What weeks in pregnancy most critical?

The first trimester is said to be the most crucial period of pregnancy because at this point, your baby is growing from an embryo to a fetus. The fetus then enters a stage of rapid development, forming most organs, facial features, skeletal tissue and limbs. This puts your growing child at a high risk of developing complications or even worse you could suffer a miscarriage.

When a pregnant woman experiences vaginal bleeding, severe abdominal or back pain, and heavy spotting, be sure to go the doctor immediately, as these are symptoms of a miscarriage. About half of the cases are due to genetic complications and are therefore unpreventable.

“We believe that the greatest cause for miscarriage is related to the integrity of the embryo itself, ‘’ added MCRM Fertility medical director, Dr. Peter Ahlering.

However, exposure to harmful substances and underlying conditions may also be factors, which is why it’s important to look after your health during this time. Refrain from smoking as well as alcohol and use of any medication. It’s either you give up unhealthy habits for you and your future child or risk experiencing a miscarriage and coping with its aftermath.

You are also opening your child up to potential birth defects if you neglect your wellbeing, and that’s if you’ve avoided a miscarriage. A study cited by The Conversation stated that babies with abnormal brains were ‘twice as likely to have a mother who used illegal drugs in pregnancy’. Other defects related to exposure to nicotine and illegal substances include cleft lip or palate, a smaller sized head and it may even result in preterm birth. Another research study on Science Signaling concluded that maternal fevers during the first trimester can lead to congenital birth defects, making personal health care all the more important. 

Moreover, Dutch researchers found a correlation between poor growth in the first trimester and early risk factors for heart disease. The study, published in the British Medical Journal, studied over 1,000 children from early pregnancy until the age of six. They found a pattern that children who were smaller at birth and underdeveloped also had a higher likelihood developing fat around the abdomen, higher blood pressure, and high cholesterol levels, which can follow them through their adult life.

What to do

In case you suffer a miscarriage, MCRM Fertility laid out the steps you can take as an individual and as a couple, and talking is the first and perhaps the most important thing. Becoming withdrawn is a natural reaction, but bear in mind that this is a time when you need each other’s patience and support the most. In an overview by Maryville University on social psychology, the detail how it is basically about understanding the reasons why people act/behave a certain way around others. This can explain the mindset of a hopeful parent who has recently experienced a truly heart-breaking event like a miscarriage or knowing that their child will have a more difficult life because of a birth defect. The important thing is to communicate with each other, in therapy, or in support groups. 

To reduce your chances of going through this difficult experience, focus on eliminating factors that can affect your baby’s health. The more you take care of your own health, the more you ensure that your child will come out healthy and happy. 

Feature solely written for Mcrmfertility.comby Stella Kravitz

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The First Trimester

The first prenatal visit

The first prenatal visit is the most thorough. A complete medical history is taken, a physical exam is done, and certain tests and procedures are performed to assess the initial health of the mother and her unborn baby. The first prenatal visit may include the following:

• Personal medical history. This may include taking record of any of the following:

  • Previous and current medical conditions, like diabetes, high blood pressure (hypertension), anemia, and/or allergies

  • Current medicines. Prescription and over-the-counter.

  • Previous surgeries

• Maternal and paternal family medical history, including illnesses, such as diabetes or intellectual or developmental disabilities, and genetic disorders, like sickle cell disease or Tay-Sachs disease

• Personal gynecological and obstetrical history, including past pregnancies—stillbirths, miscarriage, deliveries, terminations—and menstrual history (length and duration of menstrual periods)

• Education, including a discussion regarding the importance of proper nutrition, regular exercise, the avoidance of alcohol, drugs, and tobacco during pregnancy, and a discussion of any concerns about domestic violence

• Pelvic exam. This exam may be done for 1 or all of the following reasons:

  • To note the size and position of the uterus

  • To determine the age of the fetus

  • To check the pelvic bone size and structure

  • To perform a Pap test (also called Pap smear) to find the presence of abnormal cells

• Lab tests, including the following:

  • Urine tests. These are done to screen for bacteria, sugar, and protein.

  • Blood tests. These are done to determine blood type.

    All pregnant women are tested for the Rh factor during the early weeks of pregnancy. A mother and fetus may have incompatible blood types. The most common is Rh incompatibility. Rh incompatibility happens when the mother's blood is Rh-negative and the father's blood is Rh-positive and the fetus' blood is Rh-positive. The mother may make antibodies against the Rh-positive fetus, which may lead to anemia in the fetus. Incompatibility problems are watched and appropriate medical treatment is available to prevent the formation of Rh antibodies during pregnancy.

• Blood screening tests. These are done to find diseases, like rubella, an infectious disease that is also called German measles.

• Genetic tests. These are done to find inherited diseases, like sickle-cell anemia, Tay-Sachs disease.

• Screening tests. These are done to find infectious diseases, like sexually transmitted diseases.

The first prenatal visit is also an opportunity to ask any questions or discuss any concerns that you may have about your pregnancy.

What to expect during the first trimester

A healthy first trimester is crucial to the normal development of the fetus. The mother-to-be may not be showing much on the outside, but inside her body all the major body organs and systems of the fetus are forming.

As the embryo implants itself into the uterine wall, several developments take place, including:

• Amniotic sac. A sac filled with amniotic fluid, called the amniotic sac, surrounds the fetus throughout the pregnancy. The amniotic fluid is liquid made by the fetus and the amnion (the membrane that covers the fetal side of the placenta) that protects the fetus from injury. It also helps to regulate the temperature of the fetus.

• Placenta. The placenta is an organ shaped like a flat cake that only grows during pregnancy. It attaches to the uterine wall with tiny projections called villi. Fetal blood vessels grow from the umbilical cord into these villi, exchanging nourishment and waste products with the mother's blood. The fetal blood vessels are separated from the mother's blood supply by a thin membrane.

• Umbilical cord. The umbilical cord is a rope-like cord connecting the fetus to the placenta. The umbilical cord contains two arteries and a vein, which carry oxygen and nutrients to the fetus and waste products away from the fetus.

It is during this first trimester that the fetus is most susceptible to damage from substances, like alcohol, drugs, certain medicines, and illnesses, like rubella (German measles).

During the first trimester, both the mother's body and the fetus are changing rapidly.

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Fetal development during the first trimester

The most dramatic changes and development happen during the first trimester. During the first 8 weeks, a fetus is called an embryo. The embryo develops rapidly and by the end of the first trimester it becomes a fetus that is fully formed, weighing approximately 1/2 to 1 ounce and measuring, on average, 3 to 4 inches in length.

First trimester growth and development benchmarks

Just as each child grows and matures at different rates and at different times, so does that same child as it begins its life in the womb. The chart below provides benchmarks for most normal pregnancies. However, each fetus develops differently.

Changes in the mother's body

During pregnancy, many changes are also happening in the body of the mother-to-be. Women experience these changes differently. Some symptoms of pregnancy continue for several weeks or months. Others are only experienced for a short period of time. Some women experience many symptoms. Other women experience only a few or none at all. The following is a list of changes and symptoms that may happen during the first trimester:

• The mammary glands enlarge causing the breasts to swell and become tender in preparation for breastfeeding. This is due to an increased amount of the hormones estrogen and progesterone. A supportive bra should be worn.

• A woman's areolas (the pigmented areas around each breast's nipple) will enlarge and darken. They may become covered with small, white bumps called Montgomery tubercles (enlarged sweat glands).

• Veins become more noticeable on the surface of the breasts.

• The uterus is growing and begins to press on the woman's bladder. This causes her to need to urinate more often.

• Partly due to surges in hormones, a pregnant woman may experience mood swings similar to premenstrual syndrome. This is a condition experienced by some women that is characterized by mood swings, irritability, and other physical symptoms that happen shortly before each menstrual period.

• Increased levels of hormones to sustain the pregnancy may cause "morning sickness." This is feelings of nausea and sometimes vomiting. However, morning sickness does not necessarily happen just in the morning and rarely interferes with proper nutrition for the mother and her fetus.

• Constipation may happen as the growing uterus presses on the rectum and intestines.

• The muscular contractions in the intestines, which help to move food through the digestive tract, are slowed due to high levels of progesterone. This may, in turn, cause heartburn, indigestion, constipation, and gas.

• Clothes may feel tighter around the breasts and waist, as the size of the stomach begins to increase to accommodate the growing fetus.

• A woman may experience extreme tiredness due to the physical and emotional demands of pregnancy.

• Cardiac volume increases by about 40% to 50% from the beginning to the end of the pregnancy. This causes an increased cardiac output. An increased cardiac output may cause an increased pulse rate during pregnancy. The increase in blood volume is needed for extra blood flow to the uterus.

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