The number of undocumented women who have lost their pregnancies while in government detention nearly doubled in the first two years of President Donald Trump’s administration, according to a government review of medical records.

Now, following the stillbirth of a baby boy by a woman who was held in U.S. Immigration and Customs Enforcement custody despite being six months pregnant, members of Congress are calling for an investigation into Trump administration policies that they fear are worsening the crisis.

“We have heard several alarming stories of pregnant women receiving inadequate medical care and even miscarrying while in [Department of Homeland Security] custody,” Rep. Joaquin Castro (D-TX), chair of the Hispanic Caucus, said in a statement. “These tragedies make one thing very clear: ICE and [U.S. Customs and Border Patrol] should not be detaining expectant mothers in poor conditions, and the practice of detaining these women is inhumane and inconsistent with our values as Americans. We must examine the circumstances of the unfortunate and disturbing loss of this mother’s child.”

Rep. Debbie Mucarsel-Powell (D-FL), chair of the caucus’ Women’s Task Force, called the incident part of “a troubling pattern of medical negligence and disregard for humanity” on the part of immigration authorities.

“I fear this tragedy could be a consequence of that negligence,” Mucarsel-Powell said.

According to a manual review of medical records conducted by ICE and provided to The Daily Beast, 10 migrant women appear to have experienced a miscarriage either just prior to or during ICE custody between October 2016 and September 2017. As of Aug. 31, 2018, the same review found that 18 migrant women may have experienced a miscarriage while in ICE custody during the following year—nearly twice as many.

The increase—which does not take into account miscarriages or stillbirths among women in U.S. Customs and Border Patrol custody—followed Trump’s reversal of an Obama-era policy that forbade ICE from detaining pregnant women, “absent extraordinary circumstances.” The new policy, enacted in December 2017 to comport with the administration’s “zero tolerance” immigration policy, ended that presumption of release for pregnant detainees, with a caveat that ICE would “generally” not detain pregnant migrants during their third trimester of pregnancy.

The sharp rise in the number of miscarriages among women in immigrant detention, health and human rights advocates told The Daily Beast, is likely at least partially rooted in this new Trump administration policy.

“For any woman who is pregnant to be in detention is a problem,” said Dr. Alan Shapiro, pediatrician and co-founder of Terra Firma, a nonprofit organization that provides medical care to undocumented children. “Detention in and of itself can be quite traumatizing and stressful, and anything that triggers stress hormones can lead to negative outcomes in pregnancy for herself and for the fetus.”

The notion that pregnant women can be safely detained in immigration processing centers, Shapiro said, is a contradiction in terms.

“I don’t believe that any pregnant woman should be held in detention centers, for their health and for the health of their child.”

ICE policy requires that all females of reproductive age undergo a urinalysis upon entering its custody, a test that can detect hormones associated with pregnancy or a recent miscarriage. There were a total of 1,655 pregnant women booked into ICE custody at some point between October 2017 to Aug. 31, 2018, according to an ICE spokesperson. As of Aug. 31, 2018, there were 60 pregnant detainees in ICE custody.

“Generally, with limited insight into a pregnant detainee’s medical history, ICE is unable to determine what caused a given miscarriage, and cannot confirm whether a miscarriage began before or after an individual entered ICE custody,” the ICE spokesperson told The Daily Beast.

Although pregnant women are supposed to have access to prenatal care and medical specialists while in ICE custody, the Trump administration’s decision to allow for their detention at all outraged medical organizations and civil rights groups. In an April 2018 letter addressed to ICE’s acting director and signed by hundreds of groups, watchdogs decried “the arbitrary detention of pregnant people” as a violation of international human rights norms, and called for a return to the Obama-era policies on pregnant migrant detention.

Shapiro told The Daily Beast that concerns that the policy change could endanger the lives of pregnant women and their unborn children are valid.

“Things can go bad very quickly, so you can see a woman begin to develop high blood pressure—which that would need very immediate attention—and that woman might not receive that attention in a timely fashion,” Shapiro said, who co-authored a 2017 policy paper outlining the lack of consistent, quality healthcare available in immigration processing centers.

“In our own findings around the medical care of children… the healthcare services were very inconsistent in family detention centers,” Shapiro said. “Not only were those services inconsistent, but oftentimes there was greatly inadequate care.”

For pregnant detainees, whose conditions can shift quickly, a lack of constant observation and timely medical assistance can spell trouble for a woman and her fetus.

“Pregnancy is a medical condition,” Shapiro said. “Why put at risk a woman and her fetus in a stressful, potentially traumatic environment that can negatively affect her health and the baby’s health?”

The most recent incident occurred last week at the Port Isabel Service Processing Center near Los Fresnos, Texas. The 24-year-old Honduran woman, whose identity was not disclosed, was 27 weeks into her pregnancy, and four days into her detention, when she first complained of abdominal pains while being processed for release at the facility.

“At that time, she conveyed that the baby was coming,” ICE said in a statement three days after the incident. Before emergency medical services could arrive, the woman delivered an unresponsive boy at the Port Isabel facility. Both mother and son were transported to Valley Baptist Medical Center in Harlingen, Texas, roughly 40 minutes away. The infant was pronounced dead upon arrival.

ICE waited to reveal the death to the public for three days, the agency said, because “a stillbirth is not considered an in-custody death” for investigative and reporting purposes. The woman, who was originally kept in ICE custody after the stillbirth of her son, was released from detention on Feb. 26, according to agency spokesperson Dani Bennett.

Due to the difficulty in pinpointing the cause of many miscarriages and stillbirths, “there are a lot of possibilities as to what happened here,” Michelle Brané, director of the Migrant Rights and Justice program at the Women’s Refugee Commission, told The Daily Beast. But there is little question that the conditions inside immigrant detention facilities pose a particular risk to pregnant women and their fetuses.

“Custody is never a good place for pregnant women, and we have in the past heard really devastating stories of both mothers’ and babies’ health being at risk,” said Brané, who dismissed the administration’s policy of not detaining immigrant women in their third trimester as medically insufficient.

“The risks of a pregnancy are not nonexistent before the third trimester,” Brané said. “Being in immigration custody is problematic when you are pregnant, no matter what phase of pregnancy you are in, especially when you take take into account the effects of stress.”

An ICE spokesperson told The Daily Beast that they were “not aware of any concerns regarding medical care of pregnant detainees” at the Port Isabel facility, and called the stillbirth “rare.”

Other stories of lost pregnancies that have emerged from U.S. immigration detention centers are equally shocking. Drawing from the testimony of 10 women, a Sept. 2017 complaint filed with DHS by the American Civil Liberties Union and seven other advocacy organizations detailed stories of high-risk pregnancies being ignored by on-site doctors, insufficient access to prenatal vitamins, and callous official responses to serious medical emergencies.

One 31-year-old woman from El Salvador testified in the complaint that after seeking asylum at the U.S. border, she was transferred to a detention center while four months pregnant. Despite notifying immigration officials that she was bleeding and experiencing pain, the woman reported that her requests to be taken to a hospital were denied. Days after her initial pleas, the woman was notified by on-site medical staff that she had miscarried.

In addition to the stress of detention, the difficulty of the journey to the United States can take an enormous toll on pregnant women. With Trump’s “Remain in Mexico” policy forcing many asylum seekers to stay south of the U.S.-Mexico border as their asylum claims are processed—a process that has slowed to a trickle—many migrants, including those who are pregnant, have been forced to take longer and more dangerous routes to the United States.

“We know people are arriving at our border in really dire circumstances, and that is directly related to the metering that is happening at ports of entry,” said Brané. “People are arriving in more and more precarious health, and especially for a pregnant woman, it’s not surprising that she arrived in distress.”

The rising rates of lost pregnancy have raised more questions about the conditions inside immigration detention facilities, particularly regarding the quality and availability of medical care. At least 24 people have died in immigration detention facilities since Trump was inaugurated, including two minors who died in the space of three weeks, in December 2018.

“Any death in custody is a tragedy, and the loss mourned by this mother is no exception,” Rep. Lucille Roybal-Allard (D-CA), said in a statement. “We must have nothing less than a full accounting of the circumstances surrounding this tragic event,” Roybal-Allard said, “including the government’s actions.”