Clinic reports Natural Cycles app for 37 unwanted pregnancies since September

Swedish startup Natural Cycles, which offers an app-based product which it bills as a ‘digital contraceptive’, has been reported to Sweden’s Medical Products Agency (MPA) by a local hospital after it recorded 37 unwanted pregnancies among women who said they had been using the app as their contraception method.

The women’s clinic of Södersjukhuset, in Stockholm, told us that it wants the MPA to investigate how the app functions.

“We want the Swedish Medicines Agency to gather information about side effects, such as unwanted pregnancies, and look at how the app works,” said Lena Marions, a senior doctor at the clinic and associate professor in obstetrics and gynaecology.

“The midwives of our abortion reception found that there were many women who were unwanted pregnant and who stated that they used this app… Since September 2017, they noted how many women there were and then reported the number to the Swedish Medicines Agency.”

“We always report to the Medical Products Agency if we perceive that a medical product or drug is not working as it is intended to be done,” she added in the emailed statement, also noting that the clinic has previously reported other unwanted pregnancies to the MPA — in that instance related to women who had used an IUS (hormonal coil) as their contraceptive method.

A spokesperson for the MPA confirmed it is looking into the complaints, telling us it has received “approximately 50 complaints” related to unwanted pregnancies in users of Natural Cycles’ device.

“The investigation is still in an early phase. The MPA has requested the manufacturer to submit vigilance reports within two weeks,” the spokesperson added, suggesting it’s not yet clear whether or not it will initiate a full investigation.

Responding to the complaint, Natural Cycles provided us with the following statement:

No contraception is 100% effective, and unwanted pregnancies is an unfortunate risk with any contraception. Natural Cycles has a Pearl Index of 7, which means it is 93% effective at typical use, which we also communicate. Our studies have repeatedly shown that our app provides a high level of effectiveness similar to other methods.

It also said it has not yet received any information from the clinic, saying it “cannot comment on specifics”, adding: “We are however in touch with the MPA and are responding to each individual reported case.

“At first sight, the numbers mentioned in the media are not surprising given the popularity of the app and in line with our efficacy rates. We have initiated an internal investigation with our clinical department in order to confirm this.

“As our user base increases, so will the amount of unintended pregnancies coming from Natural Cycles app users, which is an inevitable reality.”

Natural Cycles’ subscription product relies on an algorithmic method to predict which days women are fertile during their monthly cycle — with an in-app color-coded calendar informing users if they could have unprotected sex on a given day or not.

Women using the app are required to measure and input their body temperature daily using a basal thermometer. Natural Cycles relies on this and other individual data inputs to algorithmically calculate the probability of the user being fertile on each day in her cycle.

As noted above, the company claims its product has an efficacy rate of 93 per cent with “typical use” — although this figure is based on a self-selecting study of its own users. As we have previously reported, Natural Cycles has not carried out a randomized control trial which would provide a higher standard of proof to back up its efficacy claims.

Nor has it carried out any comparative studies of its method against other contraceptives such as the pill or condom use. So it’s still not possible for users of the product to judge how effective Natural Cycles’ system is vs more established contraceptives methods — though co-founder Dr Elina Berglund told us last fall that it hopes to conduct such a study against condom use in future.

Last November, when Natural Cycles announced its $30M Series B, Berglund also reported the app having 500,000+ users across ~160 countries, telling us its home market of Sweden remains its largest market, followed by the UK and the US, where she suggested it was seeing sharp growth.

Asked to break out active usage in Sweden now the company declined to specify an exact number — saying only that it’s “one of our largest”.

Natural Cycles’ business gained a big regional boost in February 2017 when its product gained certification in the European Union as a contraceptive method.

It has also applied to the FDA for certification in the US, though the assessment process for accreditation there is different and remains ongoing at this stage, with no guarantees it will be granted.

As well as being criticized for loudly marketing efficacy claims that are only based on a self-selecting study, Natural Cycles’ product has attracted criticism because it requires couples to remember to use an alternative contraception method if they have sex on days when the app informs them there’s a risk of pregnancy — with some women’s health experts warning of the relative complexity of this approach.

“It requires that the user follow the instructions very carefully and protects with condom when the woman is fertile. I think you should be aware of that when using it,” noted Marions. “The app is better suited for those women who may think of getting pregnant, or older women who are less fertile.”

“There are several good contraceptives that provide good protection, such as spirals and p-rods. But there is no contraception that protects one hundred percent from pregnancy. It is always the woman who will choose what suits her body and lifestyle,” she added.

Responding to this critique, Natural Cycles said it agrees its product is better suited to older users, and further noted: “You have to be over 18 to use Natural Cycles. The average Natural Cycles user is 30 years and less than 1% are under 20.”

When we asked who Natural Cycles users were back in November, Dr Berglund also told us: “Most women are between 25 and 35, they’re in a stable relationship, they’re often thinking about that they want to have children in a few years and they don’t want to take hormones anymore.”

It does also emphasizes the choice point, saying its goal is “to increase contraceptive choice so that all women find a suitable method of contraception”.

“Today there is a big trend for women to move away from hormonal contraception, and Natural Cycles can provide a helpful option for these women. We therefore expect, in fact, overall to decrease the unwanted pregnancy rates because we’re increasing contraceptive choice, and see that many of our users are women who have not used any type of contraception before,” it added.