Influence of parity on first trimester endovascular trophoblast invasion.
OBJECTIVE
To assess the effect of parity on endovascular trophoblastic invasion in early pregnancy.


METHODS
Observational study.


METHODS
Teaching hospital.


METHODS
Healthy women at 10-14 weeks of gestation.


METHODS
Surgical termination of pregnancy for nonmedical reasons.


METHODS
Products of conception were blindly examined histologically with regard to the extent of decidual endovascular trophoblast invasion.


RESULTS
Samples were obtained from 20 nulliparous and 10 parous women. The presence of normal intradecidual endovascular trophoblast invasion was identified with a similar frequency in both groups (P=.28). However, the proportion of decidual vessels with endovascular trophoblast invasion was significantly higher in parous women (60%) compared with nulliparous women (32%, P<.001).


CONCLUSIONS
Endovascular trophoblast invasion in early pregnancy is more extensive in parous women who already had an uncomplicated pregnancy than in nulliparous women.
Division of Obstetrics and Gynaecology, St. George's, University of London, London, United Kingdom. fprefumo@sgul.ac.uk
Federico
F
Prefumo
Ramesh
R
Ganapathy
Basky
B
Thilaganathan
Neil J
NJ
Sebire
D000293:Adolescent; D000328:Adult; D010064:Embryo Implantation / Q000502:physiology; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D006801:Humans; D010298:Parity / Q000502:physiology*; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000502:physiology*; D014327:Trophoblasts / Q000502:physiology*