According to the World Health Organization (WHO), as of 2008, approximately 6,758,000 pregnancies gave way to 4,248,000 live births, 1,212,000 induced abortions, and 1,118,000 fetal losses. It was also said that about 650 women die in the United States each year as a result of complications from either pregnancy or delivery. [1, 2]
What To Expect When You’re Expecting
As one infanticipates, the body undergoes through numerous adaptive changes. These alterations are physiologic, but still, every pregnant woman should be conscious and aware of those changes. It is from those changes the complications and problems can ensue. Pregnancy complications may either be a sequence of events triggered by pregnancy, or an unrelated state aggravated by the normal changes at pregnancy. Thus, it is of severe importance that each and every pregnant woman knows what changes to expect on both herself and her unborn child.
This article is a detailed encounter on what each pregnant should expect each week as she is infanticipating.
Pregnancy Week One Symptoms : Preconception
One is not pregnant yet at this time. The week is just included for computation of age of gestation (AOG), and consequently, the expected date of confinement (EDC). These are calculated from the soon to be mother’s first day of her last menstrual period. [3, 4]
Inside the woman’s body, the lining of her uterus is starting to thicken, in preparation for a fertilization, and for pregnancy. It is, thus, in this period that the soon-to-be-mother should begin acting responsibly and start having an adequate diet, free from caffeine, alcohol, and drugs. 
Preconception consultations are also important. This is to prepare the couple for conception, determine necessary lifestyle changes to ensure a healthy course of pregnancy. Folic acid 400 micrograms is recommended to be taken a few months prior to conception to decrease risk of neural tube defects. Certain immunizations (Measles, Mumps, Rubella) are also advised pre-conception to avoid infections that are teratogenic, and even detrimental, to the baby. 
This is an image pertaining to the preconceptual lifestyle changes the soon to be mother has to make. She has to start folic acid intake and has to shift to an adequate diet even at preconception.
Pregnancy Week Two Symptoms : Ovulation
The woman is still not pregnant; however, within the mother’s body, ovulation may occur. It is the period when a mature egg is released from the ovarian follicles into the oviduct. This usually occurs between the eleventh and twenty-first day of the menstrual cycle. 
Progesterone levels of the body had increased to further prepare the uterus, in time for a possible conception. Aside from thickening, it also sets down small blood vessels. 
This is a graph representing the trend in the increasing progresterone levels, which happens in ovulation or the week 2 of pregnancy.
Body temperature levels can rise for 48 hours as the ovulation peaks. Marking the time when women are fertile, a clear, abundant, stretchy or slippery cervical mucus can be observed. Other manifestations of ovulation may also be present, such as hypogastric pain, lower back pain, diarrhea, headaches, and moodswings. 
Preconception consultation is still recommended at this point in time.
Pregnancy Week 3 : Fertilization
Finally… pregnancy! The Sperm finally met the Egg, fertilization occurred. An embryo is formed as a cluster of rapidly multiplying cells called blastocyst. This then travels from the fallopian tube, where the egg and sperm met, to the uterus, where it will implant and attach itself. [4, 5, 7]
An image of the blastocyst, a cluster of dividing cells formed from the fertilized egg after the sperm and egg met.
No manifestations of pregnancy will be present. Even a missed menstrual period will still not take place. The body, in turn, will produce the Human Chorionic Gonadotropin (HCG) hormone, which stimulates the ovaries to produce more progesterone and also prevents the body from shedding the thickened uterine lining. 
Pregnancy Week 4 Symptoms: Poppy Seed
As the start of the embryonic period, the baby’s organs will start to develop, and will be most prone for growth abnormalities. The embryo is now the size of a poppy seed, with cells of its primitive placenta arranged in such a way that blood flows, providing nutrients and oxygen to the growing baby. It also has amniotic sac, amniotic fluid and a yolk sac, offering protection and delivering nutrients to the baby until a developed placenta is present to do its functions. 
An illustration of the physiologic changes in Week 4 of pregnancy, with the primitive placenta, amniotic sac, amniotic fluid and yolk sac all functioning to protect and nourish the baby.
The soon-to-be-mom can also encounter bouts of headache, breast tenderness, backache, bloating, and mood swings. She will either miss her menstrual period or experience some bleeding once the baby is implanting and attaching itself on the uterine wall. A pregnancy test can be done as confirmation by the end of the week. [5, 10]
By the end of Week 4, a pregnancy test can be done as confirmation.
The first prenatal consult must be done, most especially after confirmation thru pregnancy test. Folic Acid 400 micrograms per day should have been started by this time, when the baby’s neural tube (the foundation of his brain and spine) is being formed. 
Pregnancy Week 5 Symptoms : Apple Seed
The baby, now C-shaped, is around 0.12 to 0.13 inches long at this stage. From a poppy seed, it transforms and now resembles an apple seed. The umbilical cord and placenta had now taken over in supplying the baby nourishment, in providing oxygen, and in evacuating his wastes. He is now beginning to form major organs like heart, stomach, liver and kidneys, along with vital body systems like the digestive, circulatory and nervous systems. [4, 5, 7, 10]
During Week 5, the baby’s organs begin to form.
Due to increasing hormonal levels, the mother would likely have more severe breast tenderness. Frequent urination can also be noted in lieu of expanding kidneys. Episodes of abdominal cramps and back pain can also be observed. If this pain worsens, an immediate consult to the obstetrician is warranted. [7, 10]
Pregnancy Week 6 Symptoms : Morning Sickness
Now about 0.25 inches long, the baby now resembles a jelly bean. His heart, now just 2-chambered, can beat around 150 beats per minute. The arms and legs are beginning to develop, his nose, eyes, ears and cheeks are also starting to form. [5, 7, 10, 11]
This image shows the baby in his 6th week, with eyes, ears, hands and feet visible.
Morning sickness and mood swings are very likely to occur. Darkened areola and continued breast tenderness, along with frequent urination, are to be expected. [3, 4, 5, 10]
Pregnancy Week 7 Symptoms : Flex It Baby!
The baby, at this time, presents as a cherry fruit, around 0.51 inches long. His nostrils, tongue, teeth, gums and lips begin to form. His intestines, liver, and kidneys start to develop, along with her joints. [7, 10]
The seven week old baby, who now has his joints, exhibits flexion of extremities.
At seven weeks on the way, the mother may start to feel some exhaustion. However, symptoms such as breast tenderness, nausea and vomiting are still likely to continue. Thus, it is very important to have adequate nourishment, exercise and proper obstetrics consult for the mother. 
Pregnancy Week 8 : The Fetus
The baby, who can now be termed as fetus, is now the size of a raspberry and is around 0.63 inches in length and 0.04 ounces in weight. His face is transforming, having a more defined nose, upper lip, and eyelids. [4, 10]
Fetal development in week 8 shows a more developed pair of eyelids and knee joints.
As for the mother, she may have some episodes of bleeding, which may be due to the increased volume of blood and, at the same time, lack of Ascorbic Acid. This may be seen as nose bleeding, gum bleeding or even breakthrough bleeding. The latter is an indication for immediate consult with the obstetrician. [5, 7]
She may also experience an increased sense of smell, constipation, indigestions and heartburn. Her breasts may also be sore as the milk producing parts of the breasts enlarge. 
Pregnancy Week 9 Symptom Symptoms : Your Tiny Olive
The fetus is now the size of an olive, with 0.9 inches in length, and a weight of approximately 0.07 ounces. The facial features are distinct, the musculoskeletal organs are visible under the thin transparent skin. Ankles are formed, thus further flexion can be noted. Despite the well developed sex organs, sex determination is still not possible. [7, 10]
The fetus in his 9th week, showing the presence of more defined facial features and extremities, along with a thin translucent skin.
Weight increase can be observed among mothers, around 1 to 5 pounds for the entire first semester. More breast soreness and morning sickness will be more likely to occur. [ 5, 7, 10]
Pregnancy Week 10 Symptoms : Prunes And Constipation
At 1.2 inches long and 0.14 ounces heavy, the fetus’ size maybe likened to that of a prune. Fingernails and hair should appear at this time. He should be swallowing, kicking, and moving much more during this stage, proofs of more developed digestive and musculoskeletal systems. [7, 10]
A week 10 fetus is compared to a prune, having a length of 1.2 inches and weight of 0.14 ounces.
Constipation may present as a problem with mothers. Thus, increase in oral fluid intake, or around 2 to 3 liters per day, is advised. A diet high in fiber can also be of help.  The first prenatal checkup should also be done by now.
Pregnancy Week 11: Ratio of 1:1
Now compared to a lime, the fetus should be weighing 0.25 oz and having a length of 1.6 inches. He should also bear a head to body ratio of 1:1. By now, he must have a more fluid movement, and tooth buds, nail beds and hair follicles should be seen developing. He is starting to pass out urine from his kidneys, and is able to suck and swallow. [ 7, 10]
During week 11, nail beds may be visualized on the fetus.
The linea nigra, a 1 cm wide purplish/brownish line traversing the mother’s abdomen, may be visible at this week. Leg cramps, moodswings and flatulence can still be noted. 
Week 12 Symptoms : Time for An Ultrasound
At this time, the fetus is likened to a plum. It has a weight of 0.49 ounces and length of 2.1 inches. The baby is about to go to the growth and maturation stage. He can now close and open his fingers, curl his toes and if poked, he will be able to move. He can be able to perform more complex reflexes. [7, 10]
Melasma, the dark patches on the mother’s face and neck, may be observed. Further weight gain may be noted. 
Dark patches on the face and neck of the soon-to-be-mothers may be noted on Week 12.
A first trimester ultrasound may be done at this point. A nuchal translucency ultrasonogram may be performed to rule out Down syndrome. 
A nuchal translucency ultrasound done on a mother at her 12th week of pregnancy, with an abnormal result: a fetus possibly with Down syndrome.
Pregnancy Week 13 Symptoms : Fingerprints Imprinted
The baby is now the size of a peach, with 2.9 inches length and 0.81 ounces. The head is approximately a third the size of his body. The spleen is beginning to develop, and bone marrow is now functioning. At this time, the baby already has his own set of fingerprints. [3, 7, 10]
As to be expected from the mother, further visibility of veins in the abdomen would be noticed, so will an increase in her sexual drive. 
Fingerprints can now be distinguished among fetuses on their 13th week.
Pregnancy Week 14: Goodbye Morning Sickness
At his 14th week, he is at a size similar to that of a lemon. He is now 3.4 inches long and 1.5 ounces heavy. He is growing his hair, the lanugo, which helps him maintain his core temperature. 
By this time, morning sickness is present no more. However, this is replaced by muscle cramps. Hence, extra servings of milk, apples and bananas might be needed to relieve these symptoms. 
Pregnancy Week 15: Long Legged Fetuses
The fetus can move all her limbs and joints at this time. He will weigh 2.5 ounces and will be 4 inches long. His lower extremities are more often longer than his upper limbs. 
This image shows a fetus on its 15th week, with lower limbs longer than his arms.
Epistaxis, or nosebleeding, can be seen among mothers. This is often associated with indigestion, increased libido and swelling of the gums. [7, 10]
Pregnancy Week 16 Symptoms : Constipation
Like the size of an avocado, the fetus is now around 4.6 inches long and weighs approximately 3.5 ounces. His eyes are beginning to be light sensitive. His eyelashes and eyebrows continue to grow. His taste buds are developing. [3, 7, 10]
Further weight gain can be experienced by the mother. Constipation is also more likely to occur due to the enlarging uterus, which puts more pressure to the intestines. A lot more back and muscle pains can also be encountered. 
Pregnancy Week 17: Male or Female?
The baby now weighs 5.9 ounces and is 5.1 inches long, a size approximate to that of an onion. He is developing more bone and a thicker umbilical cord. 
An image of the fetus at 17 weeks, showing bone development and a thicker umbilical cord.
Due to increased blood flow, vaginal discharge, sweat, and mucus are more often noted among mothers. Skin pruritus is likely to be encountered due to thinner, more stretched maternal skin. 
An ultrasound can be performed to determine the baby’s gender. 
During Week 17, an ultrasound can be done to know the baby’s gender.
Pregnancy Week 18 Symptoms : It’s moving!
Like the size of a sweet potato, the baby weighs 6.7 ounces and is 5.6 inches in length. Growing more rapidly, his movement can now be felt by his mother, who is, by the way, more swollen and now with varicosities. 
Pregnancy Week 19 Symptoms : Five Senses
The baby is now 6 inches long and 8.5 ounces heavy. He now has a coating called vernix caseosa, and has his own 5 senses: of sight, smell, hearing, taste and touch. If the baby is male, the scrotum should be formed at this time. But, if the baby is a she, her vagina is now beginning to form, but her ovaries are already full of eggs, around 6 million in number. [3, 7, 10]
At Week 19, scrotal development may be noted among male fetuses.
Leg cramps are still common among the mothers, and along with this, hip pain can now occur. 
Pregnancy Week 20 Symptoms : Sleep-Awake-Sleep
Around 10.2 ounces and 6.5 inches, these are the baby’s new anthropometrics at 20 weeks of age. He now has period of sleeping and waking. He gulps down more amniotic fluid than he did during the previous weeks. [7, 10]
Apart from swollen feet, back pains and heartburns, the mother may experience lack of breath. This is due to the enlarging uterus pressing against her lungs. She is also more prone to urinary tract infections from the continued relaxation of the smooth muscles of her genitourinary system. 
Week 21 Symptoms : Braxton Hicks
Like a size of a pomegranate, this is how a 21 week old fetus would be like. He would have at least 10.5 inches length and be 12.7 ounces heavy. The fetal skin will be wrinkled at this point, but his eyebrows will be more developed. The baby’s gastrointestinal system will begin to produce meconium, in preparation for further digestion. 
This image shows a pair of more developed fetal eyebrows, in a fetus at his 21st week.
The mother will likely experience Braxton Hicks contractions, with her uterus having period of alternate tightening and relaxation. 
Pregnancy Week 22 Symptoms : Shortness of Breath
The average fetus will weigh about 12.7 to 20.8 ounces and will have a length of 10.5 to 11.8 inches at this point. He will also be sleeping cyclically, approximately 12 to 14 hours a day. 
As the baby continues to grow inside her womb, the mother will have more episode of shortness of breath. She will have a constant weight gain. A noticeable or a sudden loss of weight can signify pregnancy complication, hence, when faced with this, a prenatal consult is a must. [ 10, 12]
Pregnancy Week 23 Symptoms : Can You Hear Me?
During this time, the baby’s nipples are beginning to form. There would still be constant weight gain, but his skin will turn out to be thicker, more opaque, and pinker as more capillaries are present. It is also in this period when the testes would be descending and the uterus and ovaries would be developed. His sense of hearing would also then be more pronounced. [5,7, 10]
A picture of a fetus at week 23, with a more pronounced hearing ability and awareness of the mother’s every move.
Episodes of heartburn and indigestion will be more frequent for the mother at this time. This may be caused by high progesterone levels enabling a slower gastric motility, causing reflux. 
At this time, determination of maternal glucose levels should be done to rule out diabetes and its complications to the fetus. 
Pregnancy Week 24 Symptoms : With His Eyes Shut
The baby’s facial and scalp hair would be present by now, but would be devoid of any pigment. His bones would now be elongating and getting firmer. The lungs would also begin to create alveolar cells, which would eventually produce surfactant. Shutting of his eyes is maintained, thus he uses his sense of touch to move and get by. [7, 12]
At 24 weeks, the baby will have his eyes shut and would comprise of lanugo (hair), which would still be devoid of pigment.
Lower abdominal pain and constipation can still be experienced by the mother, as well as numbness of her fingers and wrists. 
Pregnancy Week 25 Symptoms : Snore!
The baby’s weight increases to 1.5 to 2.5 pounds and his length at 13.6 to 14.8 inches. His skin begins to smoothen and hair color can possibly be distinguished. He may have developed a sense of direction, knowing how to go up and down. His periods of waking and sleeping are a bit more obvious at this time. [7, 12]
Aside from constipation and weight gain, nasal congestion and snoring are likely to occur. This is often due to increased blood flow throughout the body, restricting air flow to the nose. 
At week 25 of pregnancy, mother will experience nasal congestion.
Pregnancy Week 26 Symptoms : Pumping Heart
His eyes will soon start to open and his lashes have grown. As a sign of developing lungs, he is learning to inhale and exhale amniotic fluid. His heart is now pumping, with a functional circulatory system. 
At his 26th week, the fetus will now have a pumping heart.
At this stage of pregnancy, the mother is at risk for pre-eclampsia, a condition characterized by increasing blood pressure. This can be prevented by adequate diet low in both salt and fat, and continuous blood pressure monitoring. 
Pregnancy Weeks 27 to 28 Symptoms : Hiccups
The baby’s brain activity is improving, with the tissues and grooves of his brain forming. He is also breathing more rapidly, even producing episodes of hiccups. [ 5, 7, 10, 12]
Shortness of breath and swelling of face and extremities are still experienced. Resting on the mother’s left side is advised, and may even help relieve these manifestations. 
This picture shows how a mother can relieve symptoms such as shortness of breath, which is thru lying on her left side.
Pregnancy Week 29 Symptoms : Fetal Movement
Already measuring 15.2 to 16.7 inches in length, the baby now weighs around 2.5 to 3.8 pounds. All organs are now formed, but he still is gaining fat. More of the baby’s kicks can be felt, around 10 every hour. 
Aside from the baby’s kicks, the mother may experience the following symptoms related to pregnancy: headaches, back and pelvic pain, hemorrhoids, constipation, frequent urination and varicosities. 
Infrequent, or less than ten kicks felt within two hours may warrant an obstetric consult. This may signify a pregnancy complication or fetal distress. 
At 29 weeks, normal fetal movement would be around ten per hour. If movements felt are less than this, an OB consult should be done.
Pregnancy Week 30 Symptoms : Can’t Sleep!
Amniotic fluid, at this time, is estimated to be around one pint. This fluid surrounds and protects the fetus. However, it shall decrease as the fetus age and occupy more space inside the womb. 
The fetal brain also matures at this time, coordinating with the other organs, and enabling them to function on their own. With a completely functional digestive tract, the baby can handle his own nutrients at this point. 
The mother will be having trouble sleeping during this week. She will also be more clumsier and episodes of depression would sink in. 
An image showing the mother at 30 weeks AOG having depression and trouble sleeping.
Pregnancy Week 31: More Braxton Hicks
All his five senses would be functioning at this point. His irises can also react to light and his nails seem to be completely formed. 
Mother’s breasts may be leaking with colostrum, the yellowish premilk. Braxton Hicks contractions will be more often now, and so will back pains and shortness of breath. 
At 31 weeks on the way, more frequent Braxton Hicks contractions can be felt. This is usually associated with back pain and shortness of breath.
Pregnancy Week 32 : More Fats, Less Room
The baby’s appearance will still be reddish and wrinkly, but adipose tissues will continue to fill in. The umbilical cord has a gelatinous coat, protecting it from further twists and knots. His bones are now complete, but are still soft and flexible. 
Because of his larger size, the baby will have less room inside the womb and will have less area to move to. This shall also limit his movement, making him seem more calmer. Even so, the mother should still be aware and conscious of her baby’s movements, especially lack of it. 
This image shows a baby at 32 weeks, having less room inside the mother’s womb.
Pregnancy Week 33 Symptoms: Heat and Headaches
The baby should now be around 4.2 to 5.8 pounds in weight and should measure 17.2 to 18.7 inches long. His eyes are now open during the times when he is awake. He’s learning to manage sucking, swallowing and breathing processes on his own.
Mothers may feel hot because of increasing rates of metabolism. Headaches may ensue due to the ever changing hormonal levels, stress and even dehydration. 
At week 33 of pregnancy, soon to be mothers may experience more headaches.
Pregnancy Week 34 Symptoms : What He Looks Like
His facial features are distinct at this time. The bones should be hardened, except for the skull, to enable passage through the mother’s birth canal. Most of the organs, should be more matured, with the exception of the lungs. 
The image depicts a fetus at 34 weeks, with distinct facial features.
During this week, the mother may experience blurring of vision from her hormones, inability to sleep and fluid buildup. Aside from these, further constipation and the presence of hemorrhoids may be noted. She may feel a pressure pulling down her pelvis as the baby in her womb prepares to descend. 
Pregnancy Week 35 Symptoms : In Position
At this point, the baby is now positioned in preparation for delivery. The kidneys and liver are now completely matured and his lungs are close to maturity. Lanugo hair now disappears and is replaced by vellus hair. 
Pains in both the mother’s pelvis and back are to be expected. Duration and frequency of her contractions are now increasing. Shortness of breath will not be experienced that often, but there will be more episodes of urinary urgency. The baby is finally descending, putting less pressure in the lungs, but more in the bladder. [5, 12]
An image showing the baby positioning and preparing for delivery, thus the mother having more pelvic and back discomfort.
Week 36 Symptoms : Almost But Not Quite
Fat continues to fill in, making the baby plumper. The gums are getting stronger, in preparation for the sucking process, the mechanism by which he will feed after birth. His circulatory and immune systems are well-functioning and prepared for delivery. [10, 12]
Even with exhaustion, mothers still has to be prepared for childbirth. Prenatal visits should be done to ensure the health of both the mother and the baby.
Weeks 37 to 40 : The Start of the End
The baby is now full term, measuring 18.9 to 20.9 inches in length and weighing 6.2 to 9.2 pounds. His lungs are well developed and the baby is ready for delivery. [10,12]
Mothers, at this point, may experience vaginal spotting. Contractions may be more frequent and her cervix begins to dilate. With the childbirth process officially starting, a visit to the obstetrician is mandatory. [5, 10]
At week 37, more frequent and more regular contractions can be felt, signaling the beginning of labor and subsequent childbirth.
So What Now?
Pregnancy is such a complex process. It does not only entail care and management for the mother, but for the baby as well. Thus, hindering the mother from getting an adequate and correct prenatal care can cause danger to the lives of both the baby and the mother. May this article serve as a guide to the aspiring and soon to be mothers out there, that they can survive pregnancy and be the best mother to be!
- Ventura, S. et al. Estimated Pregnancy Rates and Rates of Pregnancy Outcomes for the United States, 1990-2008. National Vital Statistics Reports. 2012 June; 60 (7).
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