Non-molar triploidy followed by triploid molar pregnancy in a patient with recurrent miscarriage

1. Non-molar triploidy followed by triploid molar pregnancy in a patient with recurrent miscarriage Bapir M, Hoh J & Al-Inizi S Department of Women Health, South Tyneside District Hospital Harton Lane, South Shields, United Kingdom Discussion Generally accepted causes of recurrent miscarriage include parental chromosomal abnormalities, uterine anomalies, and Antiphospholipid syndrome. More controversial “causes” of recurrent miscarriage include luteal phase inadequacy and other hormonal diagnoses, polycystic ovary syndrome, and infection. However, clinicians and patients find it particularly frustrating that no convincing etiology is identified in at least 50% of cases.5 Warburton et al reported that there is no evidence that having had one pregnancy with a triploid karyotype, that there is any increased recurrence risk of triploidy, or any other chromosome abnormality in any subsequent pregnancy needing amniocentesis.4 Triploids that are partial hydatidiform moles, however, have a 10-fold increased risk of recurrence.6 These cases are usually detected by ultrasound at an early gestation.1 Introduction Recurrent miscarriage, defined as loss of three or more consecutive pregnancies, affect 1% of couples trying to conceive.1 50% of recurrent miscarriage are unexplained, some investigator have demonstrated an association between abortus aneuploidy and recurrent miscarriage. 2 Triploid pregnancies are pregnancies with 69 chromosome rather than 46, occurs in 1-2% of all conception. This chromosomal abnormality gives rise to early miscarriage in most of cases. Several possibilities concerning the origin of the additional set of chromosomes exist: dispermy (the most common), diandry and digyny.3 Fetuses with triploidy can be 69,XXX (female), 69,XXY (male), or 69,XYY (male). Triploidy are sporadic and a woman who has had one triploid pregnancy is not at any increased risk to have a second one.4 However, we report a case of non-molar triploidy followed by triploid molar pregnancy in a 35 years old patient with recurrent miscarriage. Case detail 35 years old, para 1+³, had 1 normal vaginal delivery followed by 3 early miscarriages. She underwent investigations for recurrent miscarriage. All the results were normal including thrombophilia screen and peripheral blood karyotypes for both partners and therefore was considered as unexplained recurrent miscarriage. Her last miscarriage was at 8 weeks gestation. The histological and cytogenetic analysis of the product of conception confirmed 69XXX, maternally derived non-molar triploidy. Four months later, she conceived naturally but was diagnosed with missed miscarriage and underwent surgical evacuation and histological and cytogenetic analysis confirmed 69XYY, paternally derived triploidy partial molar pregnancy. She was followed up appropriately with ß-hCG in the trophoblastic tumour centre. The ß-hCG level eventually dropped to normal without requiring further treatment. Conclusion It was previously reported that pregnancy with triploid karyotype has no increase recurrence risk of triploid or any other chromosomal abnormalities in subsequent pregnancies. Our case has showed that non-molar triploid pregnancy can be followed by another triploid pregnancy which can both lead to miscarriages. Women with unexplained recurrent miscarriages can still have recurrent miscarriages with triploid karyotype, therefore cytogenetic assessment of product of conception is advisable. References 1- The investigation and treatment of couples with recurrent first-trimester and second-trimester miscarriage. Green-top Guideline 17. May 2011. 2- Stern JJ, Dorfmann AD, Gutierrez-Najar AJ, Cerrillo M, Coulam CB. Frequency of abnormal karyotypes among abortuses from women with and without a history of recurrent spontaneous abortion. FertilSteril. 1996;65:250–3. 3- Jambon AC, Tillouche N, Valat AS, Guionnet B, Puech F. Triploidies. J GynecolObstetBiolReprod (Paris). 1998;27(1):35-43 4- Warburton D, Dallaire L, Thangavelu M, Ross L, Levin B, Kline J. Trisomy Recurrence: A Reconsideration Based on North American Data. Am J Hum Genet. 2004;75(3):376–385. 5- Sullivan AE, Silver RM, LaCoursiere DY, Porter TF, Branch DW. Recurrent Fetal Aneuploidy and Recurrent Miscarriage. Obstetrics & Gynecology. 2004;104(4):784-788. 6- Sebire NJ, Fisher RA, Foskett M, et al. Risk of recurrent hydatidiform mole and subsequent pregnancy outcome following complete or partial hydatidiform molar pregnancy. BJOG. 2003;110:22-26.