High Order Multiple Pregnancy Multifetal Pregnancy Reduction

High order multiple pregnancy (triplets or more) can occur with ovulation induction or with in vitro fertilization (IVF). With ovulation induction using fertility medications, the development of several mature follicles can result in fertilization by sperm of all of the released eggs. With IVF, the number of embryos transferred to the uterus influences multiple pregnancy rates. For this reason we generally recommend limiting the number of transferred embryos to two or three. However, in individual circumstances (e.g. with more advanced female age), transfer of more embryos is sometimes performed. Even with transfer of three embryos, triplets can result. Rarely, an embryo may split into identical twins, so transfer of two embryos may result in triplets or even quadruplets. Therefore, in spite of good judgment and careful decision-making, high order multiple pregnancies can occur.

While the possibility of multiple pregnancy is a good reason for concern, one should also be aware that the vast majority of women who undergo ovulation induction or IVF have singleton pregnancies, in spite of the fact that more than one egg may be released in an ovulation induction cycle and that in most IVF cycles, more than one embryo is transferred to the uterus.

Once faced with a high order multiple pregnancy, the couple must make the difficult , decision as to whether they wish to carry the pregnancy as conceived or reduce the pregnancy. Only the patients themselves can make this decision, but ft is important    _: for them to know the risks of carrying a high order multiple pregnancy as well as the risks of undergoing pregnancy reduction. For this reason we have provided the following information, that has been forwarded to us from the director of a university prenatal diagnosis center, where high risk pregnancies are cared for,, and where pregnancy reductions are performed.

RISKS OF CARRYING A TRIPLET PREGNANCY

The average gestational age at delivery for triplets is 33 weeks, which is about three weeks earlier than with twins. Because triplets are delivered earlier than twins, they spend more time in intensive care. Of great concern with triplets is the risk of very preterm delivery (<30 weeks), which occurs in as many as 30% of triplet pregnancies. Prematurity is associated with an increased risk of respiratory distress syndrome, intracranial hemorrhage, gastrointestinal problems, cerebral palsy and blindness. Spontaneous loss of the entire pregnancy before 24 weeks may be as high as 20%. Intrauterine death of one or more fetuses, intrauterine growth restriction, and congenital anomalies are more common. Lifelong disability is over 25% for babies weighing less that 2 Ib 3 oz at birth.

Maternal risks include an increased chance of antenatal hospitalization, preeclampsia, gestational diabetes, postpartum hemorrhage, and the risks associated with Cesarean section, as almost all triplets are delivered surgically.

RISKS OF CARRYING A QUADRUPLET PREGNANCY

TRIPLETS AND MULTIFETAL PREGNANCY REDUCTION

We have found one of the toughest decisions for patients with a triplet pregnancy is whether or not to reduce the pregnancy to a twin gestation.

Because of such, we have compiled the following information from the director of a prenatal diagnosis center discussing the issues regarding complications of multiple gestations, and the option of multi fetal pregnancy reduction (MFPR).

The average gestational age at delivery for triplets is 33 weeks, which is about 3 weeks earlier than with twins. Because triplets are delivered earlier than twins, they spend more time in intensive care. Maternal risks include an increased chance of antenatal hospitalization, preeclampsia, gestational diabetes, postpartum hemorrhage, and the risks associated with Cesarean section (as almost all triplets are delivered abdominally).

Of great concern with triplets is the risk of very preterm delivery (<30 weeks), which occurs in as many as 30%. In most studies, MFPR twins have an outcome very similar to all twins, and better than nonreduced triplets. There is also some data that the spontaneous loss rate of triplet pregnancies before 24 weeks may be as high as 20%, which is higher than the total loss rate of MFPR twins at this same gestational age. The procedure-related loss rate of MFPR is approximately 5-7% per reduced fetus in the largest and most recent studies.

Complications of Multiple

Gestations

The objective of infertility treatment should be the birth of a single, healthy child. Many of the treatment options presented to infertile couples, however, are associated with high risks of multiple gestation. Moreover, many couples view multiple gestation as desirable and are unaware of the risks they pose to both mother and babies. Couples should understand these potential risks before starting treatment.

Complications of the Fetus and Newborn with Multiple Gestation

•   Preterm birth occurs in over 50% of twin pregnancies, 90% of triplet pregnancies, and virtually all quadruplet pregnancies.

•   Compared to singleton pregnancies, a twin is seven times more likely and a triplet is over 20 times more likely to die in the first month of life.

•   Prematurity is associated with an increased risk of respiratory distress syndrome (RDS), intra-cranial hemorrhage, cerebral palsy, blindness, low birth weight, and neonatal morbidity and mortality. RDS accounts for 50% of all neonatal deaths associated with premature birth.

•   Intrauterine growth restriction, intrauterine death of one or more fetuses, miscarriage, and congenital anomalies are all more common.

•   Lifelong disability is over 25% for babies weighing less than 1,000 grams (2 Ibs., 3 oz.).

Maternal Complications Associated with Multiple Gestation

•   Preeclampsia, also called pregnancy-induced hypertension, occurs three to five times more frequently. Severe preeclampsia may be life threatening.

•   Premature labor requiring prolonged bed rest or hospitalization is common.

•   Placental abnormalities associated with maternal hemorrhage are more likely to occur.

•   Gestational diabetes, anemia, and polyhydramnios (excess amniotic fluid) occur more frequently.

•   Cesarean section is often needed for twin pregnancies and almost always required for triplets.

Other Considerations

•   Multiple gestation is associated with more nausea and vomiting, anemia, fatigue, weight gain, heartburn, lack of sleep, financial difficulties, depression, and marital discord.

•   Multifetal reduction may be advised for the health of the mother and to improve survival of the pregnancy. However, it is unclear how effective it is in reducing the rate of many of the above problems. Couples contemplating this option should consider counseling.

Prevention of Multiple Gestation

•   Careful monitoring during treatments with fertility drugs.

•   Limit the number of embryos transferred during in vitro fertilization (IVF). Transfer of multiple embryos may not improve delivery rates but clearly increases the risk of a multiple pregnancy. The Society for Assisted Reproductive Technology (SART) and the American Society for Reproductive Medicine (ASRM) have published guidelines recommending an optimal number of embryos for transfer based on a woman's age, embryo quality, and other criteria.

Frequently Asked Questions About Selective Reduction

Although you and your fertility physician have planned for the safest pregnancy possible, there is a chance that you may conceive a high order multiple gestation (triplets, quadruplets, quintuplets, etc.). Most likely, you have already discussed the risks associated with such pregnancies with your doctor. High order multiple gestations present health concerns for mothers, as well as for the fetuses themselves. For these reasons, the option of reducing the number of fetuses to ensure a safer pregnancy may be offered to you. We understand that this is often a difficult and emotional option to consider, especially for couples who have put so much energy into becoming pregnant.

How is a selective fetal reduction done? The first step in the process is an ultrasound and consultation at about the 10^th week of pregnancy. This will confirm the number of fetuses and identify their locations within the uterus. This is also the time to have your questions and concerns addressed regarding the specifics of the procedure. The actual procedure is usually performed at about 12 weeks. Using ultrasound guidance, a medication is injected into the fetus' heart. The fetus is then absorbed by your body over a period of time, as would occur naturally if it had died without medical intervention. You will be instructed to be on bed rest for three days following the procedure, and to avoid strenuous activity for another week. A follow up ultrasound is performed a week after the procedure to assure viability of the remaining fetus(es).

What are the risks of the reduction procedure? Because of the invasive nature of the selective fetal reduction, there is a risk of miscarrying the pregnancy after the procedure. This risk is greatest in the first two weeks following the procedure, which is why you are advised to have bed rest followed by limited physical activity. The risk for miscarriage will vary depending on the number of fetuses being reduced.

Number of Fetuses                                    Risk of Miscarriage for Entire Pregnancy

triplets to twins                                          5 to 7%

quadruplets to twins                                   8 to 10%

quintuplets to twins                                    10 to 12%

Who performs the procedure? The procedure is performed by a specially trained perinatologist. Appointments are scheduled through the Prenatal Diagnosis Unit.