Along with all the beauty and joy of having a baby comes a hefty dose of fear and uncertainty around the delivery. And if you’re a crunchy mama planning a natural childbirth, one topic you’ll want to be familiar with is medical induction.
As you know, modern medicine is keen to treat all kinds of extremely common occurrences during pregnancy as an opportunity to intervene. Often, it starts with being medically induced.
But when push comes to shove, how will you know if induction is the right choice for you? Enter, the Bishop score.
What’s my Bishop score?
To help you figure that out, we’ve put together this handy Bishop score calculator. Just enter the results of your exam and your final score will appear below.
What does the Bishop score predict? What does my Bishop score mean?
The Bishop score, aka cervix score, is a simple method that helps predict how likely it is a full term pregnant mama will achieve a vaginal birth if induction is necessary. It can also help predict whether induction may be necessary.
First published in 1964 by Dr. Edward Bishop, the Bishop score considers five different components of vaginal exam to arrive at a total score that can range from zero to twelve.
A high Bishop score means a higher chance at successful induction. A low Bishop score means a lower chance of successful induction.
Here’s what your Bishop score means:
- 8 or more points. Bishop scores above eight indicate labor will most likely start spontaneously (and soon). It also indicates that if an induction is necessary, it will more than likely be successful.
- 6 to 7 points. Bishop scores in this range aren’t a great predictor one way or the other.
- 5 or fewer points. Low Bishop scores indicate that an induction is less likely to be successful. It also means that a woman who is ill or close to the 42 week mark is more likely to need an induction.
Based on this information and whether you and baby are healthy, you can make a decision on whether induction is a good choice for you.
- For example, a full term woman who has preeclampsia and a low Bishop score may still need to try induction since preeclampsia is so dangerous.
- On the other hand, a healthy woman at 41 weeks who has a low Bishop score may wish to wait until her chances of successful induction are better (or she goes into spontaneous labor).
- A woman at week 42 with a high Bishop score may choose induction over going post-term.
Okay, got your Bishop score? Great! Keep on reading below to see what your Bishop Score says about your likelihood to need an induction.
How does each vaginal exam component affect the Bishop score?
This may be TMI, but it can’t hurt to be an informed mama. Here are Wikipedia’s descriptions for each of the Bishop score components:
- Position The position of the cervix changes with your menstrual cycle and also tends to become more anterior (nearer the opening of your vagina) as labour becomes closer.
- Consistency In women who are in their first pregnancy the cervix is typically tougher and resistant to stretching, much like a balloon that has not been previously inflated (it should feel like the bottom of your chin). With subsequent vaginal deliveries the cervix becomes less rigid and allows for easier dilation at term.
- Effacement Effacement translates to how ’thin’ your cervix is. The cervix is normally approximately three centimeters long, as you prepare for labour and labour continues your cervix will efface till it is fully effaced (paper thin).
- Dilation Dilation is a measure of how open the cervical os is (the hole). It is usually the most important indicator of progression through the first stage of labour and the most important factor in the Bishop score.
- Fetal station Fetal station describes the position of the fetus’ head in relation to the distance from the ischial spines, which are approximately 3-4 centimeters inside the vagina and are not usually felt. Health professionals visualize where these spines are and use them as a reference point. Negative numbers indicate that the head is further inside than the ischial spines and positive numbers show that the head is below the level of the ischial spines.
Is the Bishop Score the be-all end-all?
Of course not. The Bishop score is just one of many indicators of how likely you are to require a medical induction and how likely that induction is to succeed. Many women have low Bishop scores and go on to have a beautiful, natural birth after induction.
We also need to take into consideration the baby’s position. It’s very likely that it’s baby’s position that is responsible for a low Bishop score when a woman is nearing the 42 week mark. Posterior positioning (back of baby’s head towards mother’s back; baby looking at mother’s belly) doesn’t allow baby to put the right kind of pressure on the cervix, the kind of pressure that helps thin and dilate. This is where natural induction techniques that focus on getting baby into position are helpful.
Another important thing to keep in mind is that women efface and dilate at different rates and speeds. One woman may be 50% effaced and 1-2cm dilated 3 weeks before labor while another doesn’t start either until active labor begins.
The take away should be that the Bishop score can help you make the best decisions for you and your baby. If you and baby are healthy, you will want to be sure to have a high Bishop score before considering induction. If you have a high Bishop score and are healthy you may want to try induction or you may want to wait since spontaneous birth is likely around the corner.
History of the Bishop Score
In the 1960s Dr. Edward Bishop developed a pelvic scoring system, now called the Bishop Score, using cervical dilatation, effacement, station, consistency and position to determine how likely an elective induction would be successful and is sometimes used to determine whether an induction may be necessary. Based on his research he concluded that elective induction was most successful in women who had a score of 8 or greater (out of 13).
Other research showed that cervical dilation was the biggest factor in whether an induction would be successful but weighting dilation in the scoring didn’t change the accuracy of predictions.
Later, more information showed that a modified Bishop score, using only dilation, station, and effacement, is as accurate as the full test (a score of 5 being as predictive as the original tests score of 8).
Some practitioners use modifications such as adding a point for the following:
- Presence of preeclampsia
- previous vaginal deliveries (1 point each)
And subtracting a point for each of these:
- Being past her due date (greater than 40 weeks)
- No previous vaginal deliveries
- Suffered a pre-term premature rupture of membranes
There is no evidence to support these modified scores being better than the original Bishop score.
Bishop score bottom line
The Bishop score is a pre-labor scoring system developed by Dr. Edward Bishop and made public in 1964. Birth workers use the Bishop score to make an educated guess on whether induction of labor is necessary.
The Bishop score is also used to predict how likely it is that a full-term pregnant woman will have spontaneous preterm delivery.
The Bishop score is not the be-all end-all. It is just one of many methods birth workers use to predict birth outcomes and the need for interventions. Many women with low Bishop scores go on to have wonderful natural births.