In the hands of a skilled operatorand using ultrasound guided technique , amniocentesis carries a risk of fetal loss of 1% in singleton pregnancies, and 3% in multiple pregnancies.
A variety of types of fetal damage have been reported following amniocentesis. Complications are rare but include :
- damage of one eye, causing blindness
- damage to the brachial plexus
- pneumothorax
- puncture of a fetal vessel
A risk of lung hypoplasia has also been reported.
Notes:
- a prospective study found that the procedure-related risk of spontaneous pregnancy loss after mid-trimester amniocentesis was 0.06% with an upper limit of 0.49%. The study authors noted that this figure was lower than the traditionally quoted 0.5% (1)
- however a commentary concerning this study noted that the results of the study were not easily generalisable because of missing details e.g. the experience of clinicians, the needle size used. The commentary also noted that the absolute risk of miscarriage in women undergoing amniocentesis in this study was 1% (between 16 and 24 weeks gestation) compared to a 0.94% rate in the control group who did not undergo amniocentesis. The the risk of 0.06% (in this study) was therefore the additional risk attributable to the procedure (2)
Reference:
- Eddleman KA et al.Pregnancy loss rates after midtrimester amniocentesis. Obstet Gynecol. 2006 Nov;108(5):1067-72.
- Commentary. Evidence Based Medicine 2007;12:85.