1. A Month to Month Look at a Human Baby’s Development

2. Fertilization

3. Development - Differentiation
What happens during this time?
Fusion of egg and sperm forms the zygote
The zygote undergoes division to increase numbers of cells
It becomes more complex
It grows in size
The cells undergo changes in gene expression and so change with time/place in the embryo; this is called differentiation
Differentiation occurs all through development
Determination is the process by which an unspecialized cell becomes specialized
Some cells do not change; these are stem cells

5. Development of your baby
You will learn according to the month of pregnancy:
Major internal and external organ systems developing in your baby
Functional characteristics: Things your baby does
Cognitive development: Things your baby responds to
Readiness for birth and risk if born at this time
TIPS for coping with the changes of pregnancy
This briefing will help you to understand the development of your baby according to your month of pregnancy and how these developmental changes effect you.
This briefing will include: major organ systems, what your baby actually does that you can’t see, what your baby responds to in the environment, and your baby’s readiness for birth. This briefing will also offer some tips for how you can deal with the changes pregnancy brings.

6. Month 1 Gestational age: Conception to 30 days
Conception: The sperm from the male joins the egg from the female and forms a single cell—either male or female
Implantation: Fertilized egg passes down Fallopian tube into uterus and implants about Day 6
Baby is called an embryo
Embryo doubles in size every day
Gestational age is approximately 2 weeks shorter than menstrual age. This briefing uses gestational age which dates the pregnancy from conception.
Menstrual age: Commonly used by healthcare providers to calculate the estimated date of delivery. A healthcare provider may refer to a pregnancy lasting approximately 40 weeks (280 days) from the first day of the last menstrual period or approximately 38 weeks (266 days) from the date of conception since conception normally occurs about two weeks after the mother’s last menstrual period (LMP). Note that infant development is as much an experience as it is a science and only 5% of babies are born on their exact due date.
Pregnancy is subdivided into three trimesters: Each trimester is 13 weeks long. The first month of pregnancy is when a tremendous number of important changes are happening to the baby, and the mother may not even know that she is pregnant.
TIP: Live a healthy lifestyle even when you don’t know if you are pregnant. This will better prepare you to become pregnant and have a healthy baby.

7. Month 1 (continued)
Placenta and umbilical cord develop to provide nourishment and take away wastes
Bone and nerves of spinal column develop
Internal organs begin to develop
Heart begins beating on Day 25
About ½ inch long and weighs less than 1 ounce
The placenta and umbilical cord provide blood flow to your baby and take away wastes. Your baby’s major organ systems begin to develop. The baby’s heart develops and begins beating about Day 25 when the baby is only ½ inch long and weighs less than 1 ounce (40 peanuts without the shell).
First trimester: Month 1 through month 3

9. Month 2 Gestational age: 31 through 60 days
Critical time in baby’s development with risks from drugs, viruses, and environmental factors
Very rapid development of all major body systems and organs:
brain
lungs
liver
stomach
eyelids
Month 2: Critical time of physical development for your baby when a variety of factors can have ill effects. The mother may not yet know that she is pregnant so a healthy lifestyle that includes eating plenty of folate (folic acid or folacin) is essential.
The things you eat are what your baby gets for nutrition. Any alcohol, illicit drugs, or tobacco can harm your baby. Read the label on over-the-counter medications to be sure they are safe for your baby.
inner ear
ankles
wrists
sex organs

10. Month 2 (continued) Baby now called a fetus
Baby is about 1 inch long and weighs less than 1 ounce
Mom may experience mood swings
Your baby’s body systems are developing rapidly and anything that hinders this development may result in miscarriage (death of the fetus).
Your baby is now called a fetus and is about one inch long and still weighs less than 40 peanuts (without the shell).
TIP: You will likely have dramatic changes in how you feel emotionally one or more times every day. Nausea and heartburn may also occur. This is normal early in pregnancy. Keep lines of communication open and talk to your partner to help him understand how you are feeling.

11. Month 3 Gestational age: 61 through 90 days
May have begun moving hands, legs, head and opening and closing its mouth
Still too small for mother to feel movement
Fingers and toes well developed
Arms are longer than legs
Your baby is beginning to move parts of his/her body but is still too small for you to feel the movement. Fingers and toes are well developed. The baby’s size is mostly from the size of his/her head. Your baby is a great swimmer and begins to swim in the protective amniotic fluid inside the uterus.

13. Month 3 (continued) Head is large compared to the body
Hair, tooth buds, and vocal cords have developed
Heart has four chambers and beats at 120 to 160 beats per minute
Baby is about 4 inches long and weighs just over 1 ounce
Your baby’s heart now has four chambers, just like yours, and beats at a rate of 120 to 160 beats per minute. Your baby is about four inches long and weights just a little more than 40 peanuts (without the shell).
TIP: You may have a lot of “baby stuff” on your mind, but remember to take time out for yourself. Pamper yourself a little: Buy a new lipstick, rent a video that makes you laugh, take a nap.

14. Month 4 Gestational age: 91 through 120 days
Skin pink and partly transparent
Eyebrows and eyelashes appear, ears begin to form
Head is approximately one-half of baby’s entire size
Second Trimester: Months 4 through 6 of pregnancy. Your baby continues to develop rapidly with distinctive characteristics.

16. Month 4 (continued)
Baby moves, kicks, has times of sleep and awake, swallows and passes urine
Mom may feel movement in her lower abdomen (quickening) which feels like bubbles or fluttering
Record the date when this first occurs and tell your healthcare provider at your next visit
Baby is 8 to 10 inches long and weighs about 6 ounces
Your baby is performing more bodily functions and beginning to swallow. This is the earliest time when mom may feel movement in her lower abdomen. This movement of the baby may feel like bubbles or fluttering. It is important to let your healthcare provider know the date that you first feel movement since this helps to estimate the due date.
You may start to gain weight around your stomach so that your regular clothes don’t fit but you may still be too small for maternity clothes. You should be past the morning sickness phase and should also have more energy.

18. Month 5 Gestational age: 121 through 150 days
Rapid growth and development
Internal organs are maturing
Fingernails grow to the tips of fingers
Fat stored beneath baby’s skin
Your baby continues to grow and develop rapidly. The internal organs are maturing. Fingernails grow to the tips of the fingers. Fat is stored beneath the baby’s skin.

20. Month 5 (continued) Baby is growing muscle and gets stronger daily
Milk teeth begin forming under gums
Body hair begins to grow
Regular sleep and awake times, very active turning from side to side and head over heels
Baby is 10 to12 inches long and weighs about 1 pound
Muscle groups form and your baby increases its strength daily. Teeth begin forming under the gums and body hair begins to grow. Your baby’s movements become stronger with active turning from side to side and head over heels.
TIP: Because you are feeling better, you may have increased sexual desire. Sexual expression is different when pregnant and you can take steps to be comfortable with your sexuality as your pregnancy progresses.
INSTRUCTOR: The PPPT Program has an entire PowerPoint Presentation on Sexual Health During and After Pregnancy

21. Month 6 Gestational age: 151 through 180 days
Skin is covered with fine, soft hair and a pasty protective covering
Meconium stool is developing
Brown fat to keep baby warm at birth is developing under the skin
Bones are becoming solid
Your baby continues to develop in the safe environment of the uterus. The skin is wrinkled and red. The skin is covered with fine, soft hair called lanugo and a pasty protective covering called vernix. Meconium stool is forming in the large intestine. Brown fat to keep the baby warm at birth is forming under the skin. Bones are becoming solid.

23. Month 6 (continued)
Baby is nearly fully formed and looks like a miniature person
Lungs are not well developed and baby is very small
Baby cannot survive outside the uterus without highly specialized care
Baby is 11 to14 inches long and weighs about 1.5 pounds
Your baby’s now looks like a miniature human being. Lungs are still not well developed and your baby is very small. He or she has a very poor chance of survival outside the uterus.
TIP: You will feel the baby’s movement more and more. Your stomach has now grown to a point where you probably need some maternity clothes.

24. Month 7 Gestational age: 181 through 210 days
Eyes open and close, and can see light changes
Can hear outside sounds over the mother’s heartbeat
Kicks legs, flails arms, and stretches
Makes grasping motions
Third Trimester: Month 7 to month 9.
Your body is preparing for the delivery of your baby. Your baby’s organs continue to develop and begin to function. Your baby’s eyes open and close and can see changes from dark to light. Your baby hears your heartbeat and now can hear other outside noises like talking and singing. Your baby moves a lot, kicking and flailing as well as stretching and making grasping motions.

26. Month 7 (continued) Sucks thumb Still growing fast inside uterus
Poor chance of survival outside of uterus
Baby is about 15 inches long and weighs 2 to 2.5 pounds
Your baby may suck his/her thumb. Your baby continues to grow rapidly inside the uterus but there is a poor chance of survival outside of the uterus.
TIP: You may occasionally feel Braxton-Hicks contractions that are a brief tightening of the uterus that helps to prepare it for delivery. Over this third trimester your body is preparing to give birth to your baby and the best thing that you can do is be patient, prepare for delivery by attending childbirth classes and follow your healthcare provider’s instructions.

27. Month 8 Gestational age: 211 through 240 days
Continued rapid physical growth
Bones stronger, limbs fatter and brain is forming distinct regions that control body
Brain and nerves direct bodily functions
Your baby continues to grow longer and gain weight. Your baby’s bones become stronger, the arms and legs become fatter, and the brain develops specific regions that control the body. Now, the brain and nerves control bodily functions.
TIP: Make sure you have everything for your newborn baby including a crib with a firm mattress, diapers, and an infant car seat to bring baby home from the hospital.

29. Month 8 (continued) Baby can now: Good chance of survival if born now
Hiccup
Cry
Taste sweet and sour
Respond to pain, light, and sound
Good chance of survival if born now
Baby is about 17 inches long and weighs 4 pounds
Tip: You may find the physical changes of pregnancy make it more and more difficult to move around -- to bend over or get up out of chairs. Take your time and remember that in a few short weeks your baby will be born.

30. Month 9 Gestational age: 241 through 270 days
Baby gains about ½ pound each week
More fat and less wrinkled skin
Baby gets positioned for birth
Drops lower in the mother’s abdomen (lightening)
Your baby is getting big and your uterus is starting to be a little cramped for him or her. The skin is less wrinkled due to the fat deposited under the skin.
The head is now positioned down against the birth canal with the legs tucked up against the chest and the knees against the nose. Your baby drops lower in the abdomen which is called “lightening.”

32. Month 9 (continued)
More rolling side to side, kicking and punching lower in the pelvic area
Bones of the head are soft and flexible for easier passage through birth canal
Lungs are mature
Excellent chance of survival if born before due date
About 20 inches long and weighs 6 to 9 pounds
TIP: You may start to feel many emotions your due date approaches: fear for yourself and your baby, uncertainty about how things are going to turn out, nervousness about parenthood, etc.
To help relieve some stress about so many things that are going on, make a list. Write down the things you need to have at home, the things to take to the hospital, important phone numbers of people to call, etc. Check each thing off as it is done and then move on and do the next thing. This will help you to focus and relieve some of the worry that you are feeling.

33. Questions?