The
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!

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Preparing for Pregnancy
Week 0 to 1
Week 1 to 2
Week 2 to 3
Week 3 to 4
Week 4 to 5
Week 5 to 6
Week 6 to 7
Week 7 to 8
Week 8 to 9
Week 9 to 10
Week 10 to 11
Week 11 to 12
Weeks 13 & 14
Weeks 15 & 16
Weeks 17 & 18
Weeks 19 & 20
Month 6 to 7
Month 7 to 8
Month 8 to 9
Month 9 to Birth
Next
Human Prenatal Age
  • Gestational weeks 0-2
Sperm formation, egg maturation and ovulation

A new human being forms at fertilization. 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
  • PCW 1
    i
  • Days 0-6
  • Gestational Week 3
Fertilization and journey to the uterus

In the first week, 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 of pregnancy, forming a morula and blastocyst as the developing human travels through the mother’s fallopian tubes.

Human Prenatal Age
  • PCW 2
    i
  • 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 second week, the unborn baby attaches to his mother in a process called implantation.

Human Prenatal Age
  • PCW 3
    i
  • Days 14-20
  • Gestational Week 5
The emergence of a body plan

Remember how the zygote and the cells after the early cell divisions could become any cell in the human body? In the third week, the cells specialize based on their position in the embryo. Brain tissue and heart tissue begin to develop.

Human Prenatal Age
  • PCW 4
    i
  • Days 21-27
  • Gestational Week 6
First heartbeat and neural tube development

In the fourth week, the embryonic heart starts beating. The neural tube, which becomes the brain and spinal cord, forms. At this point, a woman has likely only been aware of her pregnancy for one week.

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

In the fifth week after fertilization, the unborn 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
  • PCW 6
    i
  • Days 35-41
  • Gestational Week 8
The first responses to touch

In the sixth week after conception, the embryo starts moving and responds to a light touch. This shows that neurons and muscles form functional connections, the same connections that will underly complex thought processes in an adult. The lips and the nose continue forming this week.

 

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

In the seventh week after conception, networks of neurons produce brain waves that have been recorded as early as 6 ½ weeks after conception. 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
  • PCW 8
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  • Days 49-55
  • Gestational Week 10
Fingers, toes, and a working digestive system

During the first eight weeks of development, 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
  • PCW 9
    i
  • Days 56-62
  • Gestational Week 11
Complex behaviors

The fetus moves a lot! In fact, in the ninth week after conception, the fetus does not usually stay still for more than 13 minutes at a time! Tooth buds start developing, as do male and female genitalia.

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

By the tenth week after conception, the fetus’s heart has beat over 10 million times! The fingernails start growing, and fingerprints start forming, too. If something tickles the sole of the fetus’s foot, she will curl her toes.

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

In the eleventh week after conception, 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
  • PCW 12
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  • 4 Months Pregnant
  • Gestational Week 14
Goal-oriented hand movements

In the twelfth week after conception, 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, including COVID-19.

Human Prenatal Age
  • PCW 13&14
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  • 4 Months Pregnant
  • Gestational Weeks 15&16
Sensory systems and sensations

In the thirteenth and fourteenth week after conception, eyebrows finish forming and the fetus moves each finger separately. Boys and girls move differently in the womb, and the fetus swallows more amniotic fluid if it tastes sweet and less if it tastes bitter. The fetus may respond to loud noises.

Human Prenatal Age
  • PCW 15&16
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  • 5 Months Pregnant
  • Gestational Weeks 17&18
Stress response and pain

In the fifteenth and sixteenth week after conception, the mother may feel her unborn child moving. Also, one research study shows that a fetus as young as 16 weeks after conception responds to a needle entering his hepatic vein with a stress response that includes recoiling and increasing circulating stress hormones in his bloodstream.

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

By the seventeenth and eighteenth week after gestation, the fetus shows a clear response to pain in multiple studies, and at least one brain pathway is 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
  • PCW 19&20
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  • 5-6 Months Pregnant
  • Gestational Weeks 21&22
Preparing for life outside the womb

The youngest premature babies to survive have been born in the 19th week after conception (21 weeks gestation). 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
  • PCW 21-25
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  • 6 Months Pregnant
  • Gestational Weeks 23-27
Response to sound, light, and maternal diet

In the sixth month, 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
  • PCW 26-29
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  • 7 Months Pregnant
  • Gestational Weeks 28-31
Sleep patterns and learning

In the seventh month of pregnancy, the fetus shows a variety of sleep and wake patterns throughout the day. The fetus overproduces neurons such that at 26 weeks after conception, 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
  • PCW 30-33
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  • 8 Months Pregnant
  • Gestational Weeks 32-35
Brain growth and lung maturation

In the eighth month of pregnancy the fetal brain is ready to learn! At 32 weeks after conception, 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
  • PCW 34-38
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  • 9 Months Pregnant
  • Gestational Weeks 36-40
Labor, delivery, and new beginnings

In the ninth month, the lungs finish maturing and the baby is born. In the womb, the infant’s lungs are half-filled with amniotic fluid, but the pressure of a vaginal birth helps push some fluid out, or into the lymph system. Most babies are born around 38 weeks after conception (40 weeks gestation). 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.