Monisynnytys

Monisynnytys is the Finnish term for a multiple pregnancy, in which two or more fetuses develop in one uterus at the same time. The condition is most commonly observed with identical or fraternal twins, but it can also involve triplets or higher-order multiples. Multiple pregnancies can occur naturally due to the release of more than one ovum during an ovulation cycle or can be induced by assisted reproductive technologies such as in vitro fertilisation (IVF) and ovulation‑stimulation drugs.

The incidence of monisynnytys varies worldwide, being roughly 1‑3 % of all pregnancies in most populations. Higher rates are seen in countries with widespread use of fertility treatments, and there is evidence that the risk increases with maternal age, especially after the age of 35.

Multiple gestations carry higher obstetric risks compared to singleton pregnancies. Early-onset complications include threatened miscarriage, ectopic pregnancy, and gestational hypertension. In later stages, there is an elevated risk of preterm labor, intrauterine growth restriction, and cesarean delivery. Neonatal complications frequently involve prematurity, low birth weight, and perinatal morbidity or mortality.

Management of a monisynnytys typically involves multidisciplinary care, including frequent ultrasound assessments, monitoring of maternal weight gain and blood pressure, and preparation for possible preterm delivery. Breastfeeding and bonding are encouraged, but parents may require additional support due to the increased workload and potential for neonatal care needs. Guidelines from national obstetric societies recommend individualized care plans and early referral to high‑risk obstetric units to optimise outcomes for both mother and babies.