A majority of miscarriages occur during the first trimester. Many expectant parents wait until the first three months are over to announce their pregnancy as 80% of miscarriages happen during this time.

Typically, a second-trimester miscarriage or stillbirth risk is only one percent, according to the American Journal of Epidemiology. After 20 weeks, the loss is considered a still born and not a miscarriage.

As countries and US cities move to new phases of reopening, Covid-19 cases are increasing in many places. People with underlying health conditions are cautioned to still stay at home, but what should you do if you are pregnant?

Even with cases topping well over 8 million, there is limited data on how the Coronavirus affects the placenta.

The Journal of the American Medical Association (JAMA) reported about one mother that lost her baby at 19 weeks. She was 28-years-old, obese, and pregnant for the first time. She tested positive for COVID-19 after having symptoms of “fever (102.5 °F [39.2 °C]), myalgia, fatigue, mild pain with swallowing, diarrhea, and dry cough for 2 days”

Two days later, her COVID-19 symptoms were still present, and she developed intense, severe contractions. She was 5cm dilated and began labor wearing a mask, as did the two health care professionals who assisted her. Vaginal swabs confirmed there was no presence of Coronavirus in the vagina or amniotic fluid.

The infant was active during labor, yet was stillborn 10 hours later.

Swabs from the axillae, mouth, meconium, and fetal blood obtained within minutes of birth tested negative for SARS-CoV-2 and bacterial infection. Fetal autopsy showed no malformations, and fetal lung, liver, and thymus biopsies were negative for SARS-CoV-2.

Within minutes of placental expulsion, the fetal surface of the placenta was disinfected and incised with a sterile scalpel, and 2 swabs and biopsies (close to the umbilical cord and peripheral margin) were obtained. All were negative for bacterial infection but were positive for SARS-CoV-2. At 24 hours, the placenta remained positive for SARS-CoV-2. At 48 hours, maternal blood, urine, and vaginal swab were all negative for SARS-CoV-2, whereas a nasopharyngeal swab remained positive.

Second-Trimester Miscarriage in a Pregnant Woman With SARS-CoV-2 Infection

This is a single case, and the effects of COVID-19 on the placenta warrants further investigation.

Coronavirus affects the placenta

Another study published in the American Journal of Clinical Pathology involving 16 pregnant women positive for COVID-19 found “injury to the placenta”. The placenta plays a vital role during pregnancy delivering blood, oxygen, and nutrients to the fetus, as well as removing waste.

14 of the babies in this study were healthy and carried to full term despite the damage to the placenta. Upon birth, the placentas were small than normal and showed evidence of blocked blood flow. One baby was born prematurely, and one baby was miscarried though the mother was COVID-19 positive but asymptomatic.

The authors conclude:

We report placental pathology from 16 patients with SARS-CoV-2 infection. No pathognomonic features are identified; however, there are increased rates of maternal vascular malperfusion features and intervillous thrombi, suggesting a common theme of abnormal maternal circulation, as well as an increased incidence of chorangiosis. These findings provide mechanistic insight into the observed epidemiologic associations between COVID-19 in pregnancy and adverse perinatal outcomes. Collectively, these findings suggest that increased antenatal surveillance for women diagnosed with SARS-CoV-2 may be warranted.

Placental Pathology in COVID-19

There is still much that is unknown about the Coronavirus, and the end to the pandemic is nowhere in sight. Increased testing is warranted for pregnant women, as well as voluntary shelter-in-place actions.