Week 8 · First trimester
EN
中文ZHहिन्दीHIBahasa IndonesiaIDPortuguêsPTРусскийRU日本語JAEspañolES

Week 8 fetal development and pregnancy guide — length about 1.6cm, weight 约1g (about the size of a a raspberry)

Your baby is now about 1.6cm and 约1g, about the size of a a raspberry.

Medical references: WHO INTERGROWTH-21st · China Prenatal & Pregnancy Care Guide · ACOG

View each day of week 8 →

Week 8 fetal development milestones: length / weight / ultrasound data

Key developmental changes during week 8:

  • The heart has differentiated into four chambers, and a primitive vascular network forms
  • Brain regions continue to differentiate, and the forebrain, midbrain and hindbrain structures gradually take shape
  • The liver begins producing blood cells, and the kidneys begin to form
  • The lung bronchial tree begins to branch, and different parts of the digestive tract become distinguishable
  • Fingers and toes begin to separate and no longer look webbed
  • The outer-ear outline, upper lip and nose tip form — the baby looks more human
  • The tail structure disappears and a human form gradually appears (by embryological staging, the “fetal” period begins at week 11)
Illustration of your baby about the size of a raspberry at week 8 (about 1.6cm/约1g)
Week 8 size: about the size of a a raspberry

* Values are medians from WHO/China standards; individual variation is normal. References: WHO INTERGROWTH-21st, China Prenatal & Pregnancy Care Guide, ACOG guidelines.

Week 8 daily development

Your baby quietly grows every day of week 8. Tap any day to see fetal development, maternal changes, and daily guidance for that day.

50Day 1The baby’s organs are largely formed and gradually starting to work: the liver produces blood, the heart beats steadily, and the kidneys are forming. By embryological staging, the baby is only officially called a “fetus” from week 11, but this week is still a landmark turning point in the first trimester. Pick a nickname for the baby and call it every day to gradually build the parent-child bond.51Day 2Check that your file-building documents are complete: both ID cards, the marriage certificate, the household register, and the ultrasound report confirming intrauterine pregnancy. Different hospitals may also ask for a residence certificate or maternal-child health handbook — call the target hospital first to confirm. Having everything ready at once saves you from extra trips and wasted energy.52Day 3Take DHA seriously. 200-300mg of DHA a day is very important for the baby’s brain and retina development. Deep-sea fish (salmon, sardines, cod) 2-3 times a week is the ideal natural source; moms who are vegetarian or don’t eat fish can choose algae DHA supplements. Add a memo in your phone to “eat fish twice a week” to track it.53Day 4Go through your skincare: avoid products containing retinoic acid (retinol), salicylic acid and hydroquinone. These ingredients carry potential risk to the early embryo. Products labelled “safe for pregnancy” or simply formulated without fragrance are the most reassuring. Keep up sun protection — skin is more prone to pigment deposition (melasma) in pregnancy, and physical sunscreen is the safest.54Day 5Losing a lot of hair? Actually this isn’t bad — high pregnancy estrogen puts hair into a longer growing phase, so the hair that would normally fall out now stays, making it look thicker. This is most moms’ “hidden bonus.” But don’t rush to dye or perm — chemical treatments are best avoided in early pregnancy; wait until the second trimester.55Day 6Start Kegel exercises: tighten the pelvic-floor muscles (like holding in urine) for 5 seconds, then fully relax for 5 seconds; do 10 sets each time, 2-3 times a day. You can do them sitting, standing or lying on your side, anytime, anywhere. Consistent Kegels help prevent and relieve stress urinary incontinence (leaking when coughing or sneezing) and support pelvic-floor recovery after birth — one of the most worthwhile exercises of pregnancy.56Day 7Increased discharge is a common pregnancy physiological change — estrogen increases cervical-gland secretions to form the mucus plug that protects the baby. Normal discharge is milky-white or clear with no obvious smell. Wear cotton underwear, change daily, and don’t rinse internally. If discharge turns yellow-green, has a fishy odor, or comes with vulvar itching or burning, seek care to rule out infection.

Week 8 belly changes

Illustration of belly changes at week 8: uterine position and abdominal prominence

At week 8 (first trimester) your uterus still sits low in the pelvis, so there is little visible change and your abdomen circumference barely moves. Don't worry if you don't "show" yet.

Week 8 maternal body changes and common symptoms

  • The uterus grows to about the size of an orange; lower-abdominal heaviness and possibly low-back ache begin
  • The breasts keep enlarging and the nipples and areolas darken, with veins more visible
  • Dizziness, fatigue and other early-pregnancy reactions continue; morning sickness may be near its peak
  • Frequent urination continues, from the growing uterus pressing the bladder
  • Mood swings and sleepiness, with hormones still high
  • More saliva, changed taste, smell sensitivity, and easy nausea
  • Constipation may begin, as progesterone slows intestinal movement
  • Some people have mild lower-abdominal pulling pain (ligament stretching) that eases with rest

Week 8 nutrition advice and recommended recipes

This week the baby’s organs keep taking shape and developing steadily, so the nutrition focus follows: ①DHA — important for brain and retina development; eat low-mercury deep-sea fish (salmon, sardines, cod) 2-3 times a week, or choose algae DHA if vegetarian; ②quality protein — eggs, milk, fish and soy products in a balanced daily intake; ③keep going with folic acid 400-800μg; ④dietary fiber (whole grains, fruit and vegetables) plus plenty of water to prevent constipation; ⑤vitamin D — get some sun and eat egg yolks to help calcium absorption. Morning sickness still means eating what you can and keeping it bland first. Avoid alcohol, cold-raw unpasteurized milk and high-mercury large fish; caffeine ≤200mg/day.

DHA200mgBrain & vision development
Recommended recipeWalnut and sesame paste

Walnuts and sesame are rich in alpha-linolenic acid (partly convertible to DHA), calcium and vitamin E — a light, easy-to-swallow pregnancy breakfast. Toast and grind the walnuts and sesame, then mix with warm water or warm milk into a paste; a small serving as a snack works well during the morning-sickness phase too.

Week 8 prenatal education guide

At week 8 the baby is still in the embryonic stage (by embryological staging, the “fetal” period begins at week 11), with no hearing or vision yet, so claims that “touching, shining light or playing music makes the baby smarter” have no scientific basis at this stage — and flashing a flashlight at the abdomen or pressing the belly repeatedly is not recommended (it may stimulate the uterus and has no “educational” effect). The most practical “prenatal care” now is taking care of the mother: ①stay in a good mood and reduce anxiety; ②keep a regular routine, get through morning sickness and ensure sleep; ③stay away from tobacco, alcohol, radiation and harmful factors. Talking gently to your belly is of course fine — it helps you relax and step into the mother role; no need to feel it’s a task.

Week 8 partner's role

①Help prepare and double-check the file-building documents (both ID cards, marriage certificate, household register, ultrasound report, etc.), and call the target hospital in advance to confirm its requirements; ②Keep sharing cooking and housework and help your partner avoid nausea-triggering smells; ③Pay attention to her mood and discomforts like constipation and fatigue, prepare high-fiber foods, and take walks with her; ④Quit smoking yourself and create a smoke-free environment; stay close, listen, and learn about pregnancy together.

Week 8 checkup reminders

Weeks 8-12 are the critical window for building your maternity file: bring both ID cards, the marriage certificate, the household register, and the ultrasound report confirming intrauterine pregnancy to your target hospital. Building the file usually includes a first systematic workup (blood count, blood type, liver/kidney function, infectious-disease screening, thyroid function, etc.). If the first ultrasound has not yet confirmed a heartbeat, have a repeat scan to confirm a live intrauterine pregnancy first, then build your file. Don’t miss the window, so later checks and delivery-bed arrangements aren’t affected.

Week 8 key concerns

Confirm the heartbeat and complete or repeat the first ultrasoundPrepare and double-check the file-building documentsSupplement DHA and vitamin D, and keep taking folic acidHigh-fiber diet plus plenty of water to prevent constipationGentle exercise and enough rest

Signs that need immediate care at week 8

Please see a doctor promptly if any of the following occurs: ①bright-red vaginal bleeding or bleeding heavier than a period, with abdominal pain (be alert for threatened miscarriage); ②persistent severe pain on one side of the lower abdomen with bleeding or dizziness (be alert for ectopic pregnancy); ③severe vomiting that keeps you from eating or drinking, with little dark urine (be alert for hyperemesis gravidarum); ④fever above 38°C with chills; ⑤severe headache or blurred vision; ⑥painful urination, frequent/urgent urination, or blood in the urine (urinary tract infection); ⑦heavy gush of fluid from the vagina; ⑧sudden fainting or pale face.

Week 8 frequently asked questions

What documents do I need to build my file at week 8?
Usually both ID cards, the marriage certificate, the household register, and the ultrasound report confirming intrauterine pregnancy; some areas also require a residence certificate or a maternal-child health handbook. Requirements vary a little by region and hospital, so call your target hospital before going to avoid a wasted trip.
How much blood will be drawn when I build my file? Will it affect the baby?
The first file-building usually draws 3-5 tubes of blood, checking blood count, blood type, liver/kidney function, infectious diseases (hepatitis B, syphilis, HIV, etc.) and thyroid function. The total is about 15-25ml, which has no impact on the mother or baby; you can eat normally before the draw (exception-free unless a fasting test is needed, in which case you’ll be told in advance).
Is earlier file-building always better? Can it be later?
It’s recommended to complete it within weeks 8-12. Too early (before a live intrauterine pregnancy is confirmed) it can’t be done, and too late may affect later check scheduling and delivery beds. If a heartbeat hasn’t been confirmed yet this week, confirm it first, then build your file — you don’t have to rush to be earliest.
What if morning sickness is still severe and I can’t eat at week 8?
Week 8 is often the morning-sickness peak. Eat small, frequent, bland, easily digestible meals, have a soda cracker before getting up, and avoid greasy food and strong smells; ginger, lemon water and vitamin B6 (with a doctor’s guidance) can help. If you cannot eat or drink at all, have little dark urine, or lose weight noticeably, seek care and IV fluids.
How can I ease constipation at week 8?
Progesterone slows intestinal movement, so constipation is common. Eat more whole grains, fruit and vegetables for fiber; drink 1.5-2L of water a day; take a walk after meals to promote movement; and develop a regular toilet habit without straining for long. If severe, ask a doctor before using a pregnancy-safe laxative — don’t buy medicine on your own.
Is it normal that there’s still no heartbeat at week 8?
If the gestational age is a little early or ovulation/implantation is late, it may not be visible yet; your doctor usually suggests a repeat scan in 1-2 weeks and judges together with HCG — no need to despair immediately. If there is obvious bleeding or abdominal pain, seek care promptly.
Are brown discharge or bleeding at week 8 a concern?
Small amounts of brown discharge are mostly due to a sensitive cervix or hormone swings; if only a little and without pain, you can observe and avoid exertion and intercourse. If it turns bright red, increases, or comes with sharp lower-abdominal pain, seek care immediately to rule out threatened miscarriage and ectopic pregnancy.
How should I read HCG and progesterone at week 8?
In early pregnancy, whether HCG keeps rising and doubles well matters more than any single value; progesterone fluctuates a lot day to day and varies greatly between individuals, so one low reading is no reason for excessive anxiety. Whether to use “pregnancy-protection” medication should be decided by your doctor based on ultrasound and HCG — never self-medicate.
Can I take cold medicine at week 8?
Do not self-medicate. Rest, drink plenty of fluids and eat bland food; if fever is above 38°C or symptoms are obvious, see a doctor promptly and tell them you are pregnant so they can choose relatively safe medications. Any medication in early pregnancy must be assessed by a doctor.
Can I have sex at week 8?
If there is no bleeding, abdominal pain, history of miscarriage, or low-lying placenta as a contraindication, gentle sex is usually fine — move carefully and avoid pressure on the abdomen. If you feel unwell or your doctor advises against it, pause.
Can I exercise and work at week 8?
Yes — you can work normally and do walking, prenatal yoga and other gentle exercise, while avoiding prolonged standing, overexertion, heavy lifting and high-risk activities. If your work involves radiation, chemicals or too much stress, discuss role adjustments with your doctor and employer.
Is losing weight at week 8 normal?
Yes. Morning sickness and poor appetite often leave weight flat or slightly down in early pregnancy; the baby is still tiny and needs little energy, so don’t worry. Once appetite recovers in the second trimester, weight rises steadily — you can use a pregnancy weight-gain calculator to track and manage within the recommended range for your pre-pregnancy BMI.
How many months pregnant am I at week 8? How big is the baby?
Week 8 is exactly 2 months and near the end of the first trimester. The baby is about 1.6cm, like a raspberry; all organs are largely formed and the heartbeat is clear. By embryological staging it is only called a “fetus” from week 11, and the belly is still not visibly showing.
My gums bleed — can I see a dentist?
Pregnancy hormones make the gums more sensitive and bleeding while brushing is common; use a soft toothbrush and keep up brushing and flossing. Non-urgent dental work needn’t be done this week; the second trimester (about weeks 14-20) is a relatively safe window. If you do need treatment, tell the dentist you are pregnant and avoid X-rays.
What if morning sickness suddenly disappears at week 8?
Symptoms naturally fluctuate and gradually fade, and a brief easing is usually normal. But if previously clear symptoms vanish suddenly together with abdominal pain or bleeding, seek care so HCG and ultrasound can rule out a stopped pregnancy — don’t judge by feeling alone.
Can I eat hotpot or spicy noodles at week 8?
Occasionally, but make sure food is cooked through and hot (to prevent toxoplasmosis and Listeria), and limit spicy/heavy food that can worsen morning sickness and burden digestion. Keep ingredients fresh and the broth not too salty. During the morning-sickness phase bland food is preferred — don’t eat these often.
Can I fly or travel far at week 8?
If there are no complications, traveling in early pregnancy is usually fine; move around often, drink water to prevent blood clots, and place the seatbelt under the abdomen. If you have bleeding, pain, or a history of miscarriage, consult your doctor before traveling.
Should I start calcium and iron at week 8?
When diet is balanced in early pregnancy, the focus is usually folic acid and DHA first; the main supplementation of calcium and iron generally begins in the second trimester. If a check shows anemia or clearly insufficient calcium, supplement as directed by your doctor — don’t stock up on supplements blindly.
⚡The gestational-development data on this tool is compiled from the WHO INTERGROWTH-21st fetal growth standards, ACOG (American College of Obstetricians and Gynecologists), and the Chinese Medical Association's Guidelines for Pre-conception and Prenatal Care, and is reviewed for consistency by obstetrics consultants against those authoritative standards. Daily developmental tips, maternal changes, and nutrition advice follow an evidence-based approach. Note that fetal length is measured differently by week: crown–rump length (CRL) at or before week 20, and crown–heel length (CHL) from week 21 — values either side of week 21 are not directly comparable, which is a normal measurement change.

Data sources & notes

This tool provides algorithm-based estimates from the authoritative standards above for pregnancy time planning and general reference. It does not replace a doctor's diagnosis or individualized medical advice; follow your obstetrician for all prenatal care decisions.

Week 8 daily focus

Key daily tips for this week; tap any item to view the full development and guidance for that day.

Day 1The baby’s organs are largely formed and gradually starting to work: the liver produces blood, the heart beats steadily, and the kidneys are forming. By embryological staging, the baby is only officially called a “fetus” from week 11, but this week is still a landmark turning point in the first trimester. Pick a nickname for the baby and call it every day to gradually build the parent-child bond.Day 2Check that your file-building documents are complete: both ID cards, the marriage certificate, the household register, and the ultrasound report confirming intrauterine pregnancy. Different hospitals may also ask for a residence certificate or maternal-child health handbook — call the target hospital first to confirm. Having everything ready at once saves you from extra trips and wasted energy.Day 3Take DHA seriously. 200-300mg of DHA a day is very important for the baby’s brain and retina development. Deep-sea fish (salmon, sardines, cod) 2-3 times a week is the ideal natural source; moms who are vegetarian or don’t eat fish can choose algae DHA supplements. Add a memo in your phone to “eat fish twice a week” to track it.Day 4Go through your skincare: avoid products containing retinoic acid (retinol), salicylic acid and hydroquinone. These ingredients carry potential risk to the early embryo. Products labelled “safe for pregnancy” or simply formulated without fragrance are the most reassuring. Keep up sun protection — skin is more prone to pigment deposition (melasma) in pregnancy, and physical sunscreen is the safest.Day 5Losing a lot of hair? Actually this isn’t bad — high pregnancy estrogen puts hair into a longer growing phase, so the hair that would normally fall out now stays, making it look thicker. This is most moms’ “hidden bonus.” But don’t rush to dye or perm — chemical treatments are best avoided in early pregnancy; wait until the second trimester.Day 6Start Kegel exercises: tighten the pelvic-floor muscles (like holding in urine) for 5 seconds, then fully relax for 5 seconds; do 10 sets each time, 2-3 times a day. You can do them sitting, standing or lying on your side, anytime, anywhere. Consistent Kegels help prevent and relieve stress urinary incontinence (leaking when coughing or sneezing) and support pelvic-floor recovery after birth — one of the most worthwhile exercises of pregnancy.Day 7Increased discharge is a common pregnancy physiological change — estrogen increases cervical-gland secretions to form the mucus plug that protects the baby. Normal discharge is milky-white or clear with no obvious smell. Wear cotton underwear, change daily, and don’t rinse internally. If discharge turns yellow-green, has a fishy odor, or comes with vulvar itching or burning, seek care to rule out infection.

Content sources & notes

This guide references WHO INTERGROWTH-21st standards, the China Prenatal & Pregnancy Care Guide, ACOG clinical guidelines and BabyCenter (medically reviewed).

This page is educational pregnancy information for general reference and does not replace the diagnosis or advice of a licensed healthcare provider.

View the full fetal BPD/AC/FL reference table (weeks 14–42) →

Related pregnancy tools

Pregnancy Weight Gain CalculatorCheck whether this week's gain is within a healthy rangeBMI CalculatorLearn your pre-pregnancy BMI and pregnancy adviceSafe Period CalculatorTrack your cycle to plan conception and contraceptionPregnancy CalculatorEnter your last period to see your exact week