Does dual administration of progesterone improve outcomes with in vitro fertilization?

This study investigated if dual (intramuscular and vaginal) progesterone (PG) administration improves fertility outcomes in women undergoing in vitro fertilization (IVF). They found that dual PG led to similar fertility outcomes as a single intramuscular PG administration.

Assisted reproduction (AR) is commonly used to treat infertility. Techniques like in vitro fertilization (IVF) produce embryos that can be transferred to the uterus. Embryo transfer (ET) involves delivering embryos to the uterus. This is usually done when the uterus lining (endometrium, EDM) is of a certain thickness. This increases the chance of implantation. 

Progesterone (PG) is a hormone involved in fertility. It is responsible for stimulating cells in the EDM. Low PG levels are associated with lower pregnancy rates. PG can be administered before ET to improve fertility outcomes. PG can be administered in many ways. An intramuscular (IM) injection is the most common. IM injection leads to high PG levels in the blood. The concentration in the EDM is often lower. PG can also be applied directly to the vagina. Vaginal administration (VA) can lead to higher concentrations in the EDM.

Some studies suggest that increasing PG concentrations may improve fertility. Dual application of PG using IM and VA has been suggested. However, it is unclear if dual PG could improve fertility outcomes in women undergoing IVF.

This study included 100 women that underwent IVF. This included 124 cycles. Dual PG was used in 52 cycles. Single IM-PG was used in 72 cycles. ET was performed on day 3 or 4. The main fertility outcomes evaluated were implantation rate (IR) and clinical pregnancy rate (CPR). 

EDM thickness was significantly lower in the dual PG group (10 mm) compared to the single IM group (11 mm). There was no difference IR, CPR, or pregnancy loss between the groups. 

The authors concluded that dual PG administration did not improve fertility outcomes compared to single IM-PG.

This study was based on medical records. Single IM-PG was used in one hospital only. This means that other factors like the IVF procedure could bias the results. Ideally, both IM and d-PGT would be administered in the same conditions (hospital). A randomized study is needed to confirm the findings. 

If you have any concerns regarding infertility please consult with your doctor.