Charlotte Lozier Institute

Phone: 202-223-8073
Fax: 571-312-0544

2776 S. Arlington Mill Dr.
Arlington, VA 22206

Get Notifications

Sign up to receive email updates from Charlotte Lozier Institute.

This field is for validation purposes and should be left unchanged.

Voyage of Life

Be amazed. Modern medicine and science tell us more about the development of each human being from fertilization to birth than ever before.  Join us on a journey where science enlightens us at every step, from the first time a human heart beats, toes wiggle, ears hear music, and unborn eyes see light – all before being born into the world.  It’s a journey you’ll never forget!

Weeks 1 and 2
Week 3
Week 4
Week 5
Week 6
Week 7
Week 8
Week 9
Week 10
Week 11
Week 12
Week 13
Week 14
Weeks 15 & 16
Weeks 17 & 18
Weeks 19 & 20
Weeks 21 & 22
Month 6
Month 7
Month 8
Month 9 and Birth
Human Prenatal Age
  • Preparing for Pregnancy
Sperm formation, egg maturation and ovulation

A new human being forms at fertilization, when a man’s sperm fuses with a woman’s egg. Within the next two decades, that newborn becomes a 30 trillion cell adult! Before a new life can form, a woman’s body must prepare for pregnancy, and a man’s body must produce sperm.

Human Prenatal Age
  • Post-conception week 1
  • Days 0-6
  • Gestational Week 3
Fertilization and journey to the uterus

In the third week gestation, the sperm and the egg unite to create a unique single-celled human, the zygote, with all the genetic instructions to form an adult with distinct physical features. The embryo follows a predictable set of cell divisions for the first week after conception, forming a morula and blastocyst as the developing human travels through the mother’s fallopian tubes.

Human Prenatal Age
  • Post-conception week 2
  • Days 7-13
  • Gestational Week 4
Implantation and beginning of nourishment

Just as infants need a safe, nourishing environment to grow outside the womb, the embryo needs a safe place to grow for the next 37 weeks. During the fourth week, the preborn baby attaches to his mother in a process called implantation.

Human Prenatal Age
  • Post-conception week 3
  • Days 14-20
  • Gestational Week 5
The emergence of a body plan

Remember how the zygote and the early embryonic cells could become many different types of cells in the human body? In the fifth week, the cells specialize based on their position in the embryo. Brain tissue and heart tissue begin to develop.

Human Prenatal Age
  • Post-conception week 4
  • Days 21-27
  • Gestational Week 6
First heartbeat and neural tube development

In the sixth week, the embryonic heart starts beating rhythmically, moving oxygenated blood throughout the developing embryo. Without the beating heart, the embryo cannot survive. The neural tube, which becomes the brain and spinal cord, forms.

Human Prenatal Age
  • Post-conception week 5
  • Days 28-34
  • Gestational Week 7
Limbs and major organs form

In week seven, the preborn baby is 10,000 times bigger than he was at conception, about the size of a blueberry. Almost all the major organs have started to form, and the brain starts growing at an average rate of 250,000 neurons per minute.

Human Prenatal Age
  • Post-conception week 6
  • Days 35-41
  • Gestational Week 8
The first responses to touch

In the eighth week, the embryo starts moving and responds to a light touch. This shows that neurons and muscles form functional connections, the same connections that will underlie complex thought processes in an adult. The hands and the face continue developing this week.


Human Prenatal Age
  • Post-conception week 7
  • Days 42-48
  • Gestational Week 9
Brain activity and spontaneous movements

In week nine, networks of neurons produce brain waves that have been recorded as early as 8 ½ weeks gestation. The embryo spontaneously moves his arms, hands, and legs, and may even hiccup. The embryo’s heart now has all four chambers.

Human Prenatal Age
  • Post-conception week 8
  • Days 49-55
  • Gestational Week 10
Fingers, toes, and a working digestive system

By week 10, more than 90% of the body parts have formed. Already, the embryo will show a preference for either her right or left hand as she moves in the womb. The eyeballs finish forming.


Human Prenatal Age
  • Post-conception week 9
  • Days 56-62
  • Gestational Week 11
Complex behaviors

In week 11, the fetus moves a lot! In fact, the fetus does not usually stay still for more than 13 minutes at a time! Male and female genitalia start developing.

Human Prenatal Age
  • Post-conception week 10
  • Days 63-69
  • Gestational Week 12
Growth spurt, nails, and fingerprints

By week 12, the fetus’s heart has beat over 10 million times! The fingernails start growing and fingerprints start forming. If something tickles the sole of the fetus’s foot, she will curl her toes. Tooth buds are developing as well.

Human Prenatal Age
  • Post-conception Week 11
  • Days 70-76
  • 3 Months Pregnant
  • Gestational Week 13
Complex facial features and behaviors

In week 13, the fetal heart pumps about 6 quarts of blood per day. Furthermore, antibodies from the mother transfer to the fetus, so vaccines given to the mother often provide the child with initial protection against some diseases as well.

Human Prenatal Age
  • Post-conception Week 12
  • 4 Months Pregnant
  • Gestational Week 14
Goal-oriented hand movements

In week 14, the intestines start absorbing nutrients and the fetus starts making goal-oriented hand movements. Mature tastebuds cover the tongue, and the placenta provides a barrier that protects against most bacteria and some viruses.

Human Prenatal Age
  • Post-conception week 13 & 14
  • 4 Months Pregnant
  • Gestational Weeks 15 & 16
Sensory systems and pain

Scientific advancements provide clear evidence that the fetus feels pain by 15 weeks gestation, and possibly even earlier. Eyebrows form and the fetus moves each finger separately. Boys and girls move differently in the womb, and may respond to loud noises.

Human Prenatal Age
  • Post-conception week 15&16
  • 5 Months Pregnant
  • Gestational Weeks 17&18
Stress response and sensations

In weeks 17 and 18, the mother may feel her preborn child moving. Also, one research study shows that a fetus as young as 18 weeks responds to a painful procedure with a stress response that includes recoiling and increasing circulating stress hormones in his bloodstream.

Human Prenatal Age
  • Post-conception week 17&18
  • 5 Months Pregnant
  • Gestational Weeks 19&20
Breathing, crying, and the rooting reflex

In weeks 19 and 20, the fetus shows a clear response to pain in multiple scientific studies, and early brain pathways are mature enough to create a perception of pain. The fetus also practices breathing, crying, and breastfeeding in the womb. The fetal heart has beat over 20 million times and circulates about 55 quarts of blood per day.

Human Prenatal Age
  • Post-conception week 19&20
  • 5-6 Months Pregnant
  • Gestational Weeks 21&22
Preparing for life outside the womb

The youngest premature baby to survive was born at 21 weeks and 1 day gestation (132 days premature). As hospitals invest in life-saving technologies to save their smallest, most miraculous patients, the age of viability gets younger and younger, bringing joy and hope to many families.

Human Prenatal Age
  • Post-conception week 21-25
  • 6 Months Pregnant
  • Gestational Weeks 23-27
Response to sound, light, and maternal diet

In month six, the fetus consistently responds to loud noises, music, reading, and singing with changes in behavior. The eyes continue maturing and respond to changes in light. The fetus practices breathing in the womb.

Human Prenatal Age
  • Post-conception week 26-29
  • 7 Months Pregnant
  • Gestational Weeks 28-31
Sleep patterns and learning

At seven months the fetus shows a variety of sleep and wake patterns throughout the day. The fetus overproduces neurons such that at 28 weeks, he has more neurons than he will ever have again. The fetus can start learning sound patterns, and can smell different odors in the amniotic fluid.

Human Prenatal Age
  • Post-conception week 30-33
  • 8 Months Pregnant
  • Gestational Weeks 32-35
Brain growth and lung maturation

In month eight the fetal brain is ready to learn! At 34 weeks, neurons are creating 40,000 new connections, called synapses, every second! With repeated exposures, the fetus can learn flavors, nursery rhymes, songs, and even words that she will recognize after birth!

Human Prenatal Age
  • Post-conception week 34-38
  • 9 Months Pregnant
  • Gestational Weeks 36-40
Labor, delivery, and new beginnings

In month nine, the lungs finish maturing and the baby is born. In the womb, the infant’s lungs are half-filled with amniotic fluid, but multiple processes help clear the lungs. Most babies are born around 40 weeks. A newborn has terrible visual acuity and limited color vision. However, she can identify her mother simply by her smell, voice, or a silent video of her face.