While the loss of one fallopian tube, often due to an ectopic pregnancy or salpingectomy, may slightly reduce the monthly probability of conception, it rarely eliminates the chance of natural pregnancy. Conception remains highly possible because the reproductive system has a powerful compensatory mechanism that allows the remaining tube to function for both ovaries. The overall success rate over time for a woman with one healthy, open fallopian tube remains favorable, especially when considering other individual fertility factors.
The Biological Mechanism of Single-Tube Function
The two ovaries do not strictly alternate egg release. When an egg is released, the remaining fallopian tube is remarkably mobile, using finger-like projections called fimbriae to actively move within the pelvic cavity.
This mobility allows the remaining tube to effectively “reach” across the uterus to capture an egg released from the opposite ovary. This process is known as contralateral egg pickup or transperitoneal migration. The egg travels through the pelvic fluid to the open tube, where fertilization can then occur.
While the monthly success rate per cycle may be reduced by about 30% to 50% compared to having two fully functional tubes, the cumulative chance of pregnancy over a year or two remains very high. For younger women with no other fertility challenges, the cumulative success rate within two years can be as high as 85%.
Key Factors Determining Conception Rates
If the remaining tube is open, free of scar tissue, and structurally sound, the chances of natural conception are strong. However, conditions like previous pelvic inflammatory disease or endometriosis can cause silent damage, potentially leaving the remaining tube partially blocked or non-functional.
Hydrosalpinx is a fluid-filled blockage that can severely impact fertility. If the remaining tube has a hydrosalpinx, the fluid can be toxic to a developing embryo and may leak into the uterus, disrupting implantation. This fluid can reduce the success rate of advanced treatments like In Vitro Fertilization (IVF) by up to 50%, often making surgical treatment necessary first.
Beyond the tube itself, age remains the dominant factor in fertility. A woman’s age directly correlates with egg quality and ovarian reserve, which decline predictably over time. Other non-tubal factors, such as regular ovulation and sperm health in the male partner, must also be confirmed to ensure optimal conditions for conception.
When to Consult a Fertility Specialist
Standard guidelines suggest consulting a specialist if conception has not occurred after 12 months of timed, unprotected intercourse for women under 35. This timeline should be accelerated to 6 months for women who are 35 or older.
Immediate consultation is advisable if a woman has known or suspected risk factors, such as a history of severe endometriosis, multiple pelvic surgeries, or a diagnosis of hydrosalpinx in the remaining tube. The initial workup typically includes a Hysterosalpingogram (HSG) to confirm the patency of the single tube and an Anti-Müllerian Hormone (AMH) blood test to assess ovarian reserve. A semen analysis is also performed to rule out any male factor issues.
Medical Paths to Pregnancy
Ovulation induction is a common first step, using medications to ensure consistent and predictable egg release. This consistency helps the remaining tube time its capture of the egg more precisely, increasing the monthly opportunity for fertilization.
Intrauterine Insemination (IUI) is another option. During IUI, specially prepared sperm are placed directly into the uterus, bypassing the cervix and shortening the distance to the open tube. This procedure is often combined with ovulation induction, with per-cycle success rates varying based on the underlying cause.
In Vitro Fertilization (IVF) completely bypasses the need for fallopian tubes. During IVF, eggs are retrieved directly from the ovaries, fertilized in a laboratory, and the resulting embryo is transferred to the uterus. IVF success rates are independent of whether a woman has one, none, or two tubes, depending instead primarily on the woman’s age and embryo quality.