Presentation on theme: "Bio 27 November 14, 2012 Chapter 11: Conception, Pregnancy, and Childbirth."— Presentation transcript:
Bio 27 November 14, 2012 Chapter 11: Conception, Pregnancy, and Childbirth
SPONTANEOUS AND ELECTIVE ABORTION
Miscarriage and stillbirth A spontaneous abortion happening in the first 20 weeks of pregnancy is a miscarriage; one happening in the last 20 weeks is a stillbirth Early miscarriages may occur before a woman even knows she is pregnant Having one miscarriage does not raise chances of having additional ones, but multiple miscarriages can be indicative of problems
Most common causes of miscarriage: Chromosomal abnormality Maternal age >35 years More than 5 alcoholic drinks per week More than 375 mg caffeine per day (2–3 cups coffee) Cocaine use Damaged cervix Chronic kidney inflammation Abnormal uterus Infection Underactive thyroid gland Autoimmune reaction Diabetes Emotional shock Aspirin and ibuprofen use in early pregnancy Obesity
Elective abortion Every year, 3 million American women have unplanned pregnancies In 2005, 1.2 million abortions in the U.S. 50% of U.S. women have an abortion by age 45 2/3 of women who have abortions in the U.S. say it is primarily for financial reasons 60% of abortions occur in families with an income of less than $28,000/year for a family of 3 Despite relatively restrictive laws, U.S. has one of the highest rates of abortion among developed countries – This is largely attributed to low rates of sex education and lack of access to affordable contraceptives
Utilitarian vs. Deontological ethics Utilitarian approach: something is good if it is useful, and an action is moral if it maximizes pleasure among humans. “The greatest good for the greatest number” Deontological approach: certain moral principles must guide our actions
1. The scarce drug case You are an emergency room physician, and you only have five doses of a certain drug left. Alas, you have six patients who need it. Bloggs has a very severe version of the condition for which the drug is a treatment, and it will take all five doses of the drug to cure him. Your other five patients have mild versions of the condition, and each of them will be cured by a single dose. Any one of the six who doesn’t get the full dosage they need will die.
2. The transplant case Suppose that you are a famous transplant surgeon, and that your transplants always work. You have five patients, each of whom needs a transplant. One needs a heart, one a brain, two need one lung apiece, and one needs a liver. One of your patients, Bloggs, has come in today to find out the results from some lab work. You know from the results of the lab work that Bloggs would be a perfect donor for each of your five other patients, and you know that there are no other available donors. So you ask Bloggs if he would be willing to be cut up and have his organs distributed. He declines your kind offer, but you realize that you could easily overpower Bloggs and cut him up without his consent.
3. The trolley case The driver of a trolley has passed out at the wheel, and his trolley is hurtling out of control down the track. Straight ahead on the track are five men who will be killed if the trolley reaches them. You are a passerby, who happens to be standing by the track next to a switch. If you throw the switch, you will turn the trolley onto a spur of track on the right, thereby saving the five. But Bloggs is on that spur of track on the right; and he will be killed if you turn the trolley.
Procedures for abortion: medical abortion In the U.S., 89% of abortions are performed in the first 12 weeks of pregnancy Risk of dying from a surgical abortion is 0.1 per 100,000 women (risk of dying from pregnancy is 11.8 deaths per 100,000 women Medical abortion uses a pill, RU-486, to end pregnancy – Available in Europe for 20 years before legalized here in 2000 – Account for 13% of all abortions in the U.S. currently – 99% effective in ending pregnancy before 7 weeks, and 91% effective in the 8 th week
Procedures for abortion: suction curettage Used in weeks 7–13 of pregnancy Performed at a clinic or hospital under local anesthesia and takes ~10 minutes Plastic tube is inserted into the uterus through the cervix A vacuum aspirator sucks out the placenta, uterine lining, and fetal tissue No effect on future fertility
Most abortions occur early in pregnancy
Procedures for later abortion: dilation and evacuation (D & E) Used for pregnancy termination between 13 and 21 weeks Usually requires general anesthesia Uses suction and scraping of the uterus to expel the fetus and uterine lining 8.9 women per 100,000 die from a 20-week D& E (still lower than risk of death from pregnancy)
Late-term abortion Late-term abortion: abortion performed after 20 weeks gestation Only legal when there are health risks to the mother or severe fetal abnormalities Typically done by dilation and evacuation
Illegal abortions 20 million illegal abortions are performed worldwide each year 97% of these are performed in developing nations where abortion is illegal Result in deaths, infertility, and serious health problems Abortion may be attempted by drinking poisons or inserting them into the vagina or by inserting a sharp object such as a coat hanger or stick through the cervix into the uterus Countries where abortion is illegal have higher rates of abortion
Roe v. Wade 1973 Supreme Court decision prevented states from passing laws making abortion a crime for women or their doctors Abortion access is still restricted, primarily through lack of doctors that perform it, or lack of funding for poor women seeking abortion
The anti-abortion movement “Pro choice” and “pro life” activists are at odds Pro-life advocates believe that life begins at conception and that a fertilized egg has the same rights as any other person Some pro-life advocates have committed violent acts at abortion clinics – May 2009: Dr. George Tiller was shot and killed at his church
Reducing the rate of abortion Many steps can be taken to reduce the incidence of abortion: – Preventing unwanted pregnancy through increased access to contraceptives – Improving sex education, not relying on “abstinence- only” education – Providing resources to facilitate adoption – Providing financial assistance to low-income families with children Politicians who advocate for restrictions on abortion also tend to advocate against these things
THE EXPERIENCE OF PREGNANCY
The woman’s experience A study of 1000 women found that: – 35% loved being pregnant – 40% had mixed feelings about it – 8% hated it – others had different experiences with different pregnancies 20% of women experience significant depression during pregnancy
The man’s experience Men do not physically experience pregnancy, but may gain “sympathy weight” Pregnancy can be a time of excitement, but also anxiety for expectant fathers Some fathers can feel excluded by the fact that they do not experience the physical changes of pregnancy
Sexual interaction is OK during pregnancy Regular intercourse and orgasm are associated with a LOWER risk of preterm birth First trimester: nausea, breast tenderness, and fatigue can make a woman less sexually responsive Second trimester: usually a reprieve Third trimester: physical discomfort and feelings of physical unattractiveness may reduce a woman’s desire
First trimester (0–13 weeks) Sperm and egg unite to form a zygote in the fallopian tubes The zygote divides to form a blastocyst that implants in the uterine wall after about 1 week By 9–10 weeks after the last menstrual period, the fetal heartbeat can be heard with a special instrument Fetus is about 3 inches long by the end of the 13 th week
Second trimester (14–26 weeks) Sex of the fetus can be determined, although can be difficult to see clearly before 19–20 weeks Fingernails, eyebrows, and eyelashes are clearly formed Fetus is covered by fine hair that is typically, but not always, lost by birth By 22 weeks or so, fetus typically weighs about 1 pound
Third trimester (27–40 weeks) Last two months of gestation are a period of rapid weight gain Lungs and brain mature Most babies born at any point during the third trimester will survive
Prenatal care Infant mortality in the U.S. is high; largely attributed to worse prenatal care Low-income women are less likely to receive adequate prenatal care Low-income women are also more likely to die in childbirth
Risks to fetal development Fetuses depend on maternal nutrition; adequate folic acid is particularly important; prenatal vitamins contain this Recommended BEFORE you get pregnant as especially important in first weeks of pregnancy Alcohol crosses the placenta and can cause fetal alcohol syndrome, esp. with binge drinking (5 or more drinks) Fetal alcohol syndrome can cause spontaneous abortion, low birth weight, brain damage and physical malformation Many other drugs can also be harmful to fetuses
Homework assignment Due at THE BEGINNING of class on November 19 th Write (in 300–500 words) about your feelings about assisted reproductive technology (in vitro fertilization). Are there any aspects of this technology that make you uncomfortable?