Increased risk of health issues in pregnancy after IVF or IUI

Women who conceive using assisted reproductive technology (ART) may have a higher risk of maternal complications, according to new research.

Researchers analysed nearly 470,000 deliveries in Utah between 2009 and 2017, and compared maternal morbidity between those who conceived through ART and unassisted pregnancies. The study found that women who conceived through ART, such as intrauterine insemination (IUI) and IVF, were more likely to experience serious health issues during pregnancy and childbirth compared to those who conceived naturally.

'The choice of medically assisted reproductive procedures depends on factors such as infertility duration, diagnosis, availability and cost, typically progressing from less to more invasive treatments,' the authors said in their paper, published in Obstetrics & Gynecology. 'Limited large-scale data have restricted studies investigating maternal morbidity differences by medically assisted reproduction treatment types.'

Just under five percent of pregnancies included in the study, 22,534 in total, occurred through medical assisted reproduction. Of these, 60.4 percent used fertility-enhancing drugs, 14.4 used IUI, 23.5 percent used ART with autologous oocytes (the woman's own eggs) and 1.7 percent used donor eggs. Maternal morbidity was defined as the presence of factors such as, blood transfusion, unplanned operating room procedure, ICU admission, eclampsia, unplanned hysterectomy or ruptured uterus. Women who conceived through IUI or IVF had a higher risk of maternal morbidity compared to those with unassisted pregnancies, but no increased risk was reported for women who conceived using fertility-enhancing drugs.

'Individuals becoming pregnant through medically assisted reproduction had higher risk of maternal morbidity, with odds ratios increasing as medically assisted reproduction treatments become more invasive,' the authors concluded.

The connections became much weaker when multifetal gestations – pregnancies involving twins or more – were considered, and even weaker after factoring in pregnancy-related health conditions. Pregnancies from ART using the women's own eggs also showed higher maternal morbidity risks compared to naturally-conceived pregnancies.

The researchers identified the higher prevalence of multifetal gestations among women who undergo ART as a key factor behind increased maternal morbidity risk. Multifetal pregnancies are well known to carry greater risks for both mothers and infants, including preterm birth, low birth weight, and hypertensive disorders. When the analysis was limited to singleton pregnancies and adjusted for obstetric comorbidities, the link between medically assisted reproduction and maternal morbidity was no longer statistically significant.

The researchers stressed that reducing the incidence of multifetal gestation is 'crucial' to improving maternal outcomes (see BioNews 936 and 966). They noted that Nordic countries have seen a reduction in multiple births following IVF through elective single embryo transfer (eSET), however this approach is less common in the USA where high costs of treatment may encourage multiple embryo transfers.

'The findings have implications for patients, clinicians, and public health policymakers,' the paper concluded. 'Public health initiatives promoting eSET and counselling on maternal morbidity risks associated with medically assisted reproduction-related multifetal pregnancies can guide safer treatment choices, potentially lowering maternal morbidity rates and related costs.'