What is Puerperium?

• Puerperium is a duration in which the reproductive organs and all the system of the body revert to their normal condition.
• It is followed by the delivery of the placenta and ends approximately 6 weeks later.
• Puerperium can also be defined as a period following childbirth in which the body tissues, particularly the pelvic organs return back approximately to the pre-pregnants state both anatomically and physiologically.
• Puerperium or post partum period is term given for the first 6 weeks following the birth of an infant.
• Mothers experience several physiologic and psychological changes during this time.
• They are listed as follows:

• • Reverting of the reproductive organ to their pre-pregnant stage.
  • Initiation of Lactation.
  • Recovery of the mother from the physical and emotional experiences of parturition.
  • The foundations of the relationship between the infant and its parents are established.

A. Physiological changes in reproductive system:

I. Involution of the uterus:

• Involution is a term given to the changes that the reproductive organs, specifically the uterus, goes through after their childbirth to return to their pre pregnancy size and condition.
• Involution relies on three processes:
  • a. Contraction of muscle fibres
  • b. Catabolism
  • c. Regeneration of uterine epithelium

a. Contraction of muscle fibres:

• The involution starts immediately after placenta delivery when uterine muscle fibers contact around maternal blood vessels at the region where the placenta has been attached securely.
• As the muscle fibers that have been stretched for several months contract and gradually recover their original contour and size, the uterus decreases in size.

b. Catabolism:

• Although the total number of cells remains unchanged, catabolic changes in protein cytoplasm are experienced in the enlarged muscle cells of the uterus that cause a decrease in individual cell size.
• The catabolic process products are absorbed by the blood stream and are excreted as nitrogenous waste in urine.

c. Regeneration of uterine epithelium:

• Soon after childbirth, regeneration of the uterine line begins.
• With the placenta, the outer part of the endometrial layer is expelled within 2-3 days and the remaining deciduas are divided into two layers.
• The initial layer is superficial and is shed in lochia.
• The basal layer remains intact and is the new endometrium source.
• Endometrium regeneration, except at the site of placental attachment, occurs within 2-3 weeks.
• The placental site contracts rapidly providing an elevated surface measuring approximately 7.5cm and stays elevated even at 6 weeks, until it measures approximately1.5cm.
• Healing occurs more slowly at the placental site and takes about 6-7 weeks.
• The uterus is in the midline at the end of the third stage of labor, about 2cm below the umbilicus level.
• The uterus weighs about 1000gm at this time.
• Within 12 hrs, the fundus can rise to approximately 1 cm above the umbilicus. 
• The uterus is about the same size at 24 hours postparutm as it was at 20 weeks of gestation. Involution will develop rapidly over the next few days.
• The fundus descends every 24 hours by around 1-2 cm or 1 finger, so that it is in the pelvic cavity by the 8-10th day and can not be palpated abdominally.
• And there are individual variations linked to body size.
• The uterus, which weighs approximately 11 times its pregnancy weight in full, involutes approximately 500 gm per 1 week after birth and 300-350 gm per 2 weeks after birth.
• It weighs 60gm in 6 weeks.
• Increased levels of estrogen and progesterone are responsible for promoting massive uterine growth during pregnancy.
• Prenatal uterine development results from both hyperplasia, an increase in the number of muscle cells, and an enlargement of existing cells due to hypertrophy.
• The reduction of these hormones postnatally induces autolysis, the self-destruction of excess hyperthyroid tissue.
• The powerful frequency of myometrial contractions that regulate the flow of blood to the uterus stops, making it difficult.
• By palpating the uterus, its consistency can be measured. It ought to feel firm and round.

II. Cervix:

• The cervix is formless, flabby, and open enough to accommodate the entire hand immediately after birth.
• This makes it possible, if appropriate, to manually remove the placenta and to manually inspect the uterus.
• There can be minor tears and lacerations, and the cervix is sometimes edematous.
• Rapid healing happens and the cervix feels firm by the end of the first week.
• For the first 4-6 days postpartum, two fingers may still be inserted into the cervical os, but only the smallest curette can be introduced by the end of 2 weeks.
• The external cervical os never acquires its prepregnant appearance, it is no longer shaped like a circle, but appears as a jagged slit that is sometimes portrayed as a fish mouth.

III. Vagina:

• During birth, the vagina and the vagina introitus are substantially extended to enable the fetus to move.
• The vaginal walls appear edematous, smooth, soft and some minor lacerations may be present soon after childbirth.
• Vaginal mucosa becomes atrophic during the postpartum periods, and vaginal walls do not recover their thickness until ovarian estrogen production is reestablished.
• Due to ovarian activity, and thus the development of estrogen during lactation is not well known, breast feeding mothers are likely to experience vaginal dryness and may experience intercourse discomfort.
• Estrogen deficiency is also accountable for a reduced amount of vaginal lubrication.
• In the vaginal condition, the introitus remains permanently larger.
• The hymen is lacerated and is expressed by nodular tags.
• Adequate suturing has been done in well-healed vaginal tears.
• The vagina shrinks to a non-pregnant level, but it does not return to its pregnant size fully.

IV. Perineum:

• During the second stage of labor, as the fetal head applies pressure as it descends, the pelvic floor muscle stretches and thins considerably and rotates and then expands to be delivered.
•  And an intact perineum may be edematous, erythematous and painful after delivery.
•  Swelling and tenderness as a result of the birth of a baby are initially present.
•  Healing of an episiomoty is identical to any surgical incision.
• Healing should occur between 2-3 weeks.
• When episiotomy and perineal tears are done, a scar may be present.
• Pelvic floor supporting tissue that is torn or stretched during childbirth can take up to 6 months to recover tone.
•  Kegel exercises which helps enhance perineal muscles and promote healing are suggested after childbirth.
• Adequate suturing has been done with well episiotomies and perineal tears.

V. Ovaries:

• The resumption of the ovaries’ regular function is highly variable and is profoundly affected by the breastfeeding of infant.
• The woman who breastfeeds the baby has a longer amenorrhea and ovulation cycle than the mother who does not breastfeed will ovulate after 27 days of delivery.
• Most women have a menstrual cycle of 12 weeks, with a mean duration of 7-9 weeks for the first menstrual.

VI. Lochia:

• Lochia is vaginal discharge after child birth.
• The uterine body, cervix and vagina are the sources of the discharge.
• Blood leucocytes, decidua sheds, and organisms compose the lochia.
• Initially, the lochia is bright red, but after the first week the color fades and the flow usually clears entirely within 4 weeks of delivery.
•  As involution progresses, postchild birth uterine discharge undergoes sequential modifications.
• Lochia rubra: consist primarily of blood, sheds of fetal membranes and decidua, vernix caseosa, lanugo. It may consist few small blood clots.
• Lochia serosa: fewer RBC, more leucocytes, serum, mucus, and tissue debris. These are pink colored and are released over the next 5-9 days.
• Lochia alba: contains large number of deciduous cells, leukocytes, mucus, serum, epithelial cells and bacteria. The discharges are colored pale, creamy, brown and last 10-14 days. Any signs of discharged stained blood may continue to be seen for a further 2-3 weeks. The color of lochia indicates the placental site’s healing period.
• Odor and reaction:
  • It’s got a distinct unpleasant fishy scent.
  •  Its reaction is alkaline, tending to become acid at the end.
• Amount:
  • Estimating the quantity of lochia is difficult.
  •  Due to absorption in pads, sari, etc., the true amount may be concealed.
  • The weight of the pads can also be weighed and compared with the weight of the clean dry pad (1 g of weight equal to 1 ml) or based on the amount of stain on the perineal pad, providing a definition and an approximation in milliliters of 1 hour for lochia.
  • The average discharge level is calculated to be 250ml for the first 5-6 days.
  • Scanty: less than one 2 inch (5cm) stain in one hour on the peri pad= 10 ml
  • Light: stain on the perineal pad less than 4 inches (10cm) within 1 hour= 10ml to 25ml
  • Moderate: less than 6 inches (15cm) of stain within 1 hour on the perineal pad= 25-50ml.
  • Heavy: greater than 6 inches or heavy saturated pad= 50-80 ml within 1 hour.
• Normal charateristics of lochia:
  • Lochia rubra is 1-4 days in length. Bloody,small clots.
  • Lochia serosa is 5-9 days long. Decreased amount, serosanguneous, pink or brown.
  • For 10-15 days, Lochia aalba lasts. Creamy, yellowish color, decreasing amounts.
• Clinical importance:
  • Useful knowledge about the irregular puerpural condition is provided by the character of the lochia discharge.
  • – Severe lochia suggests infection when offensive.
  • – if scanty, denotes infection or lochiometra
  • – If persistence of red color further than normal limit suggests subinvolution or retained bits of conception.
  • – Local genital lesion is suggested when it lasts past 3 weeks.

B. Physiological changes in other systems of body:

1. Vital signs:

• 1. Pulse:
  • The pulse rate is likely to be raised for a few hours after normal delivery, calming down to normal during the second day.
  • The pulse rate, however, can also increase with pain or excitement afterwards.Any tachycardia (pulses > 110 or more bpm) may be suggestive of severe bleeding or the development of puerperal infection.
• 2. Temperature:
  • As an usual physiological reaction, the temperature may be labile within the first few days following delivery.
  • Temperatures within the first 24 hours should not be above 37.2^o C.
  • After delivery, there could be a small reactionary increase of 0.5^o F, but within 12 hours it comes down to normal.
  • Due to breast engorgement, which does not last for more than 24 hours, there might be a minor temperature increase on the 3rd day.
  • Puerperal pyrexia results from genital or urinary tract infection, breaches or inflammation within the venous system.
• 3. Blood pressure:
  • Because of an increased venous return, there may be a slight rise in the blood pressure.
  • Blood pressure differs with position and in order to gain accurate results, it should be measured with the mother in the same position each time.
  • A rise from the baseline indicates hypertension caused by pregnancy, a decrease may indicate dehydration or hypovolemia due to excessive bleeding.
  • Conduct a quick initial test.

2. Respiration:

• It is necessary to maintain a normal respiration rate of 16-20 per minute.

3. Gastrointestinal System:

• i. Appetite:
  • Shortly after birth, the mother is normally hungry and can handle a light diet.
  •  New mother is normally hungry due to the extreme energy lost in labor.
  • Besides that she is generally thirsty because of fluid loss during labor, in the lochia, diuresis and prespiration.

•  
• ii. Bowel evacuation:
  • For 2-3 days after childbirth, a bowel evacuation may not occur.
  • The decreased muscle tone in the intestine during childbirth and the immediate puerperium, prelabour diarrhea, lack of food or dehydration may explain this delay.
  • The mother often observes discomfort during the bowel movement due to lack of perineal muscles, reflex pain in the perineal region, slight intestinal paresis are factors contributing for constipation.
  • When the bowel tone returns, normal bowel patterns should be reestablished.
  • The strain and pressure on the lower bowel triggers the extrusion of internal hemorrhoids during delivery.
  • They decrease in size after delivery and can be manually re-inserted into the rectum.
  •  Hemorrhoids present during pregnancy often shrink and occasionally surgical reduction.
  • The rate at which the intestine is regulated depends on everyday life, food and fluids, exercise.

4. Neurologic System:

• Induced neurological pain in pregnancy disappears after birth.
• Removal of physiologic edema through the diuresis that accompanies childbirth relieves carpal tunnel syndrome by inducing compression of median nerve.

5. Integumentary System:

• Chloasma of pregnancy typically disappears at the end of pregnancy.
• After childbirth, areola and linea nigra hyperpigmentation does not regress entirely.
• These areas may have permanent darker pigmentation for some women.
• Breast, abdomen and thigh striae gravidarum (stretch marks) can fade (silvery color in light skinned women) but typically don’t disappear.
• Hair and nail development can return to pre-pregnant patterns in a few months.

6. Respiratory System:

• The diaphragm descends to its usual location after delivery, which decreases abdominal pressure, allowing for improved lung expansion and ventilation, but the respiratory rate does not change significantly.

7. Urinary System:

i. Physical changes:

• When the fetal head moves under the uterus, the urethra, bladder and tissue around the urinary meatus may become edematous and traumatized during childbirth.
•  This also results in reduced fluid pressure sensitivity, even though the bladder is distended.
•  Owing to the diuresis that accompanies childbirth, the bladder fills easily.
•  As a result, the mother is at risk for over distention of the bladder, incomplete emptying of the bladder.
•  Body water in the extra vascular spaces and excess plasma volume from pregnancy are quickly removed.
• Yet diuresis and polyurea occur up to 3 liters/day on the second postpartum day.
•  The urine passes for a few days and returns to the usual voiding pattern after one week.
•  Bladder boosts its ability, filling up to 1000 or 1500 ml of urine without pain.
•  Regional or general anesthesia can inhibit normal function temporarily, diminishing the bladder urinary sensation.
•  The woman at risk for haemorrhage from a poorly contracted uterus is followed by urinary retention.
•  Stasis also predispose to urinary tract infection.
• Weight Loss:
  • During childbirth, about 5.5 kg (12 pounds) of weight is lost.
  • This involves the weight lost during the birth of the fetus, placenta and aminotic fluid and blood.
  • During the first 2 weeks following childbirth, an additional 2-4 kg is lost.
  •  This includes the weight lost during the first few post partum days by diuresis and diaphoresis.
• Fluid loss:
  • Total fluid loss for the first week of at least 2 liters and for the next 5 weeks of an additional 1.5 liters.
  • The loss amount depends on the amount returned during the prenatal and natal phases.

8. Musculo-Skeletal System

• Abdominal muscles: The uterine ligaments remain loose and relaxed, with less tone in the abdominal muscles, resulting in the abdomen becoming flexible and flabby.
• During the first days after birth, as the woman stands up, her belly protrudes and gives her a pregnant look.
• The abdominal wall is relaxed during the first 2 weeks after birth.
• It takes about 6 weeks for the abdominal wall to return to its state of nearly non-pregnancy.
• The restoration of muscle tone relies on the previous tone, proper exercise, and the amount of adipose tissue.
• The abdominal wall muscle distinguishes a disorder called diastasis recti abdominis sometimes with or without overdistension due to a large fetus.
• Joints: The pelvic joint, especially the symphysis pubis, can separate slightly during labor under the influence of relaxation, causing pain and discomfort, stabilizing by 6-8 weeks.

9. Cardiovascular System:

• Change in blood volume: Changes in blood volume after birth depend on many factors, such as loss of blood during childbirth and mobilization and excretion of extravascular water (physiologic edema).
• Cardiac output:
  • Due to a rise in stroke volume, cardiac output tends to increase for at least the first 48 hours postpartum.
  • This increased volume of stroke is caused by the return of blood to the systemic venous circulation of the mother, resulting from a rapid reduction in the flow of uterine blood and extravascular fluid mobilization.
  •  By 6 weeks postpartum, cardiac output generally returns to normal.
  •  The heart rate and blood pressure return within a couple of days to non-pregnant levels.
  •  After delivery, body tries to compensate for increase central venous load, slowing the heart rate, to regulate cardiac output and avoid systemic overload and hypertension.
  • Hemorrhage, inflammation, thrombosis, anxiety, discomfort or excitement at delivery may be demonstrated by a rise in pulse rate.
  • In response to anesthesia, blood pressure may decrease in the early recovery period; orthostatic hypotension may occur due to fluid changes and reduced intra-abdominal pressure.
  •  It returns to normal within a few days after delivery, unless complications such as hypertension caused by pregnancy arise in women.
• Blood Components:
  • A greater decrease in plasma volume than in the amount of blood cells occurs within the first 72 hours after childbirth.
  • Haematocrit could rise in the first 3-7 days, slowly return to normal levels by 4-5 weeks as old cells die out and fewer new ones form.
• WBC count:
  • During first 10-12 days after child birth ,value between 20,000 and 25,000/mm³ are common. It falls to normal in 4-7 days.
  • Persistent elevation implies infection.
  • The large increase in WBCs is caused by neutrophils that increase in response to inflammation, pain and stress to protect against invading species.
• Coagulation factors:
  • During pregnancy, clotting factors and fibrinogen are typically increased and remain elevated in the immediate puerperium; during healing, platelet, fibrin and fibrinogen levels are elevated. Their function is to protect against bleeding.
  • This hypercoaguable condition causes an increased risk of thormboembolism when combined with vessel damage and immobility, in particular after cersarean birth.

10. Endocrine System

• The levels of estrogen and progesterone levels drop remarkably after expulsion of the placenta and reach their lowest levels 1 week postpartum.
• Reduced estrogen levels are related with breast engorgement and with the diuresis.
• In non-lactating women, estrogen begin to rise by 2 weeks after birth.
• Human chorionic gonadotropin (hCG) disappears from maternal circulation in 14 days.
• Oxytocin continues to acts upon the uterine muscle fibres maintaining their contraction, reducing the placental site and preventing haemorrhage.
• In women who choose to breast feed babies, the suckling of the infant stimulates further secretion of ocytocin and this aids the continuing involution of the uterus and expulsion of milk.
• Prolacting levels remain elevated in the sixth week after birth in women who breastfeed.
• The level of serum prolaction is affected by the frequency of breastfeeding, the length of each feeding, and the degree to which additional feeding is used.
• Individual variations in the intensity of the sucking stimulus of an infant probably also influence the levels of prolactin.
•  In woman who breast feed, the levels of prolactin remain high and the resumption of follicle stimIn women who are breast-feeding, prolactin levels remain high and the resumption of ovary follicle stimulation is suppressed.
• Prolactin levels decrease after birth in non-lactating women and enter the pregnant range by the two to third postpartum week; this enables the follicle stimulating hormone secreted by the anterior pituitary gland to act on the ovary, contributing to the restoration of normal patterns of development of estrogen and progesterone, follicle formation, ovulation, and menstruation.

11. Menstruation and Ovulation

• The occurrence of the first menstrual period following delivery is very variable and depends on lactation.
• If the woman If the woman does not breastfeed her infant, menstruation returns in around 40 percent by the 6th week after childbirth and in 80 percent of cases by the 12th week.does not breastfeed her baby, the menstruation returns by 6^th week following delivery in about 40% and by 12^th week in 80% of cases.
• Contractive protection for women who are primarily breastfeeding is roughly 98 percent up to 6 months postpartum.
•  Breastfeeding postpones the return of both menstruation and ovulation.
•  The duration of the delay depends on the duration of lactation and frequency of breastfeeding.
• Increased frequency, length of suckling is linked with high prolactin level, prolonged ovarian suppression and lactational amenorrhoea.

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• The term in vitro refers to outside of the body, and the term fertilization states to the condition where sperm has attached to and entered the egg.
• Overall, in vitro fertilization is defined as the condition where the fertilization takes place in a laboratory dish (i.e. outside the body).
• IVF is one of the techniques of the assisted reproductive technology (ART).
• The IVF is mainly employed to assist with fertility and avoid genetic problems.
• While performing IVF at lab, firstly mature eggs are retrieved from the ovaries and are fertilized by sperm.
• Then, the fertilized eggs are placed to a uterus.
• One complete cycle of IVF may take about 3 weeks.
• The first successful test tube baby was Louise Brown, born on the year 1978 performed by Dr. Robert G.

What are the steps for In vitro fertilization (IVF)?

• The IVF comprises of basic 5 steps. They are enlisted as follows:
  • a. Stimulation
  • b. Egg retrieval
  • c. Insemination and fertilization
  • d. Embryo culture
  • e. Embryo selection and embryo transfer

Step I: Stimulation

• It is also termed as super ovulation.
• In a normal condition, a woman produce one egg during each menstrual cycle.
• However, IVF has requirement of multiple eggs because use of multiple eggs increase the probability of developing a viable embryos.
• Fertility drugs are prescribed to the woman, so that the egg production boosts up.
• The fertility drugs consist of exogenous gonadotropins and similar substances, that causes hormonal stimulation of the ovary causing the production of large number of eggs per cycle.
• On the third day of menstruation, treatment cycles are generally started, following the use of fertility medicines to trigger the  development of multiple follicles of the ovaries.
• During this step, females are required to undergo regular transvaginal ultrasounds and blood tests to check hormone levels.
• The stimulation of ovary can be performed by 2 major protocols:
  • 1.  Lengthy protocol is the one where the suppression (down regulation) of the pituitary ovarian axis is performed by the prolonged use of a gonadotropin-releasing hormone (GnRH) agonist.
  • Once the process of down regulation is accomplished, usually after 10-14 days, subsequent ovary hyperstimulation generally using follicle stimulating hormone (FSH) starts.
  • 2.  Short protocol is the one where down regulation part is neglected and consist of prescription of injectable gonadotropins under regular monitoring inorder to trigger the development of multiple follicles of the ovaries.
  • The frequent monitoring checks the level of estradiol, and the follicular growth is checked via gynecologic ultrasonography.
  • Usually ten days of injection is required.
• During the last days of stimulation, the use of GnRH antagonists usually prevents the spontaneous ovulation during the cycle.
• It blocks the natural surge of luteinizing hormones (LH) facilitating the start of the ovulation process by use of injectable human chorionic gonadotropins.

Step II: Egg retrieval

• It is also termed as follicular aspiration.
• It is a minor surgery performed for the removal of eggs from the woman’s body.
• After the ovarian follicles reach a certain level of degree of development, final maturation is induced by an injection of human chorionic gonadotropin (hCG).
• hCG  hormone plays a role as that of luteinizing hormone(LH).
• After a single hCG injection, ovulation would take place between 38 and 40 hours.
• However, the eggs are retrieved between 34 and 36 hours after hCG injection, which is, just before the rupture of follicles.
• This assists for scheduling the process of egg retrieval at a time when the eggs are completely matured.
• A technique called transvaginal oocyte retrieval is used to retrieve eggs.
• In this process, the woman are given anesthesia, prior to surgery.
• The health care provider by using ultrasound images as a guide, inserts a thin needle through the vagina into the ovary and sacs (follicles).
• Then, the needle is connected to a suction device, that pulls the egg and fluid out of each follicle, one at a time.
• The same process is repeated for other ovary.
• Generally, 10-30 eggs are removed.

Step III: Insemination and fertilization

• The best quality of embryos that are potent for successful pregnancy are selected.
• It is also termed as oocyte selection.
• Along with it, the process called as sperm washing is also conducted.
• In this process, the inactive cells and seminal fluids are removed from semen in order to prepare it for fertilization.
• In the case where semen is supplied by a sperm donor, the preparation for treatment takes place before being frozen and quarantined, then it will be thawed ready for use.
• For about 18hrs, the incubation of sperms and egg (at the ratio of about 75000:1) is done in the culture media.
• In majority of the cases, the egg will be fertilized by that time and the fertilized egg shows two pronuclei.
• In specific cases such as low sperm count or motility, intracytoplasmic sperm injection(ISCI) can be used to inject a single sperm directly into the egg.
• Now, the fertilized egg is transferred to a special growth medium and left for about 48hrs until the egg reaches the 6-8 cell stage.

Step IV: Embryo culture

• After, the fertilized egg reaches 6-8 celled stage, embryos are cultured usually 3 days after retrieval.
• Embryo culture can be performed either in an artificial culture medium or in an autologous endometrial co-culture.
• Embryo culture in artificial culture medium:
  • In this type of culture, there can be either the same culture medium throughout the process or embryo can be sequentially placed in different media by use of sequential system. Ex. One medium can be used for culture to day 3, and second medium is employed for culture after it, when culturing to blastocyst stage.
  • For the culture of human embryos to the blastocyst stage, both the single and sequential medium are equally effective.
  • The media for artificial culture usually contain glucose, pyruvate, and energy supplying components.
  • However, the addition of the nucleotides, amino acids, vitamins, and cholesterol enhances the performance of embryonic growth and development.
• The techniques that allow dynamic embryo culture along with fluid flow and embryo movement are also present.
• A new technique in development where the embryos are encapsulated in permeable intrauterine vessel.

Step V: Embryo selection and embryo transfer

• 1. Embryo selection:
  • On the basis of the number of cells, evenness of growth and degree of fragmentation, embryos are graded by embryologists.
  • For the selection of embryos, morphological scoring system is considered as best strategy that optimizes pregnancy rates as well.
  • If it is to be choosed between embryos of morphologically equal quality, presence of soluble human leukocyte antigen-G (HLA-G) is regarded as a second parameter.
  • Embryos that have reached 6-8 celled stage are then transferred 3 days after retrieval.
  • It has been seen that blastocyst stage transfer results in higher pregnancy rates.
• 2. Embryo transfer:
  • Thenumber of embryos that are to be transferred depends on the number available, the age of the woman and other health and diagnostic factors.
  • Most of the clinics and country regulatory bodies tend to reduce the risk of pregnancies carrying multiples.
  • The best embryos are transferred to the patient’s uterus by means of a thin plastic catheter that goes through the cervix.

Summaries of steps of IVF:

• The follicle maturation along with ovulation is promoted by ovarian hormonal stimulation.
• To achieve fertilization by assisted reproductive technology (ART) several fertilization methods are used.
• Under the cultured conditions, the re-implantation embryo spends certain time that will influence its further development.
• Pre implantation embryo biopsies can be used during this period of time.
• Finally, the embryo is transferred to a recipient female.

Risks of In vitro fertilization (IVF):

1. Multiple births:
   • There are chances of multiple births if more than one embryo is transferred to the uterus. A multi-fetus pregnancy carries a higher risk of early labour and low birth weight than a single-fetus pregnancy.
2. Premature birth and low body weight:
   • It is suggested that IVF causes the birth prior to the normal delivery time with low weight of baby.
3. Ovarian hyperstimulation syndrome:
   • The use of fertility drugs like human chorionic gonadotropins (hCG) to induce ovulation can result in ovarian hyperstimulation syndrome. In this condition, the ovaries get swollen and becomes painful.
4. Miscarriage:
   • For women who conceive using IVF with fresh embryos, the incidence of miscarriage is close to that of women who conceive naturally, i.e. around 15% to25%, however the rate rises with maternal age.
5. Complications of egg-retrieval process:
   • Bleeding, inflammation or damage to the intestines, bladder or blood vessels could be caused by the use of an aspirating needle to collect eggs. Sedation and general anesthesia, if used, are also associated with risks.
6. Ectopic pregnancy:
   • About 2% to 5% of women who use IVF may have an ectopic pregnancy. Ectopic pregnancy is the condition in which  the fertilized egg implants outside the uterus, generally in a fallopian tube. Outside the uterus, the fertilized egg can’t survive, and there’s no way to continue the pregnancy.
7.  Birth defects:
   • The mother’s age is the main risk factor, no matter how the baby is conceived, in the development of birth defects. To decide if babies conceived using IVF might be at increased risk of certain birth defects, further research is required.

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• It is a series of cyclic changes occurring in the reproductive tract of female with the periodicity of 28 days
• It is also known as menstrual cycle,
• also known as endometrial cycle
• It occur From puberty to menopause
• It is characterized by loss of vaginal blood (breaking of endometrium wall of uterus)
• The cycle is under Influenced of hormones secreted by pituitary gland (FSH and LH), and ovary (progesterone and oesterogen).

Complete in 3 phase

1. Menstrual phase
2. Proliferative phase or follicular or ovulatory phase
3. Luteal or secretory phase

Figure: Menstrual cycle

Menstrual phase

• This phase is characterized by discharge of blood, connective tissues and mucus due to cast off of epithelial lining of endometrium wall
• It Lasts for 3-5 days
• Ovum remain unfertilized,
• At this time level of oestrogen and progesterone is very low in blood resulting in Breaking of endometrium wall of uterus
• About 50-100 ml blood with mucus are discharges as menstrual flow.

Proliferative phase

• This phase is characterized by rapid proliferation and repair of damaged endometrium wall
• It Lasts for 9-10 days (5^th – 14^thdays)
• Anterior pituitary gland release Follicular stimulating Hormone (FSH) which stimulates development and maturation of grafian follicle. So, it is also known as Follicular Phase.
• Mature grafian follicle secrete oestrogen. Its level gradually increases and maximize at 12^thday
• Oestrogen stimulate endometrium repair and proliferation. It also stimulate Ovulation
• Endometrium become 2-3 mm thick and highly vascular

Luteal phase

• This phase is characterized by release of Ovum from mature graffian follicle which is stimulated by the secretion of luteinizing hormone (LH) by pituitary gland.
• It Lasts for 12-14 days (14^th-28^th day)
• LH along with FSH stimulate ovulation.
• Mature graffian follicle release ovum and the rapture follicular cell form corpus luteum
• Corpus luteum secrete progesterone, high level of progesterone inhibit maturation of any other follicles
• Progesterone also stimulate thickening of endometrium wall
• When ovum remain unfertilized, corpus luteum degenerate; level of both hormone (progesterone and oestrogen) decreases, causing breaking of endometrium wall continuing the menstrual phase.

Ovarian cycle (Menstrual cycle)

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Fertilization

• It is the process of Fusion of sperm and ovum to form Zygote. Fertilization usually take place in oviduct. Ovum is in secondary oocyte stage during fertilization. Secondary oocyte is surrounded by two layer-zona pellucida and zona reticulate. Sperm move toward the secondary oocyte and bind to the receptor on zona pellucida. After sperm enter the oocyte, the zona pellucida become fertilization membrane preventing other sperm to enter. It is the entry of sperm that stimulate second meiotic division of Oocyte to produce Ovum. Acrosome of sperm release proteolytic enzyme (Hyaluronidase) that digest the egg wall and then the pro-nucleuses fuse form zygote (2n).

Figure: Fertilization in oviduct and Implantation of the embryo in the uterus

Embryogenesis

• Zygote undergoes repeated cell division called cleavage. Cleavage starts as the zygote moves down from oviduct to uterus 3-5 days after fertilization, zygote develop into ball like structure of cell with central cavity; blastocyst (Blastula stage).
• Outer cell of blastocyst is known as trophoblastic cell while inner cell is known as embryonic cell. Trophoblastic cell secrete HCG (human chorionic gonadotropin) hormone; similar in function as LH. It Prevent degredation  of corpus luteum, therefore corpus luteum continue to secrete progesterone and oestrogen, which help continuous growth of endometrium wall causing menstruation cycle to stop.
• As blastocyst reaches to uterus, trophoblast cell invade endometrium wall and utilize nutrients for its growth and multiplication. This invasion establishes the embryo within 6-9 days in the uterus called Implantation. With successful implantation, trophoblast form chorion membrane, which later become part of placenta.
• Chorion membrane develop small villi like projection on its outer layer called Chorion villi that begins to grow in the endometrium and help in exchange of nutrition between embryo and uterus.  Embryonic cell grow to become embryo. It also form other embryonic membrane covering the embryo.
• Within 20 days, embryonic membrane become clearly distinguished from embryo. The amnion is a thin membrane filled with amniotic fluids that eventually surrounds the embryo and act as shock absorbent. Later allantoin membrane develop, which develop toward the chorion and get fused to form Allanto-chorion which later form Placenta. Yolk sac has no significant function in human. Embryonic disc present between yolk sac and amnion give rise to embryo. Embryonic disc differentiate into 3 germ layer (Ectoderm, mesoderm and endoderm) known as Gastulation. Embryo shows distinct from at about 4-5 weeks. Only after 6 week, embryo can be distinguished as human embryo and now embryo term as Fetus.

Figure: Stages of Human Embryonic development

Summary of embryonic and fetal development

• Week 1: fertilization, blastocyst formation, Implantataion
• Week2: 3 germ layer differentiate
• Week3: beginning of back bone and neural plate (first organ), embryo 2mm size long
• Week 4: heart, blood vessel, blood, gut start forming, umbilical cord develop, embryo 5mm size
• Week5: brain developing, limb buds, heart beats starts (seen on USG), embryo 8 mm long
• Week 6: eyes and ear form, embryo known as fetus
• Week 7: internal organs, face form, limbs, mouth and tongue, fetus 17mm size.
• By Week 12: fetus fully form, sex organ develop, fetus starts moving, 56mm long,
• By week 20: Hair and nails begins to grow, fingerprint develop, firm hand grip, movement of fetus can be felt, 160m long,
• By Week 24: eyelid opens, legal limit for abortion,
• By week 26: good chance of survival if prematurely born
• By week 28: respond to touch and sound, swallowing amniotic fluid, urinating
• By week 30: head lying down, 240 mm long
• Week 40: birth

Human Fertilization and Embryogenesis

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• It is the process of formation of respective gametes (sperm and ova) in respective gonads. It involves Spermatogenesis and Oogenesis.

Spermatogenesis

• It is the process of formation of sperm in testis.
• Testis: it is the primary male reproductive organ.
• Shape and size: pinkish oval bodies occurring in pair, size is about 4.5cm long, 2.5 cm wide and 3 cm thick.
• Location: situated outside of abdominal cavity in scrotal sac. (Temperature of 2-3°C below body temperature is required for spermatogenesis)
• Each testis is surrounded by three layers.

1. Tunical vaginalis: double membrane outer covering, made up of fibrous connective tissue
2. Tunica albuginea: it is the middle layer below the tunica vaginalis.
3. Tunica vasculosa: it is the innermost highly vascular layer with network of blood capillaries.

Histology of testis:

• Each testis consists of 200-300 lobules, and each lobule contains 1-4 convulated loops called Seminiferious tubules. In between the seminiferous tubules, there is a group of interstitial cell called Leydig cell, which secrete testosterone, a male sex hormone. Each seminiferous tubules lined with germinal epithelium produce sperm by the process Spermatogenesis

Spermatogenesis occur in three phase

Figure: stages of spermatogenesis

i) Multiplication phase: the germinal epithelium of seminiferous tubules produce primodial germ cell. These cell multiplies repeatedly by mitosis to produce large number of spermatogonia.

ii) Growth or Maturation phase: The spermatogonia undergoes maturation. It is a diploid cell. After maturation spermatogonia is known as Sperm mother cell because it will eventually develop into the mature sperm.

iii) Meiotic phase: Duplication of homologous chromosome in sperm mother cell occur and become ready for meiosis. First meiotic division produce two Primary spermatocyte with haploid number of chromosome. The first meiotic division separates the homologous chromosomes from each parent. The second meiotic division of each primary spermatocytes occur resulting altogether of 4 haploid secondary spermatocytes. The secondary spermatocytes after maturation is known as spermatids. Each Spermatids goes on metamorphosis into sperm by the process of Spermiogenesis.

Spermiogenesis:  Sperm is a motile male gamete with head, neck and tail. During Metamorphosis of spermatids into sperm, following changes occurs

• Spermatids elongates and its Nucleus
• Cytoplasm extended to develop Flagella
• Golgi body produces Acrosome
• Mitochondria aggregate to form super mitochondria around base of flagella, providing energy for sperm motility
• By tubulobular process, sertoli cell phagocytose the sheded cytoplasm

Oogenesis-

• It is the process of formation of ova or egg in ovary.
• Ovary: it is the primary female reproductive organ.
• Shape and size: grayish pink almond shaped structure, size is 2.5-3.5 cm long, 2 cm wide and 1 cm thick
• Location: in the abdominal cavity, one on either side of vertebral column behind kidney.
• Each ovary can be differentiated into 3 parts

1. Outer germinal epithelium
2. Tunica albuginea: it is middlelayer of delicate connective tissue
3. Stroma: it is the inner mass of connective tissue. It is further differentiated into 2 layer-outer cortex and inner medulla. It is lined with germinal epithelium which form ovarian follicle. Each ovary is composed of about 400000 ovarian follicle.

• Ovaries are inactive before puberty, but stroma already contain immature follicle; Primordial follicle. Priomrdial follicle mature in about 28 days, rapture and release ova; process known as ovulation. 
• The germinal epithelium of ovarian follicle give ova germ cell called Oogonia.
• Oogenesis occur in 3 phages

  

                           Figure: stages of Oogenesis

i) Multiplication: The initial phase of Oogenesis starts during fetal stage. The primary germ cell, Oogonia develop from stem cell by mitosis cell division. In adult ovaries, primordial follicle contains a primary oocyte. Primary oocyte is also known as ova mother cell, which eventually produce ova.

ii) Growth or maturation phase: the Oogonia undergoes maturation. It is a diploid cell. Mature Oogonia is knownas primary oocytes, which undergoes meiosis, howerer, meiosis stopped at Prophase-I.

iii) Meiotic phase: Completion of meiosis-I produces a secondary oocyte and a polar body. The second meiosis division os Secondary Oocyte occur with unequal distribution of cytoplaswm producing large egg and a small second polar body. Eventually 1 egg and 3 polar bodies are produced.

Gametogenesis in Human-Spermatogenesis and Oogenesis

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