Fetal Development

Day 1 (Conception)

Scientists have discovered that fireworks of light can be seen microscopically the moment reproductive cells from mother (ovum) and father (spermatozoon) merge into a new and unique living cell. Physical features including eye and hair color, and gender are written in DNA code. No other human with this same DNA has ever lived before. Nothing will be added except time, nourishment, and protection. Scientifically, this is the beginning of a new living human.

Day 5 (Implantation)

Pregnancy is defined as the moment hundreds of organizing cell systems (embryonic stem cells) attach within the mother’s womb (uterus). At this moment, the tiny offspring communicates with mom by sending chemical messages to announce arrival. Some women, if lying still, may even feel the slight pang when her child attaches within her. Once pregnant, pregnancy is then calculated from the first day of the woman’s last menstrual period (LMP), approximately two weeks prior to actual conception.

Day 21 – 3 weeks (5 weeks LMP)

All at once cells in the newly developing heart begin to beat. The heart will continue to beat for the duration of a lifetime. This is usually about the time most women find out they are pregnant.

7 weeks (9 weeks LMP)

Facial features are visible, including mouth and tongue, and eyelids begin to form. The major muscle system begins developing, and the preborn has his/her own blood type. One hundred thousand new brain cells are forming every minute. Baby’s heart is beating 140-150 beats per minute. He or she is about one inch long and weighs ¼ oz.

8 weeks (10 weeks LMP)

The preborn now swims and moves gracefully inside protective amniotic fluid. Every organ is present. Baby’s stomach produces digestive juices and the liver makes blood cells. Kidneys are beginning to function and taste buds are forming. Brain waves can be measured. Baby’s eyelids and palms of their hands are sensitive to touch. Baby is about 1.5 inches.

9 weeks (11 weeks LMP)

Baby moves from embryonic development to fetal development when all organs are fully formed and look the same as a newborn infant. Sometimes referred to as a “fetus” during pregnancy - meaning “little one” or “young one” - babies in fetal development at this age will move away if touched. Unique fingerprints and fingernails begin to show. Nerves begin to function. Preborn babies at this age can suck their thumbs. Male or female organs become visible. Baby is about 2 inches.

10 weeks (12 weeks LMP)

The child is sensitive to touch, squints, swallows, frowns, and smiles. Baby practices breathing and can make movements to cry, but without air, he/she cannot be heard. Bone cells are forming in baby’s skull and backbone. The preborn is approximately 2.5 inches long. Mom is completing her first trimester of pregnancy and typically feeling better from the earlier weeks of hormonal adjustment.

20 weeks (22 weeks LMP)

Baby is large enough for Mom to feel movement. Mom may feel baby turn, hiccup, and may be able to identify a bulge as an elbow or the child’s head. Each side of baby’s brain has a billion nerve cells and appears the same as a newborn’s brain. Mom’s heart has increased capacity to provide the extra oxygen her baby needs. Babies born this early may be able to survive with proper medical care.

25 weeks (27 weeks LMP)

The preborn is able to hear and may startle to loud noises. He or she will sleep and wake, and may nestle in a favorite position, and stretch upon waking up.

27 weeks (29 weeks LMP)

Baby’s eyelids open, preparing to see the outside world. A daughter or son starts recognizing and remembering mom’s voice and voices closest to her. The preborn starts showing preferences for certain kinds of music and food as memory forms.

37-40 weeks (39-42 weeks LMP)

Baby is full-term. Mom’s body is preparing for birth, and the final stages of mom’s development is occurring to prepare to give baby nourishment and immunity through breast milk, which will also give mom an extra protection against breast cancer. Nursing has the added bonus of helping mom lose any unwanted pounds while keeping baby up-to-date with antibodies mom produces in response to exposure to viruses. If the baby is a girl, she already has all the eggs (ova) she will produce in her lifetime. If the baby is a boy, testosterone has washed over the hemispheres of his brain. His or her lung development triggers labor. At birth, the newborn’s lungs open to take in air.