Chapter 32 Infertility
FACTORS IN INFERTILITY
The factors that may be involved in the couple’s infertility vary depending on local conditions, the population investigated and the referral procedures. Analyses reported by several clinics of large numbers of patients in the past two decades are given in Table 32.1. In a quarter of cases, more than one of the factors is believed to be involved.
Factor | Percentage of Cases |
---|---|
Male | |
Defective sperm production, insemination difficulties | 30–40 |
Female | |
Ovulation factors | 5–25 |
Tubal or uterine factors | 15–25 |
Cervical/immunological factors | 5–10 |
Unexplained after investigations | 10–25 |
INVESTIGATION OF INFERTILITY
Seminal analysis
Standards for a normal seminal specimen have been developed by the World Health Organization (WHO) and are shown in Box 32.1. If the first seminal appraisal is abnormal, two further specimens should be evaluated before a prognosis is made. The most important predictors of male fertility are the percentage of motile sperm, the quality of the motility of the sperm, the motile sperm concentration, the total motile count and the sperm morphology. The absolute count is not a good predictor.
Box 32.1 Normal seminal analysis
Volume | >2 mL |
Sperm concentration | >20 million per mL |
Total sperm count | 40 million |
Motility 60 min after ejaculation | >50% with normal progression |
Morphology | >30% with normal morphology |
When the sperm count is less than 20 million per mL, abnormal morphology and motility is often found
The semen analysis is traditionally graded as: