| A | B |
|---|
| fertilization | the joining of a sperm with an egg; conception |
| zygote | the united egg and sperm |
| blastocyst | a hollow, spherical structure made up of about 500 cells, formed when a zygote divides and grows |
| implantation | the process by which the blastocyst is attached to the wall of the uterus |
| embryo | name given to the blastocyst after it has attached itself to the wall of the uterus |
| human chorionic gonadotropin | the hormone produced by a human embryo at the time of implantation |
| placenta | the organ that holds the embryo to the wall of the uterus |
| umbilical cord | the cordlike structure that connects the embryo and the placenta |
| amniotic sac | the bag of thin tissue that encloses a developing embryo |
| amniotic fluid | the fluid within the amniotic sac, within which the embryo floats |
| fetus | name given to the developing embryo from the end of the second month of pregnancy until birth |
| trimesters | one of three-month periods into which the nine months of pregnancy are divided |
| morning sickness | attacks of nausea that may occur during pregnancy, usually during the first trimester |
| sympathetic pregnancy | a condition in which an expectant father experiences some of the mother's physical discomfort of pregnancy, such as morning sickness or frequent urination |
| fetal alcohol syndrome | a group of birth defects caused by the effects of alcohol on an unborn child |
| amniocentesis | a procedure in which a small amount of amniotic fluid is removed from the uterus and examined for the presence of substances that may indicate an inherited disorder in the fetus |
| chorionic villus samplinga small piece of the developing placenta | a procedure in which is removed and examined for signs of inherited disorder in the fetus |
| chorion | a part of the developing placenta |
| ultrasound | High-frequency sound waves to make an image of a developing fetus |
