amazing at making birth work. Have fun with these movements and positions!