When does the stable period of pregnancy begin? Explaining how to spend the stable period and things to be careful about [Doctor supervised]

When does the stable period of pregnancy begin?

Although it is not a medical term, the period when the condition of the mother’s womb becomes stable compared to the early stages of pregnancy is generally referred to as the “stable period.” How many weeks of pregnancy does this refer to?

Will you enter the stable period at 12 weeks (4 months) or 16 weeks (5 months)?

Will I enter the stable period at 12 weeks (4 months) or 16 weeks (5 months) of pregnancy?

The stable period of pregnancy generally refers to the 16th week (5th month), but since it is not an official medical term, there is no clear definition of which is correct.

Miscarriages in early pregnancy often occur between the 10th and 11th week, so your physical condition will gradually stabilize at the 12th week (4th month) mark. By the 16th week (5th month) mark, the risk of miscarriage is further reduced, so this is considered to be the stable period.

Characteristics of the mother during the stable period

What are the characteristics of a mother who has entered the stable period of pregnancy? Let’s take a closer look at the changes that occur in the mother’s body during this period.

Changes in appearance, such as belly size

Your uterus will grow to the size of an adult’s head and your belly will start to swell. Your mammary glands will develop rapidly, so be sure to wear a maternity bra that does not put pressure on your mammary glands.

Also, stretch marks will begin to appear on your stomach and chest, so it is recommended that you take measures to prevent dryness, such as applying a moisturizing cream.

Morning sickness

Although it varies from person to person, this is generally the time when morning sickness symptoms begin to subside. Your appetite will return, so be careful not to eat or drink too much.

Completion of the placenta

The risk of miscarriage decreases, and the secretion of hormones for breastfeeding begins. A milk-like liquid may come out of the nipples, so it’s reassuring to have breast pads.

Feeling the baby kick

It has been reported that 25.19% of women felt fetal movement from the fifth month of pregnancy, and 29.92% felt it from the sixth month of pregnancy. It seems that most women feel fetal movement around the fifth or sixth month of pregnancy. (※ Researched by Mynavi Parenting )

The time when you feel fetal movement varies from person to person, so there is no need to worry as long as there are no problems with the heartbeat or ultrasound scan.

NIPT (New Prenatal Testing) before entering the stable period

Unlike definitive tests (chorionic villus sampling and amniocentesis), NIPT (non-invasive prenatal testing) can be diagnosed by taking a blood sample alone, making it a test that places very little burden on the mother.

There is no risk of miscarriage, and in the case of Down syndrome (trisomy 21), it can determine fetal chromosomal abnormalities with a high level of accuracy, with a sensitivity of 99.9% and a specificity of 99.90%.

NIPT can be performed from the sixth week of pregnancy, so if you wish to take the test, we recommend that you consider it before entering the stable period.

How to spend the stable period

Even though you are in the stable period, it is important not to push yourself too hard. We will introduce in detail 4 points and 5 points to be aware of so that you can spend your pregnancy life with peace of mind.

Four points to keep in mind during the stable period

1. Moderate exercise

Regarding moderate exercise during this period, the Obstetrics and Gynecology Division’s “Safety Management Guidelines for Sports for Pregnant Women” states the following:

• Heart rate should be under 150 bpm, preferably “slightly strenuous” or less.
• Exercise 2-3 times a week for no more than 60 minutes each time
• Avoid exercises that require you to lie supine (on your back)

Be careful when exercising while lying on your back, as the weight of the fetus can compress blood vessels, making you more susceptible to low blood pressure.

2. A nutritionally balanced diet

According to the Ministry of Health, Labor and Welfare, it is recommended that women take in more nutrients than they did before and during the early stages of pregnancy. Using your regular diet as a base, try adding the following foods to your daily intake.

3. Stress relief

Stress can cause muscles throughout the body to stiffen, narrowing the uterus and reducing blood flow, making it difficult to send nutrients to the baby.

In addition, the risk of premature birth and miscarriage increases, so make sure to find ways to relieve stress and talk to your partner about stress and get their support.

4. Designed to reduce strain on the body

Even if you are in a stable period and feeling well, try to take rest and sleep. Also, try to use a body pillow or something similar to keep you in a comfortable position so as not to put strain on your body.

Five points to note during the stable period

1.Anemia

During pregnancy, your blood volume increases in order to send blood to your baby, but the number of red blood cells does not increase much. This makes you more susceptible to anemia, which can cause palpitations, dizziness, and headaches.

Try adding an item that is high in iron, such as clams, soybeans, green and yellow vegetables, dried daikon radish, hijiki, or red meat. It is better absorbed when taken with vitamin C, so it is recommended to combine it with potatoes, peppers, oranges, etc.

Foods that are high in iron, such as liver and eel, also contain a lot of vitamin A, so be careful. Do not exceed the daily upper limit of 1,500 μg, as there is a risk of birth defects in your baby.

2. Constipation

Hormonal imbalance can slow down intestinal movement, and the enlarged uterus can put pressure on the intestines, making you more susceptible to constipation.

Also, reduced physical activity during pregnancy can weaken your abdominal muscles and reduce your ability to defecate.

• People who are dehydrated: Drink fluids frequently
• People with an unbalanced diet: take in dietary fiber (seaweed) and lactic acid bacteria
• People who are not getting enough exercise: Incorporate moderate exercise 2-3 times a week.

3. Lower back pain

As your belly gets bigger, you will tend to arch your back more and more, which will cause back pain. Another cause of back pain is the secretion of hormones that make it easier to give birth, which causes the surrounding muscles to stiffen instead of the ligaments, trying to support the joints.

Even if you don’t have back pain, try to adopt a posture that reduces strain on your lower back, such as by using a cushion.

4. Motivation/Shortness of breath

The increased blood flow to the baby can cause palpitations and shortness of breath. Another cause is the uterus pushing against the internal organs, compressing the lungs.

This is a common symptom among pregnant women, so be sure to take frequent breaks and move slowly.

5. Sudden weight gain

As morning sickness is alleviated or improved, your appetite may return and you may suddenly gain weight. However, sudden weight gain can be risky for the mother, so be careful with your weight management.

Weight management differs depending on your body type before pregnancy, so please refer to the table below and pay attention to weight management.

Diseases to watch out for during the stable period

The period from 16 weeks onwards is generally called the stable period, but there are some diseases to be aware of. Let’s take a look at each one.

Preterm labor

Threatened premature labor is a condition where there is a high risk of premature birth, that is, a state just before premature birth. In general, uterine contractions such as abdominal distension and pain occur regularly and frequently. Water may break first or at the same time. In most cases, you will be instructed to rest at home or be hospitalized.

Late miscarriage

A miscarriage that occurs between 12 and 22 weeks of pregnancy is called a late miscarriage. Although it is not common, a miscarriage can occur after the stable period, which is called a late miscarriage.

Pregnancy-induced hypertension

Hypertension occurring after the 20th week of pregnancy is called pregnancy-induced hypertension. The diagnostic criteria are a systolic blood pressure of 140mmHg or higher or a diastolic blood pressure of 90mmHg or higher.

In severe cases, the mother may suffer from high blood pressure, proteinuria, seizures (eclampsia), cerebral hemorrhage, liver and kidney dysfunction, and HELLP syndrome, which is accompanied by hemolysis and thrombocytopenia in liver dysfunction. In addition, the baby’s growth may be impaired (fetal growth restriction), the baby’s condition may worsen (fetal distress), and in some cases the baby may die.

Gestational diabetes

Gestational diabetes is a glucose metabolism disorder that is first discovered during pregnancy. Gestational diabetes can cause pregnancy-induced hypertension, abnormalities in amniotic fluid volume, shoulder dystocia, retinopathy, nephropathy, or worsening of these conditions in the mother. In addition, the baby can experience miscarriage, malformations, macrosomia, cardiac hypertrophy, hypoglycemia, polycythemia, electrolyte abnormalities, jaundice, fetal death, etc.

Cervical incompetence

A condition in which the cervix opens easily without any symptoms is called cervical incompetence. The cervix opens and can cause miscarriage or premature birth, so in some cases, the cervix may be tied.

Placenta Previa

A condition in which the placenta is attached lower than normal and covers part or all of the uterine outlet is called placenta previa. If you try to give birth vaginally with placenta previa, the placenta will detach as the cervix dilates, causing heavy bleeding. Therefore, in the case of placenta previa, delivery will be by Caesarean section in almost 100% of cases.

Getting ready for the stable period

Here is a summary of what you should prepare during the stable period when you are feeling well. We recommend that you start preparing early so that you will be ready for birth at any time.

Child seat installation

If you are driving home after giving birth, you will need a car seat to carry your newborn. Failure to do so will be a violation of the Road Traffic Act, so be careful.

If you are taking a taxi, you don’t need a child seat, so if you can’t make it in time, you can take a taxi home.

Preparing baby supplies

After giving birth, you won’t be in a position to go shopping, so be sure to prepare plenty of consumable items such as diapers and wipes.

Preparing for hospitalization

□ Maternal and Child Health Handbook
□ Postpartum shorts and pads
□ Nursing bra
□ Box tissues
□ Toiletries, towels, bath towels
□ Contact lenses or glasses
□ Mobile phone and charger
□ Slippers
□ Discharge clothes for mother and child

Some hospitals may provide these items, so be sure to check in advance.

Procedures related to childbirth

We recommend that you prepare anything that can be done before the birth while you are still in the stable period. Since you don’t know how your physical condition will be after the birth, be sure to confirm the details of the procedures with your partner.

summary

We have explained some things to be careful about during the stable period of pregnancy.

During the stable period, symptoms such as morning sickness tend to subside, and the possibility of miscarriage also decreases, so you may feel a little better physically and mentally. However, just because you have entered the stable period does not mean that the possibility of problems disappears.

Pay attention to your diet, exercise, and take care of your health.

Also, if you have any concerns about your health, please do not hesitate to visit your local medical institution.

【References】

• Japan Society of Obstetrics and Gynecology – Premature birth and threatened premature birth
• Japan Society of Obstetrics and Gynecology – Pregnancy-induced hypertension
• Japan Society of Obstetrics and Gynecology – Gestational Diabetes
• Mynavi Parenting – When does fetal movement start? The general timing and how to feel it <Mom’s experience>

Article Editorial Supervisor

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Dr Hiroshi Oka

NIPT specialist clinic, MD

Graduated from Keio University, School of Medicine