More and more couples who cannot have children the natural way resort to in vitro fertilization or IVF. A number of abnormalities and disorders have been reported with the success of this assisted reproductive technology. Despite its serious or fatal impact on health, the demand for ART and IVF has not tapered.
In Vitro Fertilization
SERIOUS HEALTH RISKS
In vitro fertilization is fertilization, which takes place in a laboratory dish (Storck, 2010). Fertilization is the joining of a woman's ovum or egg and a man's sperm. This normally occurs inside a woman's body. The fertilized egg attaches itself to the womb and grows until it is expelled after 9 months, more or less. This is natural or un-assisted conception. In contrast, in vitro fertilization or IVF is a form of assisted reproductive technology or ART. ART uses special medical techniques to help a women get pregnant. IVF has proved successful since 1978. It has been the most used form when cheaper techniques fail (Storck). It appears to be the best solution for infertility, but IVF impacts health.
Basic Steps in IVF
First is stimulation or super ovulation (Storck, 2010). The woman is given medicine, called fertility drugs, stimulate the ovaries to produce more eggs or ova. Regular transvaginal ultrasounds are performed to monitor the ovaries and the hormone levels. The second is follicular aspiration, a minor outpatient surgery, which removes the egg from the woman's body. She is given painkillers for the procedure, which is guided by an ultrasound. A thin needle is inserted into the ovary and sacs through the vagina. A suction device is connected to it to suction the eggs and fluid from each follicle, one at a time. The procedure is performed for each ovary. The woman may experience temporary cramping. A pelvic laparoscopy is seldom resorted to in removing the eggs. In case the woman does not or cannot produce eggs, donated eggs may be used. The third consists of insemination and fertilization. The sperm is joined with the best eggs and then kept in a carefully controlled chamber. The combining of the sperm and the eggs is called insemination. The sperm enters or fertilizers the egg or eggs in a few hours after insemination. If the doctor judges the chances of fertilization as low, the sperm may be directly injected into the egg. The procedure is called intracytoplasmic sperm injection. This is performed in many fertility programs routinely if all conditions are normal. The fourth step is embryo culture, in which the embryo's proper growth is monitored by the laboratory staff. At this stage, the couple who has a high risk of a hereditary disorder may opt for pre-implantation genetic diagnosis. This can be done 3-4 days after fertilization. Laboratory scientists take out a single cell from each embryo and screen it for possible specific genetic disorder. The American Society for Reproductive Medicine says that parents can decide which embryo to implant at this stage. The procedure is called pre-implantation genetic diagnosis or PGD. It can reduce the chance of passing on a hereditary defect to the offspring. This technique, however, is still controversial and available in only a few centers and hospitals. The fifth is embryo transfer. The selected egg is returned to the woman's womb 3-5 days after egg retrieval and fertilization. It is performed while the woman is awake. The doctor inserts a catheter with the embryos into the woman's vagina through the cervix and the womb while she is awake. If the embryo attaches to the lining of the womb, pregnancy begins. Simultaneous implanting more than one embryo can result in more than one offspring. The number of allowed embryos for transfer is a controversial issue. It also depends on a number of factors, especially the woman's age. Un-used embryos may be frozen for donation at a latter date (Storck).
Rationale and Risks
IVF is used to treat the causes of infertility, such as the woman's advancing age, damaged or blocked fallopian tubes, endometriosis, the husband's infertility, and unexplained infertility (Storck, 2010). These benefits are offset by various risks. The patient must be physically, emotionally, and financially prepared and committed to make it work. Infertile couples have been observed to suffer from stress and depression. A woman who takes fertility drugs may experience bloating, abdominal pain, mood swings, and headaches. These drugs are administered mostly by injection several times a day for 8-10 weeks. The injections are too frequent that the health care team needs to instruct the couple on how to mix the medicine and make the injection. Bruising can result from frequent injections. In severe but rare cases, these drugs can cause In rare cases, fertility drugs may cause ovarian hyperstimulation syndrome, characterized by fluid build-up in the abdomen and chest. Current research has not yet found a reliable link between fertility drugs and ovarian cancer. Egg retrieval may react to anesthesia, bleeding, infection and damage to surrounding structures of the ovaries. Multiple pregnancies may also result from the implantation of more than one embryo. Pregnancy with more than one baby increases the risk of premature birth as well as low birth weight. Not all pregnancies from IVF lead to live births. The chances of giving birth to a live baby are highest in women under 35 at up to 43% and only 13-18% in women over 41. And IVF is a very costly procedure. Not all health insurance companies cover its costs. One IVF cycle must cover the costs of medicine, surgery, anesthesia, ultrasounds, blood tests, processing of the eggs and the sperm, embryo storage, and embryo transfer. One cycle costs from $12,000-17,000 (Storck).
Imprinting Disorders
No definite conclusions as yet have been found that ART increases the risk of imprinting disorders in children conceived through it (Owen & Segar, 2009). But biological evidence suggests that ART can change non-genomic inheritance. This can be cause for caution among those worldwide who opt for ART at 1 to 3% of births. These imprinting disorders are the Beckwith-Wiedemann Syndrome and Angelman Syndrome. Animal studies and surveys conducted among IVF children in the Netherlands and Ireland suggest a link between ART and loss of maternal metholation. More recent investigations tagged three other imprint disorders, namely Silver Russell syndrome, maternal hypomethylation syndrome, and retinoblastoma. ART procedures, including ovarian stimulation and the manipulation of pre-implantation embryos, take place at critical developmental periods of vulnerability for genomic imprints. Independent studies suggest the link between ART and BWS. Moreover, the higher percentage of BWS cases from the loss of maternal methylation after ART as compared with the general BWS population strengthens the association (Owen & Segar).
Meanwhile, reports of 5 cases of AS in children conceived by ART bolsters the link of AS with ART (Owen & Segar, 2009). Hypomethylation was frequently found in the maternal alleles in the children with the imprint disorder. The finding is not conclusive but calls for the need for follow-ups on the children. In adulthood, their small epigenic changes may affect long-term morbidity and pass on to future generations (Owen & Segar).
Ovarian Cancer
This is the fifth most common type of cancer in the Western world (Kashyap & Davis, 2003). Because infertility and nulliparity are independent risk factors, the link between fertility drugs and this cancer is a cause for concern. About 70% of cases are discovered in advanced stages III and IV. Independent studies suggest that the incidence tends to decrease with each successive live birth. Nulliparity, on the other hand, increases the risk two times. This raised concern over the increasing use of fertility drugs and its association with ovarian cancer incidence. As of now, available data have not come up with a causal relationship between these. As a matter of fact, infertility drugs even seem to afford protection for those who are able to conceive (Kashyap & Davis).
Infertility afflicts 10-15% of couples wanting to have a child (Kashyap & Davis, 2003). Statistical estimates say that 2.5% of all births in North America are through ART. Registered drugs since the 60s in the U.S. are clomiphene citrate and gonadotrophins. Earlier hormonal treatment used estrogens, progestins, OCP and pituitary radiation. This study found that ovarian cancer incidence is higher among untreated and infertile women than treated infertile women (Kashyap & Davis).
Ovarian Hyper-Stimulation Syndrome or OHSS
This is an iatrogenic complication of controlled ovarian stimulation, widely and increasingly used during ART cycles (Zivi et al., 2010). Although rare, it is serious and life-threatening. It is an exaggerated response to induced ovulation when ovarian vasoactive angiogenic substances are made to increase capillary permeability and fluid accumulates I the extravascular space. Human chorionic gonatrophin is administered to induce ovulation to lead to pregnancy. It is self-limiting in most cases and resolves after several days. In other cases, it persists longer especially when pregnancy has begun. OHSS was first reported in the 60s when patients developed the syndrome after receiving pregnant mare's serum gonadotropins. Since then, more reports came in with the increased use of gonadotropins for ART cycles. These contributed to the increased incidence of the syndrome in the past years (Zivi et al.).
Risk Factors
Primary risk factors are those observed before treatment and derived from the patient's characteristics (Zivi et al., 2010). Secondary risk factors are those discovered during actual treatment. The primary risk factors for OCHS are previous episodes of OHSS, young age, low body weight, and Polycystic Ovarian Syndrome. Secondary risk factors are high E2 serum levels or rising levels, more than 20-25 follicles in both ovaries, the number of eggs retrieved, stimulation agents used, hCG administration, and pregnancy. Younger women are more prone to the syndrome as they are more responsive to gonadotropins and have more follicles than older women. Findings suggested that a lower body mass index carries a risk. Women with PCOS are more sensitive to infused follicle-stimulating hormone and produce more follicles with gonadotropin stimulation. They are more susceptible to developing the syndrome. Those who only have an isolated characteristic of the syndrome develop a comparable exaggerated response to gonadotropins. They are thus also at a higher risk for developing OHSS (Zivi et al.).
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