PICTURING PREGNANCY: The journey from embryo to infant means incredible changes for both mother and baby. Witness some of the developmental milestones for both though medical image based illustrations from theVisualMD.com. Image: ISTOCKPHOTO/BOX5
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Genetically, children are a blend of code from both of their parents. But for the first nine months of development, a fetus gets just about everything else from its mother. The two individuals' systems are so intertwined that even after birth, material from a fetus can linger in the mother's body for decades.
The process means major changes for both mother and child. Beginning about three months into pregnancy, the growing fetus and enlarging uterus become visible as a small belly bump. At the end of the second trimester, a woman's uterus has usually reached the size of a papaya to accommodate a 23-centimeter-long fetus, and by the time of a full-term delivery, the uterus will have expanded to about the size of a watermelon, shifting other internal parts around to make room.
In addition to sheer growth, the developing organs and features of the fetus require extra input from the mother's body. In the second two trimesters of pregnancy, women often need an extra 300 calories a day and a range of nutrients to support healthy growth of a fetus—and even more after delivery if the child is being breastfed.
After birth, certain biochemical compounds are at work in both mother and child to sustain and accentuate the bond between the two. Hormones, such as oxytocin, surge in mothers after labor and during breast-feeding, promoting social and emotional bonding with the infant. And in babies, just being touched spurs the release of the same compound, helping them, in turn, bond with their moms and other care takers.
This intensive and intimate journey has been illustrated by the Visual MD, revealing the changes that both mother and child go through during their first year together.
Soon after a zygote attaches to the uterine wall, it begins to develop a simple circulatory system and a primitive neural tube that is the precursor to the nervous system. At this stage, many women still do not yet know they are pregnant.
At five weeks, an embryo has developed a four-chambered heart and begun pumping blood. The beginnings of arms and legs start to appear as small buds—along with a tail, which will eventually transform into the tailbone. Six weeks is often when the mother's body begins to physically react to the new addition, often with nausea or food cravings.