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Amniotomy, also known as Artificial Rupture of the Membranes
(AROM) is the surgical rupture of fetal membranes to induce or expedite labor.
Amniotomy is used to start or speed up contractions and,
as a result, shorten the length of labour.
Artificial rupture of the amniotic membranes during labour,
sometimes called amniotomy or ’breaking of the waters’ was introduced in the
mid-eighteenth century, first being described in 1756 by an English
obstetrician, Thomas Denman (Calder 1999). Whilst he emphasized reliance on the
natural process of labour, he acknowledged that rupture of the membranes might
be necessary in order to induce or accelerate labour (Dunn 1992). Since then,
the popularity of amniotomy as a procedure has varied over time (Busowski1995),
more recently becoming common practice in many maternity units throughout the
UK and Ireland (Downe 2001; Enkin 2000a ; O’Driscoll 1993) and in parts of the
developing world (Camey 1996;
Chanrachakul 2001; Rana 2003). The primary aim of amniotomy is to speed up
contractions and, therefore, shorten the length of labour.
The first recorded use of amniotomy in the United States was in 1810; it was used to induce premature labor. Amniotomy and other mechanical methods
remained the methods of labor induction most commonly employed until the 20th
century. Amniotomy, or artificial rupture of the amniotic membranes, causes
local synthesis and release of prostaglandins, leading to labor within 6 hours
in nearly 90% of term patients. Turnbull and Anderson found that amniotomy
without additional drug therapy successfully induced labor in approximately 75%
of cases within 24 hours.
was associated with a reduction in labour duration of between 60 and 120
minutes in various trials
was a statistically significant association of amniotomy with a decrease
in the use of oxytocin: OR = 0.79; 95% CI = 0.67-0.92 in several
does not involve any type of medication to mom or baby and is considered by
some to be the most “natural” means of induction in a hospital setting.
several randomized trials there was a marked trend toward an increase in
the risk of Cesarean delivery: OR = 1.26; 95% Confidence Interval
reviewers suggest that amniotomy should be reserved for women with
abnormal labour progress.
15 studies containing 5583 women there was no clear statistically
significant difference between women in the amniotomy and control groups
in length of the first stage of labour
does not support routinely breaking the waters for women in normally
progressing spontaneous labour or where labours have become prolonged.
- [Once membranes are broken} most obstetricians want the
baby birthed as soon as 6 hours post-onset to reduce the risk of infection
from the introduction of bacteria into the vagina due to repeated vaginal
exams. Some obstetricians will wait as long as 24 hours but that is less
common. In contrast, midwives, who do not routinely perform cervical
checks unless specifically indicated or requested, thus limiting the
chance of infection, will often allow up to 36-48 hours as long as no
indications of an active infection are present.
large study of 3000 women’s opinions of the intervention was conducted by
the National Childbirth Trust (1989). Two thirds of the women in this
study reported an increase in rate, strength and pain of contractions
following membrane rupture; they found these contractions more difficult
to cope with, needed more analgesia and felt that the physiology of labour
there is concern that labour is slowing down, benign measures to intensify
contractions such as positional changes and movement may prevent the need
for more invasive interventions (Simkin 2010). The Cochrane review of
maternal positions and mobility during first stage labour supports the
positive impact mobility has in shortening labour (Lawrence et al. 2009).
et al. 2007 studies showed that amniotomy is not an effective method of
shortening spontaneous labour and increases the risk of caesarean section
and more fetal heart abnormalities
For further exploration on your part
What do you think? Is this an option you would consider, or that you chose for during your birth?
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