Weeks 1-4: Conception and Implantation
This period is the beginning of pregnancy, from the formation of the fertilized egg to successful implantation in the endometrium, which is a critical stage for the germination of new life.
Time Calculation
Week 1: Menstrual period, the starting point for calculating gestational age Week 2: Ovulation period, fertilization occurs Week 3: Fertilized egg divides and moves to the uterus Week 4: Implantation period, HCG begins to be secreted
Fertilization Process
Week 2: Ovulation and Fertilization
- Ovary releases mature egg
- Sperm combines with egg in the fallopian tube
- Forms a single-celled fertilized egg
- Fertilized egg contains 23 pairs of chromosomes
Week 3: Cell Division
- Fertilized egg begins to divide rapidly
- Divides from 1 cell into 2, 4, 8...
- Forms a morula (16-32 cells)
- Gradually moves to the uterine cavity
Implantation Process
Week 4: Implantation
- Morula develops into blastocyst
- Blastocyst implants into the endometrium
- Develops into two parts:
- Inner cell mass: Develops into the fetus
- Trophoblast: Develops into the placenta
HCG Hormone Production
- HCG secretion begins after implantation
- Maintains corpus luteum function
- Supports progesterone secretion
- Early pregnancy test strips can detect pregnancy
Maternal Changes
Physiological Changes
- Basal body temperature remains high
- Slight implantation bleeding may occur
- Breasts begin to feel tender
- Increased fatigue
Hormone Levels
- HCG begins to rise
- Progesterone increases
- Estrogen levels rise
Fetal Development Characteristics
- Size: About 0.1-0.2 mm
- Shape: Cell mass, no clear shape
- Organs: Neural plate begins to form
- Heart: Primitive heart begins to develop
Nutritional Needs
Key Nutrients
- Folic Acid: 400-800 mcg per day to prevent neural tube defects
- Protein: Supports cell division and tissue development
- Iron: Prevents anemia
- Vitamins: B vitamins support nervous system development
Dietary Suggestions
- Balanced nutrition, diversified food
- Eat more fresh vegetables and fruits
- High-quality protein intake
- Avoid raw and cold foods
Precautions
Life Care
- Maintain a regular schedule
- Avoid strenuous exercise
- Reduce stress
- No smoking or drinking
- Avoid harmful chemicals
Emotional Regulation
- Keep a happy mood
- Communicate fully with partner
- Adapt to the role of becoming parents
Medical Checkups
Pregnancy is usually not realized at this stage, but if you are preparing for pregnancy:
- Use early pregnancy test strips after menstruation is delayed
- Seek medical attention promptly after confirming pregnancy
- Establish a pregnancy file
Common Questions
Q: When can pregnancy be detected? A: Generally 10-14 days after ovulation, that is, after menstruation is delayed, early pregnancy test strips can be used for detection.
Q: What is implantation bleeding? A: A small amount of bleeding that may occur when the fertilized egg implants, usually light pink or brown, lasting 1-2 days.
Q: Can I continue to work during this period? A: You can work and live normally, just avoid overwork.
Next Week Preview
Entering weeks 5-8, the fetus will develop rapidly, major organ systems will begin to form, and morning sickness symptoms may begin to appear.
Friendly Reminder: Every pregnant woman's experience is different. If you have any doubts, please consult a professional doctor in time.