What to know about being pregnant
with Twins
By Brittany Peats
How twins occur
If you are pregnant with twins, you will have lots of questions about how your pregnancy will be different from a pregnancy with one fetus. Twins occur about 1.2 percent of the time. There are a few ways that your twins may have been created. One way is that multiple eggs are released or there is more than one ovulation during your menstrual cycle. Two eggs are fertilized resulting in fraternal twins. Secondly, in the case of identical twins, one egg is released and fertilized but divides in two. Finally, with IVF or other reproductive technologies, there are usually 3 or more fertilized eggs put back into the uterus. The rationale is that not all of these will implant, though sometimes they do, resulting in twins, triplets or more.
There are also several different possibilities of how many placentas, implantation locations, number of amniotic sacs you are carrying. For example, you can have two babies, two placentas, and two sacs or you could have two babies one placenta, two sacs. An early ultrasound will be helpful in determining how many sacs are present and whether or not your babies share the same sac (monoamniotic). Monoamniotic sacs occur only in identical babies and places the pregnancy at a higher risk for problems like cord entanglement.
Why twins occur
Assisted reproduction can increase your changes of having twins, as can some biological factors. If you are a twin, or you have a maternal history of twins, you are more likely to have twins because it indicates the genetic disposition to ovulate more than one egg at any given point in ovulation. Consequently, these twins will usually be fraternal twins, not identical twins.
One reason for the increased incidence of multiple births in the United States is the trend toward delaying pregnancy. The incidence of twins increases for women over the age of 35 and even more if you are over 50. If you have had three or more pregnancies, you have a higher rate of having twins. Recent studies show that if you are breastfeeding when you get pregnant, you are more likely to have twins because the depletion of calcium in your system while nursing effects the egg during conception and ovulation. Both ovulation-inducing drugs (infertility treatment) and in-vitro fertilization increase the odds of having twins.
There are certain cultures that have
higher rates of having twins. African Americans are more likely to give
birth to twins than other ethnicities, while tall and large women also
have a higher rate. Interestingly, Nigeria has the highest rate of twin
births, and Japan has the lowest rate.
Knowing you are pregnant with
twins
The first trip to your doctor will usually let you know for sure whether you are pregnant with twins, although sometimes the signs are missed until later in the pregnancy. The doctor can usually detect a second fetus at an early ultrasound. With a skilled ultrasonographer, two gestational sacs, two embryos and two distinct fetal heartbeats can be seen six weeks after the first day of the last menstrual period. Since more than one fetus will increase your levels of hCG (the hormone measured in urine and blood pregnancy tests), if the doctor finds abnormally high levels of hCG in your initial pregnancy test, they may suspect that you are carrying more than one fetus. At your first exam you may be told that your uterus is "large for dates" meaning that even if your last menstrual period indicates an eight-week gestation, your uterus may feel more like 10 to 12 weeks. As your pregnancy progresses, if you are carrying more than one baby, your fundal height (uterine measurement) will consistently measure large for gestational age. A term uterus, with one baby, may reach 38 to 40 centimeters in height, measured from the pubic bone, while a term twin pregnancy may exceed 48 centimeters.
Later in your pregnancy, around 12 weeks, a Doppler
will be used to distinguish two separate heartbeats. Levels of alpha
fetoprotein (AFP), a protein released by the baby as it grows and is
found in the
mother's blood, can be elevated when
there is more than one baby. (It can also be elevated for other reasons,
such as neural tube defects.) Normally this simple blood test is given
16 to 18 weeks after your last menstrual period. Alpha fetoprotein
testing detects over half of all twin pregnancies. At around 28 weeks,
it may be possible to differentiate two fetal heads and multiple small
parts when doing an abdominal exam.
There will be many physical signs that you are carrying twins. Often
your belly will grow faster, although this does not always indicate
twins as your belly will grow much more quickly with your second or
third child, than with the first. It is very important that you gain a
healthy amount of weight when carrying twins. You will probably
experience exaggerated side effects of pregnancy such as intense morning
sickness, tender breast, frequent urination, constant hunger, and
excessive fatigue. In the second trimester, you may experience
difficulty catching your breath, swelling (edema) of the hands and legs,
an unusual rate of weight gain and abdominal enlargement and excessive
fetal movement. Anemia or low iron (decreased hemoglobin) is also common
with twin and multiple pregnancies.
Insuring a safe pregnancy
Gaining the proper amount of weight during your first and second trimesters is especially important when carrying twins as it will decrease the chances of having your babies born premature or underweight. An average-weight woman who is pregnant with twins should try to gain about a pound and a half a week; 20-30 pounds by 20 weeks, 30-46 pounds by 28 weeks, and 40-56 pounds by 38 weeks.
Some suggestions to help you gain the weight healthily include eating every two to three hours. Try to eat lots of protein, which is found in red meat, peanut butter, cheese, and eggs, and to pair the protein with carbohydrates. Women typically eat too many carbohydrates and not enough protein; protein is the building block of every cell in your body and your babies' bodies. It will help you build a good placenta and a strong amniotic sac. Calcium and whole grains are also important, and be sure that you are taking the proper pre-natal vitamins.
Since your body will be working very hard and carrying around a lot of extra weight, be sure to get enough rest. Your doctor may prescribe taking an early leave from work, getting help with the housework and even bed rest at home if it is necessary.
As a mother carrying twins, you will have more frequent checkups than you would for a pregnancy with one fetus; most care providers will see you every two weeks until twenty-four to twenty-eight weeks, when you will be seen weekly. Expert medical monitoring can help reduce many of the risks associated with multiple pregnancies. As for your health care provider, you will want to find a midwife or doctor who has experience with multiple births. There can be a higher risk for complications. You will be monitored for the normal complications of pregnancy like high blood pressure, and fetal growth. You will be monitored for things which may affect the mother and fetuses, such as miscarriage, preterm labor and/or preterm birth, preeclampsia, gestational diabetes, and serious placenta problems. They will also monitor the fetuses for Intrauterine Growth Restriction (IUGR), Twin to Twin Transfusion (TTTS), and others.
Because you are likely to deliver early, be sure to plan ahead. Ask your health professional about making arrangements to deliver at a specially equipped hospital; they will have facilities for emergency cesarean delivery, as well as a neonatal intensive care unit (NICU). Some hospitals require that all twin mothers give birth in the operating room, even if they have a vaginal birth. You might also ask about the use of epidural anesthesia, as it is also sometimes a requirement, even if there are no medications placed inside the tubing. This allows immediate anesthesia should it become necessary.
Giving birth
In years past cesarean became popular for multiple births. Now that rate is about 50% for twins, and declining. We've found that vaginal birth is usually very safe for multiples, who frequently need the stimulation and rise in hormones levels associated with labor. Whether or not you will have a vaginal birth will depend on many factors, including the position of the babies, and how the babies tolerate labor.
More than half of twins will be born vaginally. Whether this option is the right one for you and your babies is a discussion that should be discussed with your doctor or midwife. Though you will have to push twice to coax each baby out, the majority of the time the second twin is born quickly after the first (an average of 17 minutes after) and more easily than the first, as the first twin has paved the way. However, if the second twin is not coming out quickly, this is fine as long as the baby is healthy. They will continue to monitor its progress and may do another ultrasound to confirm its position. Sometimes, the second twin simply comes down head first like Twin A. If Twin B is breech however, your practitioner may decide to allow the baby to deliver breech, to turn the baby externally or internally or even do something called a breech extraction (pulling baby out by the feet).
While having twins does increase the risk of you having a cesarean, fewer than half of twins are born this way. The positioning of your babies will play a large part in the decision as to what type of birth you will have, but you could have a cesarean for many normal reasons including: placenta previa, placental abruption, maternal indications like PIH, active herpes, and labor complications like fetal distress, etc. If you give birth by cesarean prior to labor, the date will most likely be set between 37-40 weeks. If you go into labor prior to the scheduled date, your cesarean will likely happen then. If your babies are in a position where neither can move, they are said to be locked. These babies will have to be born via cesarean. Monoamniotic twins will also be born via cesarean, due to the added risk of cord entanglement. Other positions of the babies like two breeches, two transverse or Twin A breech and Twin B vertex are usually delivered via cesarean surgery. This is usually known ahead of time with ultrasound technology. However, even twins can change positions late in the game and even into labor. There is no real difference in the surgery or recovery from a cesarean with twins.
Having a combined vaginal/ cesarean birth is very uncommon and happens in only about 3 – 4 % of all twin births. Usually this is done for an emergency with Twin B, like a cord prolapse, meaning that the cord comes out with or before the baby, thereby cutting off the baby's oxygen supply. Other reasons include a severe malpresentation like a transverse baby that cannot be moved by internal or external forces, or a placental abruption in which the placenta tears away from the wall of the uterus prematurely.
There may be other concerns you have like rooming-in or breastfeeding two babies. Be sure to talk to your hospital at length about issues you may be concerned about with your babies.
After giving birth
Breast feeing two infants can be a daunting task. Some mothers are concerned that they will not produce enough milk or that they will never sleep. Your body will produce enough milk, especially if you start nursing early and often. Some mothers set us schedules, waking their babies when it is time to feed in hopes of getting some sleep. Finding a position that is comfortable for you and your babies requires some experimenting; some mothers nurse both by holding both babies with their feet pointing away from them while others have noticed that their babies like being placed one over the other.
Resources for Moms of Twins
Be sure to ask friends and relatives to help you and try to seek out the company of other mothers of twins if you are feeling overwhelmed. Some programs even pair and experienced twin moms with a new twin mom.
Sidelines National Support Network
Candace Hurley, Executive Director
P.O. Box 1808
Laguna Beach, CA 92652
(714) 497-2265
National Organization Mothers of Twins Club
12404 Princess Jeane N.E.
Albuquerque, NM 87112-4640
Parents of Twins with Disabilities
2129 Clinton Ave.
Alameda, CA 94501
Twins Magazine
5350 S. Roslyn, Suite #400
Englewood, CO 80111-2125
(303) 290-8500
Sources:
http://parenting.ivillage.com/pregnancy/pmultiples/0,,43wv-2,00.html
http://www.pregnancy-info.net/mult_pregnancy.html
http://www.webmd.com/baby/tc/Multiple-Pregnancy-Twins-or-More-Treatment-Overview
http://www.webmd.com/baby/twins-triplets-more
