A 25-year-old G0 presents to your office for preconception counseling. She is a long-distance runner and wants to continue to train should she conceive. She wants to know whether there are any potential adverse effects to a developing fetus if she were to pursue a program of regular exercise during her pregnancy.
You provide her with the following counseling about exercise during pregnancy?
Women with uncomplicated pregnancies can continue to exercise during pregnancy if they had previously been accustomed to exercising prior to becoming pregnant. Studies indicate that well-conditioned women who maintain an antepartum exercise program consisting of aerobics or running have improved pregnancy outcomes in terms of shorter active labors, fewer cesarean section deliveries, less meconium-stained amniotic fluid, and less fetal distress in labor. On average, women who run regularly during pregnancy have babies that weigh 310 g less than women who do not exercise during pregnancy. Even though birth weight is reduced in exercising pregnant women, there is not an increased incidence of intrauterine growth retardation. The American College of Obstetricians and Gynecologists recommends that women avoid exercising while in the supine position to avoid a decrease in venous return to the heart, which results in decreased cardiac output. In addition, women should modify their exercise based on symptoms. There is no set pulse above which exercise is to be avoided; rather, women should decrease exercise intensity when experiencing symptoms of fatigue. Nonweightbearing exercises will minimize the risk of injury. Since the physiologic changes associated with pregnancy will persist from 4 to 6 weeks following delivery, women should not resume the intensity of pre-pregnancy exercise regimens immediately following delivery.
She asks you what other exercises would be appropriate during pregnancy. You counsel her that which of the following exercises would also be safe during pregnancy?
There are many recreational activities that are considered to be safe during pregnancy. Riding a stationary bike, swimming, and walking are examples. Participation in sports with a high risk of abdominal trauma due to contact or due to falling is not recommended. These sports include competitive ice hockey or soccer, horseback riding, and downhill skiing. Scuba diving should be avoided during pregnancy because it places the fetus at an increased risk for decompression sickness due to the inability of the fetal pulmonary circulation to filter bubble formation.
Your patient presents for her first prenatal visit. She is 27-year-old and this is her first pregnancy. She is an achondroplastic dwarf. Her husband is of normal stature.
Which of the following statements should you tell her regarding achondroplasia?
Achondroplasia, a congenital disorder of cartilage formation characterized by dwarfism, is associated with an autosomal dominant pattern of inheritance. However, new mutations account for 90% of all cases of the disorder. Affected women almost always require cesarean delivery due to the distorted shape of the pelvis. Achondroplastic fetuses, when prenatally diagnosed, should also be delivered by cesarean to minimize trauma to the fetal neck. Women who have achondroplasia and receive adequate treatment for its associated complications generally have a normal life expectancy. The most common medical complaint in adulthood in patients with achondroplasia is symptomatic spinal stenosis.
A 25-year-old G3P0 presents for preconception counseling. She has had three first-trimester pregnancy losses. As part of her evaluation for recurrent abortion, she had karyotyping done on herself and her husband. Her husband is 46, XY. She carries a balanced 13;13 translocation.
What is the likelihood that her next baby will have an abnormal karyotype?
Carriers of balanced translocations of the same chromosome are phenotypically normal. However, in the process of gamete formation (either sperm or ova), the translocated chromosome cannot divide, and therefore the meiosis products end up with either two copies or no copies of the particular chromosome. In the former case, fertilization leads to trisomy of that chromosome. Many trisomies are lethal in utero. Trisomies of chromosomes 13, 18, and 21 lead to classic syndromes. In the latter case, a monosomy is produced, and all except for monosomy X (Turner syndrome) are lethal in utero.
A 31-year-old G1P0 presents to your office at 22 weeks’ gestation for a second opinion. She was told that her baby has a birth defect. She has copies of the ultrasound films and asks you to review them for her. The ultrasound image shows the birth defect. Which of the following is the most likely defect?
An encephalocele is a version of a NTD that involves an outpouching of neural tissue through a defect in the skull. A cystic hygroma, with which encephalocele can often be confused on ultrasound, emerges from the base of the neck with an intact skull present. Hydrocephalus is related to the size of the lateral ventricles. Anencephaly would require absence of a much larger proportion of the skull with diminished neural tissues. An omphalocele is a defect in the abdominal wall at the insertion of the umbilical cord, which may lead to herniation of the abdominal contents. Omphaloceles are associated with various other birth defects and chromosomal abnormalities.