maternal age effect

(redirected from Maternal age & chromosome defects)

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
Mentioned in ?
Full browser ?