Everything you need to know about internal exams during pregnancy and labour
This is something that brought me a great amount of fear when I was pregnant and there is a great amount of conflicting information out there. When a friend of mine approached me and asked me about it. I decided to pore over all the information out there to bring to you a primer if I may say so about this much dreaded topic. I will try and cite scientific papers so that it is evidence backed.
I have divided this post into three sections. I hope to cover the following topics.
- What is a vaginal/internal examination? When is it usually done? What are the reasons for a vaginal exam during pregnancy? What does the doctor/caregiver hope to understand through an exam?
- Is it even needed before labour? Can it predict onset of labour? What are the risks involved?
- What questions do I need to ask my doctor before consenting to the procedure? What is informed consent?
What is it?
Vaginal/internal examination are physical examinations conducted by the doctor/caregiver to determine cervical changes and progress of labour.
Typically these exams are conducted in three times during your pregnancy:
- Early Pregnancy: Around the 8th week mark. The doctor may do a physical exam for a pap smear or just to identify length, texture, and any abnormalities in the cervix if any.
- Late Pregnancy: In India, doctors begin internal exams around the 36th week mark and often this becomes a weekly routine.
- During Labour: The frequency of internal exams rise to a fever pitch and you are given one every 4-6 hours depending on the protocol of the hospital/doctor/caregiver.
What does one hope to learn from an internal exam?
- Dilation: This measures how open the cervix is on a scale of 1 cms to 10 cms
- Consistency: This measures the consistency of the cervix. Normally, the cervix is smooth, firm, unyielding. While labour kicks in, it becomes softer, "riper", stretchy. This is to prepare the cervix for the effacement and the dilation process.
- Position: During pregnancy due to changing shapes, dimensions, the cervix moves the back, during labour it transitions to the front which makes it more accessible to the doctor/caregiver.
- Station: This is an estimation of how far the baby's head has come down into the pelvis. It is measured on scale of -3 to +3 where -3 means that the head is high and unengaged to +3 where the head is visible during birth
- Effacement: This measures the thickness of the cervix on a scale of 0% to 100% where 0% is thick and long and 100% is paper thin due to the descent of the baby
- Presentation: This helps the doctor/ caregiver identify which part of the body is leading the way. Head or feet (breech)
When is it indicated before onset of labour?
- History of infertility and/or gynaecological problems
- Painful intercourse
- Suspicion of cervical problems, such as scarring or premature labour
- Medical condition that increases risk of preterm labour
- Vaginal infection
- Growth in pelvic area
In a healthy pregnancy, the main reason given by doctors is to see if the cervix is favourable and progressing towards labour.
Is an internal exam needed before labour?
It is surprising that there is such a widespread use of this intervention without good evidence of effectiveness, particularly considering the sensitivity of the procedure for the women receiving it, and the potential for adverse consequences in some settings. (Cochrane Review) ⁸
Although there are reasons why a vaginal examination might be necessary during pregnancy, it’s still an intervention, and every woman should know the risks and benefits before having one. These exams have become such a normalised part of prenatal care that nobody questions them anymore or even feel that they have to understand such an invasive and uncomfortable procedure. There are definitely cases where vaginal exams can be helpful prior to labour, in a healthy term pregnancy they don’t usually provide any necessary information.
Dahlen is one of the authors of a recent review on the routine use of vaginal examinations in labour. The review found no evidence to support or refute the routine use of vaginal exams to improve outcomes for babies or their mothers in labour, and recommended urgent research be carried out on the benefits and possible harms of this practice.¹
In a study published by NCBI suggests that pelvic examinations before term may be a significant contributing factor to the incidence of premature rupture of membranes (PROM). ²
Can an internal exam or vaginal exam predict onset of labour?
Further study has shown that contrary to the mechanistic ideal of a steady curve, cervical opening in natural labour is unpredictable and non-linear (Ferrazzi et al., 2015) ⁹
One of the things an assessment of the cervix cannot do is determine the day and time someone will go into labour. Labour is unique to each person and the gestation is typically 42 weeks and that the due date is an indicator and not a hard and fast date when the baby arrives. No woman is pregnant forever and the baby will arrive on its birthday. Even if you are a few cms dilated during your vaginal exam, that is not an indicator of when the labour will actually kick in. It could be hours or days or even weeks.
A cervix that is soft and dilated today doesn’t suggest that tomorrow or the next day it will ripen or dilate more. One of the things an assessment of your cervix cannot do is determine the day and time of onset of labour. In fact, research has discovered there’s a substance called surfactant, secreted by your baby’s lungs, which triggers an inflammatory reaction in the uterus resulting in labour ³. So the cervix is definitely not a good indicator of what might happen in the future.
Often pregnant women can be slightly dilated (1-2 cms) for weeks before labour actually begins and in other cases, women are well into labour before any dilation begins. Cervical dilation is dependent on factors that are beyond our control.
What actually happens is that instead of telling women that they should relax and go with labour, the underlying message is that labour needs to conform to a particular expected timeframe, rather than accepting all women labour in their unique way. A woman who is 4 cms may dilate completely in less than an hour, when others may dilate very slowly until 7 cms, then complete dilation in a hurry. Measurements do not indicate how labour will unfold. Also, cervical dilation does not occur in a round, uniform circle fashion. WHO’s recommendations recognize that the previous benchmark for cervical dilation rate at 1 cm/hr during the active first stage of labour may not apply to all women and is inaccurate in identifying those at risk of adverse birth outcomes. A slower cervical dilation rate than this benchmark should not be seen as a routine indication for interventions to accelerate labour or expedite birth.
Why is the vaginal exam/internal exam performed during labour?
- To monitor “progress of labour”
- To monitor heartbeat of unborn child. This is done only if the caregiver is unable to get a good trace using other non-invasive methods
- To break the waters or artificial rupture of membranes (AROM): This is done to accelerate labour.
What are the key risks involved?
- Bacterial infection: Vaginal exams/Internal exams when performed properly is not harmful to the baby but it can be a cause for infection if the waters are already broken. It can also induce labour.
- Premature labour due to stimulation of cervix and stripping of membranes: A study published in the British medical journal showed that there is rapid increases in prostaglandin production after a vaginal examination and amniotomy (breaking of waters)that leads to initiation of labour. ⁵
- Premature rupture of membranes (PROM):
- “Failure to Progress”: There is an unsaid expectation from the body to show progress. In the absence of which, the woman can be termed as "failure to progress" which is a leading cause for cascade of interventions
- Vaginal exams can interrupt/stall labour: During labour, your body produces oxytocin, which causes contractions and dilates the cervix. During this stage of labour, you need a calm, private and safe environment, with supportive caregivers, so that you can access the part of your brain that allows labour to progress normally for you. If you become distressed or upset, your body will produce noradrenaline, which counteracts oxytocin, effectively slowing down or stalling labour. VEs can be painful and invasive, at the very least disappointing when you have been labouring for some time and hear a number that doesn’t equate to progress in your head. In these situations, your fight or flight response can be stimulated, slowing or stalling your contractions – even reversing cervical dilation.
In a randomised controlled trial of routine cervical examinations in pregnancy published in The Lancet, it concluded that its findings do not support routine use of cervical examinations during pregnancy ⁶
Why do women find internal exams uncomfortable and undesirable?
- Being put on a clock and an unsaid expectation to “progress” at a certain rate
- No control or autonomy over what is being done to their bodies
- Often times consent is ignored because this is a “normalized” part of labour
What questions to ask the doctor before consenting to the procedure?
If your care provider insists on a vaginal/internal exam, it is important to know why, what, how, when of it.
- What is the specific reason for the exam?
- What is it that the test will reveal or find out?
- How it will alter anything for your pregnancy or birth?
- When will it be done?
- Is there any evidence or scientific papers that support the need for the exam?
If you aren’t convinced there’s a good reason for the exam, then you are within your rights to decline it, or to request a second opinion.
If you decide to go ahead with the exam, make sure your bladder is empty, and that you are warm, comfortable and properly covered. Your privacy must be ensured and no extra staff should be present unless you wish. Breathe deeply and relax your pelvic floor muscles to limit discomfort.
Having an internal examination during pregnancy should be something you decide only after having all the facts. The procedure must be explained to you and your informed consent must be obtained every single time before the procedure.
Your doctor/caregiver should give you the following details:
- Tell you why they want to check your cervix
- Inform you what is involved and what it may feel like
- Reassure you that the vaginal examination can be stopped at any time
- Let you know someone can be with you
- Ensure your privacy is maintained
For instance, women are asked if the doctor/midwife can do a vaginal examination to check how far long in labour they are. This is not asking for informed consent.
This brings us to an end on all things internal exam during pregnancy and labour. Let us know if you had an internal exam? When? And if you had a say in the matter and if informed consent was taken.
- Ferrazzi E, Milani S, Cirillo F, Livio S, Piola C, Brusati V, Paganelli A. Progression of cervical dilatation in normal human labor is unpredictable. Acta Obstet Gynecol Scand. 2015 Oct;94(10):1136-44. doi: 10.1111/aogs.12719. Epub 2015 Sep 3
- Other Sources: