الفهرس 
In Vitro Fertilization TechniquesOnly 14 pages are availabe for public view
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Abstract
In vitro fertilization (IVF) is increasingly being practiced in different parts of the world. Anesthesiologists are faced with peculiar challenge to follow an anaesthetic technique that allays patient anxiety with adequate pain relief and yet avoiding any deleterious effect on outcome of successful pregnancy. Majority of the patients are young and healthy but exhibit stress, anxiety and other psychological disorders associated with infertility. It is particularly important for the anesthesiologist to understand the patient anxieties and take suitable measures to allay it.
Whereas most patients undergoing procedures related to assisted reproductive technologies are young and otherwise healthy, a growing percentage have significant comorbid states that are responsible for either infertility or the inability to carry a pregnancy. For these individuals, assisted reproduction represents a mechanism to preserve infertility or to obtain oocytes for later use or transfer to gestational carriers .
There are different types of Assisted Reproductive Techniques, TUGOR, Transvaginal ultrasound-guided oocyte retrieval; GIFT, gamete intrafallopian transfer; ZIFT, zygote intrafallopian transfer; PROST, pronuclear stage tubal transfer; TET, tubal embryo transfer.
IVF is a method of assisted reproduction in which the man’s sperm and the woman’s egg are combined in a laboratory dish, where fertilization occurs. The resulting pre-embryo is transferred to the woman’s uterus. The basic steps in an IVF treatment cycle are ovulation enhancement (stimulating the development of more than one egg in a cycle), egg harvest, fertilization , embryo culture, and embryo transfer .
IVF is a reasonable choice of treatment for couples with various types of infertility. Initially, it was only used when the woman had blocked, damaged, or absent fallopian tubes (tubal factor infertility). IVF is also used to circumvent infertility caused by endometriosis or by any one of a number of problems in the male. Many programs use IVF to treat couples who are infertile due to immunologic factors or other unexplained reasons.
IVF specialists agree that the chances for pregnancy are better if more than one egg is fertilized and transferred to the uterus in a treatment cycle. Timing is crucial in an IVF treatment cycle. The doctor not only must know what is happening in the woman’s ovaries, but also when it happens relative to other events in the cycle .
One of the major benefits of IVF is the ability to know before transfer takes place if the male’s sperm has actually fertilized the eggs. If fertilization fails to take place (as may happen in some cases of male infertility), changes can be made in the semen processing or fertilization conditions during a future attempt to create an embryo.
Another benefit of IVF is embryo transfer to the uterus. Because fertilized eggs are placed directly in the uterus, the woman doesn’t need to have functioning fallopian tubes .
It has been shown that women under 40 years of age undergoing IVF have a substantially higher success rate than women over age 40. Therefore, one of the limitations of IVF is a low success rate in woman over age 40. This is believed to be due to the quality of oocytes in older women .
Any patient undergoing ovulation induction is at risk of developing ovarian hyperstimulation syndrome (OHSS). OHSS may be classified as mild, moderate or severe by symptoms and signs. The worst cases seem tend to be associated with pregnancy.
Ovarian Hyperstimulation Syndrome is the most serious complication of IVF . Any patient undergoing ovulation induction is at risk of developing OHSS, although some more than others. OHSS is a systemic disease resulting from vasoactive products released by hyperstimulated ovaries. The pathophysiology of OHSS is characterized by increased capillary permeability, leading to leakage of fluid from the vascular compartment, with third space fluid accumulation and intravascular dehydration .
In vitro fertilization (IVF) is increasingly being practiced in different parts of the world. Anesthesiologists are faced with peculiar challenge to follow an anaesthetic technique that allays patient anxiety with adequate pain relief and yet avoiding any deleterious effect on outcome of successful pregnancy. Majority of the patients are young and healthy but exhibit stress, anxiety and other psychological disorders associated with infertility. It is particularly important for the anesthesiologist to understand the patient anxieties and take suitable measures to allay it.
Anaesthetic agents in day care surgery should provide smooth and fast induction of anaesthesia, rapid and pleasant recovery and return to pre-operative functional status with optimal postoperative analgesia and minimum side effects such as postoperative nausea and vomiting (PONV).
There has been tremendous progress in the field of assisted reproduction. The techniques employed in aspiration of the oocyte and the laboratory manipulations have all been modified and updated. The anesthetic, which is important to the comfort of the patient and for the gynecologist to maximize the harvesting of oocytes, plays an important role in a successful outcome. The anesthetic agents must be short-acting, with minimal side effects. They should have little penetration into the follicle, and the oocyte should not be harmed by their presence. The key is short exposure to the least toxic agent .
Embryo transfer (ET) rarely requires any anesthetic involvement. Conscious sedation or light IVGA may be necessary in cases of significant discomfort with speculum insertion, or when there is difficulty advancing the flexible catheter past the cervical opening.
In Gamete intrafallopian transfer ( GIFT ), laparoscopy performed under general anesthesia is preferred so as to have direct visualization of the flexible catheter and fallopian tubes. Spinal anesthesia is rarely used for laparoscopic procedures because of concerns of shoulder discomfort and difficult breathing with CO2 .
Traditional analgesic methods used for transvaginal oocyte retrieval include local injection as a paracervical block, conscious sedation using various pharmacological agents, epidural block , subarachnoid block, general anaesthesia, or in some cases no analgesic at all. Male procedures are done with these same anesthetic techniques. In addition, the physician uses local anesthetic injections prior to starting the procedure. If the procedure is certain to only be a percutaneous epididymal sperm aspiration (PESA), it can be done with local anesthesia only without sedation . The anesthetist should check with the patient about the choice of anesthesia. If a PESA is not a certainty it is best to be sedated or anesthetized for the procedure so as not to be uncomfortable and create a delay in going to the next more invasive step, which is usually a testicular sperm aspiration, or occasionally a testicular biopsy. Embryo transfer can be performed without anesthesia, also some women may wish to have a mild sedative .
Plasma increases in prolactin and hormonal responses to follicular puncture were fully attenuated by spinal anesthesia and partially attenuated by the techniques requiring sedation .
Exposure to high concentrations of different local anaesthetics adversely affects fertilization and embryonal development. However, given that much lower concentrations are achieved clinically and that oocytes are washed after retrieval, the clinical effects of using local anaesthetics should be limited and no adverse effects have been reported in human trials. Nitrous oxide adversely influences DNA synthesis in humans by reducing methionine synthetase activity. Therefore, this agent cannot be recommended despite the lack of data indicating that it reduces the success rate of fertility treatment. Halogenated agents have been associated with reduced reproductive success in clinical practice and must therefore be used with caution. Opioids, and especially fentanyl and remifentanil, do not seem to affect reproductive success. In addition, midazolam and ketamine seem to be acceptable drugs for use during assisted reproduction. Propofol may be a safe alternative for use during assisted reproduction. A fentanyl/propofol based technique of choice for all in vitro fertilization procedures. This method has been reported to be safe and effective with no differences in oocyte fertilization rate or subsequent successful pregnancy outcome as compared to general anaesthesia. Electro-acupuncture appears to be an effective alternative to conventional anaesthesia during egg collection (ovum pickup) for in vitro fertilization. Paracervical block (PCB) has been used in combination with opioids, hypnotics, sedatives, and acupuncture with or without premedication during TUGOR.
A variety of anaesthetic techniques and analgesic methods has been used but no definite conclusion has yet been arrived regarding the technique of choice for IVF. No method could be considered as superior to other technique if basic concepts pertaining to IVF are taken care. Conscious sedation is suitable for cooperative females. In addition to conscious sedation and analgesia, many methods of pain relief during oocyte recovery are currently in use. In case general anesthesia is required, the anesthetic drugs should be used cautiously and efforts should be made to reduce the anesthetic duration. The preferred modality of peri-operative care should be individualized as per the requirement of the patient .