Artificial insemination - Risks of artificial insemination

Multiple births

There is an increased risk of a multiple birth, such as twins, if a woman has intrauterine insemination (IUI) in combination with fertility medication. In IUI cycles combined with follicle-stimulating hormone (FSH), a fertility hormone that increases the number of eggs produced, multiple pregnancy rates range from 10-40%. 

Multiple births are associated with an increased risk of:

• miscarriage - the loss of the pregnancy during the first 23 weeks 
• gestational diabetes - a type of diabetes that affects women during pregnancy
• low birth weight - babies born weighing under 2.5kg (5.5lbs)
• premature birth - babies born before week 37 of pregnancy

The risk of death for premature babies during the first week of the birth is five times higher for twins and nine times higher for triplets than for single babies. For more information, see the Live Well section about Risks in multiple pregnancies.

Ovarian hyperstimulation syndrome (OHSS)

Ovarian hyperstimulation syndrome (OHSS) is an uncommon but potentially serious complication that can occur when a woman uses fertility medication during a cycle of IUI treatment.

For reasons that are not fully understood, the ovaries of some women become swollen after the use of fertility medication. In most cases, the swelling is mild and causes symptoms of:

• bloating 
• mild to moderate abdominal pain 
• occasional nausea and vomiting

OHSS is severe in an estimated 3% of cases where fertility medication is used. Severe OHSS can cause symptoms including:

• chest pain 
• dehydration 
• shortness of breath

Mild cases of OHSS can be treated at home. Drinking plenty of water and taking paracetamol to help relieve the painful symptoms is recommended.

Severe cases of OHSS require admission to hospital so that the normal functions of the body can be supported until the swelling subsides.

The symptoms of OHSS usually develop four or five days after the initial use of fertility medication. Women should contact their fertility clinic as soon as possible if they think they may have OHSS.