Pregnancy is the process of reproduction and has:
- Conception between female egg and male sperm – This can be natural by sexual intercourse or through assisted reproductive technology.
- Implantation and development of fetus in uterus – It is usually divided into three trimesters or three phases.
- Delivery of fetus – This can be natural, induced or surgical.
Female releases eggs by the process called ovulation. Pituitary gland in brain secretes Follicle Stimulation Hormone FSH and Luteinizing Hormone LH which controls this release and prepares female genitalia for fertilization and implantation. Once follicle rupture in ovary and egg is released, it is picked up by fallopian tube and start to travel towards uterus. It is here the egg gets fertilized by sperm. If the egg is not fertilized, menstrual cycle occurs. The release time of eggs is about midway between two normal menstrual cycles.
Be it natural as in sexual intercourse or assisted as in artificial insemination or in vitro fertilization, the first thing to occur is the fertilization of female egg or gametes or oocyte merge with male spermatozoa. This merger also leads to merger of genes of male and female side. This fused product is called zygote or fertilized egg. This merger commonly occurs in fallopian tube.
Implantation and Development
The zygote continues to move towards uterus, reach there and gets attached to uterine wall, a process called implantation. The cell mass is now called embryo. It begins to develop different types of cells to form future structures. Supporting structures like placenta and umbilical cord which help in sustaining and growth of embryo also develops.
There are three starting dates based on events:
- From first day of woman’s last menstrual period
- From date of conception that is about two weeks before next expected menstrual period
- From the date of implantation
Normal pregnancy is estimated to be about 280 days or 40 weeks of gestational age. It is 280 days of gestational age that is from first day of last menstrual period. A difference of 8 – 10 days is commonly seen.
Full term – 40 weeks
Term – 37 to 42 weeks
Preterm or premature – Before 37 weeks
Post term post mature–After 42 weeks
Both preterm and post term babies can have complications.
Delivery or childbirth is the process in which infant is born. It begins with labor when woman begins to experience regular uterine contraction. This is followed by effacement and dilatation of cervix. Most deliveries occur naturally but in some cases induced or surgical assistance is required. This can be due to malposition of baby, problems with placenta or umbilical cord or health risk to baby or mother. During after delivery or post natal period, the mothers body return to non pregnant state.
Diagnosis and symptoms of pregnancy
- Missed menstrual period
- Nausea, vomiting, tiredness, frequent urination
- Urine and blood test for presence of HCG – 12 to 15 days after implantation
- Increased basal body temperature
- Darkening of cervix, vagina, vulva – Chadwick’s sign
- Softening of vaginal portion of cervix – Goodell’s sign
- Appearance of lineanigra, darkening of skin in midline of abdomen
- Tenderness of breast
- Increase in abdomen girth
- Baby movements inside abdomen
- Blood and urine test for detection of HCG. Commonly called as pregnancy test. Can be positive as early as 12 days of implantation. Home kits are available.
- Ultrasonography to detect pregnancy, age and how baby is doing.
- Blood and urine test to detect hormonal status and health status of mother and child
- Amniocentesis to detect chromosomal disorders
Precautions during pregnancy
- Better the health of mother better is pregnancy. Same is true for mother’s happiness
- Alcohol and smoking puts baby at risk and can cause birth defects
- Drugs like marijuana can have devastating effect
- Toxins like lead and mercury present can cause serious defects in baby
- Air and water pollution pose health risk to mother and child
- Caution must be taken to prevent injury
- Sex is safe during pregnancy but one should be cautious and discuss with the doctor
- Mild gentle exercises supports pregnancy
Complications in pregnancy
- Back pain
- Nausea and vomiting
- Increased urinary frequency
- Pregnancy induced hypertension
- Pregnancy induced diabetes
- Edema and swelling
- Heartburn and GERD
- Post delivery depression or psychosis
- Urinary tract infection UTI
- Varicose veins
- Ectopic pregnancy
- Thyroid problems
All these conditions can be prevented and well managed under medical supervision.