Search

A woman's age and the number of resting ovarian follicles determine her response to fertility drugs during in vitro fertilization, according to a study of 90 women. The size of the ovaries and the amount of blood flowing to the ovaries have no relationship to the woman's response to fertility drugs.

Fetuses whose mothers have more than one antibody against a fetal antigen are more likely to require one or more blood transfusions. Antibodies against the Rh(sub O)D antigen are most common, but other fetal antigens include the C, c, E, e, Kell, Duffy, and Kidd antigens.

The use of natural family planning to time conception may not be associated with an increased risk of miscarriages in most women. However, women using natural family planning who have a history of miscarriage may miscarry when pregnancies are conceived at a suboptimal time in the menstrual cycle. Researchers studied 868 pregnancies where the parents used natural family planning to time intercourse leading to conception. Eighty percent of the women did not have a history of miscarriage, and the rate of miscarriage among these women was a low 10%. Women who had miscarried before experienced a 22.6% rate of miscarriage if they did not conceive at the optimal time in the menstrual cycle. Optimal timing of conception may lead to more successful pregnancies.

Measuring the optical density of amniotic fluid at a wavelength of 450 nanometers (nm) throughout an Rh-immunized pregnancy may detect fetuses at risk of erythroblastosis fetalis. An Rh-immunized pregnancy is one in which an Rh-negative mother has antibodies against the Rh-factor, which she developed during a previous pregnancy. If her fetus is Rh-positive, the antibodies can attack its red blood cells, causing the anemia characteristic of erythroblastosis fetalis. The optical density of amniotic fluid samples from 538 Rh-immunized pregnant women was measured every week between 14 weeks until delivery. Seventy-five Rh-positive fetuses were affected by varying degrees of anemia, and in most cases, their amniotic fluid optical density was significantly higher than RH-negative fetuses. In addition, the optical density remained high throughout the pregnancy, while the optical density in Rh-negative fetuses declined after the 26th week.

Several changes in medicine since the 1950's will have an impact on medical education. The amount of medical information has exploded since then and medical students must learn this information while still absorbing the basics. They must be taught defensive medicine since malpractice suits are still common. They must be taught how to practice medicine in the age of managed care and they must be taught how to use the computerized information systems that will become common in the health care industry.

Erythroblastosis fetalis is a disease of a fetus or newborn caused by maternal-fetal blood incompatibility. A mother with type Rh negative blood can have developed Rh positive antibodies from a previous pregnancy. The Rh positive antibodies then enter the bloodstream in the fetus, causing a breakdown in fetal red cells (hemolytic anemia). This potentially fatal condition can occur even though pregnant mothers who are Rh negative may receive an injection to prevent this problem. To avoid invasive and risky fetal umbilical cord sampling, delta optical density analysis of amniotic fluid, the fluid surrounding the fetus during pregnancy, can be used to measure a byproduct of fetal blood cell destruction as an indicator of the severity of Rh disease. This method, when performed during the third trimester (from the 27th week of pregnancy to birth) allowed early delivery decisions to be made. However, some unnecessary premature deaths occurred may have been prevented if even earlier intervention had been possible. Midtrimester (weeks 16-27 of pregnancy) evaluation by delta optical density analysis would permit fetal transfusions to begin early, allowing the fetus more time to mature. Consecutive amniotic tests were performed on 32 patients having Rh-immunized pregnancies. Delta optical density values of grater than 0.15 indicated severe Rh disease. Values of less than 0.09 revealed mild or no Rh disease. Any number in between should have follow-up serial testing. Fetuses with severe Rh immunization should confirm the diagnosis with fetal umbilical cord sampling so blood transfusion can begin.