A twin pregnancy is a pregnancy with two fetuses developing simultaneously, and in India around 1.3 percent of all pregnancies are now twin — a rate that has risen over the last fifteen years largely because of the wider availability of IVF and IUI in tier-1 and tier-2 cities. Triplets and higher-order multiples are much rarer, mostly seen after fertility treatment, and follow broadly similar but more intensive principles. Naturally conceived twins are still more common than IVF twins in absolute numbers but the rising IVF share is the main driver of the trend.

Twins are either identical (monozygotic, from a single fertilised egg that splits) or fraternal (dizygotic, from two separate eggs fertilised by two sperm). Identical twins always share the same DNA and sex; fraternal twins are genetically like any siblings and can be the same or different sex. Fraternal twins run in families on the mother's side, are commoner in older mothers, and are the type usually produced by IVF when two embryos are transferred. Identical twins do not have a strong genetic pattern and occur at roughly the same rate worldwide.

Chorionicity describes how many placentas and amniotic sacs the twins share, and it is the single most important factor in determining the risk profile of a twin pregnancy. Dichorionic-diamniotic (DCDA) twins have two separate placentas and two separate sacs and are the safest type — all fraternal twins are DCDA and about a third of identical twins are too. Monochorionic-diamniotic (MCDA) twins share one placenta but have two separate sacs and account for around two-thirds of identical twins; they carry the specific risk of twin-to-twin transfusion syndrome (TTTS) in which blood flow imbalances between the babies through the shared placenta.

Monochorionic-monoamniotic (MCMA) twins share both the placenta and the sac, are the rarest type (about 1 percent of twins), and carry the highest risk because the umbilical cords can entangle. The chorionicity is best determined by ultrasound between 11 and 14 weeks, when the lambda sign (DCDA) or T sign (MCDA) at the membrane insertion is easily visible; after about 16 weeks the determination becomes less reliable and may need MRI. Establishing chorionicity early is the single most important thing the first-trimester scan does in a twin pregnancy and shapes every later decision about monitoring and delivery.

Twin pregnancies carry meaningfully higher rates of every major obstetric complication compared to singletons, and the additional monitoring is not optional — it is what brings the outcomes for twin pregnancies in India close to those for singletons. Gestational diabetes is roughly twice as common in twins because the extra placental tissue produces more insulin-resistance hormones. Preeclampsia is also about twice as common, partly for the same reason and partly because the larger placental load on the maternal circulation is harder to support.

Preterm labour is the single biggest risk — around 60 percent of twins are born before 37 weeks compared to around 10 percent of singletons, and many are born meaningfully earlier. Anemia is 2 to 3 times more common because the iron requirement is much higher. Intrauterine growth restriction (IUGR) affects one or both twins more often, particularly in monochorionic twins where unequal placental sharing is possible. TTTS affects 10 to 15 percent of monochorionic twins and needs early detection. Postpartum haemorrhage is also commoner because the uterus is more stretched and slower to contract back.

The antenatal schedule for twins is more intensive than for singletons and is shaped by chorionicity. In the first trimester all twin pregnancies should have monthly visits with ultrasound at 6 to 8 weeks to confirm viability and number, the chorionicity scan between 11 and 14 weeks, and the nuchal translucency screen at the same visit. After this, dichorionic twins typically have a growth scan every 4 weeks from 20 weeks onwards along with antenatal visits.

Monochorionic twins need fortnightly ultrasound from 16 weeks for TTTS surveillance — looking at amniotic fluid in each sac, bladder filling, and Doppler studies. Both DCDA and MCDA twins have cervical length measurement at the 20-week scan to screen for preterm labour risk. Routine blood tests include a CBC more often (because of anemia), the OGTT for gestational diabetes earlier (24 to 28 weeks), and regular BP and urine checks. Monthly scan costs run 800 to 2500 rupees. CTG monitoring is added from 32 weeks. For background see preeclampsia-pregnancy-bp-india.

Nutrition needs in twin pregnancy are higher across calories protein iron folic acid and calcium, and getting this right has measurable impact on baby weights and maternal anemia. Total daily calories should rise by 300 kcal in T2 and 500 kcal in T3 over pre-pregnancy (versus 200 to 300 for singletons), roughly one extra meal or two substantial snacks. Protein needs are around 1.5 g per kg body weight daily — add dal paneer egg fish and chicken (where eaten) to most meals.

Iron is doubled from 30 to 60 mg daily under Anemia Mukt Bharat for twins; many Indian OBs prescribe 60 to 100 mg. Folic acid rises to 1 mg daily (versus 400 mcg in singleton). Calcium goes from 1200 mg to 1500 mg daily, ideally split into two doses. Aim for total weight gain of 17 to 25 kg versus 11 to 16 kg in singleton — discuss with your OB. For anemia detail see anemia-in-pregnancy-india.

The complications most likely in twin pregnancy are well-defined and largely identifiable with the right monitoring schedule. Preeclampsia is roughly twice as common as in singleton (13 to 15 percent versus 6 to 8 percent) and presents with rising BP, protein in urine, swelling, headaches and visual changes; the OB will check BP and urine each visit and low-dose aspirin 75 to 150 mg daily from 12 weeks is often added. GDM is twice as common and screened earlier with the OGTT around 24 to 28 weeks.

Anemia is 2 to 3 times commoner because of the doubled iron and folate demand; haemoglobin should be checked at every trimester. Preterm labour affects around 60 percent of twins and is the main driver of NICU admission; cervical length scanning helps identify higher-risk women. TTTS affects 10 to 15 percent of MC twins, presents on ultrasound as discordant amniotic fluid and discordant baby sizes, and may need fetoscopic laser at a tertiary fetal medicine centre. IUGR affects one or both twins more often, particularly in MC twins.

A defined list of red flags in twin pregnancy means going to the labour room or calling 108 immediately rather than waiting for the next routine visit. Decreased fetal movement is the first — from 28 weeks count kicks of BOTH babies separately, target at least 10 movements from each baby over 2 hours; if either baby has reduced movements go to hospital the same day for CTG and ultrasound. Vaginal bleeding at any stage needs same-day assessment because in twins it can suggest placental problems including abruption.

Severe headache not relieved by paracetamol, sudden vision changes (blurring, flashing lights, blind spots), severe upper-abdominal pain, sudden swelling of face or hands, and a sharp rise in BP are preeclampsia warning signs needing urgent assessment. Regular contractions before 37 weeks (more than 4 to 6 per hour, or any before 32 weeks) suggest preterm labour and need the labour room same day. Leaking fluid — clear or pinkish — suggests waters have broken and needs immediate review, particularly if preterm. Severe vomiting, fever above 38 C, and sudden severe abdominal pain are also red flags. 108 ambulance is free.

Most twin pregnancies in India are delivered around 36 to 37 completed weeks, earlier than singletons, because continuing the pregnancy beyond this carries a measurably higher risk of stillbirth in twins than in singletons. DCDA twins are typically aimed at 37 to 38 weeks, MCDA twins at 36 to 37, and MCMA twins at 32 to 34 weeks with hospitalisation from around 26 weeks for continuous monitoring. The exact timing is individualised by the OB based on growth scans Doppler and any complications.

Vaginal delivery is possible for many DCDA and some MCDA twins if Twin A is cephalic and an experienced obstetrician is available — most twin vaginal deliveries happen in a labour room with anaesthetic and OT standby because Twin B may need an emergency caesarean. C-section is more common in India because of breech presentations, MCMA needing surgery, and centre preferences. The most important decision is where to deliver — choose a hospital with on-site NICU at level 2 or 3 and a paediatrician for both babies. AIIMS, Apollo Cradle, Cloudnine, Fortis, Manipal and Max all have suitable units.

Because around 60 percent of twins are born preterm and many will spend at least a short time in NICU even at 36 to 37 weeks, NICU planning is part of standard twin antenatal care. Book delivery at a hospital with NICU at the appropriate level — level 2 for late preterm and term babies needing observation, feeding or jaundice care; level 3 for very preterm or sick babies needing ventilation. Government NICUs at AIIMS and major district hospitals are free; private NICUs at Apollo, Cloudnine, Fortis or Manipal cost roughly 15000 to 50000 rupees per day.

A pre-delivery NICU orientation, where parents see the unit and meet a neonatologist, is offered by most large units on request — ask in T3. Discuss the cord blood banking decision (private with Cordlife, LifeCell, ReeLabs costs 75000 to 100000 rupees plus annual storage; public donation is free) before delivery so the kit can be ready. Plan logistics for two babies — extra clothes, feeding equipment, a designated person to shuttle between postnatal ward and NICU — and identify the family member who will be main support for the first two weeks.

Postpartum recovery after twin delivery is harder than after a singleton in three specific ways. Postpartum haemorrhage (PPH) is more common because the over-stretched uterus is slower to contract back (uterine atony); active management of the third stage of labour with oxytocin and observation in the labour room for two hours after delivery is standard, and any heavy bleeding needs immediate attention. The healing window is longer for a twin caesarean than for singleton because the incision is sometimes larger and the abdominal wall has been stretched more.

Breastfeeding twins is possible — supply responds to demand. Tandem feeding (both at once) saves time and is supported by an IBCLC lactation consultant; sessions at Apollo Cradle or independent IBCLCs cost 500 to 2000 rupees, and the first two weeks pay back over months. Sleep deprivation is amplified because feeding windows do not always align — rotating night duties with a partner or family member is essential. Joint family or village support is critical for the first six to eight weeks — discuss the arrangement explicitly in T3.