- After an initial pregnancy resulted in a spontaneous loss in the first trimester, your patient is concerned about the possibility of this recurring. Which of the following is the most appropriate answer regarding the chance of recurrence?
- It depends on the genetic makeup of the prior abortus.
- It is no different than it was prior to the miscarriage.
- It has increased to approximately 50%.
- It has increased most likely to greater than 50%.
- It depends on the sex of the prior aborted fetus.
- A 24-year-old woman has had three first-trimester spontaneous abortions. Which of the following statements concerning chromosomal aberrations in abortions is true?
- 45 X is more prevalent in chromosomally abnormal term babies than in spontaneously aborted pregnancies.
- Approximately 20% of first-trimester spontaneous abortions have chromosomal abnormalities.
c. Trisomy 21 is the most common trisomy in abortuses.
d. Despite the relatively high frequency of Down syndrome at term, most Down fetuses abort spontaneously.
e. Stillbirths have twice the incidence of chromosomal abnormalities as live births.
- A 29-year-old G3P0 presents to your office for preconcepƟon counseling. All of her pregnancies were lost in the first trimester. She has no
significant past medical or surgical history. She should be counseled that without evaluaƟon and treatment her chance of having a live birth is
which of the following?
a. <20% b. 20% to 35% c. 40% to 50% d. 70% to 85% e. >85%
- A 26-year-old G3P0030 has had three consecutive spontaneous abortions in the first trimester. As part of an evaluation for this problem, which of
the following tests is most appropriate in the evaluation of this patient?
b. Chromosomal analysis of the couple
c. Endometrial biopsy in the luteal phase
d. Postcoital test
e. Cervical length by ultrasonography
- A 30-year-old G1P0 at 8 weeks gestaƟon presents for her first prenatal visit. She has no significant past medical or surgical history. A 29-year-old
friend of hers just had a baby with Down syndrome and she is concerned about her risk of having a baby with the same problem. The paƟent
denies any family history of geneƟc disorders or birth defects. You should tell her that she has an increased risk of having a baby with Down
syndrome in which of the following circumstances?
a. The age of the father of the baby is 40 years or older.
b. Her pregnancy was achieved by induction of ovulation and artificial insemination.
c. She has an incompetent cervix.
d. She has a luteal phase defect.
e. She has had three first-trimester spontaneous abortions
- The answer is b. (Cunningham, pp 215-226.) An iniƟal spontaneous aborƟon, irrespecƟve of the karyotype or sex of the child, does not change the
risk of recurrence in a future pregnancy. The rate is commonly quoted as 15% of all known pregnancies.
- The answer is d. (Cunningham, pp 215-226.) Chromosomal abnormaliƟes are found in approximately 50% of spontaneous aborƟons, 5% of
sƟllbirths, and 0.5% of live-born babies. In spontaneous losses, trisomy 16 is the most common trisomy, with 45, X the most common single
abnormality found. At term, trisomy 16 is never seen, and 45, X is seen in approximately 1 in 2000 births. It is esƟmated that 99% of 45, X and 75% of
trisomy 21 conceptuses are lost before term.
- The answer is c. (Cunningham, pp 215-226.) Mis carriage risk rises with the number of prior spontaneous aborƟons. Without treatment, the live birth
rate approaches 50%. With treatment, successful pregnancy rates of 70% to 85% are possible in a paƟent with a diagnosis of habitual aborƟon.
When cervical incompetence is present and a cerclage is placed, success rates range as high as 90%.
- The answer is b. (Cunningham, pp 215-226.) A major cause of spontaneous aborƟons in the first trimester is chromosomal abnormaliƟes. The
causes of losses in the second trimester are more likely to be uterine or environmental in origin. PaƟents should also be s creened for thyroid
function, diabetes mellitus, and collagen vas cular disorders. There is also a correlation between patients with a positive lupus anticoagulant and
recurrent mis carriages. For recurrent second-trimester losses, a hysterosalpingogram should be ordered to rule out uterine structural
abnormaliƟes, such as bicornuate uterus, septate uterus, or unicornuate uterus. Endometrial biopsy is performed to rule out an insufficiency of
the luteal phase or evidence of chronic endometriƟs. A cervical biopsy would be of no value in the workup of recurrent pregnancy losses. A
postcoital test is useful for couples who cannot conceive, but does not address postconcepƟon losses. Measuring the cervical length by
ultrasonography is helpful in the management of patients with recurrent second-trimester losses caused by cervical incompetence.
- The answer is e. (Cunningham, pp 266-269, 296-298.) The risk of aneuploidy is increased with mulƟple mis carriages not aƩributable to other causes
such as endocrine abnormaliƟes or cervical incompetence. Paternal age does not contribute significantly to aneuploidy unƟl probably age 55, and
most risks of paternal age are for point mutaƟons. A 45, X karyotype results from loss of chromosome material and does not involve increased
risks for nondisjuncƟonal errors. Similarly, induced ovulaƟon does not result in increased nondisjuncƟon, and hypermodel concepƟons (triploidy) do not increase risk for future pregnancies.