Engagement is when the widest part of the baby’s presenting part (usually the head) enters the pelvic brim or inlet. A first baby usually engages two weeks before the due date, at 38 weeks gestation. Studies also show that engagement can happen in labor. However, engagement may be the first thing that helps the following situations:
- Labor is not starting
- Labor seems to start and stop
- Labor is not picking up into active phase, or
- The baby remains high in the pelvis, even at 10 cm dilation.
Baby has to get into the pelvis in order to go through the pelvis.
Here’s more about why a baby may not engage, what’s normal and what’s concerning, and what to do about it.
Why does baby engage?
Engagement is one of the first accomplishments of the Cardinal Movement: Descent.
Baby’s head needs to lower into the pelvic brim in a way that allows the parietal eminence to slip below the pelvic inlet. Engagement happens when 4/5ths of the baby’s head is in the pelvis. The head is no longer ballotable, meaning, the head can no longer be wiggled between the midwife or doctor’s fingers.
Why wouldn’t a baby engage?
- Baby’s chin is up, making the head measure bigger
- Occiput Posterior baby’s head overlaps the pubic bone (unfavorable diameter)
- The head really is too big for the pelvis (rare)
- Severe scoliosis
- Baby is not due yet
- The mother has given birth before and this baby will engage in labor
- The placenta blocks baby’s way, preventing engagement
- The lower uterine segment has a bit of a twist reducing space for baby
The posterior and lack of engagement
When the baby hasn’t engaged and the due date is more than 8 days past, I’ve almost always found the baby to be in the posterior position.
Of course, some posterior babies do engage. Whether they may have an issue with fitting the pelvis will reveal itself in labor.
Why wouldn’t a posterior baby be as likely to engage? Less posterior babies have flexed heads (tucked chins). The longer front-to-back length of baby’s head can put the forehead right on mother’s pubic bone. Helping this baby to tuck their chin may help them rotate around and suddenly engage.
Whether baby is posterior or not, these techniques may help. They will not move the anterior baby out of a good starting position.
Pelvic Shape and lack of engagement
Occasionally a woman’s pelvic shape relates to fetal position. But this, I believe, is secondary to soft tissue “balance.” The android pelvis and platypelloid pelvis don’t accommodate posterior presentations. Baby must rotate or will not drop into the pelvis. But the baby in a round pelvis shape (gynecoid) may. A baby in the Anthropoid pelvis (longer front to back) can fit if the muscles allow and if the mother can re-angle her pelvis to let baby in (See steep inlet below). A birth stool, a posterior pelvic tilt and standing and leaning over a dresser feels right. Most full term babies will rotate anterior before they can engage in pregnancy or in labor because of pelvic shape.
Rarely, a pelvis is too small to let the baby enter the pelvis. When a pelvis is too small its called CephaloPelvic Disproportion (CPD, or baby’s too big). Rickets, injury or an actually too-big-baby may be the cause here. CPD is rare, but does exist.
Steep Inlet and Engagement
A woman whose sacrum is sharply angled may have hours of labor before her baby engages. This woman will have a “sacral bustle” or a “ledge” on the top of her bum. To describe this, I say she could set a glass of water on this ledge, which isn’t really true, but gives the picture.
Standing and leaning forward with contractions, in early to active labor is usually what these women do naturally and usually helps engagement. If not, a birthing stool or the abdominal lift and tuck usually help strong contractions bring the baby into the pelvis. From there, the labor usually proceeds rather quickly, as the mother’s hormones are well primed by the long, strong early labor.
What happens if the baby doesn’t engage before labor?
Labor may start before baby engages. Sometimes labor seems late to start because the baby isn’t able to enter the pelvis.
When labor does start, contractions can be strong without much dilation and the baby remains high in the pelvis. Before the cervix opens well, we need to help baby come down into the pelvis well. Check baby’s position and assist chin flexion and rotation to the LOT or LOA position if possible.
Some women are recommended to have an induction, even if their baby is not engaged. Avoid or ease an induction by increasing balance of the maternal structures, by helping baby get chin flexion, if needed, and out of the posterior position, if possible, with balancing activities. See more below.
If baby isn’t posterior and earlier labors have gone well, labor will most likely engage baby. If baby is posterior and earlier labors have gone well, labor will also most likely turn and then engage this baby.
On the other hand, if labor isn’t starting, do the balance activities discussed in the daily and weekly activities in this part of the website.
A mother who had to have her first baby by cesarean because baby didn’t engage (remained high) may be more likely to have a natural birth if her next baby engages, I’ve noticed.
Techniques to help a baby engage
There are several activities and doing several increases success. Don’t expect to do only one and be done. Increase success by getting bodywork (a chiropractor can help align her pelvis and do the Webster Maneuver) and do your own activities daily at the end of pregnancy.
Techniques to help baby engage will help open the brim, tuck the chin and rotate the baby to a left-sided presentation:
- Align the pelvic brim (Chiropractic, Osteopathic, and somewhat with the Forward Leaning Inversion)
- Align the sacrum which may be torqued on a vertical axis and distorting the lower uterine segment (Standing Sacral Release)
- Relax the spasm out of the cervical ligaments (aka uterosacral or posterior ligaments, woman may have a history of retroverted cervix with Forward Leaning Inversion)
- Relax the psoas muscle pair (resolve chronic muscle tension in the illiopsoas with psoas stretch such as a forward lunge gently and frequently done through the day)
- Help baby tuck the chin, aka; flex the head (with 10 Abdominal Lift and Tuck during contractions)
- Help baby rotate to left occiput transverse (lateral), left occiput anterior, or occiput anterior (Rebozo, Dip the Hip, Sidelying Release, Forward Leaning Inversion through 1-3 contractions, 1-3x)
- Walk briskly with free-swinging thighs.
- Sit on a birth ball and make circles with the hips.
These engaging activities can be done before labor or during labor with bodywork.
Sometimes a mother or a mother and her provider can do what is needed to help baby engage before or during labor. Sometimes a bodyworker is best for a particular situation.
Sometimes, even with balancing, labor surges are necessary to rotate and engage baby.
I’m working with a woman who is about to be induced and her baby is at -2 station, should I suggest Walcher’s?
Walcher’s position is only effective with contractions. Don’t recommend it in pregnancy.
Then what shall I do?
Begin instead with Balance. This is why Balance is the first principle before Gravity and Movement.
Balance in this case means activities to help the mother’s anatomy be more symmetrical on both sides as concerns tension and relaxation (or tone) of the muscles, ligaments, and alignment of the pelvic bones.
Walcher’s during and between 3 contractions (and between because its so uncomfortable she won’t likely go back to it a second time). Walcher’s is intense, and so is for when other ways of getting baby to engage don’t work.
Be patient and keep moving in ways that open the pelvic brim. Some positions are comforting but they hold baby up.
While baby remains high avoid laboring in a:
- Child’s pose
- Knee chest (see why this is not Open-knee chest.)
Babies naturally engage in the pelvis when the broad ligament is soft enough and the brim open enough. Fetal chin tucking and coming down from the mother’s left side helps more babies fit more mother’s inlets.
Generally, we hope for flexion and rotation before engagement. This is most important when we find baby in the posterior position and high after 38 weeks pregnancy when pregnant with a first child, or going for a vaginal birth after a previous cesarean.
Work on Balance before working on rotation and descent. Sometimes we have a time issue, as when a woman’s membranes have released and when her provider has a time limit for her labor. Descent from a non-optimal position may have additional challenges that may be met with maternal positioning and activities in labor.
Fetal engagement may help the onset of labor be more spontaneous.
For a woman in labor, check out information and techniques to help the baby engage.
References On Fetal Engagement Topics
Ghi, T., et al. “Sonographic pattern of fetal head descent: relationship with duration of active second stage of labor and occiput position at delivery.” Ultrasound in Obstetrics & Gynecology 44.1 (2014): 82-89. (13.5% of babies were posterior with a 50% cesarean rate. Posterior babies came down through the pelvis better if flexed as told by observed Angle of Progression.)
Haberman, S., et al. “OP22. 08: To evaluate the value of the determination of occipito posterior position before head engagement and risk of persistent OP and Cesarean section.” Ultrasound in Obstetrics & Gynecology 38.S1 (2011): 121-121. (Before engagement, 76 (43%) fetuses were in occiput posterior position (OP), but 67 (88%) of them rotated to occiput anterior (OA) during labour. Eleven (6%) fetuses were delivered in OP, and 9 of them were in OP before engagement (P < 0.001). 22.4% of cases in the OP group underwent Cesarean section compared to 12.7% of controls (P < 0.001).
Khurshid, Nadia, and Farhan Sadiq. Management of Primigravida with Unengaged Head at Term Placenta 4.2 (2012): 4.
(The incidence of high head in primigravidas at term was 22%.The most common cause was deflexed head, next was cephalopelvic disproportion. In 40% no cause found. Vaginal delivery occurred in 67% of cases, 33% of cases had caesarean section. No interference i.e., ventouse or forceps required in 60% of cases. In 64% cases labour lasted more than 12 hrs.)
Shaikh, Farhana, Shabnam Shaikh, and Najma Shaikh. “Outcome of primigravida with high head at term.” JPMA. The Journal of the Pakistan Medical Association 64.9 (2014): 1012-1014. (The most common identified cause of non-engaged head was deflexed head in 28(28%), while no cause was found in 45(45%) women. Further, 45(45%) women presented with spontaneous labour, while labour had to be induced with prostaglandin in the rest. Vaginal delivery occurred in 59(59%) cases and caesarean section was performed in 41(41%).
Verhoeven, Corine JM, et al. “Does ultrasonographic foetal head position prior to induction of labour predict the outcome of delivery?.” European Journal of Obstetrics & Gynecology and Reprod Biology (2012).
Roshanfekr, Daniel, et al. “Station at onset of active labor in nulliparous patients and risk of cesarean delivery.” Obstetrics & Gynecology 93.3 (1999): 329-331.iology (2012).
Best outcomes for first time mothers with unengaged babies were found in this 1999 study:
Roshanfekr, Daniel, et al. “Station at onset of active labor in nulliparous patients and risk of cesarean delivery.” Obstetrics & Gynecology 93.3 (1999): 329-331.