Close this search box.

Everything you need to know about twin pregnancy

Pregnancy is always a happy and rewarding experience, but there are additional factors to consider when expecting twins. Learn what to anticipate and potential difficulties if you are pregnant with twins by reading on.



When sperm fertilises an egg within days after ovulation, conception occurs.

A menstrual cycle usually lasts 28 days, and ovulation generally occurs midcycle, around day 14. During ovulation, a woman’s ovary generally produces one egg. There are two possible causes of twin pregnancies:

  • When one or both ovaries produce more than one egg during ovulation, and each egg is fertilised and implants in the uterus, this results in fraternal twins.
  • When a single fertilised egg divides into two identical embryos, this results in identical twins.

What factors increase your chances of having twins?

Twin pregnancies are more prevalent among women who:

The absence of menstruation is the first indication of pregnancy that is definite. While it may take some time to discover if you are having twins, there are a few telltale signs.


Often, the symptoms of pregnancy are more evident in women who are carrying twins.

For instance, if you are pregnant with twins, your human chorionic gonadotropin (hCG) levels will increase more quickly and at a greater level than in a single pregnancy. More of this hormone increases the severity of nausea. Additionally, fatigue and breast discomfort may be more severe in the first trimester compared to a single-foetus pregnancy.

In addition, as your pregnancy proceeds, you will acquire more weight, which increases the pressure on your body and may exacerbate symptoms such as swelling and body pains.

Gain of Weight During Twin Pregnancy

The following is the gestational weight increase for twin pregnancies:

  • 37 to 54 pounds for women of average weight
  • 31 to 50 kg for obese women
  • 25 to 42 pounds for overweight females

To reduce the extra risks connected with having twins, it is crucial to maintain your weight as near as feasible to these standards through good food and exercise.

Initial visit to a healthcare provider

Prenatal care is crucial throughout pregnancy. If you conceive normally, your first OB appointment often occurs around the end of the first trimester. You may visit your doctor sooner if you conceive via in vitro fertilisation. Even if you have visited your healthcare provider earlier in the pregnancy, the first big checkup often occurs around the end of the first trimester (about nine to 12 weeks). This checkup may reveal that you are expecting twins.

Throughout this session, your healthcare provider will review your medical history, do a physical examination and pelvic exam, and offer an overview of your care during pregnancy. Creating a list of questions to ask your healthcare practitioner can aid in their retention.

Most pregnant women will also have an ultrasound of their babies to examine their heartbeats and anatomy. Your healthcare professional will do further blood tests to screen for infant genetic problems. Occasionally, you may be given a blood test to determine the gender of the foetus. Your healthcare professional will calculate the number of weeks you are pregnant and determine the due date.

After the first appointment, the normal schedule for OB-GYN visits is as follows:

  • Every four weeks till 28 weeks
  • Every two to three weeks from 28 to 36 weeks
  • Weekly from 36 weeks on
  • When pregnant with twins, you may need to see your OB-GYN more often than is typical

Visits to a Perinatologist

Given that having twins is considered a high-risk pregnancy, you will likely be sent to a perinatologist (high-risk obstetrician or maternal-foetal medicine expert) to work with your OB-GYN.

Dangers and Complications

Two pregnancies are more stressful on the body than a single one. There are several hazards involved with twin pregnancies, and difficulties may arise. The following items are the most common.

Premature Labour and Delivery

In twin pregnancies, preterm labour and delivery is the most prevalent problem. Preterm birth is the delivery of a baby before 37 weeks of gestation. Twin pregnancies average 36 weeks long.

Twin pregnancy and assisted reproductive technology are related to an increased risk of preterm labour and delivery. One research revealed that more than 50% of twin births were premature, compared to just 10% of single births.

Preterm birth complications depend on how early the infants are born. The sooner an infant is born, the greater the danger of difficulties. Examples include:

  • Immature lungs
  • Respiratory stress disorder
  • Apnea and bradycardia are present
  • Infection
  • Jaundice
  • Pneumonia
  • Incapability to maintain body temperature

Intrauterine Limitation of Growth

Intrauterine growth restriction (IUGR), or small for gestational age (SGA), is a problem when one or more of your infants are not developing normally. This syndrome might result in kids being born preterm or with low birth weight. This condition affects almost 50% of pregnancies with more than one child.

Your healthcare practitioner will monitor your pregnancy for IUGR, often by ultrasound, to ensure that your baby’s growth is on track. IUGR-born infants are at greater risk for:

  • Birth via Caesarean section
  • Anoxia (lack of oxygen when a baby is born)
  • Meconium aspiration, which occurs when a newborn consumes a portion of the first stool
  • Hypoglycemia (low blood sugar)
  • Polycytosis (increased number of red blood cells)
  • Extreme viscosity (decreased blood flow due to an increased number of red blood cells)
  • Motor and neurological disabilities

Your medical professional may treat IUGR with the following:

  • Ultrasound monitoring regularly
  • Monitoring foetal movement
  • Corticosteroid medications
  • Hospitalisation
  • Sometimes, preterm birth and emergency C-section may be required

Often, the timing of delivery for a woman with IUGR will depend on the following:

  • Age at conception
  • Foetal well-being
  • Quantity of amniotic fluid


Preeclampsia occurs when a pregnant woman gets high blood pressure and protein in her urine. Preeclampsia is more likely to occur in twin pregnancies. It may also arise early and be more severe in repeated pregnancies.

Does Preeclampsia Disappear Following Delivery?

Preeclampsia often begins after 20 weeks of pregnancy or after delivery. Typically, this issue heals soon after delivery.

Preeclampsia may cause harm to several organs, most frequently:

  • Kidneys
  • Liver
  • Brain
  • Eyes

Additionally, preeclampsia can:

  • Endanger a baby’s health
  • Cause placental abruption
  • Result in a low birth weight

Cause premature delivery

When preeclampsia arises during pregnancy, the babies may need to be delivered early, even if they are not quite a full term, due to the associated dangers to the mother and infants.

Preeclampsia symptoms include:

  • Headaches
  • Unclear vision
  • Seeing black patches in your eyesight
  • Right abdominal discomfort
  • Rapid enlargement of the hands and face (edema)
  • Rapid weight gain

Before pregnancy, you may reduce your risk of preeclampsia by keeping a healthy weight, exercising, and eating a balanced diet. By your healthcare provider’s advice, all of these actions become even more vital throughout pregnancy.

After 12 weeks of pregnancy, the U.S. Preventive Services Task Force advises high-risk women to take 81 mg of daily low-dose aspirin to help avoid preeclampsia.

Despite adopting protective steps, some women still develop preeclampsia. Women with preeclampsia, particularly those expecting twins, must be closely monitored by a medical professional due to the possibility of severe consequences.

Low foetal weight

Low birth weight is a frequent consequence of twin pregnancies since many twin pregnancies result in premature births. A newborn with low birth weight weighs less than 5 pounds and 8 ounces at delivery.

Babies with a birth weight of less than 1,500 grams (3 pounds, 5 ounces) are regarded to have an extremely low birth weight.

At delivery, infants weighing fewer than 1,000 grams (2 pounds, 3 ounces) are regarded to have an exceptionally low birth weight.

There are two primary reasons for low birth weight:

Babies delivered prematurely (before 37 weeks) are mostly responsible for low birth weight. Significant weight increase happens during the latter weeks of pregnancy; thus, premature infants lose out on the final development phases.

Intrauterine growth restriction: As mentioned above, this is another disease that causes low birth weight in term infants.

Complications associated with low birth weight include:

  • Low quantities of oxygen during birth
  • Difficulty keeping warm
  • Problems with eating and weight gain
  • Infection
  • Problems with breathing and undeveloped lungs (infant respiratory distress syndrome)
  • Problems with the nervous system, such as bleeding inside the brain
  • Digestive difficulties

Sudden newborn death syndrome (SIDS)

Almost all infants with low birth weight must stay in the neonatal intensive care unit (NICU) until they gain enough weight and are healthy enough to go home.

Gestational Diabetes

Gestational diabetes, characterised by elevated blood glucose (sugar) levels during pregnancy, affects twin pregnancies more often than single pregnancies.

Due to the dangers associated with gestational diabetes, pregnant women are regularly evaluated between 24 and 28 weeks of pregnancy. If your risk for gestational diabetes is greater, you may be checked early. Factors of danger include:

  • Being overweight or obese
  • A prior pregnancy with gestational diabetes
  • Having an elevated blood pressure
  • A history of cardiovascular illness
  • Having polycystic ovarian syndrome (PCOS)

Uncontrolled blood sugar levels during pregnancy may result in several maternal and infant problems. A mother’s uncontrolled blood sugar can cause an increase in her infant’s blood sugar. This may cause newborns to grow overly large.

C-section: Women with poorly regulated blood sugar have an increased risk of needing a Caesarean section.

Preeclampsia is already more prevalent in twin pregnancies. Women with diabetes are more likely to have hypertension than women without diabetes.

Hypoglycemia (low blood sugar) is a potentially life-threatening adverse effect of blood sugar-lowering medicines.

In many instances, gestational diabetes may be controlled via physical activity and a balanced diet. However, some women will also need insulin therapy.

Placental Abruption

The placenta connects the foetus to the uterus of the mother. It is a vital source that provides nourishment and oxygen to foetuses through the umbilical cord. Placental abruption is the separation of the placenta from the uterus before delivery. The placenta usually remains connected to the uterus.

Placental abruption compromises the uterus and everything that it supplies. Placental abruption is a medical emergency requiring prompt treatment since it poses a danger to the lives of both the mother and the unborn child. It may result in:

  • Prematurity and inadequate birth weight
  • Continual bleeding in the mother
  • Death of the infant (in rare cases)

About 1 in 100 pregnancies are affected by placental abruption. This illness often occurs during the third trimester, but it may potentially occur before 20 weeks.

In the third trimester of pregnancy, vaginal bleeding with discomfort is the most prevalent symptom. Occasionally, the blood will be located beneath the placenta. In this instance, no bleeding will occur. Symptoms may also include:

  • Abdominal discomfort
  • Uterine contractions
  • Tender uterus Backache

If you experience these symptoms, you must see a healthcare professional immediately.

Twin-to-Twin Transfusion Syndrome

Identical twins (or other multiples) share a placenta during twin-to-twin transfusion syndrome (CTS). Within the placenta, they share a network of blood arteries that provide crucial nutrients and oxygen for survival and growth in utero.

When TS develops, there is an uneven distribution of blood between the twins via placental blood vessel connections. One twin (the donor twin) supplies the other with blood (the recipient twin). This results in the donor twin receiving insufficient blood and the receiver twin receiving excessive blood.

This unbalanced distribution of blood and nutrients may result in serious problems and even death for one or both twins. When the donor twin donates more blood than it gets in return, the foetus is at risk for the following:

  • Malnourishment
  • No amniotic fluid around the foetus
  • A tiny or missing bladder
  • Organ failure

The receiver twin gets excessive blood, putting them at risk for heart problems such as hydrops.

The degree of cardiovascular dysfunction in foetuses is crucial in predicting the prognosis of TS. Due to this, the diagnosis of TS involves a comprehensive evaluation of the foetal heart utilising foetal echocardiography in both the recipient and donor twin.

Ultrasound and other specialised procedures assessing amniotic fluid, blood flow, and bladder fullness confirm TS.

The severity of TS is determined using the Quintero staging system by medical professionals.

The Phases of the TS

Stage I is the mildest stage. More than three-quarters of stage I patients are stable or regressed without invasive intervention. Survival is around 86%. Advanced TTTS (stages III and above) is associated with a mortality risk of 70% to 100%, particularly when TTTS is diagnosed at or before 26 weeks.

Options for treatment include:

  • Amniocentesis was performed to remove extra fluid. This seems to increase placental blood flow and reduce the incidence of premature labour.
  • Amniocentesis can preserve around 60% of afflicted infants.

It indicates that laser surgery may seal off the link between the blood vessels in 60% of afflicted infants.

If your infants are grown enough to survive outside the womb, delivery is also possible.


C-section births need an incision across the lower abdomen to remove the foetus from the uterus. Caesarean sections are performed when a vaginal birth is not safe for the mother or infant or when an emergency delivery is required.

C-sections are more prevalent in twin pregnancies compared to single births. This is because the factors that increase the chance of C-sections (low birth weight, gestational diabetes, preeclampsia, placental abruption, and intrauterine growth restriction) occur more often in twin pregnancies.

However, depending on the presentation and gestation of the kids, twins are commonly delivered vaginally. Vaginal delivery of twins is feasible when:

  • The duration of pregnancy exceeds 32 weeks
  • The larger twin is A, the infant closest to the cervix
  • Twin A is pointing down
  • Twin B is breech, head down, or sideways
  • Twin B is smaller in size than Twin A
  • There are no indications of foetal distress

Occasionally C-sections are scheduled, and sometimes they are performed in emergency conditions. There are inherent hazards involved with the surgical procedure:

  • Infection
  • Blood loss
  • A blood clot that causes embolism
  • Injury to the intestines or urinary bladder
  • A surgical procedure that may undermine the uterine wall
  • Placental abnormalities in later pregnancies
  • The dangers of general anaesthesia

Final Thoughts

pregnant woman on an ultrasound

Pregnancy might be one of the most beneficial times in a woman’s life. Maintaining a strong connection with your healthcare practitioner is essential if you expect twins to guarantee the best possible results for you and your infants.

Fertility2Family logo

Evan Kurzyp

Evan is the founder of Fertility2Family and is passionate about fertility education & providing affordable products to help people in their fertility journey. Evan is a qualified Registered Nurse and has expertise in guiding & managing patients through their fertility journeys.

Scroll to Top