Any cause of hydrops fetalis is a potential etiological factor in a fetal pleural effusion.
In addition to hydrops fetalis, a pleural effusion can be associated with numerous other underlying anomalies:
- congenital cardiac anomalies: ~ 5% of non hydropic pleural effusions 1
- underlying congenital lung anomalies
- chromosomal anomalies 1,3 (can be present in ~ 50% with an additional sonographic abnormality and ~ 12% without an additional sonographic abnormality 9)
- polydactyly: ~ 1% of non hydropic pleural effusions 1
Classically seen as anechoic fluid surrounding one or both the lungs (which are echogenic) - batwing appearance.
Ancillary sonographic features include:
- may show other features of hydrops if it occurs in association
- there maybe presence of polyhydramnios (if severe)
Treatment and prognosis
The clinical course is variable and dependent on etiology. The presence of a pleural effusion early in pregnancy (i.e. first trimester) is often associated with a poor fetal outcome 5.
Management options are also dependent on other underlying factors:
- thoracocentesis and drainage of the effusion: fluid can however reaccumulate within 24-48 hours
- insertion of pleural-amniotic shunts
- 1. Hagay Z, Reece A, Roberts A et-al. Isolated fetal pleural effusion: a prenatal management dilemma. Obstet Gynecol. 1993;81 (1): 147-52. - Pubmed citation
- 2. Weber AM, Philipson EH. Fetal pleural effusion: a review and meta-analysis for prognostic indicators. Obstet Gynecol. 1992;79 (2): 281-6. - Pubmed citation
- 3. Hwang JY, Yoo JH, Suh JS et-al. Isolated non-chylous pleural effusion in two neonates. J. Korean Med. Sci. 2003;18 (4): 603-5. J. Korean Med. Sci. (link) - Free text at pubmed - Pubmed citation
- 4. Yinon Y, Kelly E, Ryan G. Fetal pleural effusions. Best Pract Res Clin Obstet Gynaecol. 2008;22 (1): 77-96. doi:10.1016/j.bpobgyn.2007.09.004 - Pubmed citation
- 5. Hashimoto K, Shimizu T, Fukuda M et-al. Pregnancy outcome of embryonic/fetal pleural effusion in the first trimester. J Ultrasound Med. 2003;22 (5): 501-5. J Ultrasound Med (full text) - Pubmed citation
- 6. Klam S, Bigras JL, Hudon L. Predicting outcome in primary fetal hydrothorax. Fetal. Diagn. Ther. 20 (5): 366-70. doi:10.1159/000086814 - Pubmed citation
- 7. Achiron R, Weissman A, Lipitz S et-al. Fetal pleural effusion: the risk of fetal trisomy. Gynecol. Obstet. Invest. 1995;39 (3): 153-6. - Pubmed citation
- 8. Petrikovsky BM, Shmoys SM, Baker DA et-al. Pleural effusion in aneuploidy. Am J Perinatol. 1991;8 (3): 214-6. doi:10.1055/s-2007-999380 - Pubmed citation
- 9. Waller K, Chaithongwongwatthana S, Yamasmit W et-al. Chromosomal abnormalities among 246 fetuses with pleural effusions detected on prenatal ultrasound examination: factors associated with an increased risk of aneuploidy. Genet. Med. 7 (6): 417-21. Genet. Med. (link) - Pubmed citation