The eighteenth week in the second trimester of pregnancy is a period of crucial importance. In fact, most of the major second trimester exams are done between the eighteenth and twenty-second week. As usual, your doctor will have to tell you which tests are necessary to evaluate the state of your child’s growth.
The development of the fetus in the 17th week
In this week the placenta continues to grow, and has now equaled the weight of the fetus. It filters carbon dioxide and removes all waste from your baby’s body, while replenishing it with oxygen and all the vitamins, minerals, fats and proteins it needs. The umbilical cord also becomes stronger and thicker.
Her brain has started regulating the fetal heartbeat. Your baby continues to practice the motions of breathing, pushing the amniotic fluid through his tiny lungs. As already seen in the previous week, the period between the sixteenth and twenty-sixth week is vital for the development of the fetal lungs. Under his layer of skin, fats are just forming, and will soon begin to accumulate in his body until they make up about two-thirds of his weight at birth.
Between the 17th and 20th week the baby has a layer of thin hair on the skin called lanugo, which will help hold the vernix caseosa on the skin before delivery. Lanugo usually falls during the first few months after delivery.
the development of sensory organs
Hearing is now developed enough for your child to be frightened by too loud and sudden noises (for example the ringing of the bell or the telephone). Meanwhile, his eyes continue to develop, even though his lids remain sealed.
the development of the limbs
With the head now proportionate to the rest of the body, it is the legs which, on the other hand, represent the disproportionate part of the fetus. They appear longer and thinner than the arms, but will soon grow to better integrate with the rest of the body. With his little hands your baby is even able to grasp the umbilical cord .
the development of the teeth
The fetus is continuing the ossification process, with the spinal cord starting to become covered in a protective layer called myelin. Baby teeth have already formed in the gums, and are ready to grow and be integrated into the developing mouth.
the outward appearance and facial development
In the seventeenth week of pregnancy, the tiny eyes of the future baby go to position themselves in their final location, on the front of the head, while the ears are almost in place.
the size of the child
In the seventeenth week the baby is almost as big as an onion: it weighs about 140 grams. It is about 13 centimeters long.
The changes in the woman’s body
Your belly is growing gradually but steadily: you finally have the bump you’ve been waiting for since the day you found out you were pregnant. Your baby bump will be more noticeable if you are pregnant with twins . As the uterus grows, other organs are moved out of the way to create space. And all this allows you, while standing, to easily touch the top of the uterus (which appears rounder this week) with your hand. At this stage, you’re probably putting on more weight (5 to 10 pounds on average), especially since your food cravings have lessened now.
Therefore, pay attention to your food choices: make sure you make healthy choices, to avoid unwanted weight gain. A positive aspect of pregnancy in this period is to have shiny and shiny hair. Your nails grow faster, but they will also likely become more brittle.
The ultrasound at the seventeenth week
Depending on how it’s positioned in the uterus, an ultrasound can allow you to find out the sex of your baby. Through her transparent skin you can still see her developing blood vessels, and that’s because the fat layer is still quite thin. A Doppler ultrasound can help you feel your baby’s heartbeat: at 140-150 beats per minute, it’s twice as fast as yours.
The exams recommended in the seventeenth week
At this stage, unless it is a high-risk pregnancy, there are no screening tests. At this stage, routine procedures include checking the external appearance of the fetus by means of a normal or “level one” ultrasound: this in order to detect any birth defects . However, it is not possible to identify all possible anomalies with this procedure.
A “level two” ultrasound is usually performed if the “level one” ultrasound has given abnormal or negative results.
Amniocentesis – together with various other blood and urine tests – is performed in high-risk cases such as the case of a mother over 35 years of age, to identify possible neural tube defects and the genetic anomaly that accompanies Down syndrome .
Seventeenth week symptoms
The early pregnancy symptoms are probably gone now. However, these are replaced by a wide range of new, annoying symptoms, such as,
- constipation;
- acid reflux and heartburn ;
- indigestion;
- bloating and flatulence;
- increased sweating (due to increased body temperature, which in turn increased due to increased blood volume);
- feeling hungrier than normal (although some women may still have a lack of appetite);
- the increase in vaginal secretions;
- back pain;
- leg cramps;
- pain in the joints, ribs and hips;
- sciatica;
- shortness of breath;
- a pain in the round ligament of the uterus;
- appearance of “allergic” rhinitis, probably due to pregnancy hormones;
- an itch, especially around the belly, breasts and back;
- a dark line that runs vertically across your abdomen (linea nigra);
- dark spots on the skin;
- visible veins, especially around the belly;
- dry skin and stretch marks;
- stuffy or runny nose, along with other flu-like symptoms;
- headache ;
- mood swings;
- swelling or edema in the hands and feet;
- strange and vivid dreams.
When to call the doctor
The doctor should be consulted in case,
- you have any type of vaginal bleeding, even in patches, with or without other symptoms such as abdominal cramps, back pain or nausea;
- vaginal discharge that is clear or pale yellow in color (could indicate leakage of amniotic fluid);
- severe morning sickness and/or diarrhea lasting more than a day (increased risk of dehydration and weight loss);
- painful swelling on one side, or one leg more swollen than the other (this could be a sign of problems with blood clotting);
- intense itching for no rash or apparent reason (this could be a sign of liver disorders such as cholestasis of pregnancy);
- severe back pain, urine leakage, pain during intercourse, urinary tract infection symptoms (may indicate an inverted uterus or ongoing microbial infection);
- of other symptoms, such as persistent headache, fainting, regurgitation of blood, contractions similar to menstruation, rapid heartbeat or palpitations;
- noticeably blurry or altered vision (could indicate complications such as diabetes, high blood pressure, or pre-eclampsia);
- of intense constipation, associated with considerable abdominal pain.
Some useful tips for pregnancy and baby
Also in this week it is advisable to continue to follow a few simple rules:
- drink plenty of water, as the fluoride it contains is necessary for your child’s teeth and development;
- follow a balanced diet with fruit, vegetables and proteins; a diet rich in folic acid , vitamin C, omega-3 fatty acids, and iodine;
- avoid making sudden movements, such as getting up too quickly from a chair or sofa, as these movements lead to a rapid drop in your blood pressure, increasing the risk of fainting: moving slowly allows your body to adapt to the change in position;
- avoid high-heeled shoes, as your growing uterus is changing your body’s center of gravity and flat shoes give you better support;
- nail polish cannot harm you, nor your child as long as you use it in a properly ventilated environment, so as not to breathe its vapours;
- divide your three normal daily meals into five or six smaller meals, as eating “large” meals increases the chances of indigestion and heartburn;
- consult your doctor before using any medicine, even over the counter;
- sleep in the correct position (preferably on the right side);
- sign up for a prenatal yoga class , or do some light physical activity, such as (for example) exercises to strengthen the pelvic floor, in order to avoid some pain and stay fit during pregnancy.
Katherine Johnson, M.D., is a board-certified obstetrician-gynecologist with clinical expertise in general obstetrics and gynecology, family planning, women’s health, and gynecology.
She is affiliated with the Obstetrics and Gynecology division at an undisclosed healthcare institution and the online platform, Maternicity.com.