Where is the best place to see research about risk of amniotic fluid embolism...specifically the differences of induced/augmented labors vs. non-medicated?
Here are links to the abstracts of 3 studies finding an association between induction and AFE:
I'm not aware of any studies finding an association with augmentation, but that may be because very large populations are needed to detect a difference in rare outcomes, which means that studies will be of national stats. National statistical databases are likely to collect stats on induction but probably not of augmentation.
virginia howes, miss
I am midwife in the UK and have long respected your work. I run the Facebook page "One Born Every Minute-The Truth" which is a protest against the medical models of childbirth that are shown on TV. We have recently been talking about what I believe is a mythe. That the placenta will age and that the ageing process will end in a dead baby if labour in an otherwise normal pregnancy is not induced after 42 weeks. i would very much like to know (and I have looked) if there is any evidence for this that I have overlooked. Midwives are telling women this along with Dr's and I want to know what exactly does exist.
There are doubtless changes that end with initiation of labor, of course, but I am not aware of research that establishes that the placenta begins a progressive deterioration at term that will kill the fetus. I think this is a theory to explain antenatal deaths with no obvious cause. Antenatal testing is predicated on that theory, that is, that testing will pick up the decline in fetal status due to a deteriorating placenta thereby enabling rescue. Unfortunately, that has not turned out to be the case. Even in at-risk women, the few RCTs of antenatal cardiotocography failed to improve outcomes. In fact, in all four trials, there were more deaths in the results-disclosed arm. Low amniotic fluid volume has some correlation with outcomes, but the false-positive rate is too high to make it useful. The failure of antenatal testing of fetal wellbeing suggests that the theory may be wrong, nor does it account for sudden events or for what an autopsy might have revealed that explained the demise.
As for the increase in stillbirths, according to U.S. national stats, the rate holds steady in weeks 40 and 41 at 0.9 per 1000 and rises to 1.7 per 1000 in week 42. That still doesn't tell us what the rate would be in a healthy woman. The U.S. analysis found that the risk of fetal death varied according to race, marital status, and extremes of maternal age, characteristics that may be markers for other factors such as poverty, substandard care, or prior cesarean. The stats also wouldn't pick up other factors such as chronic maternal medical conditions, events such as placental abruption or pre-eclampsia, or other correlating factors such as smoking or maternal underweight.
If induction were harmless, it might still make sense to induce prophylactically in the hope of preventing stillbirth, but it isn't. In 1st-time moms it roughly doubles the likelihood of c/sec. (I know the common belief is that it doesn't. We refute the argument in the induction chapter in Optimal Care in Childbirth, but I refer you to the book because it is a longer and more complex argument than I want to go into here.) The excess c/sec rate has potential adverse consequences for moms and babies in the current pregnancy and in future pregnancies, including increased risk of stillbirth.* Meanwhile, the simplistic solution of preemptive induction prevents medical model thinkers from considering that factors associated with antepartum demise, such as abnormalities of placental attachment, chronic medical problems, smoking, maternal underweight, and racial disparities, can be ameliorated without imposing risks by social support, preventive care, improved management, closer monitoring of high-risk women, and reducing use of cesarean surgery. We could do a lot more good without doing harm by taking that course instead.
*The link will take you to the Childbirth Connection website. I happen to know that an update of the c/sec content is in process and should be up within the next month or two. I assume it will have the same URL.