Infertility is usually defined as the inability of a couple to conceive even after 1 year of unprotected, frequent sexual intercourse. It affects about 15% of all couples in the United States and at least 180 million couples worldwide. Male infertility is defined by the World Health Organization (WHO) as the inability of a male to make a fertile female pregnant for a minimum of at least 1 year of regular unprotected intercourse. The male is solely responsible for about 20% of cases and is a contributing factor in another 30% to 40% of all infertility cases. As male and female causes often co-exist, it is essential that both partners are investigated for infertility and managed together. Overall, the male factor substantially contributes to about 50% of all cases of infertility. There are several reasons for male fertility, including both reversible and irreversible conditions. Other factors can influence each partner, including age, medications, surgical history, exposure to environmental toxins, genetic problems, and systemic diseases. The key purpose for evaluating a male for infertility is to identify his contributing factors, offer treatment for those that are reversible, determine if he is a candidate for assisted reproductive techniques (ART), and provide counseling for irreversible and untreatable conditions. Up to 6% of men evaluated for male infertility will be found to have more serious underlying pathology, such as cancer. This is an additional reason to do a comprehensive evaluation of the male partners of infertile couples so that any significant, underlying medical conditions can be identified and treated.
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PMID 32965929 32965929 DOI 10.5555/medarh.2023.77.1.1 10.5555/medarh.2023.77.1.1
Cite this article
Leslie SW, Soon-Sutton TL, & Khan, D. M. A. (2025). Male Infertility. StatPearls [Internet]. https://doi.org/10.5555/medarh.2023.77.1.1
Ectopic pregnancy occurs when a fertilized egg implants outside the uterine cavity, a condition that affects approximately 1% to 2% of pregnancies in the United States. Ectopic pregnancy is a potentially life-threatening condition and accounts for 2.7% of pregnancy-related deaths. Most ectopic pregnancies (approximately 97%) occur within the fallopian tube, commonly linked to underlying fallopian tube abnormalities. Such abnormalities may result from prior infections (eg, gonorrhea or chlamydia), tubal surgeries (including sterilization), prior ectopic pregnancies, or exposure to diethylstilbestrol in utero. Additional risk factors include conception while using intrauterine devices (IUDs) or progesterone-only contraceptives. Although rare, ectopic pregnancies can also occur outside the fallopian tube, such as in the cervix, ovary, abdomen, uterine cornua, or cesarean scars. These extratubal ectopic pregnancies are less likely to be associated with the typical risk factors or tubal pathology, making their diagnosis and management particularly challenging. Regardless of the location, early detection is critical for conservative treatment and improving outcomes. Ectopic pregnancy often causes lower abdominal pain, typically on one side, along with vaginal bleeding. Symptoms like dizziness, fainting, shoulder pain, or severe pelvic pain may indicate a ruptured ectopic pregnancy. However, these signs can mimic other conditions, eg, early normal intrauterine pregnancy, miscarriage, ovarian cyst rupture, or appendicitis. Therefore, differentiating ectopic pregnancy from conditions with similar clinical features can be difficult, making prompt medical evaluation crucial for accurate diagnosis and treatment. Management primarily aims to preserve fertility, improve diagnostic accuracy, and provide psychological support. Treatment varies, depending on clinical stability, ectopic location, beta-human chorionic gonadotropin (β-hCG) levels, and ultrasound findings ranging from expectant management to surgical interventions. In select cases, nonsurgical treatment with methotrexate may be effective, especially when pregnancies are diagnosed early and meet specific criteria. However, medical treatment is less likely to succeed in cases involving larger masses, high β-hCG levels, or visible embryos. Advanced or ruptured cases typically require urgent surgical intervention.
Human embryogenesis is a complicated process by which a fertilized egg develops into an embryo. During the first eight weeks of development, the conceptus shifts from a single-celled zygote into a multi-layered, multi-dimensional fetus with primitively functioning organs. The continued growth and increased intra-embryonic complexity during the first eight weeks of development are highly dependent upon cell signaling, proliferation, and differentiation. Due to the intricacies involved, the development of the human embryo is divided into developmental events by week. Week 1 is a major part of the germinal stage of development, a period of time that continues from fertilization through uterine implantation. Important events that occur during the first week of human embryonic development include gamete approximation, contact and fusion of gametes, fertilization, mitotic cleavage of the blastomere, morula formation, blastocyst formation, and implantation of the blastocyst.
General OB/GYNPelvic Inflammatory DiseasePID-Related Tubal DamageChlamydia and Gonorrhea
Pelvic inflammatory disease (PID) is defined as an inflammation of the upper genital tract due to an infection in women. The disease affects the uterus, fallopian tubes, and/or ovaries. It is typically an ascending infection, spreading from the lower genital tract. The majority of cases of PID are related to a sexually transmitted infection. The diagnosis of PID is primarily clinical and should be suspected in female patients with lower abdominal or pelvic pain and genital tract tenderness. During the patient’s evaluation, other etiologies of pain, including ectopic pregnancy, should be considered and ruled out. PID is treated with antibiotics to cover the primary pathogens, including Neisseria gonorrhoeae and Chlamydia trachomatis. Short-term complications include tubo-ovarian or pelvic abscess. Long-term complications include ectopic pregnancy, infertility, and chronic pelvic pain. Early diagnosis and treatment can potentially prevent complications.