MULTIPLE PREGNANCY

1. What is the meaning & Definition of multiple pregnancy:

2. Types of Multiple Pregnancies

3. Incidence of multiple pregnancies:

4. Causes and risk factors of multiple pregnancy

5.  Common Twin Presentations of pregnancy:

6. Complications of multiple pregnancies:

7. Diagnosis and Monitoring of multiple pregnancies:

8. Management and Treatment Approaches

9.  SCHEMATIC DIAGRAM OF MANAGEMENT OF TWINS DURING LABOUR

10. References

11. Quiz Session on Multiple Pregnancy 

1. What is the meaning & Definition of multiple pregnancy:

Multiple pregnancy is a condition in which a woman carries more than one fetus simultaneously at the same time. The most common occurrence is the development of two fetuses, known as twins. However, in rarer cases, three fetuses (triplets), four (quadruplets), five (quintuplets), or even six (sextuplets) may develop simultaneously.

2. Types of Multiple Pregnancies:

 The most common variety of multiple pregnancies is twin pregnancy, and it is further classified into two types. Dizygotic (Fraternal, binocular) Twins (80%)

Dizygotic twin pregnancy occurs when two separate eggs are fertilized by different sperm. It is the most common type of twin pregnancy, accounting for 80% of cases. Each twin has a unique genetic makeup, just like regular siblings, and they may be of the same or different sexes. Additionally, they have individual placentas and amniotic sacs.

2. Monozygotic (Identical, uniovular) Twins (20%)

Monozygotic twins result from a single fertilized egg that splits into two embryos. These twins share identical genetic material and are always of the same sex. They are the least common type of twin pregnancy, accounting for only 20% of cases. Their placental and amniotic arrangements can vary.

3. Incidence of multiple pregnancies:

 Twin pregnancies vary in different parts of the world. It is most common in Nigeria, where it happens in about 1 out of every 20 pregnancies, and least common in Japan and East Asian countries, where it occurs in about 1 out of 200 pregnancies. In India, about 1 in 80 pregnancies results in twins.                                                                  

The rate of identical (monozygotic) twins remains steady worldwide at about 1 in 250 pregnancies. However, the number of fraternal (dizygotic) twins varies and is responsible for the differences in twin birth rates across different regions.

According to Hellen's rule (proposed in 1895), the chances of multiple births follow a pattern:

• Twins occur in about 1 in 80 pregnancies.

• Triplets occur in about 1 in 80² (6,400) pregnancies.

• Quadruplets occur in about 1 in 80³ (512,000) pregnancies, and so on. 

4. Causes and Risk Factors:

Several risk factors may contribute to multiple pregnancies, including:

• Maternal Age: Women above 30 years have a higher chance of releasing multiple eggs during ovulation.

• Genetics: A maternal family history of twins increases the likelihood of multiple pregnancies.

• Fertility Treatments: IVF and ovulation-inducing drugs enhance the probability of multiples.

• Previous Multiple Pregnancies: Women who have had twins or more previously are at higher risk.

• Ethnicity: Women of African descent have the highest twinning rates, while Asian populations have the lowest.

5. Common Twin Presentations of pregnancy:

1. Both babies in the vertex (head-down) position – Occurs in about 60% of cases (most common).

2. First twin in vertex, second twin in breech – Seen in 20% of cases.

3. The first twin is in the breech, and the second twin is in the vertex. It is found in 10% of cases.

4. Both babies in the breech – This happens in 8-10% of cases.

Most Common and Rarest Fetal Lie in Twin Pregnancies at Term:

• The most common fetal lie at term is when both babies lie longitudinally.

• The rarest occurrence is when both twins are in a transverse lie.

💡 Note: A rare complication known as twin interlocking can occur when the first baby is breech and the second is vertex, leading to challenges during delivery.

6. Complications of multiple pregnancies:

a). Maternal Complications

1. Preterm Labor & Birth (50%): Most multiple pregnancies end before 37 weeks, increasing the risk of neonatal complications.

2. Gestational Hypertension & Preeclampsia: Increased blood pressure and preeclampsia are more common.

3. Gestational Diabetes: Hormonal fluctuations elevate the risk of diabetes, requiring careful monitoring.

4. Anemia: Iron deficiency anemia is more prevalent due to higher blood volume demands.

5. Excessive Weight Gain & Physical Discomfort: Rapid weight gain causes fatigue, back pain, and breathing difficulties.

6. Nausea, Vomiting

7. Polyhydramnios/Oligohydramnios

8. Antepartum Hemorrhage

9. Postpartum Hemorrhage

10. Malpresentation

b). Fetal Complications

1. Preterm Birth & Low Birth Weight: Common in multiple pregnancies, leading to developmental challenges.

2. Twin-to-Twin Transfusion Syndrome (TTTS): In monochorionic twins, blood flow imbalance can endanger both foetuses.

3. Congenital Anomalies: Structural defects are more frequent in multiples compared to singletons.

4. Intrauterine Growth Restriction (IUGR): Some foetuses may experience restricted growth due to limited placental supply.

5. Cord Entanglement & Compression: Monochorionic and monoamniotic twins face higher risks of cord-related complications.

6. Cord Prolapse 

7. Diagnosis and Monitoring of multiple pregnancies:

 Sonography in multifetal pregnancy is done to confirm the diagnosis as early as the 10th week, check fetal viability, and detect vanishing twin syndrome in the second trimester. It helps determine chorionicity, which is identified by the lambda or twin peak sign, and is also used for pregnancy dating and detecting fetal anomalies. Regular monitoring of fetal growth every 3–4 weeks is essential for identifying IUGR while assessing the position and lie of the fetuses, ensuring proper delivery planning. Doppler studies help detect twin-to-twin transfusion, while sonography aids placental localization and measuring amniotic fluid volume.

Chorionicity is best diagnosed through ultrasound at 10–13 weeks. In dichorionic twins, a thick membrane with a triangular lambda or twin peak sign is visible at the base. In monochorionic diamniotic twins, a thin membrane with a T sign is seen.

Biochemical tests show higher levels of maternal hCG, alpha-fetoprotein, and estriol, about twice as high as in singleton pregnancies. However, these values alone cannot confirm a twin pregnancy.

8.Management and Treatment Approaches

1. Frequent Prenatal Visits: Close monitoring to track maternal and fetal health.

2. Nutritional Support: Higher caloric intake, protein, iron, and folic acid supplementation.

3. Lifestyle Adjustments: Sufficient rest, hydration, and avoidance of strenuous activities.

4. Medical Interventions: Corticosteroids for fetal lung maturity if preterm delivery is expected.

5. Delivery Planning: Mode of delivery depends on fetal position, gestational age, and maternal health.

Delivery and Postnatal Care

1. Timing of Delivery:

   • Twins: Typically delivered between 36-38 weeks.

   • Triplets or more: Often delivered before 34 weeks.

2. Mode of Delivery:

   • Vaginal delivery: Possible if both twins are in a favourable position.

   • C-Section: Recommended for higher-order multiples and malpresentations.

3. Neonatal Care:

   • Premature and low-birth-weight babies may need NICU support.

4. Postpartum Recovery:

Mothers of multiples require extended recovery periods due to greater physical strain. 

 9. SCHEMATIC DIAGRAM OF MANAGEMENT OF TWINS DURING LABOUR

10. References

Dutta DC. DC Dutta’s Textbook of Obstetrics. 8th ed. Edited by Konar H. Kolkata, New Delhi: Jaypee Brothers Medical Publishers; 2015.

Mathew, Rishi Philip & Francis, Swati & Basti, Ram & Suresh, Hadihally & Rajarathnam, Annie & Cunha, Prema & Rao, Sujaya. (2017). Conjoined twins – role of imaging and recent advances. Journal of Ultrasonography. 17. 259-266. 10.15557/JoU.2017.0038.

Ministry of Health and Family Welfare, Government of India. Skilled Birth Attendance (SBA) Guidelines for Skilled Attendance at Birth [Internet]. New Delhi: National Health Mission; [cited 2025 Mar 6]. Available from: https://nhm.gov.in/images/pdf/programmes/maternal-health/guidelines/sba_guidelines_for_skilled_attendance_at_birth.pdf

11. Quiz Session on Multiple Pregnancy 

Test your knowledge of Multiple Pregnancies by attempting this interactive quiz! Challenge yourself and enhance your understanding with engaging questions.