Infertile women may benefit from oil-based contrast during HSG

Hysterosalpingography (HSG) with an oil-based contrast medium yields a significantly higher rate of ongoing pregnancy and live birth than HSG with a water-soluble contrast medium, according to a study presented at ESHRE 2024.

“It has been known that many [infertile] women conceive within months after HSG, suggesting that tubal flushing, [particularly with oil-based contrast], might be considered a possible treatment option for infertility,” said Dr Li Yan from the Department of Obstetrics and Gynecology at International Peace Maternity and Child Health Hospital (IPMCH) in Shanghai, China.

In a prospective study conducted at IPMCH between May 4, 2020 and March 30, 2022, 1,104 infertile Chinese women underwent HSG with either oil-based (n=522) or water-soluble (n=582) contrasts. [ESHRE 2024, abstract O-023]

Within 6 months after HSG, a significantly higher rate of ongoing pregnancy, defined as an intrauterine pregnancy detected by ultrasound after 12 weeks of gestation, was observed in the oil-based group than in the water-soluble group (23.6 percent vs 17.2 percent; rate ratio [RR], 1.5; p=0.01).

It was also observed that the oil-based group had significantly higher clinical pregnancy (32.8 percent vs 24.1 percent; RR, 1.5; p<0.01) and live birth rates (23.4 percent vs 17 percent; RR, 1.5; p=0.01) compared with the water-soluble group.

The median duration of pregnancy was 38.7 months in the oil-based group and 30 months in the water-soluble group (p=0.39).

However, miscarriages were significantly more common in the oil-based group than the water-soluble group (8 percent vs 5 percent; RR, 1.7; p=0.04).

Subgroup analysis

In women with low infertility risk, those who underwent HSG with an oil-based contrast experienced significantly higher rates of ongoing (27.2 percent vs 18.5 percent; RR, 1.6; p=0.01) and clinical pregnancies (36.9 percent vs 24.1 percent; RR, 1.8; p<0.001) as well as live births (26.8 percent vs 18.2 percent; RR, 1.6; p=0.01) than those who underwent HSG with water-soluble contrast within 6 months.

Among women with high infertility risk, defined as those who either had ovulatory disturbances or were at risk for tubal disease, HSG with oil-based contrast was associated with a numerically higher ongoing pregnancy rate (23.2 percent vs 18 percent; RR, 1.4 and 18.1 percent vs 12.6 percent; RR, 1.5, respectively) compared with water-soluble contrast.

Overall, tubal flushing with oil-based contrast during HSG is an effective treatment for improving pregnancy outcomes in infertile women and should be part of any infertility workup, the researchers noted.