Baby Not Engaged? Wondering When Your Baby Might Engage?

In the third trimester, it seems there is so much focus and anticipation on a baby being engaged, so firstly, lets understand what being ‘engaged’ really means.

When your baby descends into your pelvis, how far it has descended is measured by the ‘station’, with 0 station being engaged. When a baby is at 0 station, it’s head is resting at what is called the ischial spines (sometimes just referred to as ‘spines’) which is the narrowest part of your pelvis. If your baby is above the spines, it is not engaged and is measured as a minus number, for example if your baby was 5cms above spines, you would be -5, or if baby was 1cm above the spines, -1. Once your baby descends past 0 station, it’s given a positive number, so if baby is 1cm below spines, it’s +1 and so on.

When Will My Baby Engage?

This is completely up to your baby. Yes, first time babies can engage sooner than second or subsequent, but this does not mean that if your baby doesn’t engage before labour starts, that there is a problem. Even for first time mothers, babies can engage at labour, with the early contractions helping to bring them down lower into your pelvis. So there is no formula at all to work this out, just when your baby is ready. It’s nothing to do with your body’s ability to birth or your baby being cheeky! Your baby knows when it’s the right time and will engage when he’s good and ready – so trust your body and trust your baby that they will work in unison when the time is right. Your body is designed to labour, mother nature has it worked out really well, I think we’d be in trouble as a species if our babies didn’t engage and our bodies didn’t go into labour eventually!

If My Baby Isn’t Engaged, Does It Mean It’s Too Big For My Pelvis?

Not at all. In the small number of cases where the baby doesn’t engage even at 41-42 weeks, it’s more likely that your baby has adopted a tricky position in your pelvis rather than the baby being too big for your pelvis, remembering that it simply still may be that your baby just isn’t ready to engage. For those babies who do get in a posterior or other tricky position, the spinning babies website is brilliant for helping malpositioned, posterior or breech babies, and you can also also seek alternative therapies like chiropractic and accupuncture to help with position. The spinning babies site is a great resource regardless, as it helps the baby get into the best position for birth, called ‘optimal fetal positioning’.

Also, there are two great articles on BellyBelly you must read if you are concerned about your baby’s size or your pelvis size:

Pelvises I Have Known and Loved

Small Pelvis? Big Baby? The Truth About CPD

What About Inductions?

Inducing a high baby can be disastrous – not only do inductions already increase the risk of fetal distress and caesareans, but if the waters are broken with a high/unengaged baby, cord prolapse is a big risk as the cord could drop below the baby’s head (as the head isn’t near the cervix to block it) and the cord can prolapse through the vagina. A full term pregnancy is up to 42 weeks, so given your baby is healthy and you are healthy, there is no reason to schedule an induction at least until then, to give your baby the best chance at being born on the day she / he decides is the right time.

To give you an idea, a baby induced at -5 station will give you a 70-80% risk of a caesarean section. So inductions are best avoided, and trust and waiting is the best medicine.

Will I Need A Caesarean?

There is a very low chance you will need one if you just wait and see – you are more likely to have one if you are induced. There will be a very small number of women who have a baby in a position too tricky to be born vaginally, but this can happen if your baby is engaged or not. Not being engaged does not mean this will happen to you specifically! If you are worried about position, see Spinning Babies as per above, invest in a copy of the Pink Kit and keep active in your pregnancy and the birth. Walking is great as is swimming (breaststroke or anything else belly down!) and walking the stairs, as it helps moves your pelvis for your baby. Don’t push yourself too much though!

Remember – many women with babies that engage at the time of labour go on to have healthy vaginal births.

Why the Fuss?

Unfortunately, it’s often stated in obstetric textbooks and therefore mentioned by carers that the majority of first babies should engage several weeks before labour.

Ironically, research contradicts this and suggests that approximately 70-75% of babies may not be engaged at the start labour. The research also looks at the rate of ceasareans where the baby is not engaged prior to labour, and found that approximately 85-90% of babies that were not engaged at the onset of active labor were born vaginally. Hardly anything worth worrying about! Considering we know the caesarean rate in Australia is amongst the highest in the world, well above the World Health Organisation’s recommendations, I think we need to spend more time ‘waiting and seeing’ and intervening when really needed. Unengaged babies are not distressed, they are quite happy waiting in there (unless of course there is something else going on) so why act on something that’s not broken? If it’s healthy, there is no point risking it with major surgery which carries major risks unless the risks outweigh the benefits.

Research On Unengaged Babies and Labour

Int J Biol Res Pregnancy. 1982;3(1):8-9.
Incidence and significance of the unengaged fetal head in nulliparas in early labor
Takahashi K, Suzuki K.

Our clinical experience contradicts the traditional view that in the great majority of nulliparas with cephalic presentation the fetal head is engaged 1-2 weeks prior to onset of labor. In 75.4% of the 175 cases fetal head was not engaged in early labor. No significant statistical difference between the unengaged-head group and the engaged-head group was determined for incidence of vaginal delivery, cesarean section for cephalopelvic disproportion, midforceps delivery, mean and low Apgar scores, and birth weight. Thus, absence of engagement is not always indicative of pelvic contraction. Incidence of engagement may depend on the ethnic composition of the patient population.

J Perinatol. 1998 Mar-Apr;18(2):122-5
Labor and delivery in nulliparous women who present with an unengaged fetal head.
Murphy K, Shah L, Cohen WR
Department of Obstetrics and Gynecology, Albert Einstein College of Medicine, New York, NY, USA.

OBJECTIVE: We assessed the relation of fetal station in early labor to subsequent patterns of dilation and descent and to the probability of cesarean delivery.

STUDY DESIGN: We evaluated 132 nulliparous women who were in spontaneous latent-phase labor with singleton, vertex-presenting, term fetuses. For each participant, pertinent variables relating to labor characteristics and mode of delivery and newborn characteristics were recorded. Labor curves were drawn and analyzed.

RESULTS: Of the 132 participants, 29 (22%) presented with an engaged fetal head, and 103 (78%) presented with an unengaged fetal head. In the unengaged group, 15 (11%) presented with a floating fetal head (-3 station or above), and 88 (67%) presented with a dipping fetal head (-2 or -1 station). A floating head in latent-phase labor conferred a longer second stage (p = 0.02), a trend to more active-phase labor disorders (p = 0.06), and a greater risk of cesarean delivery. Overall, 12 patients (9%) underwent primary cesarean section: 2 (6.9%) from the engaged group, 6 (6.8%) from the dipping group, and 4 (27%) from the floating group (p = 0.042).

CONCLUSION: Most nulliparous women in this study presented in labor with an unengaged fetal head. Those with a floating fetal head demonstrated higher rates of cesarean section than those with dipping or engaged heads in early labor. [Overall 90.3% delivered vaginally.]

Obstet Gynecol. 1999 Mar;93(3):329-31
Station at onset of active labor in nulliparous patients and risk of cesarean delivery
Roshanfekr D, Blakemore KJ, Lee J, Hueppchen NA, Witter FR
Department of Gynecology & Obstetrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.

OBJECTIVE: To determine whether term nulliparas with an unengaged vertex presentation at onset of active labor have a higher risk for cesarean delivery.

METHODS: A retrospective cohort of 1250 randomly chosen nulliparous patients at 37-42 weeks’ gestation who delivered between 1988 and 1989 were selected. Four hundred forty-seven patients were excluded because of nonvertex presentation, cesarean delivery before active phase of labor, multiple gestation, delivery at less than 37 weeks’ or greater than 42 weeks’ gestation, induction of labor, or missing charts. For the purpose of this study, active labor was defined as regular contractions with cervical dilatation of at least 3 cm. The station at onset of active labor was recorded. Engagement was considered to be at station 0 or below.

RESULTS: Of the 803 patients in the study group, 567 presented unengaged [70.6%] and 236 patients presented engaged [29.4%]. The cesarean rates differed significantly between the two groups: 14% of those unengaged compared with 5% of those engaged (chi2 = 11.9, P < .001). After adjusting for confounding variables, engagement at the time of onset of active labor was associated with lower risk of cesarean delivery (odds ratio .512, 95% confidence interval .285, .922).

CONCLUSION: Eighty-six percent [86%] of nulliparas with an unengaged vertex at onset of active labor delivered vaginally. Engaged vertex at the onset of active labor was associated with a lower risk of cesarean delivery.

Diegmann EK, Chez RA, Danclair WG. “Station in early labor in nulliparous women at term.” J Nurse Midwifery. 1995 Jul- Aug;40(4):382-5.

Takahashi K, Suzuki K. “Incidence and significance of the unengaged fetal head in nulliparas in early labor.” Int J Biol Res Pregnancy. 1982;3(1):8-9.

Murphy K, Shah L, Cohen WR. “Labor and delivery in nulliparous women who present with an unengaged fetal head.” J Perinatol. 1998 Mar-Apr;18(2):122-5.

Kelly Winder is a birth attendant (aka doula), the creator of BellyBelly and mum to two beautiful children. Become a fan of BellyBelly on Facebook here or add Kelly as a friend (frequently adding articles and stories) here.