Prenatal Pregnancy Visits #1
Maternal Well-Being as a Sign of Fetal Well-Being
In modern obstetric practice, fetal well-being has been determined mainly by direct monitoring and testing, but it is important not to overlook the status of the mother when determining fetal well-being.
Maternal height and prepregnancy weight and amount of weight gain during pregnancy are important in fetal development. Women who are underweight or of short stature tend to have smaller babies, and are at risk for low birthweight and preterm delivery. A teenage mother is compromised if her diet is inadequate to meet her own growth requirements and those of her fetus. In such circumstances, women less than 157 cm (5 ft) tall, especially those weighing less than 45 kg (100 lb), should be encouraged to gain at least a minimum of 11–12 kg (25 lb), if not more.
Blood pressure levels may provide a clue to subtle circulatory compromise. Normally, the mean arterial pressure drops somewhat from prepregnancy or early pregnancy values during the middle trimester. It is important to note this decline so that it does not mask a subsequent rise in blood pressure that may signal the onset of hypertension. In the third trimester, blood pressure recordings taken in the supine position may be higher than those taken in the recumbent or seated position; this also may indicate the onset of hypertension. Normal patients may have a significant drop in blood pressure in the supine position (supine hypotensive syndrome), which is corrected when the patient is in the left lateral position.
Fundal height should be measured and recorded at each visit after 20 weeks’ gestation. Measurements should be made with a centimeter tape (McDonald’s technique) from the pubic symphysis to the top of the uterine mass over the curvilinear abdominal surface. Progress is especially important in the third trimester, when fetal growth retardation is most easily determined.
FHTs can usually be heard by 10–12 postmenstrual weeks using a hand-held Doppler device. This may be helpful when gestational age is in doubt or in the presence of threatened abortion or other abnormal observations in the late first trimester. Attention should be paid both to rate and rhythm and to any accelerations, decelerations, or irregularities. Significant abnormalities may be further assessed by ultrasonography, fetal echocardiography, or electronic fetal heart rate monitoring, depending on gestational age.
At each prenatal visit, abnormal or potentially abnormal findings should be noted, and a careful record should be made of any unusual events that have occurred since the last visit. Transient episodes of general edema or swelling should be noted. Lower-extremity edema in late pregnancy is a natural consequence of hydrostatic changes in lower body circulation.
Edema of the upper body (eg, face and hands), especially in association with relative or absolute increases in blood pressure, may be the first sign of preeclampsia. A moderate rise in blood pressure without excessive fluid retention may suggest a predisposition to chronic hypertension.
Manual assessment of fetal size and position is always indicated after about 26 weeks’ gestation. The fetus may assume a number of positions before late gestation, but persistence of an abnormal lie into late pregnancy suggests abnormal placentation, uterine anomalies, or other problems that should be investigated by ultrasound. If an abnormal lie persists, consider external version after 37 weeks’ gestation. Suspected abnormal fetal size should also be investigated; a difference between gestational age and fetal heart size by 2 cm or more should prompt consideration of ultrasound evaluation.
Source : Current Obstetrics and Gynecology, 2007
