Impact of ovulation and implantation timing on first-trimester crown-rump length and gestational age.
Ultrasound Obstet Gynecol
; 40(6): 630-5, 2012 Dec.
Article
en En
| MEDLINE
| ID: mdl-22858888
ABSTRACT
OBJECTIVE:
To determine the impact of ovulation and implantation timing on first-trimester crown-rump length (CRL) and the derived gestational age (GA).METHOD:
One hundred and forty-three women who were trying to conceive were recruited prospectively. The timing of ovulation and implantation and the ovulation to implantation (O-I) interval were established in 101 pregnancies using home urinary tests for luteinizing hormone and human chorionic gonadotropin. In 71 ongoing pregnancies, GA determined by measurement of fetal CRL at 10-14 weeks' gestation was compared with GA based on ovulation and implantation day. First-trimester growth was determined by serial ultrasound scans at 6-7, 8-9 and 10-14 weeks.RESULTS:
The median ovulation and implantation days were 16 and 27, respectively, with an O-I interval of 11 days. GA estimated from CRL at 10-14 weeks was on average 1.3 days greater than that derived from ovulation timing. CRL Z-score was inversely related to O-I interval (ρ= -0.431, P=0.0009). There was no significant relationship between CRL growth rate and the difference between observed CRL and expected CRL based on GA from last menstrual period (ρ=0.224, P=0.08).CONCLUSIONS:
Early implantation leads to a larger CRL and late implantation to a smaller CRL at 10-14 weeks, independent of CRL growth rate. Implantation timing is a major determinant of fetal size at 10-14 weeks and largely explains the variation in estimates of GA in the first trimester derived from embryonic or fetal CRL.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Ovulación
/
Implantación del Embrión
/
Largo Cráneo-Cadera
/
Desarrollo Fetal
Tipo de estudio:
Diagnostic_studies
/
Observational_studies
Límite:
Adult
/
Female
/
Humans
/
Pregnancy
Idioma:
En
Revista:
Ultrasound Obstet Gynecol
Asunto de la revista:
DIAGNOSTICO POR IMAGEM
/
GINECOLOGIA
/
OBSTETRICIA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Reino Unido