Amniotomy: To Break or Not to Break!

Amniotomy: To Break or Not to Break!

Approximately 10% of women will have their water break before the onset of labor. So for the other 90% out there, they will either face the choice of an amniotomy (breaking of the amniotic sac) or have their membranes rupture on their own, called spontaneous rupture of the membrane (SPOM).

Why do I even bring this subject up? One of my doula friends, Nikita, was attending a birth last week where there was great debate regarding if and when the mother should have her membranes ruptured by the doctor. After much time and discussion, the client opted for this procedure. She was fortunate enough to have a well educated birth doula with her to explain the pros and cons of such an intervention. For those forging forward on their own, here is a breakdown of why you may or may not want this intervention should you be confronted with this decision.

What is an amniotomy?

This is a procedure that is done to artificially rupture of the membrane (AROM) also known as “breaking the water.” This should not be attempted by anyone other then your care provider. To do this, your care provider will insert an amniotic hook (looks like a crocheting needle) into the vagina to perforate the amniotic sac.

Why it’s done?
There are a few reasons why a care provider may choose to rupture the mother’s membranes.

*Enables care practitioner to insert an IFM (Internal Fetal Monitor) if he or she does not feel that the External Fetal Monitor is giving an accurate reading.

*If there is concern about fetal distress, this allows care provider to view the amniotic fluid to see if there is maconium.

*Progress dilation. Without the pool of fluid surrounding the baby, it is believed the baby can descend deeper into the pelvis and apply more direct pressure on to the cervix increasing dilation.

*May help move labor along. The mechanism of action behind amniotomy is thought to be the release of prostaglandin E2 (PGE2) and rise in oxytocin level. Which will therefore stimulate stronger uterine contractions. It is also important to consider the timetable the care provider is judging the need to “speed things along.” The WHO (World Health Organization) defines primiparous women (first time moms) in labor for more then 18 hours as prolonged labor. If the mother has only been in labor a 6 or 8 hours, then there may not be a need to push her quicker then her body is ready to move.

However, I have sometimes advised my doula clients to use this option in two scenarios. One scenario being that the care provider give the laboring mother two options- starting pitocin or breaking the water. Depending on where the mom is in labor- breaking the water can be a good way to avoid the use of pitocin and help move the mother into a more consistent labor pattern. While the use of pitocin and an amniotomy are both interventions, pitocin tends to require the need for more immediate interventions. For example, when using pitocin, the mother will be hooked up to an IV and require full time fetal monitoring. Some hospitals also have a rule that once pitocin is administered, the mother is restricted to the bed. That said, I would not recommend breaking the bag of water too early in labor.

The second scenario in which I have advised breaking the water is if the mother is in transition (8-10cm), and she is in pain and needing a final push to reach the end of labor. Rupturing the membranes at this point can speed things along rapidly by removing the fluid filled bulging bag and adding extra pressure to the cervix to reach full dilation.

Are there Risks to Rupturing the Membranes?

*Increased chance of cord prolapse. When the bag is ruptured there is a chance of the cord slipping between the baby and through the cervix as the water releases out. This would cause compression on the cord, which compromises the baby’s oxygen supply and is very dangerous for the baby. Cord prolapse occurs in 0.6% of deliveries

* Once the bag of membranes is ruptured, the mother’s body will continue to produce amniotic fluid, however, the buoyancy created in uterine is no longer there. The baby no long has a cushion of fluid which helps him or her shift and move easily to adjust in the pelvis to find the best fit for the head to apply pressure to the cervix.

*Increased chance of cord compression. Drawing on the same theory stated above- the lack of intrauterine buoyancy being diminished- the cord can get compressed between the baby and the uterine wall or placenta. During the contraction, the uterus squeezes inward applying pressure on the baby to help push the cervix open. Should the cord be in a precarious place, there could be a compression of it and it would momentarily cut off the oxygen supply to the baby. A certain amount of this is normal and can be remedied by shifting the mother and baby. Although prolonged periods of this cord compression can cause fetal distress.

*Increase chance of introducing infection with the protective barrier gone

*Labor contractions are often perceived as much more painful once the water has broken

*The “time clock” starts. Many care providers would like to see the baby out within a certain amount of time ounce the membranes have ruptured. This applies to both spontaneous rupture as well as artificial rupturing. Some care providers I have worked with are willing to stretch the rules -which is usually 24 hours after rupture- if the mother and baby are not showing any sign of fever or distress. I recommend checking with your provider ahead of time to find out her/his protocol on this situation.

*Increased risk of Caesarean section. A study put out by the Cochrane Review, a respected worldwide source of information about evidence-based care, stated “Nine trials involving 4370 women reported this outcome. Women in the amniotomy group had an increased risk of delivery by caesarean section compared to women in the control group.”

What if my water doesn’t break on it’s own?

Most care providers are going to break the bag before delivery if it has not ruptured on it’s own. There is a rare occurrence called being born “in the caul” which means the baby is born in an intact amniotic sac. It is supposed to be an auspicious sign. Some believe this is harmless and the caul or veil of membranes can easily be wiped away. Others are concerned that the baby will try to take the first breath and ingest amniotic fluid that may have meconium present. Although, many sources I have come across have rebutted the idea of the baby in the fluid as perfectly fine.

For those interested- here is the link to a site that shows a series of pictures of a baby being born in the caul

Final thoughts
The Cochrane review concluded “There were 14 studies identified, involving 4893 women, none of which assessed whether amniotomy increased women’s pain in labour. The evidence showed no shortening of the length of first stage of labour and a possible increase in caesarean section. Routine amniotomy is not recommended for normally progressing labours or in labours which have become prolonged.”

Just like with any intervention, it is important to weigh the risks versus the benefits. I also strongly advise expectant parents to discuss with their care provider what the protocols are for an amniotomy.

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