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A case of confined placental mosaicism with double trisomy associated with stillbirth
Placenta 32 (2011) 699e703
Contents lists available at ScienceDirect
Placenta journal homepage: www.elsevier.com/locate/placenta
A case of confined placental mosaicism with double trisomy associated with stillbirth L.R. Goodfellow a, *, G. Batra b, V. Hall c, E. McHale d, A.E.P. Heazell a a
Maternal and Fetal Health Research Centre, Manchester Academic Health Sciences Centre, 5th floor (Research), St Mary’s Hospital, Oxford Road, Manchester M13 9WL, UK Department of Paediatric and Perinatal Pathology, Central Manchester University Hospitals Foundation Trust, Manchester, UK c Department of Obstetrics and Gynaecology, Macclesfield District General Hospital, Macclesfield, UK d Department of Cytogenetics, Central Manchester University Hospitals Foundation Trust, Manchester, UK b
a r t i c l e i n f o
a b s t r a c t
Article history: Accepted 13 June 2011
We present a case of stillbirth in which the fetus was well grown and karyotypically normal, but the placenta was morphologically abnormal and had confined placental mosaicism (CPM) for a double trisomy of chromosomes 12 and 15. A compilation of published cases of CPM reveals that whilst approximately 80% of pregnancies progress normally, there is an association with abnormal placental morphology, intrauterine growth restriction, fetal abnormalities and stillbirth. This case highlights the potential adverse effects of CPM and the benefit of placental examination in determining the cause of stillbirth. Ó 2011 Elsevier Ltd. All rights reserved.
Keywords: Placenta Stillbirth Confined placental mosaicism Cytogenetics Placental mesenchymal dysplasia
1. Introduction Stillbirth affects 1 in 200 pregnancies in the developed world. Modern classification systems identify placental pathology as a cause in 26e70% of stillbirths [1]. This frequently represents infarction or inflammatory pathologies [2]. However, rarer causes of placental dysfunction may also result in stillbirth. Here, we present a case of stillbirth with abnormal placental morphology in which confined placental mosaicism (CPM) was identified. 2. Case report A 34 year old Caucasian woman presented in her third pregnancy at 13 weeks gestation. She was healthy and had a history of a spontaneous first trimester miscarriage and a normal delivery of a live born male at term. The father was 34 years old, Caucasian, healthy, and no biological relation to the mother. First and second trimester assessments, including Down’s syndrome screening and ultrasounds, were normal. At 32 weeks and 4 days gestation she presented with absent fetal movements for 24 h. There was no history of abdominal pain or vaginal bleeding. A diagnosis of fetal death in utero was made. Following induction of labor a stillborn male infant weighing 2.02 kg (58th centile) was born. There were no external congenital malformations or dysmorphic features. * Corresponding author. Tel.: þ44 161 276 5460. E-mail address: [email protected] (L.R. Goodfellow). 0143-4004/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.placenta.2011.06.008
Post mortem revealed a left-sided diaphragmatic hernia, with the pleural cavity containing a substantial loop of small intestine and the spleen. The left lung weight was smaller than expected, in keeping with the restricted left pleural space. Organ weights of the heart, liver, kidneys, spleen, adrenals and brain were below that expected for gestation. However, all were anatomically and histologically normal. The remaining alimentary, endocrine, musculoskeletal and genitourinary systems were normal in shape, position and size. Review of the images of the second trimester USS by a consultant obstetrician (VH) failed to show the diaphragmatic hernia, suggesting it had developed later in gestation. Placental weight was 451 g, (just below 50th centile [3]). Examination of eight placental biopsies showed approximately 50% of large stem villi had excessive stromal tissue (Fig. 1A), placental mesenchymal dysplasia was considered but it was not felt to be typical. Arteries within stem and intermediate villi were excessively muscularised (Arrows, Fig. 1B) but without features of fetal thrombotic vasculopathy, specifically there was no evidence of haemorrhagic endovasculitis, intimal cushions or occlusive thrombi. Terminal villi showed normal development of vasculosyncytial membranes (Fig. 1C). Analysis of cultured placental membrane and villus samples showed a male karyotype with trisomy for both chromosome 12 and chromosome 15 (Fig. 1D). No evidence of mosaicism was detected in 56 cells from the mesenchymal core, which originates from the inner cell mass. Cytocell 12 and 15 centromere probes were used to perform fluorescence in situ hybridization studies (FISH) on 40 uncultured fetal skin
700
L.R. Goodfellow et al. / Placenta 32 (2011) 699e703
Fig. 1. A) Low power view showing enlarged stem villi with excessive stromal tissue (marked with arrows). B) View of enlarged stem villus showing muscular hypertrophy surrounding artery. C) Terminal villi showing appropriate development of vasculosyncytial membranes for 32 weeks gestation D) Chromosome spread from placental tissue showing trisomy 12 and 15 (marked with arrows) E) fISH from fetal skin fibroblast cells showing diploid state for chromosomes 12 (red) and 15 (green).
fibroblast cells. Due to maceration tissue from the internal organs was not sent for cytogenetic analysis. All fetal skin cells examined showed a normal diploid signal for both chromosomes 12 and 15 (Fig. 1E). This suggests the pregnancy was affected by CPM with the abnormal 48, XY, þ12, þ15 cell line confined to the extra-fetal tissues. Chromosomal analysis of mother and father revealed normal karyotypes. 3. Discussion This case of stillbirth was associated with CPM of both chromosome 12 and chromosome 15 in a histologically abnormal placenta. This is the first such case described. CPM is found in approximately 1e2% of pregnancies when chorionic villus sampling (CVS) is performed late in the first trimester [4], but interestingly about half of the cases of mosaicism seem to regress and are not found at term [5]. In cases of mosaicism of viable trisomies (13, 18 and 21) diagnosed on CVS, amniocentesis is offered to assess the risk of mosaicism in the fetus. The relationship between CPM and pregnancy outcome in rare placental trisomies is summarized in Table 1. Overall, excluding terminations of pregnancy, CPM is associated with: normal live births (79.7%), fetal anomalies (2.7%), 68 FGR (9.3%), 53 FDIU/spontaneous miscarriage (7.2%) and 8 neonatal deaths (1.1%). Therefore, in the case of rarer trisomies it is normal to reassure parents that this is unlikely to affect pregnancies
that survive the first trimester [6]. However, persistent CPM is clearly linked to preeclampsia, fetal growth restriction and stillbirth (Table 1) [7]. The reasons for the variations in perinatal outcome may result from inherent differences in CPM. Firstly, the cell type affected affects pregnancy outcome. In type 2 CPM (trisomy confined to mesenchymal cells) the incidence of preterm birth and FGR is comparable to controls. However, with type 3 CPM (trisomy in cytotrophoblast and mesenchymal core) the incidence of FGR and preterm birth is increased (p < 0.001) [8]. Secondly, the nature of the abnormality conferred by the extra chromosome(s) is likely to alter the structure, and function of the placenta although no definitive microscopic abnormalities have been described. Notably, a review of 24 placentas with CPM found 10 had abnormalities including lymphocytic villitis, perivillous fibrin deposition and focal villous immaturity [9]. It can be speculated that abnormal morphology impacts on placental function, leading to FGR. In this case trisomy of two chromosomes could have had a larger impact on placental function than either trisomy alone, which may have contributed to fetal demise. Finally, the process of abnormal chromosomal development may also affect the fetus. In the case of CPM developing during meiosis it is necessary for the fetal cells to undergo “trisomic rescue” whereby one of the unmatched chromosomes is expelled, reverting to a diploid karyotype. However, if the remaining chromosomes are of the same parental origin then the fetus will be
Table 1 Summary of studies detailing outcomes of pregnancies affected by CPM of rare trisomies. Studies have been excluded in which all/part of the dataset has been reported previously. In appropriate studies only the relevant data has been extracted from the whole dataset. *Triploidy reported meeting Noomen’s criteria for “high level”. ASD ¼ atrial septal defect,CVS ¼ chorionic villous biopsy, FDIU ¼ Fetal death in utero, IUGR ¼ Intrauterine growth restriction, as defined by the study, live born unless otherwise stated, SM ¼ Spontaneous miscarriage, TOP ¼ Termination of pregnancy, NND ¼ Neonatal death. Author
Reference
Number of pregnancies with CPM
Method of identifying CPM
Trisomic chromosome
Gestation range (weeks)
Infant outcome/ complications
Follow up period of child/children
Kalousek and Dill
Science 1983; 221:665e7
2
X, 22
38, 40
2 IUGR
Birth
Kalousek et al Johnson et al
Hum Genet 1987; 77:163e7 Obstet Gynecol 1990; 75:573e7
5 49
Placental cytogenetics of normal and IUGR pregnancies CVS CVS
12, 13, 14, 17, marker Not stated
Term Not stated
Birth Birth
Kalousek
Placenta 1990; 10:69e77
3
Not stated
1st trimester
Kalousek et al
Prenat Diagn 1991; 11:743e50
34
Placental and fetal cytogenetics of complicated pregnancies CVS with confirmation in placenta at delivery
2TOP, 3 normal live birth 4 SM, 7 TOP, 2 FDIU, 1 NND, 1x cerebral atrophy, 1 IUGR, 33 normal live births 3 1st trimester SM (from sample of 20 1st trimester SM)
2, 7,6p, 8, 10, 12, 13, 16, X, triploidy
20-term
Only 17/34 CVS diagnosed CPM were found in placenta at delivery. Of these 1 SM at 20 weeks, 5 IUGR, 11 normal live births. CPM in CVS only (n ¼ 17) all normal live births
Birth
Wapner et al
Prenat Diagn 1992; 12:347e55
108
CVS
Not stated
39.2þ/ 1.9
Birth
Fryburg et al
Prenat Diagn 1993; 13:481e94
39
CVS
2, 5, 7,8, 9, 13, 16, 18, 20, 21, X
20-term
Roland et al
Prenat Diagn 1994; 14:589e93
26
CVS
mean ¼ 39.8
Birth
Wolstenholme et al “Study 1”
Prenat Diagn 1994; 14:345e61
73
CVS
7, 8, 9, 12, 15, 16, 17, 18, 20, X, markers 2, 3, 5, 7,8, 9, 10, 11p, 13, 15, 16, 18, 20, 21,X, rearrangements, multiple, markers, triploid, tetraploid
3 SM <16 wks, 3 SM/FDIU 17e27 wks, 1 FDIU>27 wks, 74 live births. 8 TOP (USS normal), 1 SM at 20 weeks, 2 IUGR, 1 NND, 27 normal live births 1 SM at 11 weeks, 25 live births. 2 SM, 5 TOP, 1 FDIU, 57 live births, 4 unknown. Significant increase in both low and high birthweights compared to matched controls
Wolstenholme et al “Study 2”
Prenat Diagn 1994; 14:345e61
6
9, 16, 22, multiple, del (13)(q13)
27e35
3 IUGR, 2 NND, 1 FDIU
5e30 months
Artan et al
Prenat Diagn 1995; 15:1135e42
6
14, 21, 18, X, triploidy*
36e41
All IUGR live births
Birth
Christian et al
Prenat Diagn 1996; 16:323e32
4
Placental cytogenetics of IUGR pregnancies Placental cytogenetics of term pregnancies CVS
15
15-term
Birth
Schaffer
Prenat Diagn 1996; 16:899e905
9
CVS
2
34-term
Goldberg et al
Am J Obstet Gynecol 1997; 178:1349e53
114
CVS
Not stated
Not stated
Robinson et al
Am J Hum Genet 1997; 60:917e27
49
CVS (47 cases) and placental cytogenetics (7 cases)
2, 3, 7, 8, 9, 10, 12, 15, 16, 22, multiple, marker
Not stated
Saks et al Djalali et al
Prenat Diagn 1998; 18:1202e4 Prenat Diagn 2000; 20:933e938
1 1
CVS CVS
8 12 and 13
37 Not stated
1 TOP for PradereWilli syndrome, 3 normal live births 1 TOP, 2 IUGR, 6 normal live births 5 SM and 5 TOP, 9 preterm delivery, 2 IUGR, 94 normal live births 5 TOP (2 associated with IUGR), 2 IUFD, 13 IUGR (2 leading to NND), 1 neonatal anomalies, 28 normal live births IUGR. Developmentally normal. TOP, post mortem showed facial dysmorphism
5e65 months
Birth
L.R. Goodfellow et al. / Placenta 32 (2011) 699e703
32e42
n/a
Birth 0e5 years
Birth
1 year n/a 701
(continued on next page)
702
Table 1 (continued ) Author
Reference
Number of pregnancies with CPM
Method of identifying CPM
Trisomic chromosome
Gestation range (weeks)
Infant outcome/ complications
Follow up period of child/children
Kuchinka et al
Prenat Diagn 2001; 1:36e9
2
CVS
4
30, term
1 year
Stipoljev et al
Fetal Diagn Ther 2001; 16:4e9
2
15, 16p-
32, 35
Bryan et al
Prenat Diagn 2002; 22:137e40
1
Cytogenetic analysis of IUGR placentas CVS
1 FDIU at 30 weeks, 1 normal live birth Live births, IUGR
22
32
1 year
Roberts et al
Prenat Diagn 2003; 23:564e5
1
CVS
2
26
Stetten et al
Am J Med Genet 2004; 131A:232e9
28
CVS
X, 7, 8, 9, 10, 18, 20, 21 multiple, triploidy
13-term
Minor et al
Am J Med Genet 2005; 140A:24e30
3
7q/Xp, tetraploidy
Term
Amor et al
Prenat Diagn 2006; 26:443e8
36
Placental cytogenetics of pregnancies derived through ISCI CVS
IUGR and hypospadias. Developmentally normal. Oligohydramnios, IUGR and NND aged 3 days 1 SM at 13 weeks, 3 TOP (one with holoprosencephaly), 24 live births including 3 preterm births (32, 35 and 35 weeks) and 1 speech and language delay at 42 months. 1 spina bifida, 2 normal live births
2, 7, 8, 9, 12, 13, 17, 18, 20, markers, X
Not stated
Langlois et al
Prenat Diagn 2006; 26:548e58
19
CVS
16
30e41
Miura et al
Am J Med Genet 2006; 140A:1827e33
8
2, 7, 13, 22, multiple, del(2) (p16)
35e38
Wilkins-Haug et al
Prenat Diagn 2006; 26:428e32
12
Cytogenetic analysis of IUGR placentas Cytogenetic analysis of IUGR placentas and matched controls
8, multiple (17 and 21), triploidy*
29e40
Yong et al
J Obstet Gynecol Can 2009; 31:605e10
69
CVS
2, 4, 7, 8, 9, 10, 11, 13, 15, 16, 17, 18, 20, 21, 22 and multiple
Not stated
Robinson et al
Prenat Diagn 2010; 30:1e8
5 (one set of twins)
2, 7, 13
31e41
Sifakis et al
Prenat Diagn 2010; 30:329e32 Prenat Diagn 2010; 30:1155e64
44
Placental cytogenetics of IUGR or abnormal maternal serum screen pregnancies CVS
2
32e42
57
CVS
2, 5, 6, 7, 8,9, 10, 12, 15, 16, 17, 18, 20, 21, 22, markers, X, multiple
17-term
1 SM at 15 weeks, 6 IUGR live births, 37 normal live births 1 SM at 17 weeks, 1 FDIU at 27 weeks, 1 FDIU at 35 weeks, 1 TOP for PradereWilli syndrome, 18 IUGR, 1 NND, 34 normal live births
3 days 0e42 months
Birth
4e11 years
1e15 years
1 year
Birth
Birth
Birth
Birth Birth
L.R. Goodfellow et al. / Placenta 32 (2011) 699e703
Toutain et al
Followed children born following antenatal diagnosis of CPM. No increase in IUGR between cases and matched controls between 4 and 11 years. 2 hypospadias, 1 left renal agenesis, 1 cardiac anomaly, 1 thyroid agenesis and IUGR, 2 cardiac anomaly and IUGR, 2 IUGR, 1 speech delay, 9 normal live birth 1 ASD and hypospadias, 1 Russell-Silver syndrome- died aged 12 months, 6 IUGR 11 IUGR of which 9 had abnormal placental histology (infarct, decidual vasculopathy or intervillous thrombus). 1 normal live birth. 1 imperforate anus, 1 hypospadias, 1 hip dysplasia, 1 hydronephrosis, 1 VSD, 2 familial phenotypes, 56normal live births (89%). 1 FDIU at 31 weeks (twin A), 4 IUGR (including twin B), 1 normal live birth
Birth
L.R. Goodfellow et al. / Placenta 32 (2011) 699e703
affected with uniparental disomy which can cause birth defects if it affects imprinted genes (such as the association between chromosome 15 and PradereWilli/Angelman syndromes) [10]. It is possible that our case had true fetal mosaicism for one or both chromosomal trisomies. However, a compilation of 469 cases of antenatally diagnosed mosaicism in CVS samples which were followed for fetal outcome found that only 3.2% of fetuses had evidence of trisomy when the CVS showed a rare autosomal trisomy. This is in contrast to 19% of fetuses having affected tissues following a CVS result of trisomy 13, 18 or 21 [11]. Mosaicism affecting two chromosomes was not described in the largest study of rare trisomy mosaicism to date [12], although a smaller study showed multiple trisomy in 5 cases (7%) [9]. This case highlights the benefit of placental examination in determining cause of stillbirth and potential adverse effects of CPM. In the absence of structural fetal anomalies and presence of abnormal placental structure, placental cytogenetics may be justified to identify CPM. Therefore, it may be prudent to take a fresh frozen sample of placental tissue before fixing the placenta for histological examination after a stillbirth. Further studies are needed to investigate the link between CPM and adverse perinatal outcome. References [1] Korteweg FJ, Gordijn SJ, Timmer A, Holm JP, Ravise JM, Erwich JJ. A placental cause of intra-uterine fetal death depends on the perinatal mortality classification system used. Placenta 2008;29(1):71e80.
703
[2] Heazell AEP, Martindale EA. Can post-mortem examination of the placenta help determine the cause of stillbirth. Journal of Obstetrics and Gynaecology 2009;29(3):225e8. [3] Thompson JMD, Irgens LM, Skjaerven R, Rasmussen S. Placenta weight percentile curves for singleton deliveries. BJOG: An International Journal of Obstetrics and Gynaecology 2007;114(6):715e20. [4] Kalousek DK, Dill FJ. Chromosomal mosaicism confined to the placenta in human conceptions. Science 1983;221(4611):665e7. [5] Kalousek DK, Howard-Peebles PN, Olson SB, Barrett IJ, Dorfmann A, Black SH, et al. Confirmation of CVS mosaicism in term placentae and high frequency of intrauterine growth retardation association with confined placental mosaicism. Prenatal Diagnosis 1991;11(10):743e50. [6] Amor DJ, Neo WT, Waters E, Heussler H, Pertile M, Halliday J. Health and developmental outcome of children following prenatal diagnosis of confined placental mosaicism. Prenatal Diagnosis 2006;26(5):443e8. [7] Kalousek DK, Barrett I. Confined placental mosaicism and stillbirth. Pediatric Pathology 1994;14(1):151e9. [8] Toutain J, Labeau-Gauzere C, Barnetche T, Horovitz J, Saura R. Confined placental mosaicism and pregnancy outcome: a distinction needs to be made between types 2 and 3. Prenatal Diagnosis 2010;30(12e13):1155e64. [9] Yong PJ, von Dadelszen P, McFadden DE, Barrett IJ, Kalousek DK, Robinson WP. Placental weight in pregnancies with trisomy confined to the placenta. Journal of Obstetrics and Gynaecology Canada 2009;31(7):605e10. [10] Christian SL, Smith ACM, Macha M, Black SH, Elder FFB, Johnson JMP, et al. Prenatal diagnosis of uniparental disomy 15 following trisomy 15 mosaicism. Prenatal Diagnosis 1996;16(4):323e32. [11] Phillips OP, Tharapel AT, Lerner JL, Park VM, Wachtel SS, Shulman LP. Risk of fetal mosaicism when placental mosaicism is diagnosed by chorionic villus sampling. American Journal of Obstetrics and Gynecology 1996;174(3): 850e5. [12] Hsu LYF, Yu MT, Neu RL, Van Dyke DL, Benn PA, Bradshaw CL, et al. Rare trisomy mosaicism diagnosed in amniocytes, involving an autosome other than chromosomes 13, 18, 20, and 21: karyotype/phenotype correlations. Prenatal Diagnosis 1997;17(3):201e42.
Contents lists available at ScienceDirect
Placenta journal homepage: www.elsevier.com/locate/placenta
A case of confined placental mosaicism with double trisomy associated with stillbirth L.R. Goodfellow a, *, G. Batra b, V. Hall c, E. McHale d, A.E.P. Heazell a a
Maternal and Fetal Health Research Centre, Manchester Academic Health Sciences Centre, 5th floor (Research), St Mary’s Hospital, Oxford Road, Manchester M13 9WL, UK Department of Paediatric and Perinatal Pathology, Central Manchester University Hospitals Foundation Trust, Manchester, UK c Department of Obstetrics and Gynaecology, Macclesfield District General Hospital, Macclesfield, UK d Department of Cytogenetics, Central Manchester University Hospitals Foundation Trust, Manchester, UK b
a r t i c l e i n f o
a b s t r a c t
Article history: Accepted 13 June 2011
We present a case of stillbirth in which the fetus was well grown and karyotypically normal, but the placenta was morphologically abnormal and had confined placental mosaicism (CPM) for a double trisomy of chromosomes 12 and 15. A compilation of published cases of CPM reveals that whilst approximately 80% of pregnancies progress normally, there is an association with abnormal placental morphology, intrauterine growth restriction, fetal abnormalities and stillbirth. This case highlights the potential adverse effects of CPM and the benefit of placental examination in determining the cause of stillbirth. Ó 2011 Elsevier Ltd. All rights reserved.
Keywords: Placenta Stillbirth Confined placental mosaicism Cytogenetics Placental mesenchymal dysplasia
1. Introduction Stillbirth affects 1 in 200 pregnancies in the developed world. Modern classification systems identify placental pathology as a cause in 26e70% of stillbirths [1]. This frequently represents infarction or inflammatory pathologies [2]. However, rarer causes of placental dysfunction may also result in stillbirth. Here, we present a case of stillbirth with abnormal placental morphology in which confined placental mosaicism (CPM) was identified. 2. Case report A 34 year old Caucasian woman presented in her third pregnancy at 13 weeks gestation. She was healthy and had a history of a spontaneous first trimester miscarriage and a normal delivery of a live born male at term. The father was 34 years old, Caucasian, healthy, and no biological relation to the mother. First and second trimester assessments, including Down’s syndrome screening and ultrasounds, were normal. At 32 weeks and 4 days gestation she presented with absent fetal movements for 24 h. There was no history of abdominal pain or vaginal bleeding. A diagnosis of fetal death in utero was made. Following induction of labor a stillborn male infant weighing 2.02 kg (58th centile) was born. There were no external congenital malformations or dysmorphic features. * Corresponding author. Tel.: þ44 161 276 5460. E-mail address: [email protected] (L.R. Goodfellow). 0143-4004/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.placenta.2011.06.008
Post mortem revealed a left-sided diaphragmatic hernia, with the pleural cavity containing a substantial loop of small intestine and the spleen. The left lung weight was smaller than expected, in keeping with the restricted left pleural space. Organ weights of the heart, liver, kidneys, spleen, adrenals and brain were below that expected for gestation. However, all were anatomically and histologically normal. The remaining alimentary, endocrine, musculoskeletal and genitourinary systems were normal in shape, position and size. Review of the images of the second trimester USS by a consultant obstetrician (VH) failed to show the diaphragmatic hernia, suggesting it had developed later in gestation. Placental weight was 451 g, (just below 50th centile [3]). Examination of eight placental biopsies showed approximately 50% of large stem villi had excessive stromal tissue (Fig. 1A), placental mesenchymal dysplasia was considered but it was not felt to be typical. Arteries within stem and intermediate villi were excessively muscularised (Arrows, Fig. 1B) but without features of fetal thrombotic vasculopathy, specifically there was no evidence of haemorrhagic endovasculitis, intimal cushions or occlusive thrombi. Terminal villi showed normal development of vasculosyncytial membranes (Fig. 1C). Analysis of cultured placental membrane and villus samples showed a male karyotype with trisomy for both chromosome 12 and chromosome 15 (Fig. 1D). No evidence of mosaicism was detected in 56 cells from the mesenchymal core, which originates from the inner cell mass. Cytocell 12 and 15 centromere probes were used to perform fluorescence in situ hybridization studies (FISH) on 40 uncultured fetal skin
700
L.R. Goodfellow et al. / Placenta 32 (2011) 699e703
Fig. 1. A) Low power view showing enlarged stem villi with excessive stromal tissue (marked with arrows). B) View of enlarged stem villus showing muscular hypertrophy surrounding artery. C) Terminal villi showing appropriate development of vasculosyncytial membranes for 32 weeks gestation D) Chromosome spread from placental tissue showing trisomy 12 and 15 (marked with arrows) E) fISH from fetal skin fibroblast cells showing diploid state for chromosomes 12 (red) and 15 (green).
fibroblast cells. Due to maceration tissue from the internal organs was not sent for cytogenetic analysis. All fetal skin cells examined showed a normal diploid signal for both chromosomes 12 and 15 (Fig. 1E). This suggests the pregnancy was affected by CPM with the abnormal 48, XY, þ12, þ15 cell line confined to the extra-fetal tissues. Chromosomal analysis of mother and father revealed normal karyotypes. 3. Discussion This case of stillbirth was associated with CPM of both chromosome 12 and chromosome 15 in a histologically abnormal placenta. This is the first such case described. CPM is found in approximately 1e2% of pregnancies when chorionic villus sampling (CVS) is performed late in the first trimester [4], but interestingly about half of the cases of mosaicism seem to regress and are not found at term [5]. In cases of mosaicism of viable trisomies (13, 18 and 21) diagnosed on CVS, amniocentesis is offered to assess the risk of mosaicism in the fetus. The relationship between CPM and pregnancy outcome in rare placental trisomies is summarized in Table 1. Overall, excluding terminations of pregnancy, CPM is associated with: normal live births (79.7%), fetal anomalies (2.7%), 68 FGR (9.3%), 53 FDIU/spontaneous miscarriage (7.2%) and 8 neonatal deaths (1.1%). Therefore, in the case of rarer trisomies it is normal to reassure parents that this is unlikely to affect pregnancies
that survive the first trimester [6]. However, persistent CPM is clearly linked to preeclampsia, fetal growth restriction and stillbirth (Table 1) [7]. The reasons for the variations in perinatal outcome may result from inherent differences in CPM. Firstly, the cell type affected affects pregnancy outcome. In type 2 CPM (trisomy confined to mesenchymal cells) the incidence of preterm birth and FGR is comparable to controls. However, with type 3 CPM (trisomy in cytotrophoblast and mesenchymal core) the incidence of FGR and preterm birth is increased (p < 0.001) [8]. Secondly, the nature of the abnormality conferred by the extra chromosome(s) is likely to alter the structure, and function of the placenta although no definitive microscopic abnormalities have been described. Notably, a review of 24 placentas with CPM found 10 had abnormalities including lymphocytic villitis, perivillous fibrin deposition and focal villous immaturity [9]. It can be speculated that abnormal morphology impacts on placental function, leading to FGR. In this case trisomy of two chromosomes could have had a larger impact on placental function than either trisomy alone, which may have contributed to fetal demise. Finally, the process of abnormal chromosomal development may also affect the fetus. In the case of CPM developing during meiosis it is necessary for the fetal cells to undergo “trisomic rescue” whereby one of the unmatched chromosomes is expelled, reverting to a diploid karyotype. However, if the remaining chromosomes are of the same parental origin then the fetus will be
Table 1 Summary of studies detailing outcomes of pregnancies affected by CPM of rare trisomies. Studies have been excluded in which all/part of the dataset has been reported previously. In appropriate studies only the relevant data has been extracted from the whole dataset. *Triploidy reported meeting Noomen’s criteria for “high level”. ASD ¼ atrial septal defect,CVS ¼ chorionic villous biopsy, FDIU ¼ Fetal death in utero, IUGR ¼ Intrauterine growth restriction, as defined by the study, live born unless otherwise stated, SM ¼ Spontaneous miscarriage, TOP ¼ Termination of pregnancy, NND ¼ Neonatal death. Author
Reference
Number of pregnancies with CPM
Method of identifying CPM
Trisomic chromosome
Gestation range (weeks)
Infant outcome/ complications
Follow up period of child/children
Kalousek and Dill
Science 1983; 221:665e7
2
X, 22
38, 40
2 IUGR
Birth
Kalousek et al Johnson et al
Hum Genet 1987; 77:163e7 Obstet Gynecol 1990; 75:573e7
5 49
Placental cytogenetics of normal and IUGR pregnancies CVS CVS
12, 13, 14, 17, marker Not stated
Term Not stated
Birth Birth
Kalousek
Placenta 1990; 10:69e77
3
Not stated
1st trimester
Kalousek et al
Prenat Diagn 1991; 11:743e50
34
Placental and fetal cytogenetics of complicated pregnancies CVS with confirmation in placenta at delivery
2TOP, 3 normal live birth 4 SM, 7 TOP, 2 FDIU, 1 NND, 1x cerebral atrophy, 1 IUGR, 33 normal live births 3 1st trimester SM (from sample of 20 1st trimester SM)
2, 7,6p, 8, 10, 12, 13, 16, X, triploidy
20-term
Only 17/34 CVS diagnosed CPM were found in placenta at delivery. Of these 1 SM at 20 weeks, 5 IUGR, 11 normal live births. CPM in CVS only (n ¼ 17) all normal live births
Birth
Wapner et al
Prenat Diagn 1992; 12:347e55
108
CVS
Not stated
39.2þ/ 1.9
Birth
Fryburg et al
Prenat Diagn 1993; 13:481e94
39
CVS
2, 5, 7,8, 9, 13, 16, 18, 20, 21, X
20-term
Roland et al
Prenat Diagn 1994; 14:589e93
26
CVS
mean ¼ 39.8
Birth
Wolstenholme et al “Study 1”
Prenat Diagn 1994; 14:345e61
73
CVS
7, 8, 9, 12, 15, 16, 17, 18, 20, X, markers 2, 3, 5, 7,8, 9, 10, 11p, 13, 15, 16, 18, 20, 21,X, rearrangements, multiple, markers, triploid, tetraploid
3 SM <16 wks, 3 SM/FDIU 17e27 wks, 1 FDIU>27 wks, 74 live births. 8 TOP (USS normal), 1 SM at 20 weeks, 2 IUGR, 1 NND, 27 normal live births 1 SM at 11 weeks, 25 live births. 2 SM, 5 TOP, 1 FDIU, 57 live births, 4 unknown. Significant increase in both low and high birthweights compared to matched controls
Wolstenholme et al “Study 2”
Prenat Diagn 1994; 14:345e61
6
9, 16, 22, multiple, del (13)(q13)
27e35
3 IUGR, 2 NND, 1 FDIU
5e30 months
Artan et al
Prenat Diagn 1995; 15:1135e42
6
14, 21, 18, X, triploidy*
36e41
All IUGR live births
Birth
Christian et al
Prenat Diagn 1996; 16:323e32
4
Placental cytogenetics of IUGR pregnancies Placental cytogenetics of term pregnancies CVS
15
15-term
Birth
Schaffer
Prenat Diagn 1996; 16:899e905
9
CVS
2
34-term
Goldberg et al
Am J Obstet Gynecol 1997; 178:1349e53
114
CVS
Not stated
Not stated
Robinson et al
Am J Hum Genet 1997; 60:917e27
49
CVS (47 cases) and placental cytogenetics (7 cases)
2, 3, 7, 8, 9, 10, 12, 15, 16, 22, multiple, marker
Not stated
Saks et al Djalali et al
Prenat Diagn 1998; 18:1202e4 Prenat Diagn 2000; 20:933e938
1 1
CVS CVS
8 12 and 13
37 Not stated
1 TOP for PradereWilli syndrome, 3 normal live births 1 TOP, 2 IUGR, 6 normal live births 5 SM and 5 TOP, 9 preterm delivery, 2 IUGR, 94 normal live births 5 TOP (2 associated with IUGR), 2 IUFD, 13 IUGR (2 leading to NND), 1 neonatal anomalies, 28 normal live births IUGR. Developmentally normal. TOP, post mortem showed facial dysmorphism
5e65 months
Birth
L.R. Goodfellow et al. / Placenta 32 (2011) 699e703
32e42
n/a
Birth 0e5 years
Birth
1 year n/a 701
(continued on next page)
702
Table 1 (continued ) Author
Reference
Number of pregnancies with CPM
Method of identifying CPM
Trisomic chromosome
Gestation range (weeks)
Infant outcome/ complications
Follow up period of child/children
Kuchinka et al
Prenat Diagn 2001; 1:36e9
2
CVS
4
30, term
1 year
Stipoljev et al
Fetal Diagn Ther 2001; 16:4e9
2
15, 16p-
32, 35
Bryan et al
Prenat Diagn 2002; 22:137e40
1
Cytogenetic analysis of IUGR placentas CVS
1 FDIU at 30 weeks, 1 normal live birth Live births, IUGR
22
32
1 year
Roberts et al
Prenat Diagn 2003; 23:564e5
1
CVS
2
26
Stetten et al
Am J Med Genet 2004; 131A:232e9
28
CVS
X, 7, 8, 9, 10, 18, 20, 21 multiple, triploidy
13-term
Minor et al
Am J Med Genet 2005; 140A:24e30
3
7q/Xp, tetraploidy
Term
Amor et al
Prenat Diagn 2006; 26:443e8
36
Placental cytogenetics of pregnancies derived through ISCI CVS
IUGR and hypospadias. Developmentally normal. Oligohydramnios, IUGR and NND aged 3 days 1 SM at 13 weeks, 3 TOP (one with holoprosencephaly), 24 live births including 3 preterm births (32, 35 and 35 weeks) and 1 speech and language delay at 42 months. 1 spina bifida, 2 normal live births
2, 7, 8, 9, 12, 13, 17, 18, 20, markers, X
Not stated
Langlois et al
Prenat Diagn 2006; 26:548e58
19
CVS
16
30e41
Miura et al
Am J Med Genet 2006; 140A:1827e33
8
2, 7, 13, 22, multiple, del(2) (p16)
35e38
Wilkins-Haug et al
Prenat Diagn 2006; 26:428e32
12
Cytogenetic analysis of IUGR placentas Cytogenetic analysis of IUGR placentas and matched controls
8, multiple (17 and 21), triploidy*
29e40
Yong et al
J Obstet Gynecol Can 2009; 31:605e10
69
CVS
2, 4, 7, 8, 9, 10, 11, 13, 15, 16, 17, 18, 20, 21, 22 and multiple
Not stated
Robinson et al
Prenat Diagn 2010; 30:1e8
5 (one set of twins)
2, 7, 13
31e41
Sifakis et al
Prenat Diagn 2010; 30:329e32 Prenat Diagn 2010; 30:1155e64
44
Placental cytogenetics of IUGR or abnormal maternal serum screen pregnancies CVS
2
32e42
57
CVS
2, 5, 6, 7, 8,9, 10, 12, 15, 16, 17, 18, 20, 21, 22, markers, X, multiple
17-term
1 SM at 15 weeks, 6 IUGR live births, 37 normal live births 1 SM at 17 weeks, 1 FDIU at 27 weeks, 1 FDIU at 35 weeks, 1 TOP for PradereWilli syndrome, 18 IUGR, 1 NND, 34 normal live births
3 days 0e42 months
Birth
4e11 years
1e15 years
1 year
Birth
Birth
Birth
Birth Birth
L.R. Goodfellow et al. / Placenta 32 (2011) 699e703
Toutain et al
Followed children born following antenatal diagnosis of CPM. No increase in IUGR between cases and matched controls between 4 and 11 years. 2 hypospadias, 1 left renal agenesis, 1 cardiac anomaly, 1 thyroid agenesis and IUGR, 2 cardiac anomaly and IUGR, 2 IUGR, 1 speech delay, 9 normal live birth 1 ASD and hypospadias, 1 Russell-Silver syndrome- died aged 12 months, 6 IUGR 11 IUGR of which 9 had abnormal placental histology (infarct, decidual vasculopathy or intervillous thrombus). 1 normal live birth. 1 imperforate anus, 1 hypospadias, 1 hip dysplasia, 1 hydronephrosis, 1 VSD, 2 familial phenotypes, 56normal live births (89%). 1 FDIU at 31 weeks (twin A), 4 IUGR (including twin B), 1 normal live birth
Birth
L.R. Goodfellow et al. / Placenta 32 (2011) 699e703
affected with uniparental disomy which can cause birth defects if it affects imprinted genes (such as the association between chromosome 15 and PradereWilli/Angelman syndromes) [10]. It is possible that our case had true fetal mosaicism for one or both chromosomal trisomies. However, a compilation of 469 cases of antenatally diagnosed mosaicism in CVS samples which were followed for fetal outcome found that only 3.2% of fetuses had evidence of trisomy when the CVS showed a rare autosomal trisomy. This is in contrast to 19% of fetuses having affected tissues following a CVS result of trisomy 13, 18 or 21 [11]. Mosaicism affecting two chromosomes was not described in the largest study of rare trisomy mosaicism to date [12], although a smaller study showed multiple trisomy in 5 cases (7%) [9]. This case highlights the benefit of placental examination in determining cause of stillbirth and potential adverse effects of CPM. In the absence of structural fetal anomalies and presence of abnormal placental structure, placental cytogenetics may be justified to identify CPM. Therefore, it may be prudent to take a fresh frozen sample of placental tissue before fixing the placenta for histological examination after a stillbirth. Further studies are needed to investigate the link between CPM and adverse perinatal outcome. References [1] Korteweg FJ, Gordijn SJ, Timmer A, Holm JP, Ravise JM, Erwich JJ. A placental cause of intra-uterine fetal death depends on the perinatal mortality classification system used. Placenta 2008;29(1):71e80.
703
[2] Heazell AEP, Martindale EA. Can post-mortem examination of the placenta help determine the cause of stillbirth. Journal of Obstetrics and Gynaecology 2009;29(3):225e8. [3] Thompson JMD, Irgens LM, Skjaerven R, Rasmussen S. Placenta weight percentile curves for singleton deliveries. BJOG: An International Journal of Obstetrics and Gynaecology 2007;114(6):715e20. [4] Kalousek DK, Dill FJ. Chromosomal mosaicism confined to the placenta in human conceptions. Science 1983;221(4611):665e7. [5] Kalousek DK, Howard-Peebles PN, Olson SB, Barrett IJ, Dorfmann A, Black SH, et al. Confirmation of CVS mosaicism in term placentae and high frequency of intrauterine growth retardation association with confined placental mosaicism. Prenatal Diagnosis 1991;11(10):743e50. [6] Amor DJ, Neo WT, Waters E, Heussler H, Pertile M, Halliday J. Health and developmental outcome of children following prenatal diagnosis of confined placental mosaicism. Prenatal Diagnosis 2006;26(5):443e8. [7] Kalousek DK, Barrett I. Confined placental mosaicism and stillbirth. Pediatric Pathology 1994;14(1):151e9. [8] Toutain J, Labeau-Gauzere C, Barnetche T, Horovitz J, Saura R. Confined placental mosaicism and pregnancy outcome: a distinction needs to be made between types 2 and 3. Prenatal Diagnosis 2010;30(12e13):1155e64. [9] Yong PJ, von Dadelszen P, McFadden DE, Barrett IJ, Kalousek DK, Robinson WP. Placental weight in pregnancies with trisomy confined to the placenta. Journal of Obstetrics and Gynaecology Canada 2009;31(7):605e10. [10] Christian SL, Smith ACM, Macha M, Black SH, Elder FFB, Johnson JMP, et al. Prenatal diagnosis of uniparental disomy 15 following trisomy 15 mosaicism. Prenatal Diagnosis 1996;16(4):323e32. [11] Phillips OP, Tharapel AT, Lerner JL, Park VM, Wachtel SS, Shulman LP. Risk of fetal mosaicism when placental mosaicism is diagnosed by chorionic villus sampling. American Journal of Obstetrics and Gynecology 1996;174(3): 850e5. [12] Hsu LYF, Yu MT, Neu RL, Van Dyke DL, Benn PA, Bradshaw CL, et al. Rare trisomy mosaicism diagnosed in amniocytes, involving an autosome other than chromosomes 13, 18, 20, and 21: karyotype/phenotype correlations. Prenatal Diagnosis 1997;17(3):201e42.