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. However, ultrasound determination of the date of ovulation has the same imprecision as does the ultrasound estimate of the gestational age and, therefore, a precise date of conception cannot usually be determined as with in vitro fertilization. In addition, although a woman is most likely to become pregnant if she has sex on the day of ovulation conception may also occur from live sperm still in her reproductive tract on the day of ovulation if she had sex for up to five days before ovulation [26,27]. The due date may be estimated by adding days 9 months and 7 days to the first day of the last menstrual period LMP. This is the method used by "pregnancy wheels".

Ultrasound scans in pregnancy



Pregnancy Due Date Calculator
Last Updated on March 23, An ultrasound scan sends high-frequency sound waves to the uterus during pregnancy to capture the image of the foetus. Images in ultrasound scans reveal the developmental phases of the body, often revealing bones and tissues through shades of white and grey. An ultrasound scan is used to get a sneak peek of your baby and analyse how the foetus is faring inside the womb. However, the gender of the baby is not revealed through an ultrasound scan in India, as it is considered illegal. Nowadays, 4D and 3D colour scans are popular ultrasound choices during pregnancy for revealing high-quality images of babies.


Ultrasound during pregnancy
By Anna Nowogrodzki. Early pregnancy can feel unreal. So the first ultrasound picture can feel momentous: Finally, your whirring brain can be placated with direct proof. For this guide, I interviewed two obstetricians who specialize in ultrasounds — and a radiologist whose observation led to a diagnostic breakthrough — to find out what you need to know about prenatal ultrasounds. Usually an ultrasound technician or your ob-gyn will perform an ultrasound.




A prenatal ultrasound scan uses sound waves to create a visual image sonogram of your baby, placenta, and uterus during pregnancy. It allows your healthcare practitioner to gather valuable information about the progress of your pregnancy and your baby's health. During the test, an ultrasound technician sonographer uses a handheld instrument called a transducer to send sound waves through your uterus. These waves bounce off your baby, and a computer translates the echoing sounds into video images that reveal your baby's shape, position, and movements.