Your patient has just had twins and wonders if there is any way to determine whether the twins are identical. You correctly tell her which of the following?
Answer(s): C
Different-sex twins must be dizygous. Prenatal ultrasound can detect monochorionic, monoamnionic twins, and these must be monozygous. For same-sex twins, careful examination of the amniotic membranes after birth can reveal monozygous twins if the placental membranes are monochorionic. Dichorionic membranes can occur with either monozygous or dizygous twins. Ultimately, assessment of DNA polymorphism is the best way to determine twin zygosity
An 11-year-old girl has her first menses. Both ovaries contain approximately how many oocytes?
The maximum number of oocytes is 67 million at approximately 20 gestational weeks. At birth, the number of oocytes has decreased to about 1 million, and the number at puberty is 300,000500,000. Women at menopause still have a small number of oocytes, a number insufficient to produce an amount of estrogen to prevent vasomotor symptoms. By simple mathematics, women lose approximately 1000 oocytes per menstrual cycle: one by ovulation and the remainder by follicular atresia.
A healthy 29-year-old gravida 2 woman at 39 weeks has been in labor for 3 hours. She had a positive vaginal-anal culture for GBS at 37 weeks' gestation. Which one of the following statements is correct?
Answer(s): D
Approximately 20% of pregnant women have positive rectovaginal cultures. Vertical transmission rate from mother to baby is approximately 75%. A rectovaginal culture is not indicated at the first prenatal visit because the pregnant woman may subsequently convert from a negative to a positive culture. For this reason, all pregnant women should have a rectovaginal culture at 3637 gestational weeks. If the woman goes into preterm labor before a culture is obtained, she should be treated with penicillin (gentamicin if she is penicillin allergic). The rate of neonatal sepsis is 1% of colonized mothers, a serious infection that may cause pneumonia, meningitis, and death.
Which of the following statements is true regarding contraception?
Diaphragms can be used successfully for contraception with proper patient education and motivation.Proper fitting is most important for efficacy. The diaphragm should be coated with spermicide prior to insertion (within the dome and along the rim), and inserted no more than 6 hours before intercourse is planned. Conversely, the device should be left in place at least 6 hours but no more than 24 hours after intercourse. If multiple episodes of intercourse take place, additional spermicide should be used. The vaginal ring is designed to be worn for 3 consecutive weeks (i.e., one ring, not three rings changed weekly) and then removed for 1 week. Depo- Provera does not affect liver enzymes but actually increases the seizure threshold, making it a great choice for patients with seizure disorders. Amenorrhea is common (20- 60%) with patients using the levonorgestrel IUD, and is so effective in preventing pregnancy that this symptom should not raise alarm (as long as other pregnancy symptoms --e.g., nausea and breast tenderness--are not present). Over 10 years, tubal ligation failure rates approach 1 per 100 procedures
Post your Comments and Discuss USMLE STEP2 exam with other Community members:
Alken commented on January 04, 2025 No comments yet Still watching the pattern of exam UNITED STATES upvote
Allen commented on January 04, 2025 Nice approach UNITED STATES upvote
Our website is free, but we have to fight against bots and content theft. We're sorry for the inconvenience caused by these security measures. You can access the rest of the STEP2 content, but please register or login to continue.