Triploid Pregnancies Research Articles

Maternal thyroid function and free beta human chorionic gonadotrophin level in triploid pregnancies of paternal origin

Maternal thyroid function and free beta human chorionic gonadotrophin level in triploid pregnancies of paternal origin

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.

Distribution of diandric and digynic triploidy depending on gestational age

PurposeTo establish the distribution of diandric and digynic triploidy depending on gestational age.Methods107 triploid samples tested prospectively in a single genetic department during a four-year period were analyzed for parental origin of triploidy by Quantitative Fluorescent Polymerase Chain Reaction (QF-PCR) (n=95) with the use of matching parental samples or by MS-MLPA (n=12), when parental samples were unavailable. Tested pregnancies were divided into three subgroups with regard to the gestational age at spontaneous pregnancy loss: <11 gestational weeks, 11–14 gestational weeks, and >14 gestational weeks.ResultsDiandric triploidy constituted overall 44.9% (46.5% in samples miscarried <11 gestational weeks, 64.3% in samples miscarried between 11 and 14 gestational weeks, and 27.8% in pregnancies which survived >14 gestational weeks).ConclusionsThe distribution of diandric and digynic triploidy depends on gestational age. The majority of diandric triploid pregnancies is lost in the first trimester of pregnancy. In the second trimester, diandric cases are at least twice less frequent than digynic ones.

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.

Maternal complications in molecularly confirmed diandric and digynic triploid pregnancies: single institution experience and literature review

ObjectivesAssessment of the maternal complications in molecularly confirmed diandric and digynic triploid pregnancies.MethodsSonographic features, biochemical results, and clinical presentation were analyzed. Beta-hCG level was controlled after diandric triploidy.ResultsThe study included nine diandric and twelve digynic triploid pregnancies at the mean gestational age at diagnosis of 14.9 and 18.0 weeks, respectively (p = 0.0391). Mean value of total-hCG was 979 703.6 U/ml in diandric cases and 5 455.4 U/ml in digynic ones (p < 0.000). Maternal complications occurred in 88.9% of diandric triploid pregnancies, including: thecalutein cysts (44.4%), hyperemesis gravidarum (44.4%), symptomatic hyperthyreosis (33.3%), early onset gestational hypertension (22.2%) and vaginal bleeding (11.1%). No case of proteinuria, preeclampsia or HELLP syndrome was observed. Only maternal complication observed in digynic triploidy was vaginal bleeding (50.0%). The mean time of beta-hCG normalization after diandric triploid pregnancies was 84 days (range 11–142 days). No case of gestational trophoblastic neoplasia (GTN) was observed.ConclusionsMaternal complications (except for vaginal bleeding) are associated with diandric triploidy. The relatively low incidence of hypertensive maternal complications and their less severe course in our cohort may be attributed to the earlier prenatal diagnosis. The frequency of GTN after diandric triploidy may be lower than previously reported.

Prenatal sonographic features can accurately determine parental origin in triploid pregnancies.

ObjectiveTo describe the prenatal sonographic features and maternal biochemical markers in triploid pregnancies and to assess whether prenatal phenotype can determine genetic origin.MethodsWe performed a retrospective multicenter cohort study that included all triploid pregnancies diagnosed between 2000 and 2018 in two Fetal Medicine Units in Amsterdam. Fetal growth, presence of structural anomalies, extra‐fetal anomalies, and maternal biochemical markers were retrieved. Asymmetrical intrauterine growth restriction was diagnosed when the head‐to‐abdominal circumference (HC/AC) ratio was >95th centile. Parental origin was analyzed via molecular genotyping in 46 cases (38.3%).ResultsOne hundred and twenty triploid pregnancies were identified, of which 86 cases (71.6%) were detected before 18 weeks of gestation. Triploidy of maternal origin was found in 32 cases (69.6%) and was associated with asymmetrical growth restriction, a thin placenta, and low pregnancy‐associated plasma protein A and free beta‐human chorionic gonadotrophin (β‐hCG) levels. Triploidy of paternal origin was found in 14 cases (30.4%) and was associated with an increased nuchal translucency, placental molar changes, and a high free β‐hCG. Prospective prediction of the parental origin of the triploidy was made in 30 of the 46 cases based on phenotypical ultrasound presentation, and it was correct in all cases.ConclusionAsymmetrical growth restriction with severe HC/AC discrepancy is pathognomonic of maternal triploidy. Placental molar changes indicate a paternal triploidy. Moreover, triploidy can present with an abnormal first trimester combined test, with serum levels on the extreme end. When available results of maternal serum markers can support the diagnosis of parental origin of the triploidy, an accurate assessment of the parental origin based on prenatal sonographic features is possible, making DNA analysis redundant.

Early prenatal detection of triploidy: a 9-year experience in mainland China

Objective In this study, we report the indications for prenatal cytogenetic diagnosis of triploid cases, in an attempt to identify clues to early diagnosis. Study design This was a retrospective analysis of prenatal cases of triploidy during a 9-year period at mainland China. Clinical data were reviewed for these cases, including maternal demographics, indications for invasive testing, fetal ultrasound findings, and pregnancy outcomes. Results A total of 22 singleton pregnancies affected with triploid fetuses were detected. The fetal karyotype included 69,XXX (72.7%) and 69,XXY (27.3%). Eighteen cases were identified by the first trimester screening program. One case was missed by maternal cell-free DNA testing, but detected by second trimester anatomy scan. Three cases escaped the first trimester screening and were detected by second trimester anatomy scan. Conclusions The present study demonstrates that most triploid cases can be diagnosed prenatally during the first trimester. The early asymmetrical fetal growth restriction, structural anomalies, and extremely high risk serum screening result for trisomy 21 or 18 should alert the physicians to the investigation of triploidy. Key Message Ultrasound-based first-trimester screening plays a major role in early diagnosis of fetal triploidy. Future replacement of routine first-trimester screening by cell-DNA testing might miss the chance of early diagnosis and management of triploid pregnancies.

Triploidy - variability of sonographic phenotypes.

To analyze sonographic abnormalities in triploid pregnancies and assess the usefulness of the classification proposed by McFadden and Kalousek for prenatal sonographic assessment of triploid fetuses. We conducted a retrospective analysis of the sonographic features in a series of 67 triploid fetuses evaluated between 11 and 30weeks of gestation in a single referral center between 1997 and 2015. Non-specific structural fetal defects were visualized in the majority of fetuses (61.2%) regardless of the parental origin of the triploidy. A 'diandric phenotype' was identified in eight relatively well-grown fetuses (11.9%) that presented with cystic placentas. A 'digynic phenotype' was identified in 47 asymmetrically growth-restricted fetuses with non-cystic placentas (70.2%). In 12 cases (17.9%), features of both phenotypes were present. Nearly 40% of triploid fetuses do not have any apparent structural abnormalities, and only careful assessment of fetal growth and placenta may lead to the suspicion of the diagnosis. As diandric triploidy carry a high risk for maternal complications, identification of these cases is vital for prenatal counseling. In nearly 20% of triploid pregnancies, parental origin cannot be established based on sonographic assessment. © 2017 John Wiley & Sons, Ltd.

51 - Triploidy in a Live-Born Female With Normal Non-Invasive Prenatal Testing Results

Non-invasive prenatal testing (NIPT) has become an increasingly popular option for pregnancies with abnormal ultrasound (U/S) findings. Although it has high clinical sensitivity and specificity for trisomy 21, some other, rarer cytogenetic conditions are less likely to be detected with certain NIPT methods. Triploidy is a rare genetic condition that usually results in miscarriage or stillbirth. Very few triploid pregnancies result in a live birth. We present a case of a female neonate with multiple anomalies and normal non-invasive testing who was diagnosed with dygynic triploidy after birth. Fetal U/S at 19 weeks was abnormal for a two-vessel cord, a cardiac defect and intrauterine growth restriction (IUGR). NIPT at 20w indicated a normal female result. Due to the abnormal U/S findings, further diagnostic testing was recommended but parents declined amniocentesis due to normal NIPT. Subsequent U/S at 30w identified anomalies including IUGR, a congenital heart defect, cerebellar hypoplasia, thoracic hemivertebrae, absent right kidney, absent left hand, right hand syndactyly and abnormal posturing of the hands and feet. The patient was born at 33 weeks gestation by C-section due to severe IUGR and fetal distress. She had additional anomalies including small posterior fossa, atrial septal defect, pulmonary hypoplasia, toe syndactyly, cutis aplasia and cleft palate. She had respiratory distress requiring mechanical ventilation. She developed bilateral pneumothoraces and progressive respiratory failure and died after 3 days. Direct FISH and cytogenetic analysis revealed a female triploid karyotype. The NIPT method used (InformaSeq) is used by many laboratories and is unable detect triploidy. This case highlights the need for more sensitive NIPT methods for detecting non-trisomic abnormal cytogenetic findings. In the context of MCA and normal NIPT, amniocentesis and karyotype and/or CMA should be recommended for families that desire diagnostic testing.

Circulating cell free DNA testing: are some test failures informative?

The proportion of circulating cell free DNA derived from the feto-placental unit (fetal fraction or FF) correlates with test success and interpretation reliability. Some fetal disorders are associated with systematically lower FF, sometimes resulting in noninformative results. We analyzed results from pregnancies tested in a nested case/control study derived from a cohort of 4664 high-risk pregnancies. Low FF was defined before and after adjusting for maternal weight and gestational age. Compared with euploid pregnancies, the median FF was significantly higher in Down syndrome pregnancies (ratio 1.17) and significantly lower in trisomy 18 and triploid pregnancies (ratios 0.71 and 0.19, respectively). Among 2157 pregnancies tested, 13 (0.6%) had FF <3.0% (all noninformative), including three trisomy 18 and three triploidy fetuses. After adjustment, 16 pregnancies (0.7%) had FF <0.3 multiples of the median (six informative), including one trisomy 18 and three triploidy fetuses. Modeled positive predictive values for low and high-risk populations were 7% and 30%, respectively. Among women with noninformative results attributable to low FF, trisomy 18 and/or triploidy risk are sufficiently high to warrant offering additional assessments (e.g. ultrasound). If the testing indication is ultrasound abnormality, amniocentesis and karyotype/microarray should be considered. © 2014 John Wiley & Sons, Ltd.

Detection of triploid, molar, and vanishing twin pregnancies by a single-nucleotide polymorphism–based noninvasive prenatal test

We sought to determine the ability of single-nucleotide polymorphism-based noninvasive prenatal testing (NIPT) to identify triploid, unrecognized twin, and vanishing twin pregnancies. The study included 30,795 consecutive reported clinical cases received for NIPT for fetal whole-chromosome aneuploidies; known multiple gestations were excluded. Cell-free DNA was isolated from maternal blood samples, amplified via 19,488-plex polymerase chain reaction, and sequenced. Sequencing results were analyzed to determine fetal chromosome copy number and to identify the presence of additional fetal haplotypes. Additional fetal haplotypes, indicative of fetal triploidy, vanishing twin, or undetected twin pregnancy, were identified in 130 (0.42%) cases. Clinical confirmation (karyotype for singleton pregnancies, ultrasound for multifetal pregnancies) was available for 58.5% (76/130) of cases. Of the 76 cases with confirmation, 42.1% were vanishing twin, 48.7% were viable twin, 5.3% were diandric triploids, and 3.9% were nontriploid pregnancies that lacked evidence of co-twin demise. One pregnancy had other indications suggesting triploidy but lacked karyotype confirmation. Of the 5 vanishing twin cases with a known date of demise, 100% of losses occurred in the first trimester; up to 8 weeks elapsed between loss and detection by NIPT. This single-nucleotide polymorphism-based NIPT successfully identified vanished twin, previously unrecognized twin, and triploid pregnancies. As vanishing twins are more likely to be aneuploid, and undetected residual cell-free DNA could bias NIPT results, the ability of this method to identify additional fetal haplotypes is expected to result in fewer false-positive calls and prevent incorrect fetal sex calls.

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%.

First trimester screening: What does biochemistry tell US?

Objective To review clinical information derived from first trimester biochemistry. Methods Study group included: (i) aneuploid: trisomy 21 ( n =128), trisomy 18 ( n = 51), trisomy 13 ( n = 14), triploid ( n = 28), sex chromosome aneuploidies ( n = 24); (ii) failed pregnancies ( n = 374); (iii) fetal structure: anencephaly ( n = 12), fetal growth restriction ( n = 11); and (iv) maternal health: gestational trophoblastic disease (n = 13), sub-chorionic bleeding ( n = 21). PAPP-A, FphCG, AFP and uE3 were quantified (DELFIA DXpress; Perkin Elmer) and marker MoM values calculated by LifeCycle v2.2 (Perkin Elmer), using lot specific derived polynomial regression curves. Results Median PAPP-A MoM values were depressed in failed pregnancies (0.17 ±0.04), pregnancies which failed after testing (0.43 ±0.15), pregnancies carrying an aneuploid fetus (Tri 21 = 0.46 ± 0.24; fetus with lethal aneuploidies = 0.18 ± 0.05 or fetuses with severely restricted growth (0.25 ±0.09). F(βhCG levels were increased in pregnancies carrying trisomy 21 fetus (2.01 ± 0.28), pregnancies with coexistent trophoblastic disease (21.94 ±66.95) or triploid pregnancies with 69XXY karyotype (10.86 ±8.44). AFP levels were increased in pregnancies which experienced transplacental bleeding (4.06 ±2.79) or pregnancies carrying a fetus affected with neural tube defects, such as anencephaly (1.70± 0.41). Conclusions: The above findings confirm: (i) low PAPP-A level is cause for concern requiring assessment of fetoplacental well-being, (ii) elevated FβhCG level warrants examination of fetal and trophoblast development, and (iii) elevated AFP levels may be due leakage of fetal blood into maternal circulation.

Detection of triploidy at 11-14 weeks' gestation: a cohort study of 198 000 pregnant women

To assess the detection rate of triploidy at first-trimester screening for trisomy 21 and evaluate outcome in triploid pregnancies. From 2008 to 2011, 198 427 women with singleton pregnancies underwent first-trimester screening between 11 + 2 and 14 + 0 weeks' gestation. Screening parameters included nuchal translucency, maternal serum free β-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein-A (PAPP-A). In all triploid fetuses, these parameters were re-evaluated. Karyotypes were established by invasive testing (chorionic villus sampling or amniocentesis) or postabortem and obtained from the Danish Cytogenetic Central Register and the Danish Fetal Medicine Database. A total of 30 triploid fetuses underwent first-trimester screening. Twenty-five were diagnosed as a result of abnormal first-trimester scan findings, a detection rate of 83.3%. Twenty-three fetuses were identified due to a high risk for trisomy 13, 18 or 21 and two fetuses due to structural abnormalities. The incidence of triploidy at first-trimester screening was 1:6614. A smaller crown-rump length than that estimated by date of last menstrual period was found in 95% of the fetuses with data available for evaluation. Eight fetuses had a larger biparietal diameter than expected for gestational age. Fetuses with a 69,XXX karyotype had significantly lower multiples of the median values for β-hCG and PAPP-A than did 69,XXY fetuses (P = 0.045 and P = 0.02 forβ-hCG and PAPP-A, respectively). No infants with triploidy were born in the study period. Among the triploid gestations detected on first-trimester screening, 20 (80.0%) women chose termination of pregnancy, four (16.0%) had spontaneous miscarriage and one (4.0%) was stillborn. First-trimester screening for trisomy 21 also provides a high detection rate for triploidy.

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.

The role of morphology in combination with ploidy analysis in characterizing early gestational abortion

Morphology in combination with flow cytometry is an inexpensive and fast tool to characterize important reasons for early gestational loss. Early partial hydatidiform moles are especially difficult to identify as not all have developed the typical histological features of central cistern formation and trophoblastic hyperplasia of the chorionic villi. Angiomatoid formation of the blood vessels, irregular chorionic villi, diffuse villous stromal fibrosis, trophoblastic pseudoinclusions, and pleomorphic trophoblast at the implantation site have therefore been proposed as additional morphological criteria. In our study, we investigated the correlation between morphological features and results of ploidy analysis to assess the additional criteria for practical use. Morphological features of the placentas of up to 13 weeks of gestation were evaluated on hematoxylin and eosin sections. Ploidy analysis was performed by flow cytometry on formalin-fixed, paraffin-embedded tissue. Statistical analysis was performed by binary logistic regression. One hundred fifty samples were included in the study. Of the samples, 23 were triploid, 19 were tetraploid, and the remaining ones were diploid. Statistical analysis showed a poor predictive power based on all morphological criteria alone. The most important result of this study was the identification of five triploid placentas that showed diffuse fibrosis of the chorionic villi, angiomatoid changes of the blood vessels, trophoblastic pseudoinclusions, and focal pleomorphic changes at the implantation site, but none of the classical morphological features of triploid pregnancies were identified. Our study demonstrates that the use of additional morphological criteria increases the number of missed abortions with identified causes for pregnancy loss.

Valoración de una reacción en cadena de la polimerasa cuantitativa y fluorescente (QF-PCR) para el diagnóstico rápido de aneuploidías

Introduction Quantitative fluorescence polymerase chain reaction (QF-PCR) identifies in less than 24 h the most common chromosomal anomalies looked for in conventional prenatal karyotyping: numerical alterations of chromosomes 13, 18, 21, X and Y. Several polymorphic markers are used in QF-PCR for each chromosome, allowing a high reliability of results, speed, low cost and automation. Nevertheless, QF-PCR can not detect structural abnormalities, low-level mosaicism or marker chromosomes. Objective To develop and evaluate a fast, reliable and feasible method for detecting aneuploidies of chromosomes 13, 18, 21, X and Y, in the samples received for prenatal karyotyping in a cytogenetics department. Materials and methods In addition to the 465 amniotic fluids received during last year, stored DNA samples in which a disease was detected in the previous two years were assayed (corresponding to the study of around 1,000 prenatal samples). DNA extraction is automated. The STR polymorphic markers used, with high heterozygosity, are accepted internationally (Association for Clinical Cytogenetics. QF-PCR for the diagnosis of aneuploidy best practice guidelines (2007). Available at http://www.cytogenetics.org.uk/prof_standards/professional_standards.htm). The test has the same PCR amplification conditions for all four multiplex mixtures used. In each of them All the necessary components were included in each of them, except the sample, which was added at the time of the assay. Each amplified mixture is analyzed into the ABI3130 Genetic Analyzer, Applied Biosystems. Fragments analysis is achieved following the published recommendations. Results The results of all the tested samples, normal or pathological, matched the outcome of the conventional karyotype. In total the QF-PCR assay detected: 12 trisomy 21; 5 trisomy 18; 3 women 45,X ; 2 trisomy 47,XXY ; 2 trisomy 13 ; 2 Triple XXX ; 2 men XYY; and 2 triploid pregnancies. In each of these cases the proposed QF-PCR was diagnostic. A partial monosomy of chromosome 18 could not be detected, but a partial trisomy of chromosome 18 was identified. Conclusions The evaluated QF-PCR is a useful tool for the rapid diagnosis of aneuploidies (24 h). It is extremely valuable when the amniocyte cultures fail to grow, or suffer microbiological contamination. It serves to reduce maternal anxiety until the conventional karyotype is reported, and to take quick decisions when ultrasound anomalies are found in the second trimester of pregnancy.

Transient early preeclampsia in twin pregnancy with a triploid fetus: a case report

IntroductionTriploid pregnancies have an increased risk of early preeclampsia. Twin pregnancies consisting of one healthy fetus and one complete or partial molar, with or without a triploid fetus, are rare and management is complex.Case presentationA 33-year-old Caucasian woman presented with a dichorionic diamniotic twin pregnancy. One fetus showed early growth restriction resulting in fetal death at 20 weeks. The placenta was enlarged with some cysts. Chorionic villus biopsy confirmed triploidy. At 21 weeks, the patient developed preeclampsia with a blood pressure of 154/98 mmHg and proteinuria (24 hour protein excretion of 2.5 g/L), for which she was hospitalized. Without pharmacological interventions, the blood pressure normalized and proteinuria disappeared. At 35 weeks, she again developed preeclampsia. A cesarean section was performed at 38 weeks and a healthy child was born.ConclusionsSurvival of the healthy fetus is possible in a twin pregnancy with a triploid fetus complicated by early preeclampsia. The pregnancy should not be terminated if the triploid twin has died and as long as conservative management is safe.

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.

Triploidy: 109 Prenatal Diagnoses

Triploidy is a common finding both in early spontaneous miscarriages and in the fetal period, presenting in 1–2% of pregnancies. It may be the result of diandry (an extra paternal haploid set) or digyny (an extra maternal haploid set). Diandry predominates in cases of triploidy without embryos after nine weeks or in the second trimester with fetuses of relatively normal size and with placental findings of partial hydatidiform mole. Digyny predominates in early miscarriages before nine weeks with embryos or in the second trimester with fetuses with a marked asymmetrical intrauterine growth retardation and a small placenta. We reviewed 109 prenatal diagnoses of triploidy in a ten-year period. In the group with the first trimester diagnosis &lt;14 weeks ( n=62), an interesting finding is the high percentage of recurrent miscarriage as an indication for chromosomal analysis ( n=26/62; 42%). In the second and third trimesters &lt;14 weeks ( n=47), 29 cases had ultrasound characteristics of digynic triploidy with an asymmetrical fetal growth retardation with oligohydramnios of which three pregnancies continued above 20 weeks with abnormal Doppler waveforms and velocities. Thirteen cases had ultrasound characteristics of diandric triploidy with only mild growth retarded or normal grown fetuses with a thickened placenta. Other indications for chromosomal analysis were maternal age ( n=1) and a positive maternal serum triple test screening without ultrasound specifications ( n=4). Early prenatal recognition of triploid pregnancies, certainly those with placental findings of partial hydatidiform mole, is important since these mothers are at risk of preeclampsia and persistent trophoblastic disease.