LH surge kit good alternative to transvaginal sonography in certain settings: IJOGR

Assessment of infertility is done by knowing the above-mentioned factors. Ovulation detection, tubal patency tests and semen analysis are the most common investigations to know the aetiology of infertility.

To know the ovulation, the most common method used is transvaginal sonography (TVS). Other modalities are urinary luteinizing hormone (urinary LH) detection, urinary follicular stimulating hormone (FSH) detection, serum progesterone levels, analysis of cervical mucus and salivary ferning. Ideal approach means, easy availability, noninvasiveness, devoid of cost, easy to use, timely detection and sensitive. Same is true for the methods to detect ovulation as well as there should be appropriate fertility window (begins 2-3 days earlier than rupture of follicle and continues 1-2 days after ovulation). By TVS detailed follicular monitoring, preovulatory changes and ovulation can be detected very precisely. LH surge in urine may be very sensitive, convenient, non-invasive, and precise method for ovulation detection. From new menstrual cycle day 10 to day 11 (day 1 is described as the first day of menses) or four days earlier than the expected day of ovulation, ladies can measure their LH in urine a couple of times a day. Urine LH kits can detect LH levels as little as 22 mIU/mL, even as the normal levels of LH in urine varies from 20-100 mIU/mL

It was observed that if single intercourse is made from 2 days prior and until the day of ovulation, clinical pregnancy rate is highest. This time can be best predicted by urinary LH surge kits. Since urinary LH surge kits are superior to TVS in terms of accuracy, affordability, ease of use, and non-invasiveness, we intend to investigate their efficacy in ovulation detection.

Prospective observational cohort study on 144 women with anovulatory infertility aged 18-35 years, fulfilling the inclusion criteria were given letrozole for ovulation induction. All were randomly divided into two groups. Group 1 women were asked to check ovulation by urinary LH surge kits and group 2 women were called for follicle monitoring by TVS.

Letrozole has no negative effect on the endometrium; the induced cycle has a larger diameter of follicle (median: 22 mm). In the induced cycle ovulation occurs later compared to normal cycle (D-16) and half of the women had a BMI more than the recommended WHO criteria (average was 25.28 kg/m2). Number of letrozole cycles (p=0.2642), dose requirement (p=0.0812) and pregnancy rates (10.26% versus 18.19%) were comparable in both groups.

Eighteen to twenty-five percent of women who present with infertility and require ovulation induction have an ovulatory problem. TVS is an invasive method that may sometimes also need a radiologist to document the results and provides a clear definition of ovulation time. But many a times women hesitate for TVS examination. So, a new noninvasive technique for detection of ovulation is the LH surge kits (i.e., LH surge assessment in urine), which a woman can use on her own without a radiologist or special environment. Compared to TVS, these over-the-counter alternatives are readily available and simple to use.

Using the assessment approach, it was found that the average day of ovulation diagnosis was 15.21 days for group 1 and 16.24 days for group 2. So, it is clearly apparent that, in comparison to the TVS, ovulation was diagnosed approximately one day prior in the LH surge kit group (p = 0.0124), results of which were found to be statistically significant. The results demonstrated that, the total pregnancy rate for both the groups were 13.89%, with comparable results. In terms of clinical characteristics and demographics, both groups were similar. Previous research has demonstrated comparable outcomes when describing techniques for ovulation detection by urine LH surge rather than ultrasonography due to its high accuracy, low cost, and less invasive nature.

Since the LH surge kit is a subjective method for ovulation assessment, there is a greater chance of error. However, because it is practical, affordable, non-invasive, and convenient, it can be recommended for patients who live far from the radiologist, cannot afford to travel to the hospital, or are uncomfortable undergoing any kind of invasive procedure. TVS is advised as the standard modality for ovulation detection since it is an objective, more accurate, and error-free means of assessing ovulation. However, it is costly, intrusive, and impractical in isolated places. Therefore, authors propose that LH surge kits, as analternative to TVS follicular monitoring, can be a useful tool for ovulation assessment.

Source: Verma, Gupta and Chauhan / Indian Journal of Obstetrics and Gynecology Research 2024;11(3):358–363