Reproductive Systems Flashcards
What is the role of internal genitalia?
Transport, storage, nutrition & maturation of gametes
What is the role of the external genitalia?
Transfer of gametes
What is fertilisation?
Fusion of haploid gametes, ovum and sperm
When is genetic sex determined?
At fertilisation
XX female
XY male
Karyotype
When does genital development start?
Week 7
At similar time to gut rotation
Where does the Genito urinary system develop from in the three layered embryonic disc?
Intermediate mesoderm
What occurs at 3 weeks in the development of a gonad?
Primordial diploid germ cells arise in yolk-sac which reflect genetic sex of new individual
What occurs at 6 weeks in the development of a gonad?
Intermediate mesoderm becomes raised into paired genital ridges
Epithelium proliferates and penetrates mesenchyme to form primitive sex cords in an indifferent gonad
Germ cells migrate from yolk sac by amoeboid action and invade genital ridges and indifferent gonad
Induce development of indifferent/primordial gonad into testis or ovary
What state is the gonad in at week 6?
Indifferent/primordial
What happens to the indifferent gonad for it to become an ovary?
Germ cells are XX
Colonise cortex of primordial gonad
Surface epithelium continues to proliferate
Germ cells become surrounded by clusters of mesenchymal cells-primordial follicles
Remaining cords degenerate
What happens to the indifferent gonad if no germ cells arrive?
Cortex develops and they follow the ovary lineage
What happens to the indifferent gonad to become a testis?
Germ cells are XY (genes on Y chromosome influence subsequent
masculinisation)
Primitive sex cords continue to proliferate
Colonise medullary region of primordial gonad to form medullary or definitive sex cords
Dense tunica albuginea separates cords from surface epithelium
Sertoli cells differentiate from surface epithelium
Leydig cells differentiate from mesenchyme
Secretion of Testosterone by leydig cells in 8th week-influences further sexual differentiation of genitalia of embryo
Sex cords acquire a lumen at puberty as seminiferous tubules
Where do the gonads move to?
Gonads develop on posterior abdominal wall
Testis descends to end up in scrotum
Ovary descends to end up in pelvis
Describe the descent of the male gonad
Fold of peritoneum, processus vaginalis descends into labioscrotal folds (developing scrotum)
Passes through abdo wall, carries with it fascial layers of abdo wall
Gonad follows caudal descent as it is attached to abdominal wall by gubernaculum
Testis passes through inguinal canal into the scrotum
What forms the tunica vaginalis?
Lower part of processus vaginalis (fold of parietal peritoneum) forms tunica vaginalis
Why do the testis descend?
Testes need lower temperature of scrotum to permit maturation of sperm
When do testes descend?
28 weeks- migrate through inguinal canal
33 weeks - entering scrotum
Both testes in scrotum in 97% of male newborns at term
Gonad drags its supply lines with it
What is tissue is the testicle a derivative of?
Intermediate mesoderm derivative that develops high on posterior abdominal wall
Where does lymph drain to from the testicle and why?
Point of origin relevant to blood supply origin and lymph drainage
Blood supply & lymph vessels dragged with testicle
Lymph drains to para-aortic nodes ~L2 (not inguinal nodes)
Descends through inguinal canal (via gubernaculum)
Spermatic cord coverings = layers of anterior abdo. wall
What are the primordia for the male and female internal genitalia?
Fetus has primordia for male and female internal ducts Mesonephric ducts (Wolffian) - male Paramesonephric ducts (Mullerian) - female
Describe the development of the male internal genitalia
Para mesonephric (Mullerian) duct growth inhibited by Mullerian inhibitory hormone (MIH) Secreted by Sertoli cells Mesonephric (Wolffian) duct growth is stimulated by testosterone from leydig cells Develops into Epididymis, Vas deferens and Seminal vesicles
Describe the development of the female internal genitalia
Paramesonephric (Mullerian) duct develops into Fallopian tubes, Uterus, Cervix, Upper part of vagina
Mesonephric (Wolffian) duct regresses spontaneously
What do Uterine tubes and uterus develop from?
Paired paramesonephric ducts
What can Uterine & vaginal malformations lead to?
Primary amenorrhoea, infertility/problematic pregnancy
What do the external genitalia develop from?
Primordia bipotential
Urethral folds
Genital swellings
Genital tubercle
What do the male external genitalia develop from?
Urethral folds develop into Shaft of penis
Genital swellings develop into Scrotum
Genital tubercle develops into glans of penis
Influenced by testosterone from gonad
What are key features of male external genitalia development?
Enlargement
Elongation
Fusion
What do the female external genitalia develop from?
Urethral folds develop into Labia minora
Genital swellings develop into Labia majora
Genital tubercle develops into Clitoris
What are key features of female external genitalia development?
Slight enlargement
No fusion
What happens with gonads at puberty?
Begin to produce increasing quantities of hormones
Gametes begin to complete their development and be released
Secondary sexual characteristics facilitate interaction between sexes
What are male secondary sexual characteristics?
Body size Body composition & fat distribution Hair & skin Facial hair, male pattern baldness Smell Central nervous effects
What are female secondary sexual characteristics?
Size - sexual dimorphism Subcutaneous fat distribution Hair & skin Breasts Sensory dimorphism Central nervous effects
What determines a persons sexual phenotype?
Assignment at birth: External genitalia
Secondary sexual Characteristics
What controls development at puberty?
HPG axis
Hypothalamic pituitary gonadal axis
What is the default human sexual condition?
Female
What is gametogenesis?
Diploid cells separated early in embryonic life in yolk sac to form germ cells
What are the female and male gametes?
Female - ovum
Male - sperm
What happens to germ cells once they have colonised the gonad?
After colonising gonad: Proliferate by mitosis Reshuffle genetically Reduce to haploid by meiosis Mature by cytodifferentiation
Describe the formation of sperm
XY germ cells colonise sex cords - medulla of gonad
Before birth, proliferate by mitosis, forming spermatogonia which cluster around edges until puberty
Group of spermatogonia divide a fixed number of times by mitosis to form a clone of cells (about 64)
Primary spermatocytes: spermatogonia replaced by mitosis available for up to and beyond 70 years
Clone of primary spermatocytes all linked by cytoplasm
Meiosis begins: Each spermatocyte forms 4 haploid spermatids, Moving towards the lumen as it does
Spermatids are released and undergo remodelling / maturation as
they pass down tubule through rete testis, ducti efferentes and
epididymis - spermiogenesis
To form sperm-added to the semen for release into female tract
How long does sperm production take?
70 days
How often are new groups of spermatogonia recruited?
Every 16 days
What is the spermatic wave?
All stages of process of sperm production are occurring at the same time in different sections of the tubule, visible on histology
Sperm production is continuous
Why is sperm production continuous?
Exploit time limits of female fertility
What are the contents of semen?
Secretions of seminal vesicle (46-80% vol)
Secretions of Prostate (13-33% vol)
Secretions of testis and epididymis: Sperm (via vas deferens) (5%)
Secretions of bulbo-urethral glands (2-5%)
How are semen contents mixed?
Emission
How many sperm can be in 1 ejaculation?
300 million but about 50 get to site of fertilisation
How much semen is ejaculated?
1.5-4 ml
What are Gonads?
Site of gamete production
Female: ovary
Male: testis
How are ova formed?
XX germ cells colonise cortex (outer layers of gonad) oogonia
Proliferate rapidly by mitosis
Max numbers reached mid gestation 7 million, Most die during gestation
Remaining 2 million all enter meiosis before birth
Meiosis stops at early stage, primary oocyte surrounded by single layer of granulosa cells to form primordial follicle until puberty
By what time has a female created her entire stock of gametes?
Before birth
What happens to ova during the menstrual cycle?
At puberty, each month 1 or 2 complete development to mature ovum
Meiotic division only resumes at ovulation- start of short period of fertility (36hr)
Limited by number that can be supported through preparation for
fertilisation and long gestation
What does successful fertilisation require?
Right no. of gametes at right time
Male and female together at right time
Effective transfer and transport of gametes to right place
Co-ordinated by HPG hormones
What does successful reproduction require?
Fertilisation
System of support for conceptus, embryo, fetus in female tract
Birth at the right time
Co-ordinated by HPG hormones
What are the main hormones of reproduction?
H: Gonadotrophin Releasing Hormone
P: Follicle Stimulating Hormone, Luteinizing Hormone
G: Inhibin, Oestrogen, Progesterone and Testosterone
What is the Sella turcica?
Saddle-shaped depression in body of sphenoid bone of skull
serves as a cephalometric landmark which forms a seat for the pituitary
What is the endocrine function of the hypothalamus?
Most dominant portion of the entire endocrine system
Output regulates function of: Thyroid gland, Adrenal gland, Gonads
What is the pituitary and what are its roles?
Function dependent on hypothalamus
Lies at base of brain
Connected to hypothalamus by a stalk containing nerve fibers and blood vessels - median eminence
Consists of two lobes: anterior, posterior
What is the anterior pituitary?
Connected to hypothalamus by superior hypophyseal artery
Consists of groups of hormone producing glandular cells
What peptide hormones are produced by the anterior pituitary?
Prolactin Growth hormone (GH) Thyroid stimulating hormone (TSH) Adrenocorticotropic hormone (ACTH) Follicle-stimulating hormone (FSH) Luteinizing hormone (LH)
What is the advantage of the portal system between the hypothalamus and anterior pituitary?
Only need low levels of hormone from hypothalamus to stimulate release from pituitary
Describe the action of gonadotrophin releasing hormone
GnRH – decapeptide, Originates from cleavage of prepro-GnRH
Short half-life,
Where does the signal for puberty come from?
The brain. HPG axis
What are Gonadotrophins?
FSH (follicle stimulating hormone), LH (luteinising hormone)
Glycoproteins Secreted from anterior pituitary
Levels low after birth, but rise during puberty when pulsatile GnRH production begins
Where does LH act in the male reproductive system?
Leydig cells to stimulate testosterone release
Where does FSH act in the male reproductive system?
Sertoli cells to stimulate Inhibin release and increase androgen receptor expression
Leydig cells to stimulate testosterone release
Which hormones are required for the release of sperm?
At puberty pulsatile GnRH stimulates the anterior pituitary to produce LH and FSH
Both (LH) and (FSH) are required to produce and release sperm
How does LH contribute to spermatogenesis?
Binds to LH receptors on Leydig cells and induces them to produce testosterone
Testosterone binds to testosterone (androgen) receptor on Sertoli Cells
lining seminiferous tubules- stimulating spermatogenesis
How does FSH contribute to spermatogenesis?
Binds to FSH receptor on Sertoli cells
Induces expression of androgen receptor increasing responsiveness to
androgens
Also stimulates inhibin
What feedback loops exist with testosterone and Inhibin?
High levels of testosterone exert negative feedback over LH secretion acting on both hypothalamus and anterior pituitary
High levels of inhibin exert negative feedback over FSH acting primarily through anterior pituitary
What are androgens?
Mainly testosterone, steroid hormone derived from cholesterol
Produced by Leydig cells
4-10mg/day in humans
What are roles of testosterone?
Some migrates to seminiferous tubules
Converted to dihydrotestosterone (more active) by Sertoli cells
Some binds to androgen receptors in Sertoli cells
T from testis also acts on: Muscle, Bone, Growth, Hair, Libido, Secondary sexual characteristics, Metabolism/Adipose tissue
Describe the HPG axis in females
Pulsatile GnRH
Stimulates FSH and LH release from anterior pituitary
This stimulates oestrogen and progesterone release from ovaries
Inhibin provides negative feedback
What is the role of FSH in females?
Stimulates development of follicles
Stimulates secretion of oestrodiol
What is the role of LH in females?
Stimulates ovulation and development of corpus luteum
Stimulates secretion of oestradiol
Stimulates secretion of progesterone
What are the feedback loops of FSH and LH secretion by oestrodiol?
Negative feedback: Low to moderate circulating levels of Oestradiol
suppresses gonadotrophin levels
Positive feedback: Large increase in oestrodiol (200 to 400% higher than during
follicular phase)↑ FSH and LH surge mid cycle
Important in preparing a dominant follicle leading to ovulation
Describe the Preparation of Follicle for Ovulation by FSH and LH
LH stimulates theca cells to release androgen which acts on granulosa cells
Oestrodiol levels rise and stimulate follicle
FSH stimulates granulosa cell directly
What happens post ovulation?
Disrupted follicle forms corpus luteum
LH stimulates corpus luteum to secrete progesterone and oestrogen
Increase in progesterone and oestrogen as corpus luteum expands
What endocrine changes occur at the menopause?
Declining oocyte numbers
Low oestradiol
High FSH and LH as hypothalamus is still releasing GnRH
Oestrogen levels decrease
What are the roles of oestrogen?
Increases muscular contraction in uterine tubes and uterus to facilitate sperm passage
Proliferates uterine lining to prepare for implantation
Makes cervical mucus thin and alkaline to allow sperm entry
Supports breast development at puberty and in pregnancy
Female body fat distribution and hair
Genital lubrication
Supports bone growth
When does menstruation occur?
Day 1-7 of cycle
During follicular phase
When does ovulation occur?
Day 14
FSH, LH and oestrogen levels surge
What are the phases of the uterine cycle?
Menses day 1-7
Proliferative phase day 7-14
Secretory phase day 14-28
What causes the progesterone surge after ovulation?
Corpus luteum
What are the functional windows in the menstrual cycle?
Regeneration window day 1-5 stem cell driven
Fertile window day 11-13 probability of more than 5% pregnancy
Implantation window day 19-21 endometrium becomes receptive
Selection window day 23-27 pregnancy response
Describe the spatial organisation of the endometrium
Functionalis, basalis and myometrium layers
Only functionalis shed at menstruation
Blunted hormone response in the basalis
Rich in specialised immune cells such as uterine natural killer cells
Describe actions of the myometrium
Hormone dependent differentiation which mirrors changes in endometrium
Forms the placental bed in pregnancy
Specialist contraction waves throughout the cycle
What are the ACTIONS OF STEROID HORMONES ON ENDOMETRIAL CELLS?
Ovarian hormones act as transcription factors
Cause gene expression of chemokines, cytokines and growth factors which have autocrine, paracrine and juctacrine actions to stimulate proliferation, differentiation and apoptosis
What is MENARCHE?
First period
Usually age 13 y but can be 8-16 y
When does the menopause usually occur?
Age 52
Can be 45-55 y
Which phase of the menstrual cycle is the more variable?
PROLIFERATIVE PHASE MORE VARIABLE: 10 – 16 D
LUTEAL PHASE: 14 D growth and degeneration of corpus luteum
What is regular and irregular in terms of menstruation variability?
INTERCYCLE VARIABILITY: REGULAR ( ≤ 8 D)
IRREGULAR (> 8 - ≤ 20 D)
VERY IRREGULAR (> 20 D)
What is Spinbarkeit?
Spinnability of vaginal mucus
What changes in the cervix occur during the fertile window?
Thick mucus which is normally present gets thinner until it reaches a watery peak
What is the fertile window?
Defined by probability of intercourse resulting in pregnancy of >5%
Spans 4 - 5 days before and 1 day post-ovulation
Involves coordinate changes in cervix (mucus, positioning, softness) Cervical changes allow estimation of fertile and infertile days
What moves the embryo along the Fallopian tubes?
Fimbria
What is required for pregnancy?
Depends on implantation of a developmentally competent embryo in a receptive endometrium
Describe GENETIC DIVERSITY IN HUMAN EMBRYOS AT IMPLANTATION
A SIGNIFICANT PROPORTION OF HUMAN EMBRYOS ARE CHAOTIC
REMAINDER ARE LIKELY MOSAIC
VAST ARRAY OF CHROMOSOMAL ERRORS HAVE BEEN DESCRIBED
NO TWO HUMAN EMBRYOS ARE IDENTICAL AT IMPLANTATION
What drives reproductive success or failure?
Natural selection and implantation
Describe the natural selection process which occurs at implantation
Spontaneous decidualization Maternal encapsulation Embryo quality control Default rejection / menstruation Uterine plasticity
What do decidual cells do?
TROPHOBLAST INVASION HAEMOSTASIS IMMUNOMODULATION OXIDATIVE STRESS DEFENCES PROMOTE IMPLANTATION EMBRYO BIOSENSORING REJECTION & RENEWAL UTERINE PLASTICITY
Describe THE IMPLANTATION WINDOW
IMPLANTATION WINDOW (2 - 4 D) SYNCHRONISES EMBRYO DEVELOPMENT AND ENDOMETRIAL MILIEU
SPONTANOUS DECIDUALIZATION IS LINKED TO MENSTRUATION AND PROTECTS THE MOTHER AGAINST HIGHLY INVASIVE CHROMOSOMALLY CHAOTIC EMBRYOS
DECIDUAL CELLS HAVE THE PROPENSITY TO MIGRATE AND ENCAPSULATE THE EMBRYO AND ENGAGE IN ‘SENSORING’ EMBRYO QUALITY
What causes menstruation and regeneration?
Caused by progesterone withdrawal after decidualization
Acute inflammation and proteolytic breakdown of the superficial layer Cyclic menstruation starts at menarche, 1st uterine bleed occurs after brith
Menstrual blood is rich in regenerative stem-like cells
What defines heavy periods? And how can this be assessed?
> 80 ML per cycle
Assessed either subjectively, pictorial blood loss assessment chart
or alkaline hematin method
What is a major cause of endometriosis?
Retrograde menstruation through the Fallopian tubes
What is dysmenorrhea?
Painful periods
What is dyspareunia?
Pain during or after sexual intercourse
What is mittlesmerch?
Pain in the middle of the cycle
What is menorrhagia?
> 80 ml or > 7 d but regular
What is menometrorrhagia?
Irregular menorrhagia (heavy periods)
What is hypomenorrhea?
Abnormally light periods
What is amenorrhoea?
Abnormal absence of menstruation
More than 3 months without a period
What is oligomenorrhoea?
Infrequent periods, more than 35 days
What is polymenorrhoea?
Frequent periods, less than 21 days
What are Disorders of the Physical reproductive tract?
Ovarian cysts Adhesions Polyp Fibroid Cervical intra epithelial neoplasia Ectopic Hydrosalpinx (distally blocked fallopian tube with serous or clear fluid)
What are Disorders of the Functional reproductive tract?
Impaired ovarian steroidogenesis
Ovary: policystic ovaries, premature ovarian failure, genetic mutations
Hypothalamus/Pituitary: stress, weight loss, drugs, hyperprolactinaemia, thyroid dysfunction
Impaired steroid hormone responses: Inflammation / impaired immune response, Exogenous hormones/ Endocrine disruptors
What is sexuality?
Complex: elements of self identity and external influences during childhood and development
What does sexual behaviour involve?
Physiological and psychological processes
Why have sexual behaviours evolved?
Ensure meeting of gametes for fertilisation
What is erection and what causes it?
Stimulus (physical or psychological)
Parasympathetic dilation of arteries
Increased blood flow compresses veins
Build-up of blood causes erection
What is ejaculation and what causes it?
Sympathetic impulses
Urethra fills with semen
Contraction of muscles at base of penis
Pressure forces semen through urethra
What are the 4 stages of coitis?
Excitement
Plateau
Orgasm
Resolution
What happens to sperm after coitis?
Deposited in upper vagina and enter cervix
Supported by mucus components and form reservoir in cervical crypts
Swim (or are transported) into uterus and tubes
Relatively few sperm reach site of fertilisation in ampulla (few hundred)
What do the testis and epididymis contribute to ejaculate?
Sperm, testosterone, L-carnitine (antioxidant affecting motility)
What do the seminal vesicles contribute to ejaculate?
Fructose, proteins, semen clotting factors, interleukins, prostaglandin E
What does the prostate gland contribute to ejaculate?
Phosphate and bicarbonate buffers Prostate specific antigen (PSA) Coagulase (liquefying) Zinc Citric acid Spermine and spermidine Putrescine
What do Bulbourethral 2-5% and urethral glands contribute to ejaculate?
Lubrication of male reproductive tract. Can include anti-sperm antibodies
What are normal ranges for ejaculate to indicate fertility?
After 3-5 days abstinence: Volume: >1.5 ml Liquefaction time: within 60 min pH 7.2 or more Sperm concentration: >15 million per ml Total sperm count: >39 million per ejaculate Motility: >32% total progressively motile (total motility >40%) Morphology: >4% normal forms Vitality: >58% live White blood cells:
Which follicles are recruited for ovulation?
Antral follicles
What is a polar body of a human oocyte?
Where half of genetic material is ejected during meiosis
What is the zona pelluicda?
Specialised extracellular matrix surrounding developing oocyte within each follicle in ovary
Formed by secretions from oocyte and follicle granulosa cells
What are granulosa cells and what do they do?
Somatic cell of sex cord associated with developing female gamete in ovary
Production of sex steroids and growth factors
FSH stimulates cells to convert androgens (from thecal cells) to estradiol by aromatase during follicular phase
After ovulation, cells turn into granulosa lutein cells that produce progesterone. Maintain a potential pregnancy and causes production of thick cervical mucus to inhibit sperm entry into uterus
What are thecal cells and what do they do?
Layer of the ovarian follicles which appear as they become tertiary
Theca interna responsible for production of androstenedione and indirectly estradiol, by supplying neighboring granulosa cells with androstenedione that with the help of aromatase can be used as a substrate for estradiol
Which phase are oocytes arrested in?
Metaphase II
What are essential features of sperm for fertilisation?
Motility - swim against action of tubal cilia
Capacitation - changes to outer glycoprotein coat
Acrosome reaction - penetrate zona pellucida
Describe fertilisation
Occurs in ampulla of oviduct
Mature capacitated sperm meets metaphase II oocyte
Hyperactivation and acrosome reaction of sperm, zona penetration
Causes final maturation of oocyte/release of second polar body
Sperm binding to oolemma causes calcium transients which:
Activate oocyte for further development
Release cortical granules avoiding polyspermy
What allows sperm entry into the zona pellucida?
Acrosome reaction
What prevents polyspermy during fertilisation?
Release of cortical granules
How many pronuclei should their be in a successfully fertilised egg?
2
What could dispermic fertilisation result in?
Abnormal conceptus eg triploid
Possible abortion
At what time does a successful embryo reach the uterus?
Day 4-5
Describe the initial stages of embryo development
Pronucleate 6-20 hr Cleavage 18hr-3 days Compaction 3-4 days Blastocyst 5-7 days Hatching 6-7 days
Describe embryonic genome activation
mRNA inherited from oocyte supports embryo development through fertilisation and early cleavage
Onset of mRNA production from embryonic genome principally at 4-8 cell stage
What does the inner cell mass of the blastocyst become?
Becomes embryo ‘proper’ Undifferentiated Stem cell markers Minority of cells (~20%) Female imprinting important
What does the trophoectoderm of the blastocyst become and what does it do?
Becomes placenta and extraembryonic features
Secretes hCG (basis of pregnancy test)
Accommdates some abnormal cells (NB prenatal diagnosis)
Invasive/adhesive
Male imprinting important
What is implantation? And when does it occur?
Around 7 days after ovulation Usually in upper part of uterus Apposition, Adhesion and Attachment Specific orientation and maternal/embryonic communication mechanisms Immunologically complex
Which is the most likely failure stage of IVF treatment?
Implantation
70% failure rate per embryo
Post-implantation failure of pregnancy ~15-20%
What is infertility?
1-2 years of attempting pregnancy (84% of couples in general population conceive within1 yr and 92% within 2 years if having regular sex and not using contraception)
When does fertility begin to decline?
Age 30
What can be medically diagnosed causes for female infertility?
Anovulation: Primary or secondary ovarian failure, Polycystic ovarian disease
Tubal disease or blockage
Uterine anomaly
Age
What are IVF diagnosed causes for female infertility?
Anti sperm antibodies Egg anomaly (genetic, cytoplasmic, maturation) Fertilisation failure or abnormality Abnormal embryo development Implantation problem
What can cause Oligo ovulation or anovulation?
Polycystic ovaries (common in fertile population too) Endocrine anomalies: high LH, high androgens, insulin insensitivity Overweight
What can be endocrine treatments for oligo ovulation?
Anti or partial estrogens
FSH - ovarian stimulation, produce more eggs
What is the aim of IVF treatment?
Bring gametes together more reliably rather than fix cause of infertility
What can be male causes for infertility?
Impotence (Psychosexual, drug induced, paraplegia)
No sperm in ejaculate (azoospermia): testicular failure, Obstructive (vasectomy, CBAVD), Retrograde ejaculation
Not many sperm (oligozoospermia
What are options for male fertility treatments?
Correct hormonal imbalances/blockages/psychological problems Obtain best sample from ejaculate
If too poor, obtain best sample from surgical retrieval
If sperm available, apply treatments to female partner in order of least invasiveness/appropriate to any female factor of infertility: Artificial insemination, Intrauterine insemination, IVF, ICSI
If no sperm available, or ICSI declined, consider donor sperm
What is ICSI?
Injection of one immobilised sperm into egg avoiding presumed position of oocyte spindle near polar body
Fertilisation, embryo development and pregnancy rates similar to
IVF with normal sperm
Some increased abnormality rate, likely due to parental factors
What are risks of fertility treatment?
Failure (~70% per cycle)
Over response of woman to stimulation drugs (multiple ovulation)
Multiple pregnancy
Advanced maternal age increases every obstetric risk
Psychological
Known risks of embryological processes (ICSI, sex chromosomal disorders, inheritanceof infertility, possibly imprinting disturbance)
Unknown risks of embryological processes
