Miracle Milestones

            Click on the trimester links below to track your baby’s development. Each section includes facts and photos that will help you visualize your “Miracle Within.” If you would like a more complete guide to your pregnancy, you can purchase your own copy of The Miracle Within right here on the site.

Trimester One      Trimester Two      Trimester Three

Trimester One

Welcome to the First Trimester.
                       
From finding out you’re pregnant to your baby’s development from an embryo to a fetus, the first trimester of your pregnancy is filled with some of the most important developments your baby will make while in the womb.

Out of the thousands of sperm released only one, the “hero sperm” unites with the nucleus of the egg.  When sperm come into the vicinity of an egg, their tail movement becomes more forceful and erratic, propelling them towards their target.  This forceful tail motion helps the sperm to penetrate the egg.
Photo:  © Mona Lisa/Eurelios/Phototake  2006

                       
Are You or Aren’t You? You haven’t missed a period, but lately you haven’t been feeling well. You feel nauseous, overtired, and your breasts are slightly tender. You wonder if you could be pregnant so you pick up an over the counter pregnancy test. The tests measure hCG (human Chorionic Gonadotropin), a hormone secreted by the developing placenta shortly after the egg implants itself into the uterus. The hormone is measured in thousandths of International Units. What does that mean for you? When determining how sensitive a test is, you should look for a lower mIU. The lower the mIU, the more sensitive the test is and, therefore, the earlier the test can detect a pregnancy.

Within 24 hours after fertilization, the fertilized egg divides in half creating two parts. The new entity formed is called a zygote.  The cells begin to multiply rapidly, growing at an unprecedented rate.  It splits from two to four, four to eight, and so on, getting tighter and tighter until the cells are almost fused together.
Photo: © ICAM/Mona Lisa/Eurelios/Phototake 2006

From Zygote to Embryo. The test results are in, and you are definitely pregnant. That was a long two-minute wait, wasn’t it? While you were waiting, your little miracle was going through quite a few changes. It went from a zygote to an embryo! Your embryo will increase in size and develop three layers: the ectoderm, the endoderm, and the mesoderm. Each layer will develop a different system. The ectoderm will form the skin, hair, nails, breasts, lens of the eyes, and enamel of the teeth. Endodermal structures include: lungs, liver, pancreas, bladder, thyroid gland, and the lining of the intestines. The mesoderm will form the entire skeleton (except the skull), muscles, lymph system, spleen, the testes, and ovaries. The most exciting development in this stage is the very primitive heartbeat will develop around the fifth or sixth week.

By the time you are two weeks overdue for your period your little embryo is tube-shaped and about the same size as an uppercase “C”.  Its head fold is now very distinct from its tail fold.  The embryo has a pointed tail and gill-like structures from which several other structures will develop, such as the lower jaw and voice box. There is a mouth opening and the beginning of an inner ear.

Photo: © Petit Format / Photo Researchers, Inc 2006.

The Early Embryo.  Although your embryo is going through a lot of changes, it is still very small—about the same size as an uppercase “C.” A simple one-chamber heart has formed. The heartbeat can be detected by ultrasound and beats between 40-80 times per minute. During the course of the week, the heart will double in size! Other organs are also present in very primitive form: lungs, liver, pancreas, and thyroid. Cells that will become sperm or eggs may be seen in the yolk sac wall. These cells start migrating toward the site of the developing testes or ovaries.    

Around the seventh or eighth week your unborn baby measures about 0.3 of an inch.   The embryo’s head which is still bent onto the chest is much larger now and will grow even more to accommodate its rapidly enlarging brain.  Arm buds are now larger than leg buds and there is an obvious tail.  The backbone is now formed and the embryo’s skin is so thin that it is actually transparent.  A face is beginning to appear.

Photo: © Petit Format / Photo Researchers, Inc  2006

Bring on Those Arms and Legs! At six to ten weeks, your embryo is making a lot of progress. The heart now has its final form. The baby’s upper lip, nose, and eyes are all forming. The hands and feet have developed and are shaped like paddles. The arm buds are larger than the leg buds and there is an obvious tail. When the eighth week arrives, your unborn child will now be called a fetus. Your baby has taken a huge leap forward!
By ten weeks all organs are represented and nearly all major structures are formed. Now, your baby’s development will consist of growing in size.

Movement Begins. At eleven or twelve weeks, your baby’s head is erect, and s/he is capable of spontaneous whole body movements. These movements are primitive reflexes and are not regulated by the brain. The brain is not yet developed enough to regulate them and won’t be until after the birth. For the first time, it is possible to distinguish by external appearance whether your fetus is a boy or a girl. Your uterus is now about three to four inches in diameter, is too big to stay in the pelvis, and rises into your abdominal cavity.

Dining for Two. If junk foods were your pre-pregnancy foods of choice, it’s time to toss them in the trash. Not only are they bad for you and your baby, but they also increase your discomfort by causing more heartburn, nausea, vomiting, and constipation. Remember, you are eating for two now, and you are your baby’s only source for nutrients. An adult woman usually needs 1,800 to 2,200 calories per day. Now you will need about 300-600 more calories a day, which can be fulfilled with a glass of milk and a sandwich. You should eat foods that are protein-rich and low in saturated fats, such as fish, turkey, lean beef, and chicken (skinless, of course). Vitamins and minerals are also very important. Get the right amount of calcium to ensure that your baby is a healthy weight when s/he is born. Taking folic acid (600 micrograms/day) will help prevent spinal cord defects. Be sure to take the prenatal vitamins your doctor gives you daily, and remember to stick to that healthy diet.

End of the First Trimester. Both you and your baby have gone through quite a few changes. Your child has completely developed all of the necessary organs, limbs, and features that make him/her distinct. Ultrasounds can now detect breathing-like movements, and the lips are open, allowing your baby to swallow amniotic fluid and excrete it back as urine. As for you, you have probably gained around two pounds and your heart is beating four to eight beats more per minute to accommodate the increase in blood volume. Now, you are truly the caretaker of the generations!

Back to Top

Trimester 2

Welcome to the Second Trimester.

Congratulations . . . you’ve hit the second trimester. Hopefully, you are starting to feel better and are taking on that pregnancy “glow.” Now you can really start to enjoy your pregnancy!

This is your baby around week 14.  Cheeks are developing and movement becomes regular.  In a couple of more weeks you will most likely experience those movements as butterflies in your tummy  At fourteen weeks your baby’s arms and legs are well differentiated.  The skin is very thin and transparent.  Photo:  © Claude Edelmann / Photo Researchers, Inc 2006

A Time of Rapid Growth. Your baby is increasing in length, weight, and density. Now the fetal head can be measured by ultrasound and an estimate of the duration of pregnancy can be calculated from this measurement. Your baby’s eyes are beginning to appear more forward on the baby’s head and the bridge of the nose has developed. The legs have grown in length so that they are now longer than the arms. It may be hard to believe, but at this point the fetus has the same number of nerve cells as an adult!

Your baby at about the 4th month of development, showing the head & upper limbs & the umbilical cord which connects the fetus (at the navel) to the placenta.  There is a lot of room within the uterus and amniotic fluid right now, so the baby just floats freely.  Growth at this time is rapid: the head is still relatively large with a bulging forehead, the outer ear is formed, as are the nose & mouth and the eyes have migrated from the sides of the head. Forearms, wrists, hands & fingers are well differentiated, developing at a faster rate than the lower limbs. 

Photo: © Nestle / Petit Format / Photo Researchers, Inc

Tiny Beats. One of the most exciting moments of your pregnancy will be the first time you hear your baby’s heart beating. When you reach the second trimester, the fetal heart pumps at 117 to 157 beats per minute. The sound can be heard with the aid of a Doppler probe, a small device that amplifies the sound of blood flow within the vessels. It can detect your baby’s heartbeat, amplify it and then transmit it through a speaker so that you and your healthcare provider can hear it.

This beautiful photo of a fetus at 19 weeks shows this baby sucking the thumb surrounded by the transparent membranes of the amniotic sac. 

Photo: © Bromhall / Photo Researchers, Inc 2006

Boy or Girl? At this point in your pregnancy, you may be making the decision about whether or not you want to know the sex of your baby before the day of the birth. Meanwhile, the course of nature is deciding whether you will be having a boy or a girl. If female, the fetus’s ovaries descend from the abdomen into the fetal pelvis. If male, the prostate gland is now first seen. The female fetus has approximately six million eggs by now, but even this early in its development, the fetus’s eggs start to disappear by some still mysterious process of degeneration. By the time of birth, the number of eggs will be reduced to about one million. During a woman’s reproductive life, only 300 to 400 will mature and be released (one each month) as potential candidates for fertilization by sperm. At the end of this trimester, sexual organ differentiation will be complete.

Baby Aerobics. In the second trimester, the fetal skeleton continues to produce more bone. Your baby can bend its arms at the elbow and wrist and make a fist. At this point, however, these movements are purely reflexive and are not controlled by the brain. By week twenty-two, your baby can react to loud noises and music! We don’t know if this represents exercise, but it is fun to think of your fetus doing baby aerobics inside the uterus. The baby will have alternating periods of sleep and wakefulness, and a tap on mother’s abdomen can awaken a sleeping fetus.

Breathing Practice. The fetus can move amniotic fluid into and out of the lungs, about a pint a day it is thought, and excretes a similar amount through fetal urine. True gas exchange will not occur until the air sacs of the lungs expand. This expansion cannot take place until a baby takes its first breath. Swallowing and breathing require complex coordination between the nerves and muscles. It is truly an amazing process!

Walk, Two, Three, Four! To keep both you and your baby healthy, be sure to keep up a moderate exercise routine of about thirty minutes or more a day. Safe exercises include jogging (if you were jogging prior to pregnancy), bicycling, walking, yoga, Pilates, and any other moderate intensity activity that does not involve high-impact contact. If you have questions about what an appropriate form of exercise would be, consult your doctor. If you experience any of the following symptoms while exercising: vaginal bleeding, dizziness, headache, chest pain, muscle weakness, calf pain or swelling, contractions, decreased fetal movement, or amniotic fluid leakage, consult your doctor immediately!!

The Mystery of Genetics. Now is the time for you and your doctor to discuss having an amniocentesis and genetic counseling. Your doctor will base his decision on your family history (any congenital defects or Down’s syndrome), your age, and your exposure to potential toxins. The amnio tests the amniotic fluid for chromosomal abnormalities such
as Down’s syndrome, spinal cord defects, and several X-linked disorders (which means they are handed down from the female side of either parent). If your amnio is normal, it will offer you a great deal of reassurance. If not, you will be armed with information and can begin making preparations at home and within your family for the event of this special birth.

At 20 weeks your baby is very thin, has very little fat underneath the skin and is covered by lanugo (downy hair).  Until he gets more time in the womb he will remain red and wrinkled.  

Danger Zones. During your pregnancy you want to ensure that you are at your healthiest. It is imperative that you avoid habits that endanger you and your baby, such as smoking, drinking, and abusing recreational drugs. Smoking during pregnancy can cause premature births, uterine growth restriction, attention deficit disorder, math and language problems, and auditory processing difficulties. It has also been linked to sudden infant death syndrome. The best thing you can do for your baby is to abstain from smoking and stay away from secondhand smoke as well! Alcohol abuse can cause fetal alcohol syndrome. It is unknown how much alcohol it takes to harm the unborn child; therefore, your best bet is to stay away from it all together. Fetal alcohol syndrome can produce babies who are born early and underweight, have difficulty eating or sleeping, have problems learning or paying attention, or have heart defects and may need medical care all of their lives. Some may die before they are born. Of course, abusing other recreational drugs can negatively affect your baby. Babies born addicted to cocaine and/or crystal meth are underweight, have severe developmental disorders, and do not sleep or eat well. If you are addicted or abuse any of these substances, please seek the help of a doctor immediately. Your baby’s life depends on it!

Back to Top

Trimester 3

Welcome to the Third Trimester.

Well, you’re almost there! Now you are beginning your third (and final!) trimester. This trimester will most likely be your busiest as you attend baby showers and Lamaze classes, have more frequent doctor visits, and prepare your home for your new arrival!

This fetus is about 24 weeks young.  You can see how transparent and thin the baby’s skin remains at this point in its development.  Photo: © Claude Edelmann / Photo Researchers, Inc 2006

Nearing Completion. Your unborn child is maturing at a rapid rate. At the beginning of the third trimester, your unborn child will be about 10 inches in length (crown to rump) and weigh about 2 pounds, 12 ounces. Its foot will measure about 2.1 inches, about the size of a large paper clip. By the end of the trimester, your unborn child will be about 14.5 inches long (crown to rump) and weigh slightly more than 7 pounds.

Getting Ready for Birth. Your baby is beginning to “snuggle” into the pelvis in preparation for birth. There are three possible positions the baby could end up in: cephalic, breech, and transverse. In a cephalic presentation, the fetus’s head is leading and is turned toward the mother’s tailbone. Breech presentations occur only about 3 percent of the time. In a breech presentation, the fetus’s legs are in the bottom of the uterus in various positions. The rarest presentation is the transverse position, which occurs when the baby is lying sideways in the uterus. Unless it can be moved into a cephalic position, a baby in transverse must be delivered by cesarean section. 

Preemies. The closer your baby is born to forty weeks, the greater its chance of survival. Unfortunately, some babies are born too soon. If a baby is born weighing five pounds or less, s/he is considered to be premature. The biggest problem facing most preemies is the trouble they have breathing because their lungs are too immature to perform the complexities of respiration. Thankfully, hospitals throughout the nation have special units designed just for these babies and there are doctors who specialize in the care of premature infants.

Seat Belts. You have gotten much bigger than your pre-pregnancy self, which is making many activities a little more difficult than before—even riding in a car! You know you are always supposed to wear a seat belt, but now that you are far along in your pregnancy, you may be worried about putting a seat belt across your expanding abdomen. Guess what! Your seat belt protects your baby as much as it protects you. Wear it whenever you are in the car, and wear it properly with the lap belt under the abdomen, over both hip bones and the shoulder strap placed between the breasts. Do this and you will be maximizing you and your baby’s safety! 

This is a colored 3-dimensional magnetic resonance imaging (MRI) scan of a healthy fetus approaching full term. The baby is facing towards the mother's back (left). The umbilical cord, is seen at center. The baby’s brain, spinal column, heart, liver and lungs are also visible.  Notice how close to the diaphragm the uterus is.

Braxton Hicks. No, this isn’t a name suggestion for your new baby. Braxton Hicks are periodic uterine contractions. They are usually experienced as a tightening at the top of the uterus that spreads downward and then relaxes. The contractions do not occur at frequent or regular intervals, so they can be distinguished from the start of actual labor. The contractions strengthen the uterus and often provide early dilation or effacement of your cervix before actual labor begins.

Baby’s First Meal. Did you know your fetus has a way of guaranteeing its first meal? While still in the womb, the fetal adrenal gland makes a male hormone called androgen, which circulates to the placenta and is changed to a female hormone, estrogen. The placenta cannot take large amounts of estrogen without this fetal building-block. Large amounts of estrogen, in turn, cause the mother to make a breast-stimulating hormone called prolactin. This process helps create a sticky, watery, milk-like substance known as colostrum, which will be present in your breasts, can usually be expressed from them by hand, and will be the first form of nutrition you give your baby.

This is a full-term infant in the womb.  He will be born with the waxy covering that you see on his head (vernix).  The cord will be clamped and cut and only a small remnant will be left behind.  This remnant will fall off within about 10 days.  It looks like this baby is going to have a full head of hair too.

Making Things Easier. While the goal of many women today is an unmedicated or “natural birth,” medication during labor can be beneficial to the mother and not harmful to the fetus. Pain relief may sufficiently change a mother’s breathing pattern so that the acid content of her blood is better for her baby. Some women choose to receive epidurals and spinals administered in the spinal or epidural space surrounding the spinal cord. These anesthetics have the advantage of blocking sensation in the lower half of the body while the mother remains awake and alert to assist in the birth.

Banking Cord Blood. After the birth, you may choose to bank your baby’s cord blood. The cord blood contains stem cells, which research suggests will be the new wave of treatment for disease. A sample is taken immediately after delivery and mailed to a company that will freeze and then store the sample. Stem cells contain the building blocks necessary to become any cell within the body. Therefore, the sample can be used to treat you, your partner, your child, or a sibling. When stimulated properly, the stem cells have the potential to replace damaged heart cells, kidney cells, and even liver cells. One day stem cells may be used to treat diseases such as Alzheimer’s, Parkinson’s, stroke, kidney failure, diabetes, heart attacks, immune deficiencies, Tay Sachs, testicular cancer, Hodgkin’s, multiple myeloma, brain tumors, and other devastating diseases. However, storing cord blood is expensive. It can cost as much as $2,000 along with a yearly fee, and, unfortunately, it is not covered by insurance.

Back to Top