TWIN PREGNANCY 101
You’ve just found out your pregnant…with twins! Finding out that you’re carrying more than one baby can be both exciting and overwhelming. Women’s Health Physiotherapist (and twin mum) Stephanie takes us through how carrying twins may affect your pregnancy and how to ensure the best possible outcome for you and your little ones.
The difference between twins
Twins can be fraternal (dizygotic) or identical (monozygotic); fraternal twins occur when two eggs are released and fertilised by two sperm, whilst identical twins occur when one fertilised egg splits. They are classified by their chorionicity (number of placentas) and their amnionicity (number of amniotic sacs) and while fraternal twins are always dichorionic diamniotic, identical twins may be dichorionic diamniotic, monochorionic diamniotic or monochorionic monoamniotic depending on when the zygote splits.
Multiple pregnancies are generally considered higher risk than singleton pregnancies, however monochorionic pregnancies do have a higher risk for complications due to the sharing of one placenta. If you have a monochorionic pregnancy you can expect more appointments and more ultrasounds to monitor your little ones growth, which is great - you get to see them way more often!
Get to know your pelvic floor
The pelvic floor muscles, known as levator ani, create a supportive hammock at the base of your pelvis, extending from your tailbone to your pubic bone. Functions include supporting your abdominal organs and maintaining continence. Pregnancy and birthing weaken the pelvic floor muscles, which may cause symptoms such as incontinence, prolapse and pain. Some facts about the pelvic floor muscles, pregnancy and twins:
During pregnancy the pelvic floor muscles are working harder to support the weight of a growing baby - now times that weight by two if you have twins!
The pregnancy hormone relaxin has a softening effect on connective tissue, which makes the pelvic floor muscles have to work harder. Women carrying twins have higher levels of pregnancy hormones compared to singletons.
The pelvic floor muscles are stretched during vaginal delivery to allow the passage of babies through the birth canal. The use of forceps may exacerbate this.
C-sections are major abdominal surgery and disrupt the inner abdominal wall. The pelvic floor muscles have to compensate for the loss of stability around the pelvis and therefore have to work much harder.
Fortunately, pelvic floor muscle exercises are very effective in preventing and managing pelvic floor dysfunction and are recommended to commence antenatally. A Women’s Health Physiotherapist can assess these muscles and tailor an exercise program just for you to address any tone, strength, endurance or functional deficits. Just like every pregnancy is unique, every pelvic floor is unique, which is why a proper assessment and individualised exercise program is most effective.
Take a break from vigorous abdominal exercises … for now
Women with twins or higher order multiples have a higher risk for developing a rectus abdominus diastasis (RAD) and umbilical hernia, primarily due to the increased stretch on the abdominal wall to accommodate more than one baby. A RAD, colloquially described as abdominal separation, relates to an impairment of the linea alba, which is the fibrous connective tissue between the rectus abdominus muscles that widens and thins during pregnancy to accommodate your growing babies. The RAD often resolves naturally within the fourth trimester when the body is undergoing a lot of healing. However, sometimes a RAD can persist, and may be associated with pelvic floor dysfunction, pelvic pain or back pain.
Guidelines for the prevention of RAD recommend pregnant women avoid exercises that target the outer abdominal wall (such as sit-ups) and instead focus on inner core (pelvic floor and transversus abdominus) exercises. Postnatally it may also be helpful to wear a compression garment such as a belly band, SRC shorts or tubigrip, particularly if you have a C-section.
A Women’s Health Physiotherapist can assess for RAD and prescribe appropriate exercise progressions to help you safely return to the exercise you want to do. So it does not mean you have to avoid sit-ups forever!
Pelvic girdle pain
Remember that hormone relaxin and how levels are higher for women with twins? While it is very useful in creating space in the pelvis for your babies, the softening effect it has on connective tissue increases the likelihood of developing pregnancy related pelvic girdle pain (PGP). Furthermore, the anatomical changes associated with pregnancy are exaggerated in a twin pregnancy due to the increased size and weight of the uterus. PGP may be felt at the very bottom of your spine at the sacroiliac joints, at the pubic symphysis at the front of your pubic bone, or in both areas. Rolling over in bed, climbing stairs, getting in and out of the car and walking longer distances are common aggravating activities for PGP.
Exercises that target the muscles supporting the pelvis including the gluteal, adductor, pelvic floor and transversus abdominus muscles can be effective in preventing and managing PGP. Other strategies to help include wearing a supportive pregnancy belt, hydrotherapy and avoiding aggravating positions such as wide stances (pretend you are wearing a mini skirt) and asymmetrical or single leg loading.
Rest while you can
No seriously, you won’t get the chance again for a long time once they’re born! People will tell you this a thousand times but it is really important particularly with a twin pregnancy to rest and listen to your body. Supporting two babies takes a lot of energy; so put your feet up and drink plenty of water to help keep your babies happy and healthy for as long as possible.
While there is now evidence to support exercise throughout a normal, uncomplicated pregnancy, there is little research that looks specifically at twin pregnancies. Leading authorities advise some conditions where exercise is contraindicated such as pre-eclampsia, pregnancy induced hypertension, intrauterine growth restriction and risk factors for premature labour including multiple birth, cervical insufficiency and premature contractions. If you are pregnant with twins (or higher order multiples) it is a good idea to discuss the advantages and disadvantages to exercise at each stage of your pregnancy with your obstetric health care provider. They can advise if you have any absolute contraindications to exercise or the level of exercise that it appropriate to you.
While carrying (and caring for) twins has its challenges, you really do get double the love and I know that I wouldn't have it any other way.
And for the ‘twin mums to be’ reading this blog, welcome to the club!
This blog was created by our very own Twin mum and Pelvic Health Physio Steph! We are thrilled to have recently welcomed back Steph from Maternity Leave and she is now available every Saturday morning for appointments. If you after a session with our twin expert- you can book here!
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Royal Australian and New Zealand College of Obstetricians and Gynecologists. (2020). Exercise during pregnancy: C-Obs 62.
Woodley, S. J., Lawrenson, P., Boyle, R., Cody, J. D., Mørkved, S., Kernohan, A., & Hay-Smith, E. J. C. (2020). Pelvic floor muscle training for preventing and treating urinary and faecal incontinence in antenatal and postnatal women. Cochrane Database of Systematic Reviews(5). doi:10.1002/14651858.CD007471.pub4