Of all multiples, twins normally face the fewest medical problemsand complications. Each additional baby a woman carries at one timeincreases the possibility of developing complications.
What are the most common complications associated with multiples?
- Preterm Labor/Delivery
- Low Birthweight
- Intrauterine Growth Restriction (IUGR)
- Fetal Demise/Loss
Preterm labor/deliveryis defined as delivery before 37 completed weeks of pregnancy. Thelength of gestation decreases with each additional baby. On averagemost single pregnancies last 39 weeks, twin pregnancies 36 weeks,triplets 32 weeks, quadruplets 30 weeks, and quintuplets 29 weeks.Almost 60% of twins are delivered preterm, while 90% of triplets arepreterm. Higher order pregnancies are almost always preterm. Manytimes premature labor is a result of preterm premature rupture ofthe membranes (PPROM). PPROM is rupture of membranes prior tothe onset of labor in a patient who is at less than 37 weeks of gestation.
Low Birth Weight:
Low birth weight is almost always related to preterm delivery. Lowbirth weight is less than 5.5 pounds (2,500 grams). Babiesborn before 32 weeks and weighing less than 3.3 pounds (1,500 grams)have an increased risk of developing complications as newborns. They are at increased risk for having long-term problems such as mental retardation, cerebralpalsy, vision loss, and hearing loss.
Intrauterine Growth Restriction (IUGR):
Multiple gestations grow at approximately the same rate as a singlepregnancy up to a certain point. The growth rate of twin pregnanciesbegins to slow at 30 to 32 weeks. Triplet pregnancies begin slowingat 27 to 28 weeks, while quadruplet pregnancies begin slowing at 25to 26 weeks. IUGR seems to occur because the placenta cannot handleany more growth and because the babies are competing for nutrients.Your doctor will monitor the growth of your babies by ultrasound andby measuring your abdomen.
Preeclampsia,Pregnancy Induced Hypertension (PIH), Toxemia, and high bloodpressure are all synonymous terms. Twin pregnancies are twice as likelyto be complicated by preeclampsia as single pregnancies. Half of tripletpregnancies develop preeclampsia. Frequent prenatal care increasesthe chance of detecting and treating preeclampsia. Adequate prenatalcare also decreases the chance of a serious problem resulting frompreeclampsia for both the babies and mother.
The increased risk for gestationaldiabetes in a multiple pregnancy appears to be a result of thetwo placentas increasing the resistance to insulin, increased placentalsize, and an elevation in placental hormones. The occurrence of gestationaldiabetes in a multiple pregnancy is still being tested at this time.In one study, an increased risk of gestational diabetes did seem tobe apparent, but the doctors involved recommended that further testingbe conducted.
Placentalabruption is three times more likely to occur in a multiple pregnancy.This may be linked to the fact that there is an increased risk ofdeveloping preeclampsia. It most often occurs in the third trimester,but the risk significantly increases once the first baby has beendelivered vaginally.
Fetal Demise or Loss:
Intrauterine fetal demise is extremely uncommon. Your healthcareprovider will determine whether it is best to expose the other baby(ies)to the fetus that has died or to proceed with delivery. If the pregnancyis dichorionic (two chorions present), then intervention may not benecessary. (The chorion is a membrane that forms the fetal portionof the placenta. Fraternal twins always have two chorions while identicaltwins can have one or two chorions.) If the pregnancy has a singlechorion then fetal maturity will be assessed to see if immediate deliveryis achievable. In this situation it would be necessary to evaluatethe risks between having a premature baby to the risks of remainingin utero.
If you are pregnant with multiples it does not necessarily meanthat you will have a cesareanbirth. The common recommendation for the delivery of tripletsand higher order multiples is a cesarean, but twins are commonlydelivered vaginally. The vaginal delivery of twins depends on thepresentation of the babies. Twins can be delivered vaginally when:
- The gestation is greater than 32 weeks
- Twin A (the baby closest to the cervix) is the largest
- Twin A is head down
- Twin B is head down, Breech, or sideways
- Twin B is smaller than twin A
- There is no evidence of fetal distress
- There is no cephalopelvicdisproportion (CPD)