Welcome to week 5 of your pregnancy!
What’s Happening During Week 5:
Fertiliztion usually occurs within a day of ovulation (day 15 of your 28 day cycle) typically inside longest and widest portion of the fallopian tube as I described in week 3. After the fusion of the sperm as well as the egg this new form is known as a zygote. A zygote is the earliest developmental stage of the human and is a cell containig 46 chromosomes, formed with the joining of 23 chromosomes from each parent. 5th week of pregnancy This new cell remains a zygote for about 2 days during which this cell mass divides repeatedly since it travels down the fallopian tube towards the uterus. Once it forms in a solid ball of 12 or more of these cells, the zygote starts to resemble a mulberry hence this new structure is now referred to as a morula which is Latin for mulberry. ( morula video ) This morula enters the uterine cavity on day 18 or 19 of the cycle. Fluid inside endometrial cavity penetrates this cell mass to create a central cavity. When this occurs the morula is changed into what is now termed as a blastocyst. When this happens the blastocyst as well as tissue is divided into two extremely important layers. The surface, the trophoblast creates the chorionic membranes and also the fetal contribution towards the placenta. The inner cell layer develops in to the embryo, amnion, umbilical cord and the yolk sac. In the end of the 3rd week the blastocyst begins to implant into the thickened endometrium. Through the 4th week the blastocyst measuring merely the size of a pin head across becomes fully imbedded in the emdometrial tissue. The endometrial tissue will be the lining of your uterus or womb this is certainly thick in preparation for this implantation. It is at this time in the event the blastocyst and trophoblastic tissue invades the endometrium which a small amount of bleeding can happen, called implantation bleed, and flows out of your vagina and can be confused with a menstrual period. This is a time once the cells multiply and differentiate rapidly. Part of this formation is the yolk sac a structure that provides nutrients in the early days plus a tiny embryo develops involving the yolk sac and the amnion and primitive placental circulation is now offering been established. At the moment this formation of conception has grown to about 2 to 3 mm which enable it to be identified by advanced ultrasound equipment as a tiny fluid filled sac. 5th week of pregnancy During week 5, a final week of the conception stage of pregnancy you have missed your period and pregnancy is now able to confirmed with the level of HCG in your blood or urine. The fluid filled sac called the chorionic or gestational sac has grown to around 5mm and the yolk sac can be identifed within this fluid filled sac. The embryo has transformed itself into three different layers the ectoderm, mesoderm and endoderm despite these transformations merely the fluid filled sac can be detectable by ultrasound and never the embryo just yet. 5th week of pregnancy |