A serodifferent relationship, where one partner is living with HIV and the other is not, requires careful planning when considering pregnancy. Modern medical advances make it safe and possible for these couples to conceive a child without transmitting HIV to the negative partner or the baby. This journey requires working closely with a healthcare team specializing in both HIV and reproductive health. They will focus on optimizing both partners’ health and employing specific strategies to eliminate transmission risk during conception, pregnancy, and delivery.
Achieving Undetectable Status
The most significant step for the HIV-positive partner is achieving and maintaining an undetectable viral load through consistent treatment. The viral load measures the amount of HIV present in the blood. Antiretroviral therapy (ART) is a combination of medications that stops the virus from multiplying, dramatically lowering the amount of HIV in the body. When ART is taken daily as prescribed, the viral load becomes so low that standard tests cannot detect it; this is known as undetectable status. This status is the foundation of “Undetectable = Untransmittable” (U=U), meaning a person with a sustained undetectable viral load cannot sexually transmit HIV. For conception, the positive partner should maintain an undetectable viral load for at least six months before attempting pregnancy. Consistent adherence to medication and regular monitoring are paramount to confirm the viral load remains suppressed.
Protecting the HIV Negative Partner
The HIV-negative partner plays an active role by utilizing Pre-Exposure Prophylaxis (PrEP). PrEP is a medication taken by HIV-negative individuals to prevent HIV acquisition. It works by maintaining sufficient levels of antiretroviral drugs in the bloodstream to block HIV from establishing infection if exposure occurs. Although the positive partner’s undetectable status offers virtually zero risk, PrEP provides an additional layer of protection. Taking PrEP consistently, starting several weeks before conception attempts, ensures maximum efficacy during condomless sex. Guidelines recommend continuing PrEP for at least one month after conception is achieved. This dual approach—ART for the positive partner and PrEP for the negative partner—is the most effective strategy. The negative partner will also undergo regular HIV testing throughout this period to confirm their status remains negative.
Safe Conception Methods
With the positive partner’s viral load suppressed and the negative partner on PrEP, the simplest method for achieving pregnancy is timed, condomless intercourse. This involves tracking the female partner’s cycle to identify the fertile window—the few days each month when conception is most likely. Limiting condomless sex to this window maximizes pregnancy chances while minimizing exposures. For couples facing fertility challenges, assisted reproductive technologies (ART) are an option. Intrauterine Insemination (IUI) places sperm directly into the uterus, often after “sperm washing,” which separates sperm cells from seminal plasma. Due to the U=U paradigm, IUI and sperm washing are now typically reserved for cases where the positive partner cannot achieve an undetectable viral load or where fertility issues exist. Other advanced options, such as In Vitro Fertilization (IVF) or Intracytoplasmic Sperm Injection (ICSI), may also be used for documented male or female infertility.
Protecting the Baby During Pregnancy and Delivery
Once pregnancy is achieved, the focus shifts to preventing mother-to-child transmission (vertical transmission). Since the female partner is HIV-negative, the baby is not at risk of acquiring HIV from the father. However, the mother’s HIV status will be monitored throughout the pregnancy, with testing recommended early in the first and third trimesters to detect any new infection. If a mother acquires HIV during pregnancy, immediate ART commencement is necessary to reduce the viral load and protect the baby. When the mother is HIV-positive and maintains a viral load below 1,000 copies/mL near delivery, the transmission risk is less than one percent. If the viral load is consistently undetectable throughout the pregnancy, the risk is even lower. Delivery protocols are tailored based on the mother’s viral load near the end of the pregnancy. If the viral load is suppressed, a vaginal delivery is generally considered safe. If the viral load is high (above 1,000 copies/mL), a planned Cesarean delivery may be recommended to reduce the baby’s exposure. Following delivery, the newborn is given a short course of antiretroviral medication for two to six weeks as prophylaxis.