Contents
Reproductive Challenges and Choices
The basics of heredity, the genetic transmission of characteristics from biological parents to their children, by examining how we receive our genetic endowment. How can we deal with reproductive challenges through genetic counseling and, in some cases, manipulation of a child’s genes and what choices the parents need to make.
Genes are only one part of the story of prenatal development. We’ll also consider the ways in which a child’s genetic heritage interacts with the environment in which he or she grows up—how one’s family, socioeconomic status, and life events can affect a variety of characteristics, including physical traits, intelligence, and even personality.
In the past, many couples with genetic disorders in their families chose not to bear a child at all rather than risk the birth of an abnormal baby. Today, genetic counseling and prenatal diagnosis help people make informed decisions about conceiving, carrying a pregnancy to term, or adopting a child.
Genetic Counseling- Reproductive challenges and choices
Genetic counseling is a communication process to help couples. To assess their chances of giving birth to a baby with a hereditary disorder. And choose the best course of action in view of risks and family goals. Individuals likely to seek counseling are those who have had difficulties bearing children. For example, repeated miscarriages—or who know that genetic problems exist in their families.
In addition, adults who delay childbearing are often candidates for genetic counseling. As maternal age rises beyond age 35, the rates of Down syndrome and other chromosomal abnormalities increase sharply. However, older paternal age presents a heightened risk of DNA mutations as well. After age 40, it associates with increased incidence of several serious psychological disorders (Zitzmann, 2013).
If a family history of intellectual disability, psychological disorders, physical defects, or diseases exists, the genetic counselor interviews the couple and prepares a pedigree, a picture of the family tree to identify the relatives. The pedigree estimates the likelihood that parents will have an affected child. For many disorders traceable to a single gene, blood tests or genetic analyses can reveal whether the parent is a carrier of the harmful allele.
When all the relevant hereditary information is in, genetic counselors help people consider appropriate options. These include taking a chance and conceiving, choosing from among a variety of reproductive technologies or adopting a child.
Prenatal Diagnosis and Fetal Medicine
If couples at risk for bearing a child with abnormalities decide to conceive, several prenatal diagnostic methods. Women of advanced maternal age are prime candidates for amniocentesis (Insert a hollow needle through the abdominal wall to obtain a sample of fluid in the uterus. For genetic defects, they examine the cells. Performed by the 14th week after conception; require1 to 2 weeks for test results. Small risk of miscarriage.) or
Chorionic villus sampling. (Insert a thin tube into the uterus through the vagina, or a hollow needle through the abdominal wall. Remove a small plug of tissue from the end of one or more chorionic villi, the hair like projections on the membrane surrounding the developing organism. For genetic defects, they examine the cells. Performed at 9 weeks after conception; results are available within 24 hours. Entails a slightly greater risk of miscarriage than amniocentesis. Also associated with a small risk of limb deformities, which increases the earlier they perform the procedure).
Prenatal diagnosis has led to advances in fetal medicine. For example, by inserting a needle into the uterus, doctors can administer drugs to the fetus. Give blood transfusions to the fetuses with blood disorders . And those with immune deficiencies have received bone marrow transplants that succeeded in creating a normally functioning immune system (Deprest et al., 2010).
These techniques frequently result in complications, the most common being premature labor and miscarriage (Danzer & Johnson, 2014).
Adoption
Adults who are infertile or likely to pass along a genetic disorder, same-sex couples, and single adults who want a family are turning to adoption in increasing numbers. Couples who have children by birth, too, sometimes choose to expand their families through adoption.
Adopted children and adolescents, whether or not they are born in their adoptive parents’ country, tend to have more learning and emotional difficulties than other children. A difference that increases with the child’s age at time of adoption. The biological mother may have been unable to care for the child because of problems believed to be partly genetic, such as alcoholism or severe depression, and may have passed this tendency to her offspring. Or perhaps she experienced stress, poor diet, or inadequate medical care during pregnancy, factors that can affect the child.
Furthermore, children adopted after infancy often have a pre-adoptive history of conflict-ridden family relationships, lack of parental affection, neglect and abuse, or deprived institutional rearing. Finally, adoptive parents and children, who are genetically unrelated, are less alike in intelligence and personality than are biological relatives, differences that may threaten family harmony.
And children with troubled family histories who are adopted at older ages generally improve in feelings of trust and affection for their adoptive parents as they come to feel loved and supported (Veríssimo & Salvaterra, 2006). When parents have been warm, open, and supportive in their communication about adoption, their children typically forge a positive sense of self (Brodzinsky, 2011).
Reproductive technologies, such as donor insemination, in vitro fertilization, and surrogate motherhood, enable individuals to become parents. Who otherwise would not, but they raise legal and ethical concerns.
The Pros and Cons of Reproductive Technologies
Some people decide not to risk pregnancy because of a history of genetic disease. Many others, in fact, one-sixth of all couples who try to conceive—discover that they are infertile. And some never married adults and gay and lesbian couples want to bear children. Today, increasing numbers of individuals are turning to alternative methods of conception technologies that have become the subject of heated debate.
Donor Insemination and In Vitro Fertilization
For nearly fifty years, to overcome male reproductive difficulties, they use donor insemination method i.e. injection of sperm from an anonymous man into a woman. It also permits women without a male partner to become pregnant. In vitro fertilization is another commonly used reproductive technology.
With in vitro fertilization, a woman is given hormones that stimulate the ripening of several ova. They remove it surgically and place it in a dish of nutrients, to which sperm they add sperms. Once an ovum fertilizes and duplicates into several cells, they inject it into the mother’s uterus. Usually, in vitro fertilization is to treat women with permanently damaged fallopian tubes. But a single sperm can now be injected directly into an ovum, thereby overcoming most male fertility problems.
In vitro fertilization poses greater risks than natural conception to infant survival and healthy development. About 26 percent of in vitro procedures result in multiple births. Most are twins, but 3 percent are triplets and higher-order multiples. Consequently, among in vitro babies, the rate of low birth weight is nearly four times as high as in the general population.
Surrogate Motherhood
An even more controversial form of medically assisted conception is surrogate motherhood. In this procedure, in vitro fertilization impregnate a woman (called a surrogate) with a couple’s fertilized ovum. Alternatively, sperm from a man whose partner is infertile may be used to inseminate the surrogate, who agrees to turn the baby over to the father. The child is then adopted by his partner. In both cases, the surrogate is paid a fee for her childbearing services.
Nevertheless, because surrogacy usually involves the wealthy as contractors for infants and the less economically advantaged as surrogates, it may promote exploitation of financially needy women. In addition, most surrogates already have children of their own, and knowledge that their mother would give away a baby may cause these children to worry about the security of their own family circumstances.
Reproductive Frontiers
Experts are debating the ethics of other reproductive options. Doctors have used donor ova from younger women in combination with in vitro fertilization to help postmenopausal women become pregnant. Most recipients are in their forties, but some in their fifties and sixties, and a few at age 70, have given birth. These cases magnify health risks to mother and baby and bring children into the world whose parents may not live to see them reach adulthood.
Today, customers at donor banks can select ova or sperm on the basis of physical characteristics and even IQ.
Inherited and Genetic Disorders: When Development Deviates from the Norm.
Phenylketonuria (PKU) is an inherited metabolic disease transmitted as an autosomal recessive trait. And a deficiency of an enzyme (phenylalanine hydroxylase) needed to utilize the amino acid phenylalanine is marked.
PKU is just one of several disorders that may be inherited. Moreover, PKU allows phenylalanine to build up to toxic levels, causing brain damage and mental retardation (Moyle et al., 2007; Widaman, 2009; Deon et al., 2015). Like a bomb that is harmless until its fuse is lit, a recessive gene responsible for a disorder may be passed on unknowingly from one generation to the next, revealing itself only when, by chance, it is paired with another recessive gene. It is only when two recessive genes come together like a match and a fuse that the gene will express itself and a child will inherit the genetic disorder.
But there is another way that genes are a source of concern: in some cases, genes become physically damaged. For instance, genes may break down due to wear and tear or chance events occurring during the cell division processes of meiosis and mitosis. Sometimes genes, for no known reason, spontaneously change their form, a process called spontaneous mutation.
Read about the teratology and hazards to prenatal development, here.
Reference.
- Robert. S. Feldman. (2017). Development Across the Lifespan. (8th ed.). Pearson Education.
- Laura. E. Berk. (2018). Development Through the Lifespan (7th ed.). Pearson Education.