From the Guidelines
Recurrent cases of hydrops fetalis in consecutive pregnancies can be caused by genetic disorders, such as alpha thalassemia major, where both parents carry the alpha thalassemia trait, resulting in a 25% chance of affected pregnancies, as well as other genetic causes, infections, and structural cardiac defects. The most common causes of nonimmune hydrops fetalis (NIHF) include genetic disorders, such as alpha thalassemia major, which is particularly prevalent in Southeast Asian populations 1. Other genetic causes include lysosomal storage diseases, chromosomal abnormalities, and certain metabolic disorders. Infections like parvovirus B19, cytomegalovirus, or syphilis can also cause hydrops in multiple pregnancies if the mother experiences recurrent infections 1.
Some key points to consider in the evaluation of NIHF include:
- Detailed ultrasound monitoring, including fetal echocardiogram
- Maternal history, including family history, medications, and exposures
- Middle cerebral artery Doppler evaluation for anemia
- Fetal karyotype and/or chromosomal microarray analysis
- Testing for infections, such as parvovirus, cytomegalovirus, and syphilis
Women with two consecutive pregnancies affected by hydrops should undergo comprehensive genetic counseling, detailed ultrasound monitoring in subsequent pregnancies, and possibly invasive testing, such as amniocentesis or chorionic villus sampling, to identify the underlying cause 1. Early identification of the specific cause is crucial for appropriate management and potential interventions in future pregnancies. It is essential to prioritize the health and well-being of both the mother and the fetus, and to consider the potential risks and benefits of different management strategies, including the risk of mirror syndrome, a rare but potentially life-threatening complication of NIHF 1.
From the Research
Possible Causes of Hydrops in Consecutive Pregnancies
- Immune causes, such as fetal anemia due to anti-D, anti-Kell, or anti-c antibodies, can lead to hydrops fetalis 2
- Non-immune causes, including human parvovirus B19 infection, aneuploidy, primary hydrothorax, cardiac causes, cystic hygroma, twin-twin transfusion syndrome, massive transplacental hemorrhage, fetal akinesia, and muscular dystrophy, can also result in hydrops fetalis 2
- Genetic causes, such as lysosomal storage disorders, congenital nephrosis, RASopathies, and other genetic disorders, can lead to non-immune hydrops fetalis 3, 4
Recurrence Risk of Hydrops in Consecutive Pregnancies
- The recurrence risk of pregnancy complications, including preterm birth, gestational diabetes mellitus, gestational hypertension, and preeclampsia and eclampsia, is increased in all subsequent pregnancy groups, including singleton-singleton, twin-singleton, and singleton-twin pregnancies 5
- However, there is no direct evidence on the recurrence risk of hydrops fetalis in consecutive pregnancies, and more research is needed to determine the specific risk factors and causes of hydrops in women who have had previous pregnancies affected by this condition
Factors Influencing the Risk of Hydrops in Consecutive Pregnancies
- Family and obstetric history, as well as pathology examination, can provide clues to establish a diagnosis of hydrops fetalis 3, 4
- Prenatal ultrasound findings, genetic testing, and other factors can also help identify the underlying cause of hydrops fetalis 3, 4
- Routine first-trimester antibody screening and referral guidelines can help reduce the risk of hydrops fetalis in women with red cell alloimmunization 6