Table 2.
Clinical features, risk factors, and outcome of amniotic fluid embolism.
| Clinical features | % in series/report | RR/aOR |
|---|---|---|
| Cardiac arrest | 30–87%, 40%‡ | – |
| Shock/severe hypotension | 32.5%, 63%‡ | – |
| Respiratory distress, SOB‡ | 14.2%–72%, 62%‡ | – |
| Coma/seizure | 1.7%/15%‡, 10–48% | – |
| Disseminated intravascular coagulation, haemorrhage | 22–83%, 62%–65%‡ | – |
| Foetal distress/compromise | 43%‡, 50–100% | – |
| Risk factors - Age ≥35 years | 5.7%, 38%# | 2.3, 2.15#, 1.9†, 4.8⁋ |
| African/other American (versus White American) | – | 2.4/2.3Ѱ |
| Polyhydramnios | 19.0% | 3.8, 3.0† |
| Blunt abdominal trauma and surgical trauma | – | – |
| Procedures—pregnancy termination, amniocentesis, etc. | – | – |
| Pre-eclampsia/eclampsia (pre-existing hypertension) | 7.0%/75.5% | 1.7/16.3, 1.4/11.5†, 7.3/29.1Ѱ, (9.5) Ѱ |
| Induction of labour (all methods) | 41%#, 47%‡ | 2.53#, 3.86‡, 3.5/5.6Ѱ |
| Medical induction of labour | 4.9% | 1.9, 1.8†,1.9/3.4⁋1 |
| Placenta praevia/abruption | 21.6%, 3%# | 5.0, 5.75#, 3.5†, 10.5/13.3⁋2,15.6/17.3 Ѱ, 30.4/8.0 Ѱ |
| Foetal distress | 6.5% | 1.5, 1.7† |
| Instrumental delivery | 4.8% | 7.6, 5.9/2.9†2, 40.6⁋3, 1.9/2.9/4.3/5.9/8.9/11.6/36.0 Ѱ |
| Vaginal breech delivery | – | 15.1 Ѱ |
| Caesarean delivery | 7.4% | 11.7, 12.5/8.6†1, 23.3Ѱ, 8.1/48.5⁋4, 8.84‡ |
| Cervical laceration/uterine rupture | 56.2% | 12.7, 3.8† |
| Manual removal of placenta | 25% | 19.4⁋ |
| Multifoetal pregnancy | 9.3%, 12%#, 8%‡ | 2.5, 5.3 Ѱ, 7.75#, 10.9‡ |
| Gestational age <37 weeks | – | 9.7 Ѱ |
| Postdated pregnancy | 5.1% | 1.8 |
| Foetal macrosomia (≥4500 g) | 4%# | – |
Compiled from Refs. [[24], ∗[25], [26], ∗[27], [28], ∗[29], [30]]. Source of figures as indicated Ѱ [25], † [26] (†1cephalic/non-cephalic, †2forceps/vacuum), ‡ [28], # [29], ⁋ [30] (⁋1medical induction (ns)/vaginal PGE2 induction, ⁋2placenta praevia/abruption, ⁋3instyrumental/breech, ⁋4caesareran section before (ns)/after labour), unmarked from Refs. [24,27].