Twin Pregnancy
Understanding How Multiples Develop
Twins and higher-order multiples can develop in a few different ways. As people age, hormonal changes can trigger the release of more than one egg during ovulation, increasing the chances of having twins. Assisted reproductive technologies, like in vitro fertilization (IVF) and other fertility treatments, also raise the likelihood of multiples. There are two main types of twins:
- Fraternal twins form when two eggs are fertilized by two separate sperm. These twins may look different from each other and can be the same or different genders. Each grows in its own amniotic sac with its own placenta.
- Identical twins develop when a single fertilized egg splits into two embryos. They usually share the same genetic traits, blood type, and are always the same gender. Identical twins may share the same placenta and, in some cases, the same amniotic sac. Rarely, identical twins are born physically connected, called being conjoined.
Multiple pregnancies with three or more babies can include both identical and fraternal siblings, or a mix of both.
Table: Basic Types of Twin Pregnancies
| Type | Number of Eggs | Number of Sperm | Placenta/Sac | Genetic Similarity | Sex |
|---|---|---|---|---|---|
| Fraternal Twins | 2 | 2 | Separate | Like siblings | Same/Different |
| Identical Twins | 1 | 1 | Shared/Partially | Nearly identical | Same |
Signs and Detection of a Multiple Pregnancy
Most health providers discover multiple pregnancies during routine ultrasounds. An ultrasound can identify more than one embryo or fetus early in pregnancy. Sometimes, the provider might suspect twins or more if the uterus grows faster than normal, if someone has severe symptoms like extra morning sickness, or if tests show high levels of pregnancy hormones such as hCG or alpha-fetoprotein.
Occasionally, two sacs or heartbeats appear early but only one baby arrives at birth. This can happen due to “vanishing twin syndrome,” where one embryo stops developing in the first trimester. This experience can be emotional for parents, and clear reasons are often not found. Common signs that may suggest a twin pregnancy include:
- Faster weight gain or a larger belly earlier in pregnancy.
- More intense pregnancy symptoms (like breast tenderness or fatigue).
- Early and stronger fetal movements.
- More frequent or severe morning sickness.
- Higher hormone levels in routine blood tests.
However, symptoms alone are not reliable, and only an ultrasound can confirm twins or multiples.
What a Multiple Pregnancy Means for Expecting Parents
Carrying twins or more brings unique experiences and needs. Expecting parents should prepare for extra medical attention and more appointments to track both the babies’ growth and their own health.
Health providers do frequent ultrasounds, listen in on the babies’ heartbeats, and check regularly for any complications. Key changes and recommendations for those expecting multiples include:
- More frequent prenatal care. Visits happen more often than in single pregnancies. This helps spot problems early and monitor development closely.
- Weight gain. People expecting twins should gain more weight compared to those expecting one baby. The recommended range is about 37 to 54 pounds for adults at a healthy pre-pregnancy weight. Eating an extra 600 calories per day may be suggested, but it’s important to follow a provider’s guidance. A diet rich in folic acid, iron, vitamins, and minerals supports extra growth and lowers the risk of anemia.
- Earlier delivery. Labor often starts before the due date. If not, the healthcare team may suggest inducing labor or scheduling a cesarean section (C-section), usually before 38 weeks, to keep both parent and babies safe.
- Preparation for possible C-section. Vaginal birth may be possible if the first baby is in the right position, but a planned or emergency C-section is more common with twins and nearly always needed for three or more babies.
- Increased support. Partners, family, and friends should expect to help more, as caring for twins or more newborns can be exhausting, especially if the babies arrive early or need special care.
Checklist: Important Points for Expecting Parents with Multiples
- Schedule and attend all prenatal visits.
- Follow nutrition and weight-gain recommendations.
- Prepare for early labor and delivery.
- Create a support network for after birth.
Complications and Health Concerns With Multiple Pregnancies
While many twins and higher-order multiples are born healthy, the risks are higher than in single pregnancies. Some common complications include:
- Premature Labor and Birth: Multiples often arrive before 37 weeks. Premature birth can cause issues like difficulty breathing, eating problems, infections, and the need for longer hospital stays. Doctors may give steroid shots to help babies’ lungs develop if early birth seems likely.
- Gestational Diabetes: This type of diabetes starts during pregnancy and is more common with multiples. High blood sugar can affect both parent and babies, but special attention, changes to diet, or medication can often manage it.
- High Blood Pressure and Preeclampsia: Blood pressure problems, especially preeclampsia, happen more often in multiple pregnancies. These conditions can harm organs like the kidneys or liver and may require early delivery.
- Twin-to-Twin Transfusion Syndrome (TTTS): In some identical twin pregnancies, blood flow in the shared placenta is uneven, and one twin receives too much blood while the other too little. TTTS is serious and may need special treatments before birth.
- Other Possible Complications:
- Anemia
- Placental problems such as placental abruption
- Intrauterine growth restriction (IUGR)
- Low birth weight
- Higher chances of cesarean delivery
- Birth defects (though these are still uncommon)
- Increased risk of postpartum depression
Table: Common Risks for Multiple Pregnancies
| Complication | Description | Possible Effects |
|---|---|---|
| Premature birth | Birth before 37 weeks | Breathing, eating, infection |
| Gestational diabetes | High blood sugar during pregnancy | Larger babies, delivery risks |
| High blood pressure / Preeclampsia | Blood pressure problems and organ danger | Early delivery, health threats |
| Twin-to-twin transfusion syndrome | Uneven blood flow between identical twins | Heart problems, growth issues |
| Low birth weight | Babies under 5 lbs. 8 oz. at birth | Extra care at birth |
| Postpartum depression | Depression after childbirth | Impacts parent’s daily life |
Tips and Guidance for Caring for Twins and Multiples
After the babies are born, caring for multiples takes energy, planning, and support. Even healthy twins or triplets need frequent feeding, diaper changes, and comforting, often at the same time. Immediate needs include:
- A safe sleep space for each baby.
- Enough supplies for feeding (breastfeeding, formula, or a mix), bottles, and diapers.
- Coordinating caregiving between parents and helper.
If the babies are born early or with health concerns, they might need time in the neonatal intensive care unit (NICU). With several babies at once, parents often feel tired, anxious, or overwhelmed. Here are some ways to support care for multiples:
- Ask for help. Reach out to trusted relatives, friends, or community services to share child care tasks.
- Create a care schedule. Use written charts or digital apps to track feedings, diapers, and medications for each baby. This helps prevent confusion, especially in the early weeks.
- Regular check-ins with healthcare providers. Babies and parents both need regular appointments to monitor growth, health, and recovery. Multiples can be at higher risk for health concerns after going home.
- Watch for signs of postpartum depression. Parents of multiples have a higher chance of emotional challenges after birth. Symptoms include sadness, loss of interest in usual activities, trouble sleeping (not just from baby care), or withdrawal from others. It is important to speak up and seek advice if any of these signs appear.
- Breastfeeding multiples. Feeding two or more babies at the breast is possible but may take practice. Lactation consultants can offer helpful strategies if needed.
List: Common Early Challenges With Multiples
- Coordinating naps and feeding times.
- Managing sleep deprivation.
- Caring for babies with different needs or health issues.
- Juggling multiple pediatric appointments.
Support Resources
- Parent support groups (local or online) for families with twins or more.
- Parenting classes focused on multiples.
- Guidance from pediatricians and nurses with experience in multiple births.
Healthy twins and multiples develop on their own timelines. Celebrating small milestones and accepting help can make the journey easier. With attentive care and preparation, families can manage the unique challenges and joys of life with multiples.
