First Trimester Scans
|The first trimester is months one, two, and three of your pregnancy.|
Below are scan pictures taken during the early weeks of pregnancy. Measurements taken at these early scans will help to; confirm a pregnancy, date the pregnancy and to see any problems that may occur in the pregnancy ( low lying placenta, twins etc.).
Scans for week:
Gestational Sac size = 3 to 6mm
Week 4 Scan
The gestational sac first appears at about 4 weeks gestational age, and grows at a rate of about 1 mm a day through the 9th week of pregnancy.
It initially appears as a round, anechoic structure. In experienced hands, it may be detected as early as 30 days gestation by TVU.
At 4 weeks and 3 days, a tiny gestational sac becomes visible within the decidua.
While a gestational sac is sometimes seen as early as during the 4th week of gestation, it may not be seen until the end of the 5th week, when the serum hCG levels have risen to 2500 - 3500 mIU/mL.Gestational Sac week 4 ultrasound scan
Week 5 Scans
An experienced sonographer can detect a yolk sac with transvaginal ultrasound when the gestational sac has reached a mean diameter of 8 mm to 10 mm. The presence of a yolk sac confirms the diagnosis of an intrauterine pregnancy and excludes ectopic pregnancy, except in rare cases of simultaneous intrauterine and extrauterine gestations.The yolk sac is first visible at 5 weeks and it is always present by 5 weeks and 4 days. There are lacunary structures [cavities or spaces] at the site of implantation. The embryonic pole appears adjacent to the yolk sac, soon showing cardiac activity. Since the connecting stalk is short, the embryonic pole is found near the wall.
With transvaginal ultrasonography, cardiac motion can sometimes be seen in a 2-mm to 3-mm embryo, and is invariably detected in normal pregnancy when the length of the embryo reaches 5 mm. At the end of week 5, the heart rate is about 60 – 90 bpm.
Week 6 Scan
The fetal pole grows at a rate of about 1 mm a day, starting at the 6th week of gestational age. Thus, a simple and accurate way to "date the fetus" in an early pregnancy is to add the length of the fetal pole (in mm) to 6 weeks. Using this method, a fetal pole measuring 5 mm would have a gestational age of 6 weeks and 5 days.
More Ultrasound Scan Information:
Charts and tables for: - CRL - BPD - OFD - HC - HL - FL scan measurements.
The gender prediction test result is easy to read! The control test window will change color to either pink (Girl) or blue (Boy).Enjoy - First class