Amniotic Sac Is Ruptured by Doctors (and Midwives) More Often than Necessary, According to Studies and Experts
We are all appreciative of the advances that have been made in safely delivering infants in our modern age, which have increased the number of live births, compared to many decades ago. However, just like doctors can get carried away doing unnecessary medical interventions and prescribing drugs that aren’t really needed, in general and specialized medicine, the specialty of obstetrics is no different.
An expectant woman does well to gather all the information she can about labor and delivery, before her due date arrives. Quite unfortunately, in regular hospitals, it is more the norm than the exception to subject mother and baby to procedures that go too far, and which can result in unnecessary complications for mother and infant.
Such is the case with amniotomies — the manual rupturing of the amniotic sac, using various instruments, including a crochet-like stick referred to as a “hook.” Amniotomies, or artificial rupture of membranes (ARM), have become commonplace in hospitals worldwide, including in the United States. But women and experts alike have begun calling attention to the fact that they are being performed far too often, even when there is no medical indication to do them.
Why Do Doctors/Midwives Perform Amniotomies?
Amniotomies are done in an effort to speed up a spontaneous (naturally induced) labor that is taking too long, or even labor of average duration. In a hospital-induced labor, they are done because the amniotic sac membranes can prevent the artificially induced contractions from effectively pushing the baby out into the birth canal.
Additional medical indications for ARM include post-term pregnancies and pregnancy-induced hypertension (PIH) in the mother.
In spontaneous labor, doctors have also been of the belief that by rupturing the amniotic sac and letting the amniotic fluid drain out, the baby’s hard head can then put more pressure on the cervix, causing it to dilate more quickly.
But a Cochrane review (published in 2013) of existing medical literature and studies found that the length of the first stage of labor (the time between the first contraction and when your cervix is fully dilated) is not decreased by performing an ARM. The review also found a possible slight increase in births by caesarean section following the procedure. Reviewers went on to recommend that amniotomies not be regularly done for labor which is progressing at a normal pace, or even for labor that is progressing slowly.
Risks of Amniotomy for Mother and Baby
In addition to the slightly greater probability of a caesarean birth, there are other unwanted and possibly serious effects involved with getting an amniotomy. These include:
- Contractions may become more intense, and the pain of contractions and pain felt in the cervix will likely be stronger
- Contractions may be less effective, slightly increasing the need to use synthetic oxytocin, to augment labor (source: National Center for Biotechnology Information, National Institutes of Health)
- It adds stress for the infant, who feels the walls of the uterus collapsing on him/her. This fetal distress is confirmed by studies that have shown the baby’s heart rate increases and blood flow is altered after an ARM is performed (Fok et al, 2005)
- In cases where baby passes its first stool, meconium, the risk of infection to the infant is greater, as there is less fluid in the amniotic sac to dilute stool and carry it to placenta for removal; also, amniotic fluid contains antimicrobial peptides, which help to guard against infections
- Umbilical cord prolapse is more likely: cord can drop out into vagina or get lodged next to baby’s head before infant is born; cord can get compressed, reducing oxygen supply to baby. This may require a caesarean section and immediate birth, to limit possibility of harm from lack of oxygen to infant
- Placenta gets compressed during contractions, thereby reducing oxygen supply to baby
- Blood vessels that run through amniotic membranes may be ruptured, leading baby to lose blood and causing another emergency situation
- Instrument used by doctor or midwife to perform ARM may inflict injury to the baby’s scalp, forehead, eyelids or shoulders. These injuries can leave superficial pink marks on baby’s skin, or even bloodied lacerations from skin being cut
For all these reasons, increasing numbers of health professionals, as well as expectant mothers, are steering away from doing/getting amniotomies when there is no clear medical indication for them.
Barring manual intervention, your amniotic sac is most likely to rupture before your cervix is fully dilated, as the contractions push the lower end of the sac into the vagina. The pressure on the amniotic membranes, combined with the pressure applied by the baby’s head, will cause the sac to burst.
In rare cases, it is even possible for a baby to be born with the amniotic sac intact — that is, the baby will be born in the liquid-filled bubble where he or she resided inside your uterus. This is known as an “en caul” or “veiled” birth, and there is nothing wrong or dangerous about it. Your baby is still continuing to receive oxygen and nutrients from your placenta, which is still attached to you at this point.
En caul births are more common in water births and among premature babies. In addition, when an infant is born by caesarean section, it may be beneficial to leave the baby inside the amniotic sac until he or she is removed from the womb, as that will protect a fragile preemie from pressure trauma inside the uterus.
Points to Discuss with Your Doctor or Midwife Before Your Due Date
The best plan of action, to insure that things are done according to your wishes when you have your baby, is to discuss specifics with the hospital doctor, or midwife at a natural birthing center or hospital, who will be assisting you with your delivery.
Points to consider are how much freedom you will have to move, to get into a comfortable position and one that is conducive to your baby being in the anterior position, which will facilitate birth the most. The anterior position is when the infant’s face faces your pelvis. This is in contrast to the posterior or occiput posterior (OP) position, where the back of your baby’s head is facing your pelvis. A posterior position is not ideal, as it may cause the amniotic sac to tear prematurely, being that the back of your baby’s head is pressing against your pelvis, so that when contractions come, the pressure can lead the waters in front of the infant’s face to burst. In the anterior position, the infant flexes his or her head down during a contraction, tucking the chin into their chest, thus leaving more space on the back of the head.
Instead of turning to artificial means of helping your baby be born, all you may need to do is let gravity help, by assuming an upright position during childbirth (or even a squatting position, which is favored by many midwives in natural birthing centers). Some midwives may also use other natural techniques, such as rocking your hips gently, to help baby ease into the anterior position.
Ask the person who will be assisting you how they feel about letting childbirth progress naturally, even when it’s slow. Many moms don’t want to feel any pressure that they need to be finished giving birth by a certain length of time.
By Cynthia Sanchez. A graduate of the University of Washington, Cynthia has extensive experience writing about health and wellness topics for different media.