Pregnancy Week by Week in Grand Rapids, Michigan

Pregnancy is an exciting and sometimes overwhelming journey. Understanding what happens week by week can help you feel more prepared and confident as you move through each stage. This guide is tailored for parents-to-be in Grand Rapids, Michigan, with local resources and context to support you throughout your pregnancy.

How Long Does Pregnancy Last?

An unborn baby spends about 38 weeks growing in the womb, but pregnancy is usually counted as 40 weeks. This is because pregnancy is dated from the first day of your last menstrual period (LMP), which is usually about 2 weeks before conception.

Pregnancy is divided into three trimesters:

  • First trimester: Conception to 12 weeks
  • Second trimester: 13 to 27 weeks
  • Third trimester: 28 to 40 weeks

Every pregnancy is different. Babies are considered “full term” if they are born between 37 and 42 weeks.

Early Signs of Pregnancy

Common early pregnancy symptoms include:

  • Missed period
  • Nausea and vomiting (morning sickness – can happen any time of day)
  • Breast tenderness or changes
  • Tiredness and fatigue
  • Frequent urination

If you:

  • Notice these symptoms, or
  • Think you might be pregnant

…it’s important to take a pregnancy test as soon as you can. You can:

  • Use a home pregnancy test from a Grand Rapids pharmacy
  • See your family doctor (GP) or OB/GYN
  • Visit a local clinic such as Spectrum Health, Trinity Health Grand Rapids, Metro Health, or Mercy Health for testing and follow-up care

The sooner a pregnancy is confirmed, the sooner you can receive prenatal care and discuss your options.

Miscarriage: What You Should Know

Around 1 in 4 pregnancies end in miscarriage. Most miscarriages (about 75–80%) happen in the first 12 weeks of pregnancy. Many miscarriages are never reported or even recognized because they occur very early, sometimes just looking like a heavier period.

If you experience:

  • Heavy bleeding
  • Severe cramping
  • Passing clots or tissue

contact your doctor, midwife, or seek care at a Grand Rapids emergency department (such as Corewell Health Butterworth Hospital or Trinity Health Grand Rapids Hospital), or call 911 in an emergency.

Conception and the Earliest Weeks

Week 1: Your Menstrual Period

Week 1 of “pregnancy” is actually the first week of your menstrual cycle. You are not pregnant yet, but this is how due dates are calculated.

Week 2: Preparing for Ovulation

Around this time, your body is preparing to release an egg (ovulation). Conception has not yet occurred, but you are in your fertile window.

Week 3: Conception

Fertilisation of the egg by sperm (conception) usually happens near the end of week 2 or start of week 3.

  • The fertilised egg is called a zygote.
  • About 30 hours after conception, the cell divides into two.
  • After 3 days, it has divided into about 16 cells.
  • After 5 days, it travels down the fallopian tube into the uterus.
  • Around 7 days after conception, it burrows into the uterine lining (endometrium).

At this stage, the zygote is now called a blastocyst. The baby is much smaller than a grain of rice, but cells are already starting to form the major body systems, including the digestive system and the neural tube, which will become the brain and spinal cord.

First Trimester: Conception to 12 Weeks

Weeks 4–5: Hormones and Missed Period

By this time:

  • The developing baby is called an embryo (about 3 mm long).
  • It begins secreting hormones (like hCG) that prevent your menstrual period.
  • A home pregnancy test will usually be positive.

You may feel:

  • Nausea or vomiting
  • Breast tenderness
  • Tiredness
  • Mood changes

In Grand Rapids, winter pregnancies can feel especially tiring due to shorter daylight hours and cold weather, so try to get enough rest, light exposure, and stay active indoors when possible.

Weeks 6–7: The Heart Starts Beating

  • The heart is beating.
  • The placenta and amniotic sac are developing.
  • The placenta burrows into the uterine wall to access oxygen and nutrients from your bloodstream.
  • The embryo is around 1.3 cm long.
  • The early spinal cord may look like a small tail.

Weeks 8–9: Rapid Growth

  • The head is large compared to the rest of the body.
  • The eyes, mouth, and tongue are forming.
  • Tiny muscles allow the embryo to start moving (though you won’t feel it yet).
  • The liver is making blood cells.
  • By the end of this stage, the embryo is called a fetus and is about 2.5 cm long.

Weeks 10–12: Organs and Screening

  • All major organs are formed, though still immature.
  • Hands and feet, once like paddles, are forming fingers and toes.
  • The brain is active and has measurable brain waves.
  • Teeth buds are forming inside the gums.
  • The heart continues to develop.
  • Fingers and toes are recognizable but may still have webs of skin between them.

Around week 11–12, your provider may offer a first trimester screening test (a combination of maternal blood test and ultrasound) to check for:

  • Down syndrome (trisomy 21)
  • Trisomy 18 (Edwards syndrome)

In Grand Rapids, these tests are commonly available through:

  • Spectrum Health Maternal Fetal Medicine
  • Trinity Health Grand Rapids
  • Metro Health – University of Michigan Health

Second Trimester: 13 to 27 Weeks

Many people find the second trimester easier. Morning sickness often improves, and you may feel more energetic.

General Changes in the Second Trimester

  • Your pregnancy becomes more visible.
  • You may gain steady, healthy weight, which is important for you and your baby.
  • It’s also important not to gain too much weight. A balanced diet and regular exercise (like walking in local Grand Rapids parks, indoor swimming, or prenatal yoga) can help.

Your provider will also screen for gestational diabetes, usually between 24 and 28 weeks, though it can occur earlier. This is especially important in Michigan, where rates of diabetes and obesity are higher than average.

Weeks 13–14: Active Fetus

  • The fetus can swim around quite vigorously.
  • It’s now more than 7 cm long.
  • The eyelids are fused over the fully developed eyes.
  • The baby has vocal cords and could “cry” silently in the womb.

Weeks 16–18: Growing Features

  • The fetus may start sucking its thumb.
  • Fingernails and toenails are growing.
  • By around 14–16 weeks, the fetus is about 14 cm long.
  • Eyelashes and eyebrows appear.
  • The tongue develops taste buds.

Around week 16, you may be offered maternal serum screening (a blood test) if first trimester screening was not done.

Weeks 18–20: Detailed Ultrasound

Between 18 and 20 weeks, you’ll usually have a fetal morphology ultrasound. This scan checks:

  • Baby’s organs and structures
  • Placenta position
  • Number of babies (single or multiples)

At this stage:

  • The fetus is about 21 cm long.
  • Hiccups are common and may even be seen on ultrasound.
  • The ears are fully functioning, and your baby can hear muffled sounds from the outside world.
  • The fingertips have fingerprints.
  • The genitals can usually be seen on ultrasound if you want to know the sex.

Third Trimester: 28 to 40 Weeks

During the third trimester, your baby grows rapidly and your body prepares for birth.

General Third Trimester Changes

It’s normal to experience:

  • More tiredness
  • Back pain
  • Breathlessness
  • Sleep difficulties
  • Increased Braxton Hicks contractions (practice contractions)

Your baby will eventually move down into your pelvis and “engage” or “drop,” which can make breathing easier but may increase pelvic pressure.

There is a higher risk of developing preeclampsia (a serious condition involving high blood pressure and organ involvement) in the second half of pregnancy, especially in the third trimester. Regular prenatal visits in Grand Rapids clinics are essential to monitor your blood pressure, urine, and overall health.

Around 28 Weeks

  • Your baby weighs about 1 kg (2 lb 2 oz).
  • Measures about 25 cm from crown to rump and about 37 cm from head to toe.
  • The body has grown to “catch up” with the head and looks more in proportion.

32–36 Weeks

  • Your baby spends most of the time asleep.
  • Movements are strong and coordinated.
  • By around 36 weeks, the baby is about 46 cm long.
  • Most babies move into a head-down position, getting ready for birth.
  • The skin is covered in fine hair (lanugo) and protected by a waxy coating (vernix).
  • The baby practices breathing movements with the lungs.

37–40 Weeks: Full Term

  • The eyelids, which were once fused, now open and close.
  • The baby is around 51 cm long and considered ready to be born.
  • If born around this time in a Grand Rapids hospital, the chances of survival are excellent.
  • Lung development is rapid in the last few weeks.

It is not fully understood what exactly triggers the onset of labor. It is likely a combination of:

  • Physical changes
  • Hormonal signals
  • Emotional and physiological factors between mother and baby

Calculating Your Due Date

Your expected birth or due date (EDD) is usually calculated from the first day of your last menstrual period. Your provider may:

  • Use a gestation calculator
  • Confirm or adjust the due date with an early ultrasound

Remember, the due date is an estimate. Only a small percentage of babies are born exactly on that date.

Staying Healthy During Pregnancy in Grand Rapids

To support a healthy pregnancy:

  • Follow a balanced diet rich in fruits, vegetables, whole grains, and lean proteins.
  • Take prenatal vitamins as recommended (especially folic acid and iron).
  • Stay active with safe pregnancy exercises (walking, prenatal yoga, swimming at local community centers).
  • In cold Michigan winters, try indoor activities to stay active and avoid slips on ice.
  • Stay hydrated, especially during humid West Michigan summers.

Your healthcare provider may give you specific advice based on your health, weight, and any existing conditions.

Local Pregnancy and Prenatal Care Resources in Grand Rapids, MI

If you are pregnant or think you might be pregnant, you can get help and information from:

  • Your GP (family doctor) or OB/GYN
  • Obstetricians and midwives at:
    • Spectrum Health / Corewell Health – Grand Rapids
    • Trinity Health Grand Rapids
    • Metro Health – University of Michigan Health
    • Mercy Health facilities
  • Kent County Health Department – offers maternal and child health programs and resources
  • Grand Rapids Public Health clinics – for reproductive health, STI testing, and referrals
  • Local maternal and child health nurses and lactation consultants (often connected through your hospital or pediatrician)
  • Pharmacists – for advice on over-the-counter medications safe in pregnancy

In an emergency (such as heavy bleeding, severe pain, reduced fetal movements, or signs of preeclampsia like severe headache, vision changes, or sudden swelling):

  • Call 911
  • Or go to the nearest emergency department in Grand Rapids

Key Points

  • Pregnancy is counted from the first day of your last period, not from the actual date of conception.
  • Miscarriage is common, and many miscarriages occur very early and may go unrecognized.
  • The embryo and then fetus develop rapidly in the first trimester, including the heartbeat, organs, brain, and limbs.
  • Steady weight gain and healthy lifestyle choices during pregnancy are important for you and your baby.
  • The onset of labor is still not fully understood and likely involves multiple factors.
  • Regular prenatal care in Grand Rapids through local hospitals, clinics, and public health services helps ensure the best outcomes for both you and your baby.

If you are unsure where to start, contact your primary care provider or the Kent County Health Department for guidance on prenatal care options in Grand Rapids, Michigan.