Triploid pregnancy–Clinical implications

Abstract

Triploidy is a life‐limiting genetic aberration resulting from an extra haploid set of chromosomes of paternal (diandric triploidy) or maternal origin (digynic triploidy). Triploidy affects around 1%–2% of all conceptions. The majority of cases is miscarried at early developmental stages. In consequence of genomic imprinting, parental origin affects the phenotype of triploid pregnancies as well as the prevalence and spectrum of related maternal complications. Distinctive ultrasound features of both triploid phenotypes as well as characteristic patterns of biochemical markers may be useful in diagnosis. Molecular confirmation of the parental origin allows to predict the risk of complications, such as gestational trophoblastic neoplasia, hyperthyroidism, hypertension, or preeclampsia associated with the paternal origin of triploidy. Diagnosis of partial hydatidiform mole associated with diandric triploidy is challenging especially in the first trimester pregnancy loss due to the limitations of both histopathology and ultrasound. We present important clinical aspects of triploid pregnancies and indicate unresolved issues demanding further studies.

Atypical preeclampsia before 20 weeks of gestation with multicystic placenta, hyperreactio luteinalis, and elevated sFlt-1/PlGF ratio as manifestations of fetal triploidy: A case report

“…Fetal-placental disorders, however, might be recognized solely on the basis of fetal ultrasound unless rapid genetic testing is performed. The most important ultrasound finding related to diandric triploidy is multicystic large placenta with a normal-sized fetus with structural anomalies [ 7 ]. Fetal structural anomalies detected in triploidy are extremely heterogenous; central nervous system anomalies are common; cardiac defects are usually severe and complex; and renal abnormalities, including renal agenesis, multicystic kidneys, and hydronephrosis, are also sometimes observed.…”

“…Other minor findings, such as absence of the gall bladder, hypoplastic lungs, omphalocele, syndactyly of the third and fourth fingers or toes, club hands or feet, or polydactyly may be observed. Theca lutein cysts of both maternal ovaries, also known as hyperreactio luteinalis, are frequently seen [ 7 ]. There are other differential diagnoses in early-onset preeclampsia with multiple fetal malformations, multicystic placenta, and/or hyperreactio luteinalis.…”

“…Triploidy results from an extra haploid set of chromosomes of paternal or maternal origin [ 7 ]. As most fetuses are miscarried in the first trimester, triploidy occurs in only about 0.002% of viable pregnancies between 16 and 20 weeks of gestation [ 8 ].…”

“…As most fetuses are miscarried in the first trimester, triploidy occurs in only about 0.002% of viable pregnancies between 16 and 20 weeks of gestation [ 8 ]. Triploidy of paternal origin (diandric triploidy) is reported to be associated with placental overgrowth and preeclampsia as early as the second trimester [ 7 , 9 ]. Here we present the case of a healthy woman who had conceived naturally and developed preeclampsia at 18 weeks of gestation as a manifestation of diandric triploidy.…”

Relationship between serum cadherin 6 and 11 levels and severe and early-onset preeclampsia: A pilot study

“…Also, it was shown that cadherin 11 is predominantly expressed in complete hydatidiform mole ( 20 , 28 ) and preeclampsia can be seen in the first trimester in hydatidiform mole. Similarly, the risk of preeclampsia in the second trimester in triploidy pregnancies is 35% ( 29 ) . It could be speculated that the relationship between preeclampsia risk and hydatidiform mole might be due to the cadherin 11 protein.…”