maternal age effect


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maternal age effect

The adverse impact that increased age in the mother has on obstetric events: increased complication rate; increased foetal defects, due to various effects of ageing on the uterus and eggs); and increased frequency of non-disjunctional chromosomal events in Down syndrome and other aneuploidies, as well as Prader-Willi syndrome, in which there is uniparental disomy of chromosome 15.

Maternal age and chromosome defects 
[Age—Frequency of trisomy 21 (Down syndrom)—Frequency of other defects] 
▪ <20—1/1900—1/526
▪ 25—1/1200—1/476
▪ 30—1/885—1/384
▪ 35—1/365—1/178
▪ 40—1/109—1/63
▪ 45—1/32—1/18
▪ 49—1/12—1/7

maternal age effect

The adverse impact that ↑ age has on obstetric events: ↑ complication rate, ↑ fetal defects–possibly due to an unknown effect of aging on the uterus and eggs; ↑ frequency of non-disjunctional events in Down syndrome and other aneuploidies, as well as Prader-Willi syndrome, in which there is uniparental disomy of chromosome 15. See Elderly primigravida. Cf Paternal age.
Maternal age & chromosome defects  
 Age Trisomy 21 Others
 <20 1/1900 1/526
 25 1/1200 1/476
 30 1/885 1/384
 35 1/365 1/178
  40 1/109 1/63
 45 1/32 1/18
 49 1/12 1/7
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References in periodicals archive ?
For older mothers, the maternal age effect may be due to differential selection and accumulation of trisomy 21 oocytes in the ovarian reserve of older women.[sup][53]
The study revealed absence of the maternal age effect on thalassemia diagnosis.
A search for evidence for a paternal age effect independent of a maternal age effect in birth certificate reports of Down's syndrome in New York State.
"The data suggests that what at first looks seems like a negative advanced maternal age effect is an illusion driven by the mother's education and the age at which the child loses the mother," Myrskyla said.
However, results of maternal age effects on larval energy stores and growth in the laboratory may not be an accurate predictor of success in the natural environment (Marshall et al., 2010).
Only eggs laid during this 48-h period were used in this experiment to control for maternal age effects on larval survivorship and development, in which later-laid offspring develop from smaller eggs, have lower survivorship, and take longer to develop (e.g., Wasserman and Asami 1985; Fox 1993; Fox and Dingle 1994).

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