f) Changes in the urinary system: the kidneys must work extra hard excreting the mother's waste products plus those of the foetus increasing the urinary output but decrease in the specific gravity. Sometimes experiences show that woman may develop urine stasis and pyelonephritis in the right kidney.

This is due to pressure exerted on the right ureter resulting from displacement of the uterus slightly to the right of the sigmoid colon. Frequent urination is a common complaint, especially during the first trimester. However, as the uterus rises out of the pelvic cavity towards the end of the first quarter, pressure on the bladder decreases and frequency diminishes. Then, due to lightening during the final weeks of pregnancy, pressure on the bladder returns to cause frequency.

g) Changes in the skeletal system: there is a realignment of the spinal curvatures during pregnancy to maintain balance (see figure 4.4). This happens as a result of the increase in size of the uterus and the pressure placed on the abdominal wall. The patient walks with head and shoulders thrust backward and chest protruding outward to compensate. In doing so, the patient gets a "waddling" gait which is a slight relaxation and increased mobility of the pelvic joints allowing stretching at the time of delivery of the fetus.

Figure 4.4 Postural changes during pregnancy.

h) Changes in the gastrointestinal system: as mentioned above under uterine changes throughout the gestational period, the uterus rises out of the pelvic cavity and increases up towards the sternum as the pregnancy progresses. This action displaces the stomach, intestines, and other adjacent organs. As a result, peristalsis slows down because of the production of the hormone progesterone, which decreases tone and mobility of smooth muscles. This slowing down of the peristalsis enhances the absorption of nutrients but slows the secretion rate of hydrochloric acid and pepsin leading to slow emptying of the bowel exacerbating nausea, heartburn and constipation.

The constipation is due to increased water absorption. Since the relaxation of the cardiac sphincter occurs, again there will be increased regurgitation and heartburn. The remedy for mothers with nausea and/or heartburn is advice to eat small but frequently. The food must be well- balanced diet especially high in protein, iron, and calcium for it is also necessary for the normal growth of the fetus. In order to prevent constipation, the woman should be advised to take more fluid and eat food rich in fiber. Besides, she should not lie flat after food because this may again aggravate the heartburn and/or the regurgitation.

It should be noted that a mother with more than one foetus will require a higher protein and calorie diet. As the food intake of mothers during pregnancy determine the development of the healthy foetus, it is necessary that the diet of the mother be reviewed at each prenatal visit.

Figure 4.5.- Changes occurring in the gastrointestinal system

i) Change in body weight: the normal weight gain during pregnancy is about 9 to 12 kgs. However, a mother with multiple foetuses should gain much more weight than a mother with only one foetus. Initially, with a woman carrying only one foetus, there will be a slight loss of weight if the she experiences much nausea and vomiting ending up with 1to 1.5 kgs weight gain towards the last week of the first trimester. In general, a gain of one pound per week is expected during the second and third quarters.

Also, close monitoring of weight gain should be done in conjunction with that of the blood pressure. Lack of significant weight gain needs to be carefully noted as it could be an indication of intrauterine growth retardation (IUGR) of the infant for which adequate protein diet intake should be emphasised.

Last modified: Sunday, 26 February 2017, 5:38 PM