Congratulations on your pregnancy! Arkansas Children’s mission is to champion children by making them better today and healthier tomorrow. We care about the health and well-being of you and your baby.  

Arkansas Children’s walks with expectant parents to prepare them for the road ahead. While we do not provide labor and delivery, our partner, the University of Arkansas for Medical Sciences, has a compassionate labor and delivery program. UAMS Pregnancy & Childbirth webpage provides several educational videos and resources that journey with women during and after pregnancy.  

Fast facts: Trimesters

Pregnancy lasts about 40 weeks. The calculation starts on the first day of the mother’s last period. According to the Office of Women’s Health, part of the U.S. Department of Health & Human Services, here is a breakdown of fetal development by trimester and changes mothers will experience.

Baby development

  • Weeks one to two:
    • Period of early embryo development and implantation

  • Weeks four to five:
    • Baby’s brain, spinal cord and heart begin to form, along with arm and leg buds
    • Embryo, one-twenty-fifth-inch long

  • Week eight:
    • Baby’s heartbeat is a regular rhythm
    • Major organs and external body structures start forming, including sex organs, arms and legs, fingers and toes
    • Eyes and eyelids are formed
    • About an inch long, weighing less than one-eighth ounce

  • Week 12:
    • Baby’s nerves and muscles work together, allowing baby to make a fist
    • External sex organs are visible
    • Eyelids protect a baby’s eyes and will not open until week 28
    • About 3 inches long and weighs about an ounce

Mother’s physical and emotional changes

  • Extremely tired
  • Morning sickness
  • Tender/swollen breasts
  • Mood swings
  • Cravings or food aversion
  • Peeing more
  • Constipation
  • Headaches
  • Heartburn
  • Fluctuating weight

Baby development 

  • Week 16:
    • Muscle, tissue and bone continue forming to create a skeleton, along with skin
    • Meconium developed in intestines, allowing for first bowel movement
    • Baby begins sucking motions with their mouth
    • About 4 to 5 inches long, weighing about 3 ounces

  • Week 20:
    • Mothers can feel their baby move
    • Baby has lanugo (fine hair) and vernix (waxy coating) protecting developing skin
    • Fingernails, toenails, eyebrows and eyelashes are formed.
    • Baby can scratch, hear and swallow
    • About 6 inches long, weighing about 9 ounces.

  • Week 24:
    • Bone marrow makes blood cells
    • Tastebuds, footprints, fingerprints and lungs formed; lungs do not yet work
    • Hair growth on baby’s head
    • Hand and startle reflexes develop; regular sleeping and waking
    • In boys, testicles move into scrotum; In girls, uterus and ovaries are in place
    • About 12 inches long, weighing about 1 ½ pounds

Mother’s physical and emotional changes

  • Body aches
  • Stretch marks
  • Dark skin around nipples
  • A line that runs from the belly button downward
  • Dark skin patches on face
  • Numbness or tingling in the hands
  • Itching on abdomen, palms and soles of feet
  • Ankles, fingers and face swelling

Contact doctor immediately if itching symptoms occur with nausea, vomiting, jaundice, fatigue, loss of appetite, as it could indicate a liver problem. Preeclampsia is a risk if a woman has extreme swelling or weight gain.

Baby development

  • Week 32:
    • Bones formed, still soft
    • Forceful kick and jab movements
    • Eyelids open and close and can sense light
    • Baby practices breathing motions
    • Baby’s body stores vital minerals
    • Lanugo falls off
    • About 15 to 17 inches long, weighing about 4 to 4 ½ pounds
    • Weight gained at about one-half pound each week

  • Week 36:
    • Vernix thickens
    • Body fat increases, less space to move
    • About 16 to 19 inches long, weighing about 6 to 6 ½ pounds

  • Weeks 37-40:
    • At 39 weeks, baby is full-term, meaning organs can function on their own
    • Baby’s body turns downward in preparation for birth
    • Baby’s weight varies at birth, with most about 6 pounds, 9 ounces to 9 pounds, 2 ounces; 19 to 21 inches long.

Mother’s physical and emotional changes

  • Shortness of breath
  • Heartburn
  • Ankles, fingers and face swelling
  • Hemorrhoids
  • Breast tenderness, possibly leaking colostrum
  • Protruding belly button
  • Trouble sleeping
  • Baby moving lower in the abdomen
  • Contractions, real or false

Prenatal appointments

At the beginning of pregnancy, appointments are scheduled every four to six weeks. At 28 to 36 weeks of pregnancy, appointments are scheduled every two weeks. Weekly visits begin at 36 weeks until the baby is born. Abnormal pregnancies may require more appointments. Learn more from the UAMS Women’s Clinic.

The first prenatal visit typically includes:

  • Full physical exam
  • Bloodwork
  • Possible breast, pelvic and cervical exams
  • Calculation of the due date

Most prenatal visits include:

  • Blood pressure and weight checks
  • Abdomen measurement
  • Checking baby’s heart rate

Learn more from the Office of Women’s Health.


According to the American College of Obstetricians and Gynecologists, an ultrasound is sound wave energy. Sound waves are sent through the body with a transducer during an ultrasound exam. The waves bounce back like echoes against tissues, bones and body fluids. The echos are converted to images. The type of ultrasound depends on what images the OGBYN needs to get. A transabdominal ultrasound means the transducer moves atop and across the mother’s abdomen. A transvaginal ultrasound places the transducer in the vagina.

An ultrasound allows an OBGYN to view the baby in utero. Expecting mothers should have at least one standard ultrasound during pregnancy, typically between 18 to 22 weeks. It will detect the estimated gestational age, number of fetuses, the baby’s heart rate and screen for genetic disorders and ectopic pregnancy. If the baby is in a proper and visible position, it’s possible to tell the baby’s sex. Learn more from the ACOG.

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