Lifespan Development. Tara L. Kuther. Читать онлайн. Newlib. NEWLIB.NET

Автор: Tara L. Kuther
Издательство: Ingram
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Жанр произведения: Зарубежная психология
Год издания: 0
isbn: 9781544332253
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their children will inherit genetic defects and chromosomal abnormalities.

      Michelle Del Guercio/Science Source

      The genetic counselor interviews the couple to construct a family history of heritable disorders for both prospective parents. This service is particularly valuable when one or both prospective parents have relatives with inborn disorders. If a disorder is common in either parent’s family or it appears that they are likely to carry a genetic disorder, genetic screening blood tests may be carried out on both parents to detect the presence of dominant and recessive genes and chromosomal abnormalities associated with various disorders. The tests determine whether each parent is a carrier for recessive disorders and estimate the likelihood that a child may be affected by a genetic disorder. The genetic counselor interprets the results and helps the parents understand genetic concepts by tailoring the explanation to match the parents’ knowledge (Nance, 2017).

      Once prospective parents learn about the risk of conceiving a child with a disorder, they can determine how to proceed—whether it is to conceive a child naturally or through the use of in vitro fertilization—after screening gametes for the disorders of concern. Given advances in our knowledge of genetic disorders and ability to screen for them, some argue that genetic counseling should be available to all prospective parents (Minkoff & Berkowitz, 2014). Others argue that abnormalities are rare and so few would be discovered that universal screening is of little utility (Larion, Warsof, Maher, Peleg, & Abuhamad, 2016). Whether to seek genetic counseling is a personal decision for prospective parents based on their history, view of their risks, and their values. Adults who carry significant risks of conceiving a child with a genetic disorder sometimes consider alternative methods of reproduction.

      Reproductive Technology

      Couples turn to reproductive technology for a variety of reasons. As noted, some couples at risk for bearing children with genetic or chromosomal abnormalities seek alternative methods of conception. About 15% of couples in the United States experience infertility, the inability to conceive (Thoma et al., 2013). About 35% of the time, factors within the male are identified as contributors to infertility (Centers for Disease Control and Prevention, 2017). In addition, single men and women, as well as gay and lesbian couples, often opt to conceive with the use of reproductive technology.

A health care technician working in an in vitro fertilization laboratory injects sperm directly into a harvested egg.

      In vitro fertilization is a form of reproductive technology in which an ovum is fertilized outside of the womb.

      Mauro Fermariello/Science Source

Cycles started: 169,568 Embryo transfers: 138,029 Pregnancies: 68,988 Live-birth deliveries: 56,028 Infants: 68,782 Singleton live-birth deliveries: 43,544 Multiple live-birth deliveries: 12,484

      Figure 2.7 Number of Outcomes of Assisted Reproductive Technology Procedures, by Type of Outcom—United States and Puerto Rico, 2014

      Source: Sunderam et al., 2017.

      Artificial insemination refers to the injection of sperm into a woman. The male partner’s sperm may be used or, if the male experiences reproductive difficulties, a donor’s sperm may be used. Artificial insemination through a donor also enables women without male partners, whether single or lesbian, to conceive.

      Another common method, in vitro fertilization, introduced in the United States in 1981, permitted conception to occur outside of the womb. A woman is prescribed hormones that stimulate the maturation of several ova, which are surgically removed. The ova are placed in a dish and sperm are added. One or more ova are fertilized, and the resulting cell begins to divide. After several cell divisions, the cluster of cells is placed in the woman’s uterus. If they implant into the uterus and begin to divide, a pregnancy has occurred.

      The success rate of in vitro fertilization is about 50% and varies with the mother’s age. For example, the success rate is 47% in 35-year-old women, 27% in 41- to 42-year-old women, and 16% in 43- to 44-year-old women. Artificial insemination contributed to 1.6% of all infants born in the United States in 2014 (Saswati et al., 2017). As shown in Figure 2.7, about 40% of in vitro cycles begun result in pregnancy. Infants conceived by artificial insemination are at higher risk of low birthweight (Fauser et al., 2014), although it has been suggested that it is because of maternal factors, such as advanced age, and not in vitro fertilization per se (Seggers et al., 2016). Infants conceived by artificial insemination show no differences in growth, health, development, and cognitive function relative to infants conceived naturally (Fauser et al., 2014). Because in vitro fertilization permits cells to be screened for genetic problems prior to implantation, in vitro infants are not at higher risk of birth defects (Fauser et al., 2014). However, about 40% of births from artificial insemination included more than one infant (38% twins and 2% triplets and higher). Multiple gestations increase risk for low birth weight, prematurity, and other poor outcomes (Sullivan-Pyke, Senapati, Mainigi, & Barnhart, 2017).

      Surrogacy is an alternative form of reproduction in which a woman (the surrogate) is impregnated and carries a fetus to term and agrees to turn the baby over to a woman, man, or couple who will raise it. Single parents, same-sex couples, and couples in which one or both members are infertile may choose surrogacy. Sometimes the surrogate carries a zygote composed of one or both of the couple’s gametes. Other times, the ova, sperm, or zygote are donated. Despite several highly publicized cases of surrogate mothers deciding not to relinquish the infant, most surrogacies are successful. In 2015, 2,807 babies were born through surrogacy in the United States, up from 738 in 2004, according to the American Society for Reproductive Medicine (Beitsch, 2017). Longitudinal research suggests no psychological differences at least through age 14 between children born through surrogacy compared with other methods (Golombok, 2013; Golombok, Ilioi, Blake, Roman, & Jadva, 2017). In addition, mothers of children who were the product of surrogates do not differ from those conceived using other methods and surrogate mothers show no negative effects (Jadva, Imrie, & Golombok, 2015; Söderström-Anttila et al., 2015). Finally, some argue that surrogacy may pose ethical issues. For example, women are often paid at least $30,000 to surrogate a fetus (Beitsch, 2017), creating financial incentives for surrogacy that may be difficult for low socioeconomic status women to resist.

      Adoption

      Another reproductive option for prospective parents is adoption. Adults who choose to adopt have similar motives for parenthood as those who raise biological children, such as valuing family ties, continuing a family line, feeling that parenting is a life task, and the desire for a nurturing relationship with a child (Jennings, Mellish, Tasker, Lamb, & Golombok, 2014; Malm & Welti, 2010). Heterosexual and same-sex adults report similar reasons for choosing adoption (Goldberg, Downing, & Moyer, 2012).

A same-sex couple and their two young children of different races/ethnicities pose for a picture. Everyone is smiling and laughing.

      Adults choose to adopt for a variety of reasons, such as infertility, the desire to raise a child with a same-sex partner, and to provide a home for a child in need.

      iStock/CREATISTA

      Adoptive children tend to be raised by parents with higher levels of education and income than other parents. This is partly due to self-selection and partly because of the screening that adoptive parents must go through before they are allowed to adopt. Adoptive children also tend to spend more time with their parents and have more educational resources than other children (Zill, 2015).

      Yet adopted children show less engagement in class and tend to have more academic difficulties. Longitudinal research suggests that adoption is associated with lower academic attainment achievement across childhood, adolescence, and emerging adulthood compared with nonadopted comparison groups (Brown, Waters, & Shelton, 2017). Adopted children are also more likely than their nonadopted peers