Complications increase with each additional fetus in a multiple pregnancy and include severe nausea and vomiting, Cesarean section, or forceps delivery.
If you are pregnant with twins or more, or if you are at risk for a multiple pregnancy, you should be aware of these and other potential problems you might experience.
Premature labor and delivery pose the greatest risk to a multiple pregnancy. Feasibility of a vaginal
delivery depends on the size, position, and health of the infants, as well as the size and shape of the
pelvic bones. Cesarean section is often needed for twin pregnancies and is expected for delivery of
triplets. Although only 1% of all deliveries are twins, they account for 10% of all premature deliveries.
Compared to singletons, of which eight per 1,000 die in the first month of life, twins are seven times
more likely to die, and triplets are 20 times more likely to die.
Since premature labor and delivery present such a serious risk, the pregnant mother must understand the warning signs for early labor. Pelvic pressure, low back pain, increased vaginal discharge, or a change in the frequency of “false labor” pains should be reported to the physician, who can sometimes delay premature delivery by a few days or more if it is detected early. Each day gained provides valuable fetal growth and development. Once advanced labor is established, delivery cannot be stopped. In rare instances, delivery of a second twin can be delayed. This delay, when possible, allows for continued growth in the protective environment of the uterus.
The placenta is attached to the wall of the uterus, and the fetus is attached to the placenta by the
umbilical cord. The placenta provides blood, oxygen, and nutrition to the fetus through the umbilical
Placental function is likely to be abnormal in a multiple pregnancy. The placenta ages prematurely
and may slow fetal growth, especially late in the third trimester. If the placenta is unable to provide
adequate oxygen or nutrients to the fetus, the fetus cannot grow properly. Twins and multiples that
are more than 30% “underweight” by ultrasound measurements are at increased risk of complications and have death rates of nearly 25%.
Another placental problem is twin-twin transfusion, a life threatening condition in identical twins. This transfusion occurs when blood flows from one fetus to the other. Poor growth occurs in the “donor” twin, and excessive blood passes to the “recipient” twin. Therapeutic amniocentesis and laser coagulation of blood vessels may reduce complications of twin-twin transfusion.
This condition is also known as toxemia and occurs three to five times more often in multiple
pregnancies. Preeclampsia is diagnosed when the mother’s blood pressure becomes elevated and
protein is detected in the urine. The condition may progress and threaten the health of the mother and the pregnancy. When severe, the mother may have seizures or even a stroke.Diabetes
Women with multiple pregnancies are more likely to develop gestational diabetes during pregnancy. Babies of diabetic mothers are more likely to experience respiratory distress and other newborn complications.
Fetal and Newborn Complications
Premature delivery places an infant at increased risk for severe complications or early death. A baby’s lungs, brain, circulatory system, intestinal system, and eyes may be too immature. Survivors of premature birth may have lifelong handicaps.
Of the premature babies who die, 50% succumb to respiratory distress syndrome, the inability to
circulate oxygen from the lungs throughout the body. Brain damage is responsible for almost 10% of
premature newborn deaths. Birth defects and stillbirths account for about 30% of the deaths in twins
and multiple pregnancies. Low birth weight of less than 5 and a half pounds (2,500 grams) occurs in 50% of twins. The average birth weight is approximately 4 pounds (1,800 grams) for triplets and 3 pounds (1,400 grams) for quadruplets. As a result of prematurity, the risk for cerebral palsy is four times more likely to occur in twins. The rate is even greater for triplets and higher order multiple births. Prematurity may also result in visual impairment or blindness.
The overall survival rate is 85% for newborns over 2 lb., 3 oz. (1,000 grams), and less than 40% for
those under 2 lb., 3 oz. Birth weight also corresponds closely to the severity of disability throughout
the childhood years. Disability occurs in over 25% of children with a birth weight less than 2 lb., 3 oz.