#twinning- So You’re Having Twins?


By Lindsey Deschamps

I am not one of those women who loves being pregnant.  In fact, I do not terribly enjoy being pregnant at all.  Oh, don’t get me wrong, I love the excitement of finding out I’m pregnant, the fun of revealing it, the anticipation of the birth, and then I love, oh how I love, seeing my belly move up and down from those wriggly little babies.  But the day-to-day of those ten (yes…TEN!) months are just not my favorite.  In fact, I have always been a bit envious of women who have the “pregnancy glow.”  I have always wondered how some women are blessed with “the glow,” and others, like myself, get acne and “cankles”.  

When I found out I was expecting twins, it was the pregnancy that worried me the most.  Call me naïve, but I was not afraid of caring for TWO little humans.  “We’ve got this!” was my initial response (after the tears, of course).  I had been through med school and residency; I had put in 100 hours of work in one week; I had survived fourteen weeks straight of night-float.  I was no stranger to grueling hours.  And parenting a newborn wasn’t new to me.  I understood the long sleepless nights, the cracked and sore nipples, the reflux baby.  But the physical aspect of carrying two humans for ten months was utterly terrifying to me.

So what was it really like?  How is a twin pregnancy different than a singleton pregnancy?  Of course, every pregnancy is different, and every twin pregnancy is different, but there are some generalizations that hold true.

First, let’s start with some basic science, and clear up some common misconceptions.  First, how do twins come to be?  Despite the rumors, twinning does not “skip a generation,” is not passed down from your father’s mother’s family, and certainly has nothing to do with when during the lunar calendar you “did the deed” (yes…these are all things that patients have asked me).  Another common misconception is that twins always come from infertility treatments.  The incidence of twins is increasing, and this is partly because due to infertility treatments.  However, race, genetics, obesity, and maternal age all play a role.  

Back to Biology 101….  Twinning happens when a single egg is released and then splits into two (called monozygotic twinning), or when two eggs are released (called dizygotic twinning).

Monozygotic twins have the same genetic make-up; they are also known as “identical twins.”  They are always the same gender.  Monozygotic twins can have two separate placentas, or they can share a placenta.  If they share a placenta, they can share the sac (monochorionic/monoamniotic), or they can have their own sacs (monochorionic/diamniotic).  

Confused yet?  Dizygotic twinning is a little bit easier.  These twins come from two eggs and two sperm; they are also called “fraternal twins.”  Fraternal twins are essentially the same as any two siblings, they just happen to be born at the same time.  In dizygotic, or fraternal, twin pregnancies, each fetus has its own placenta and its own sac; this is called dichorionic/diamniotic.  So if you see twins that are different genders, you know that they are di/di twins.  Whew… got all that?  

So…. What does all of this mean for you Twin Momma??  Your pregnancy management will largely be determined by the type of twinning.  Di/di twins are the most common, and the lowest risk.  Two sacs, two placentas, two mostly separate pregnancies.  The complications increase when the babies share a placenta.  They can develop a scary condition known as Twin-Twin-Transfusion, which is when abnormal and unequal amounts of blood flow through the placenta.  And when they share a sac, as in mono/mono twins, even more potential complications can arise from cord entanglement.

Here a few general guidelines that explain how we manage twin pregnancies.…

  1. More frequent doctor’s appointments.  That’s right, you and your doctor or midwife are going to be very good friends by the end of this, so find an office that you like!  The incidence of hypertensive disorders (hypertension and preeclampsia) is double that of a singleton pregnancy (almost 13% vs only 5-6%), so you’ll have to be seen more frequently, especially at the end, for regular blood pressure and urine checks.  The incidence of gestational diabetes is higher too, so you may be asked to do your glucose tolerance test earlier in pregnancy, and then repeat it at 26-28 weeks.  Your appointments are an opportunity for your doctor or midwife to screen for these issues, as well as other more rare, but serious, complications, so make sure that you feel your questions are answered thoroughly and your concerns addressed!
  2. More aches and pains.  With more baby, more placenta, more blood, and more hormones come more physical discomforts.  Pelvic and low back pain are common.  Make sure that you invest in good quality shoes and a maternity girdle to help support the extra weight.  Compression stockings are a must.  Not only do they relieve lower extremity edema and discomfort, but they decrease your risk of DVT or blood clots in the calves.  Hyperemesis gravidarum (nausea and vomiting) is common as well.  Make sure you talk to your doctor or midwife about this, as they will want to rule out other causes of nausea and vomiting in pregnancy.
  3. Weight gain and nutrition (aka, WOOHOO, BRING ON THE CAKE!!)  Normal weight women (BMI 18.5-24.9) need to gain 37-54 pounds.  While at first, this seems like license to overindulge, you’ll soon find yourself regretting that extra piece of pizza.  Progesterone causes slower gastric motility, so constipation and reflux are common.  Go easy, Momma.  Try to gain that amount of weight by eating nutritious food.  Before long you will feel full much faster and your appetite will lag.
  4. Extra vitamins.  Anemia is more likely, so you’ll have to take iron, as well as 1mg of folic acid daily.  Find a good prenatal vitamin, and buy it in bulk.
  5. Screening.  Traditional screening with the “quad screen” is not as accurate in twin pregnancies because there are two fetuses contributing to the chemicals in your blood.  If you opt for prenatal screening, a measurement of the nuchal translucency (skin on the back of the babies’ necks) in the first trimester increases the sensitivity of the test.  We also recommend an anatomy screen at 18-22 weeks to screen for congenital anomalies, or birth defects.  Your risk of anomalies is greater simply because there are two babies. However, monozygotic twins have a higher rate of congenital anomalies than do dizygotic twins or singletons.  Of course, any screening is optional, and your OB or midwife will present you with your options.  These options can be confusing, so make sure you get your questions answered.
  6. Ultrasounds and fetal monitoring.  The earlier the ultrasound the better. This helps to accurately diagnose the type of twins (chorionicity), which largely determines your risks and management. After your anatomy survey at 18-22 weeks, you will have regular ultrasounds for fetal growth since twins have a higher rate of growth problems (it gets cramped in there!!).  Depending on the type of twinning, the frequency of ultrasounds and fetal monitoring is very different, with more intensive monitoring for monochorionic twins than for dichorionic twins.
  7. Monitoring for preterm labor.  Approximately 60% of twins deliver before 37 weeks, and 12% deliver before 34 completed weeks.  Familiarize yourself with the warning signs of preterm labor, and communicate any concerns with your doctor.  And don’t wait until the last minute to prepare…have a plan for delivery, for childcare for older children, and for your medical leave.
  8. Labor and delivery.  Don’t worry, you’ll be hearing more about this from me soon.  One thing to remember…a vaginal delivery may be possible.  It will depend on the positions of the babies (particularly the presenting twin), and your doctor’s comfort level with vaginal twin deliveries.  There will be more extensive monitoring, more nurses, and likely you will deliver in the Operating Room, even in the case of a vaginal delivery.    Prepare to discuss this with your doctor late in the second trimester or early in the third trimester, so that you have a plan and your doctor is aware of your expectations.

Are you overwhelmed?  I sure was!  As a physician, I was all too aware of the complications of twin pregnancies.  As a mom, I just wanted to bring home two healthy, chubby babies.   Find a doctor or midwife that you trust, educate yourself, and take a deep breath, Twin Momma, you’re going to do great.   


_DSC3315Lindsey Deschamps, MD: Three amazing kids call me Mom.  Alice is my sweet, clever, and compassionate daughter who is 3 going on 30; Luke and Thomas are my two little balls of energy who just turned one.  We recently relocated from Utah to North Carolina so our kids could grow up closer to their grandparents and their cousins.  Along with the move came a major career change.  I left private practice to be an OB Hospitalist, an emerging role in our field.  At work, I am involved in several patient safety initiatives which emphasize one goal – to deliver the best patient care possible, while optimizing the patient’s birth experience.  Our home-life could only be made possible my husband Paul, a former high-school teacher who is now a full-time stay-at-home parent (and an amazing chef).  He makes our home-life possible.   You can occasionally find me reading or working-out, but more likely changing diapers, doing laundry, or coloring.

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