Best Evidence Topics
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Emergency caesarean section in cardiac arrest before the 3rd trimester.

Three Part Question

In [a second trimester pregnant female in cardiac arrest] is [emergency caesarean section effective] at [improving outcome for mother and foetus]?

Clinical Scenario

A pregnant patient who was the restrained passenger in a motor vehicle accident was brought in my ambulance 10 minutes ago unconscious, all of a sudden she goes into cardiac arrest. CPR is commenced and you wonder if the next thing to do would be a caesarean section but she is only 24 weeks pregnant.

Search Strategy

Medline 1950 to 07/2008 using Ovid Interface
EMBASE 1980-2008 Week 1
The Cochrane Library
[{exp pregnancy/ OR OR exp pregnancy complications/ OR pregnancy} AND { exp heart arrest/ OR cardiac} AND {exp caesarean section/ OR caesarean} AND { OR OR exp cardiopulmonary resuscitation}] LIMIT to human and English language

Search Outcome

15 papers were identified of which 4 were relevant to the issue of caesarean section in the second trimester.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Mallampalli A, Guy E,
Pregnant women in cardiac arrestReview of literature States that there is little information on whether the delivery of a pre-viable foetus would improve maternal outcome as the haemodynamic benefits would not be expected to be as significant as later in pregnancy. Perimortem caesarean may improve maternal outcome in cardiac arrests. The report does not recommend caesareans in cases of <24 weeks gestation and suggests CPR should be continued to achieve restoration of the circulation of the mother. The review primarily deals with medical support following brain death in the mother in order that the foetus can reach full term. The review also states that the primary goal of a Perimortem caesarean section is the survival of the foetus.
Strong TH, Lowe RA,
Pregnant patients in cardiac arrest over 24 weeks pregnantReviewInitiate procedure if it is clear mother has little chance of recovery continue resuscitation for maximum uteroplacental perfusionIf foetus is over 24 weeks carry out a PMCS in the hope of foetal salvage.No search strategy Aim of PMCS is seen to be foetal salvage as opposed to restoring circulation to the mother
Mallampalli A, et al,
Pregnant patientsNarrative reviewPrimary goal is foetal salvage, not known if PMCS on gestation less than 24 weeks will improve outcome as haemodynamic effects caused by the gravid uterus may not have come into playA perimortem caesarean section is not recommended if the gestational age is less than 24 weeksNo search strategy Views PMCS in terms of foetal viability
Atta E, Gardner M,
Pregnant patientsNarrative reviewIt is not known if perimortem caesarean section carried out earlier in pregnancy to produce a pre-viable foetus is beneficial to maternal outcome.It may be reasonable to perform a PMCS when the gestational age is 20 -23 weeks.No search strategy


In a pregnant patient presenting with cardiac arrest a fundus that extends quite high above the umbilicus causes aortocaval compression and can make CPR difficult and ultimately unsuccessful. The gestational age that this will usually occur as commonly quoted in the literature found for this BET will be from approximately 20-24 weeks. However, it is important to note that in the literature found from the search for the BET concerning fundal height (see BET on is fundal height an accurate indicator of gestational age at it has been found that the fundus may reach the umbilicus between 15 and 19 weeks gestation. A caesarean section performed within 4 minutes of the arrest has been known to increase maternal survival. There is still much debate over the issue of what age a foetus can survive and this procedures ultimate aim is that of a life-saving one for the mother, not of foetal salvage.

Clinical Bottom Line

If the fundus extends high above the level of the umbilicus carry out a PMCS regardless of the gestational age and hence viability of the foetus as there is a high possibility that circulation may be restored to the mother.


  1. Mallampalli A, Guy E. Cardiac arrest in pregnancy and somatic support after brain death. Critical care medicine. 2005:33(10);325-32
  2. Strong TH, Lowe RA. Perimortem caesarean section. American Journal of Emergency Medicine. 1989:7(5);489-94
  3. Mallampalli A, Powner DJ, Gardner MO. Cardiopulmonary resuscitation and somatic support of the pregnant patient. Critical Care Clinics. 2004:20(4);5-8
  4. Atta E, Gardner M. Cardiopulmonary resuscitation in pregnancy. Obstetric & Gynecology Clinics of North America. 2007:34;585-97