Polyploidies in abortion material decrease with maternal age

Abstract

Among 639 spontaneous abortions between the 8th and 14th week of gestation 342 (53.5%) revealed an abnormal karyotype. While the rate of trisomies distinctly increased with advancing maternal age, a decrease in the rate of 45,X conceptuses and polyploidies was observed among abortions from older women. The overall relation of XXXX:XXYY among the tetraploidies was 14:11 and that of XXX:XXY:XYY among the triploidies was 26:36:1. However, when the latter was related to maternal age, a reversal of the XXX:XXY ratio of 1:2 in the younger to 2:1 in the older age groups became evident. Furthermore a decrease in the rate of "paternally" derived partial hydatidiform moles was found among the triploid abortion specimens from older women. From these observations we conclude that digyny plays a major role in the origin of triploidy in the increased maternal age groups, while diandry related to immaturity of oocytes and impairment of oocyte cortical function is more frequent in triploid abortions from younger women.

The consequences of tetraploidy and aneuploidy

“…Some mammalian tissues and organs have significant numbers of tetraploid cells that arise as part of the developmental program and usually result in terminally differentiated cells (see Box 2). However, unscheduled polyploidy is not well tolerated in animals; indeed, among spontaneous miscarriages in humans with chromosomal abnormalities, triploidy and tetraploidy are responsible for approximately 20%, and this corresponds to 10% of total miscarriages (Carr et al, 1978;Eiben et al, 1990;Hassold et al, 1980;Neuber et al, 1993;Warburton et al, 1994). Furthermore, an increasing body of evidence suggests that aberrant polyploidy can trigger cell transformation (Duelli et al, 2007;Fujiwara et al, 2005).…”

Epidemiology of triploidy in a population‐based birth defects registry, Hawaii, 1986–1999

“…Investigations into the relationship between triploidy and maternal age either found no association [Uchida and Freeman, 1985;Rochon and Vekemans, 1990;Ford et al, 1996] or a decreased risk of triploidy with increasing maternal age [Neuber et al, 1993]. Triploidy risk does not appear to be influenced by maternal diabetes [Moore et al, 2002], but may be related to delayed fertilization associated with prolonged menstrual cycles or the cessation of oral contraceptive use [Niebuhr, 1974].…”

“…As a consequence of the sex chromosome distribution, the sex ratio of triploidy is 63% male and 37% female [Jacobs et al, 1982;Uchida and Freeman, 1985;Ohno et al, 1991;Neuber et al, 1993;Miny et al, 1995]. Fetuses with triploidy are frequently divided into two phenotypic groups based on the appearance of the fetus and the placenta: well-formed fetus with a normal or small head and large placenta containing cystic changes (type I) and growth-restricted fetus with a large head and small placenta without cystic changes (type II) [McFadden and Kalousek, 1991].…”

“…However, the majority of triploidy conceptuses die in utero, with only one-third surviving beyond 15 weeks' gestation [Warburton et al, 1994] and an estimated 0.08% surviving to term [Doshi et al, 1983]. Triploidy occurs in 1-10% of all spontaneous abortions [Shepard et al, 1989;Ohno et al, 1991;Neuber et al, 1993;Ford et al, 1996;Redline et al, 1998]. Triploidy is uniformly lethal, with no live births reported surviving beyond 10.5 months of age [Sherard et al, 1986].…”

The hydatidiform mole

“…Thus, the number of PHM of dispermic origin are reduced with the age of the patient. 55 This new explanatory framework proposes that the oocyte presents an abnormal cortical reaction which would support the entry of 2 spermatozoids 51 (normally, the release of the cortical granules enzymatic contents prohibits the access to the oocyte to more than one sperm). These various hypotheses assume that the differentiation of the oocyte was inadequate, which reinforces the hypothesis of an immature oocyte.…”