Pregnancy week 5
At almost the size of a grain of rice, pregnancy week 5 sees the continuation of the development of the baby’s organs. During week 5, the different chambers of the heart begin to divide and start to actually pump blood. The middle layer of cells, the mesoderm, forms into the heart, the muscles, cartilage, and bone. Therefore, there is the possibility of skeletal structures forming during this week. The placenta and umbilical cord continue to develop as the top layer of cells form the neural tube. The top layer also yields the skin, nails, hair, and sweat glands of the baby. The endoderm, or the third layer of cells in the developing baby produce the lungs, intestines, thyroid and pancreas.
Bloating is one symptom related to week 5. Nausea becomes an indicator of pregnancy during this week along with an increase in the need to urinate more often, and soreness in the breasts. Despite these common symptoms, the most prevailing symptom at week five is fatigue. Fatigue is common during the entire pregnancy but is usually worse in the early weeks. Exercise such as a brisk walk around the block in fresh air is the best way to combat fatigue during these early stages. Coffee or other caffeinated products can potentially harm the developing fetus.
Some things to watch out for during early pregnancy can help avoid complications and future impairments. An ectopic pregnancy is when the fertilized egg implants outside of the uterus, generally in the fallopian tube but possibly in the ovary or cervix. The chances of having an ectopic pregnancy are about one in one hundred and increase if there is a history of pelvic inflammatory disease and if the woman has already experienced an ectopic pregnancy. Major signs include vaginal bleeding, abdominal pain, and nausea. Because these symptoms often resemble regular pregnancy signs, the best way to identify an ectopic pregnancy is by measuring the levels of HCG in the blood, or by having an ultrasound done. Any abnormal symptoms should be discussed with the family prenatal care provider.
Current guidance (today's medical sources): Week five is a period of rapid early development: the neural tube, which becomes the brain and spinal cord, is forming, and the early heart begins to develop and beat. Many people first notice classic early-pregnancy symptoms now, including fatigue, nausea, tender breasts, and needing to urinate more often, although symptoms vary widely. Booking a first prenatal appointment is commonly advised.
Sharp one-sided pelvic pain, shoulder-tip pain, or vaginal bleeding with dizziness can be signs of an ectopic pregnancy and need urgent medical assessment. Contact your healthcare provider promptly about heavy vaginal bleeding, severe or persistent abdominal pain, a high fever, severe or sudden headache, vision changes, or fainting. Seek urgent care if you are worried — these can be signs that need medical attention.
Sources: NHS — 5 weeks pregnant; Mayo Clinic — Fetal development: The 1st trimester; MedlinePlus (NIH/NLM) — Prenatal Care. Informational only. See our sources & medical-review policy.
Frequently asked questions
How many months is 5 weeks pregnant?
Week 5 falls in the first trimester. Pregnancy is usually counted in weeks (about 40 in total) rather than months, because weeks are more precise.
What is happening to the baby at 5 weeks?
The neural tube (future brain and spinal cord) forms; the heart begins to develop and beat.
What symptoms are common at week 5?
Early symptoms such as tiredness, nausea, sore breasts, and frequent urination may begin. Symptoms vary a lot from person to person; discuss anything that worries you with your healthcare provider.
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See every week from 1 to 40, grouped by trimester.
See the week-by-week guide →Informational only — not medical advice. Pregnancy Week to Week is a general educational reference. It is not a substitute for professional medical care, diagnosis, or treatment. Every pregnancy is different: always consult your doctor, midwife, or other qualified healthcare provider about your own pregnancy, and never disregard or delay professional advice because of something you read here. In an emergency, contact your maternity unit or local emergency number immediately.