By this time, the nausea and vomiting has usually subsided. By the end of the tenth week, your blood volume has increased by thirty to forty percent to provide for the needs of the growing babies, uterus, breast tissue, and placenta. Because of this, your pulse will increase by about fifteen beats per minute. Most of this additional blood is concentrated in the pelvic area, so you may experience periods of lightheadedness or even faint when you stand up suddenly. You will also be more prone to nosebleeds and nasal congestion during this time.
Multiple Facts.
- Twins are typically born at thirty-five to thirty-six weeks gestation. Fifty-seven percent of twins arrive prior to thirty-seven weeks; 12 percent arrive prior to thirty-two weeks—seven to eight weeks premature.
- A woman with a normal weight should gain between forty and fifty-six pounds when pregnant with twins.
Diet and Weight Gain.
Unlike the advice you receive when pregnant with one child—to eat only 300 extra calories a day—women pregnant with twins need to gain more weight earlier in pregnancy to help thwart premature births. Your early weight gain (by twenty weeks gestation) has a significant positive influence on your twins’ growth from twenty to twenty-eight weeks, and from twenty-nine weeks until birth—a benefit not unlike money in the bank earning interest! This early weight gain in part reflects the growth of the placenta (or placentas)—the critical middle-man for your babies’ nutrition. If the placentas are well-developed and healthy, your twins will flourish. But if you don’t gain enough weight early in your pregnancy—or if you actually lose weight—your babies’ growth in the second and third trimesters may be slower, which will increase your risk for premature labor.
For women who are underweight before their twin pregnancies, this early period is especially critical. Even women with a body mass index (BMI) above the normal range need to gain appropriately, especially during this early period. If you’re experiencing nausea severe enough to keep you from eating and staying hydrated, ask your health professional to prescribe an anti-emetic.
