Triploid Pregnancy Research Articles

Triploid pregnancy-Clinical implications.

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.

VP31.03: Recurrent triploidy: a rare case report with a recognisable phenotypic pattern

Triploidy associated with fetal development and survival beyond the first trimester of pregnancy is rare and a wide range of phenotypic presentations is described. There are still no susceptibility factors identified; current knowledge supports the theory that there is no increased risk for recurrence of triploidy after a first triploid pregnancy. We report a case of two consecutive triploid pregnancies achieving the 2nd trimester of pregnancy in a Caucasian woman. She had three singleton spontaneous pregnancies: the first one was a non-complicated pregnancy at 29 years old, resulting in a healthy newborn delivered at term, the second was a triploid pregnancy at 32 years old and the third a triploid pregnancy at 34 years old. In both triploid pregnancies similar findings were identified, such as: 1st trimester screening revealing low levels of PAPP-A and free β-HCG; 1st trimester ultrasound with no major anatomic defects and a normal NT measurement; 2nd trimester ultrasound revealing a restricted fetus with an increased cephalic circumference/abdominal circumference ratio, oligohydramnios and the presence of cerebellar vermis hypoplasia. Both pregnancies were electively terminated during 2nd trimester, after an amniocentesis showing a triploid karyotype. In both cases, fetal autopsy revealed a small fetus with macrocephaly, cerebellar vermis hypoplasia, low implantation of the ears, hypertelorism, proptosis, small nose, micrognathia, syndactyly between the 2nd and 3rd fingers and club foot; placenta had low weight for gestational age and umbilical cord had a single umbilical artery. Reported findings are highly suggestive of digynic recurrent triploidy. Considering the significant phenotypic variation in triploidy, the finding of a specific phenotypic pattern in both recurrent triploid pregnancies raises the question if there is a genetic basis for this condition: further studies are needed to evaluate this hypothesis, which could revolutionise prenatal counselling.

Triploid pregnancies: genetic and clinical features of 158 cases

The purpose of this study was to analyze the correlation between the genetic constitution and the phenotype in triploid pregnancies. One hundred fifty-eight triploid pregnancies were identified in hospitals in Western Denmark from April 1986 to April 2010. Clinical data and karyotypes were collected retrospectively, and archived samples were retrieved. The parental origin of the genome, either double paternal contribution (PPM) or double maternal contribution (MMP) was determined by an analysis of methylation levels at imprinted sites. There were significantly more PPM than MMP cases (P < .01). In MMP cases, the possible karyotypes had similar frequencies, whereas, in PPM cases, 43% had the karyotype 69,XXX, 51% had the karyotype 69,XXY, and 6% had the karyotype 69,XYY. Molar phenotype was seen only in PPM cases. However, PPM cases with a nonmolar phenotype were also seen. For both parental genotypes, various fetal phenotypes were seen at autopsy. Levels of human chorionic gonadotropin in maternal serum were low in MMP cases and varying in PPM cases, some being as low as in the MMP cases. In a triploid pregnancy, suspicion of hydatidiform mole at ultrasound scanning, by macroscopic inspection of the evacuated tissue, at histology, or because of a high human chorionic gonadotropin in maternal serum level each predict the parental type PPM with a very high specificity. In contrast, the sensitivity of these observations was <100%.

Methylation‐specific multiplex ligation‐dependent probe amplification: utility for prenatal diagnosis of parental origin in human triploidy

When a triploid pregnancy is diagnosed prenatally, gynaecologists have traditionally relied on the histopathological examination of the tissue from the terminated pregnancy to determine if the pregnancy is molar. However, reproducibility is poor and variability is high when diagnosing hydatidiform moles. Triploid pregnancies can have either the chromosomal constitution of two maternal and one paternal set, or two paternal and one maternal set, but only the conceptuses with two paternal sets have the potential to cause maternal complications. Therefore, it would be beneficial to introduce a method that gives the gynaecologist the parental origin of the genome of the triploid conceptus as early as possible, without delaying the process by first collecting parental samples. Using methylation-specific multiplex ligation-dependent probe amplification, we measured methylation levels at different imprinted sites. We were able to correctly determine the parental origin of the genome in all 105 triploid pregnancies analysed. We present methylation-specific multiplex ligation-dependent probe amplification as a method capable of determining the parental origin of the genome of triploid conceptuses within 24 h; it is inexpensive, simple and easy to use, and parental samples are not needed.

Pregnancy Complicated by Triploidy: A Comparison of the Three Karyotypes

We evaluated triploid pregnancy to determine whether there are clinically important differences between the three karyotypes: 69,XXX, 69,XXY, and 69,XYY. Prospectively maintained cytogenetic databases at five tertiary care centers were retrospectively reviewed over a 10-year period to identify all triploid pregnancies. Targeted ultrasounds were reviewed to identify fetal and placental findings. Sonographic findings were compared by karyotype. There was a total of 549 triploid gestations; preimplantation genetic diagnosis (PGD) detected 413 triploid embryos, and the cytogenetic databases provided 136 clinical pregnancies with triploidy. In triploid embryos with PGD, the frequency of the 69,XYY karyotype was 8.7% (36/413), compared with 0.74% (1/136) during the first trimester of clinical pregnancies (p = 0.002). In clinical pregnancies, 60% (36/60) of 69,XXY fetuses survived the first trimester of development compared with 69% (52/75) of 69,XXX fetuses (p = NS). No clinically important differences were observed between 69,XXX and 69,XXY karyotypes in terms of type, number, or severity of fetal or placental anomalies. Gestations with a 69,XYY karyotype are found less frequently compared with gestations with a 69,XXX or 69,XXY karyotype. The decline in fetal survival of the 69,XYY triploid karyotype needs further investigation. There are significant abnormalities detected during prenatal sonography in most all clinically recognized cases of triploidy. Sonography cannot reliably distinguish between the 69,XXY and 69,XXX karyotypes.

Theca-lutein cysts complicating recovery after termination of a triploid pregnancy

The article reports on a case of a patient whose conception was terminated due to confirmed triploidy and bilateral theca-lutein cyst development after her delivery. Clinical examination found that both patients ovaries have slightly enlarged with multifollicular activity similar with polycystic ovarian syndrome. The patient was advised for surgical intervention in the right ovarian cyst which was not predicted during the dating scan.

Ultrasound and Genetic Features of a Term Triploid Pregnancy

A 69,XXY triploid term infant is reported to demonstrate the prenatal sonographic findings of first trimester intrauterine growth retardation as an important early indicator of this diagnosis. Progressive lag in early sonographic dating for gestational age should raise suspicion of triploidy, which can lead to an early diagnosis, genetic counseling, and a realistic management plan.

Elevated Maternal Serum and Amniotic Fluid α-Fetoprotein in a Triploid Pregnancy

Elevated Maternal Serum and Amniotic Fluid α-Fetoprotein in a Triploid Pregnancy

Human chorionic gonadotropin levels in pregnancies with aneuploid fetuses.

Maternal serum human chorionic gonadotropin (hCG) and the free alpha-hCG subunit were evaluated in 249 women from 9 to 11 weeks gestation who subsequently underwent chorionic villus sampling for determination of fetal karyotype and in 20 women of 18 or more weeks gestation who were ascertained to have an aneuploid fetus by genetic amniocentesis. Seven of the first-trimester pregnancies were determined to be aneuploid and six had hCG levels in the normal range (one triploid pregnancy had elevated hCG levels) whereas 12 of the 20 second-trimester cases had abnormal hCG levels and an additional three had elevated levels of alpha-hCG. This study confirms the previous report of abnormal maternal serum hCG levels in women with an aneuploid fetus at greater than or equal to 18 weeks gestation and demonstrates that hCG evaluation is not useful at 9-11 weeks gestation for selecting pregnancies at risk for fetal aneuploidy.