Dating pregnancy late ovulation
Determining the Date of Conception Because the human egg is capable of fertilization for only 12 to 24 hours after ovulation the date of ovulation may be taken as being the date of conception.
Berghella V, et al., Does transvaginal sonographic measurement of cervical length before 14 weeks predict preterm delivery in high-risk pregnancies? American College of Obstetricians and Gynecologists. Clinical management guidelines for obstetrician-gynecologists. 303, February 2014 Society of Obstetricians and Gynaecologists of Canada.
Multifetal gestations: twin, triplet, and higher-order multifetal pregnancies.
Other Methods For Estimating the Gestational Age Clinical Examination A pelvic examination supported by good menstrual records in the first trimester has been reported to be a reliable method for dating of pregnancy .