A major milestone happens this week: the tiny heart starts beating. It is still a simple tube pumping blood, but it is already beating around 100 to 120 times per minute. The embryo is growing at an incredible pace.
Your Baby This Week
Size: Lentil (about 4 mm)
The embryo is curled in a C-shape. Key developments this week:
- Heart: Now beating and circulating blood through primitive vessels
- Face: Dark spots where the eyes will be, small openings for the nostrils, and pits where ears will form
- Limbs: Tiny buds appear where arms and legs will grow
- Brain: Dividing into three main sections (forebrain, midbrain, hindbrain)
- Kidneys and liver: Beginning to develop
The embryo is surrounded by amniotic fluid and connected to the yolk sac, which is still providing most of its nutrition.
Your Body
Symptoms may intensify this week:
- Morning sickness at its most challenging for many people
- Bloating and gas as progesterone slows digestion
- Mood swings driven by hormonal changes
- Heightened sense of smell that can trigger nausea
- Breast tenderness continuing
Your uterus is growing but still hidden behind the pelvic bone. No one can tell from the outside yet.
What to Do This Week
- Try ginger or vitamin B6 for nausea. Studies show both can help reduce morning sickness (ACOG, 2023). Talk to your provider about the right dose.
- Get enough rest. Fatigue in the first trimester is real. Listen to your body.
- Choose a prenatal provider if you have not already. OB-GYN, midwife, or family physician? Consider your preferences for labor and delivery.
Common Questions
What if I cannot keep food down?
Mild nausea is common, but if you are vomiting multiple times a day, cannot keep fluids down, or are losing weight, contact your provider. This could be hyperemesis gravidarum, a severe form of morning sickness that may need treatment.
Is it safe to exercise?
Yes. For most healthy pregnancies, moderate exercise is safe and recommended. Walking, swimming, and prenatal yoga are excellent choices. Avoid contact sports and activities with a high fall risk.